Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

310 files changed, 78822 insertions, 0 deletions

diff --git a/netwerk/base/ARefBase.h b/netwerk/base/ARefBase.h
new file mode 100644
index 0000000000..207b5fe03c
--- /dev/null
+++ b/netwerk/base/ARefBase.h
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_ARefBase_h
+#define mozilla_net_ARefBase_h
+
+#include "nsISupportsImpl.h"
+
+namespace mozilla {
+namespace net {
+
+// This is an abstract class that can be pointed to by either
+// nsCOMPtr or nsRefPtr. nsHttpConnectionMgr uses it for generic
+// objects that need to be reference counted - similiar to nsISupports
+// but it may or may not be xpcom.
+
+class ARefBase {
+ public:
+  ARefBase() = default;
+  virtual ~ARefBase() = default;
+
+  NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/ArrayBufferInputStream.cpp b/netwerk/base/ArrayBufferInputStream.cpp
new file mode 100644
index 0000000000..cd4f951f8a
--- /dev/null
+++ b/netwerk/base/ArrayBufferInputStream.cpp
@@ -0,0 +1,132 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <algorithm>
+#include "ArrayBufferInputStream.h"
+#include "nsStreamUtils.h"
+#include "js/ArrayBuffer.h"  // JS::{GetArrayBuffer{ByteLength,Data},IsArrayBufferObject}
+#include "js/RootingAPI.h"  // JS::{Handle,Rooted}
+#include "js/Value.h"       // JS::Value
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/dom/ScriptSettings.h"
+
+using mozilla::dom::RootingCx;
+
+NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream,
+                  nsIInputStream);
+
+NS_IMETHODIMP
+ArrayBufferInputStream::SetData(JS::Handle<JS::Value> aBuffer,
+                                uint64_t aByteOffset, uint64_t aLength) {
+  NS_ASSERT_OWNINGTHREAD(ArrayBufferInputStream);
+
+  if (!aBuffer.isObject()) {
+    return NS_ERROR_FAILURE;
+  }
+  JS::Rooted<JSObject*> arrayBuffer(RootingCx(), &aBuffer.toObject());
+  if (!JS::IsArrayBufferObject(arrayBuffer)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  uint64_t buflen = JS::GetArrayBufferByteLength(arrayBuffer);
+  uint64_t offset = std::min(buflen, aByteOffset);
+  uint64_t bufferLength = std::min(buflen - offset, aLength);
+
+  // Prevent truncation.
+  if (bufferLength > UINT32_MAX) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mArrayBuffer = mozilla::MakeUniqueFallible<char[]>(bufferLength);
+  if (!mArrayBuffer) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mBufferLength = bufferLength;
+
+  JS::AutoCheckCannotGC nogc;
+  bool isShared;
+  char* src =
+      (char*)JS::GetArrayBufferData(arrayBuffer, &isShared, nogc) + offset;
+  memcpy(&mArrayBuffer[0], src, mBufferLength);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Close() {
+  mClosed = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Available(uint64_t* aCount) {
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+  if (mArrayBuffer) {
+    *aCount = mBufferLength ? mBufferLength - mPos : 0;
+  } else {
+    *aCount = 0;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::StreamStatus() {
+  return mClosed ? NS_BASE_STREAM_CLOSED : NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount,
+                             uint32_t* aReadCount) {
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                     uint32_t aCount, uint32_t* result) {
+  NS_ASSERTION(result, "null ptr");
+  NS_ASSERTION(mBufferLength >= mPos, "bad stream state");
+
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  MOZ_ASSERT(mArrayBuffer || (mPos == mBufferLength),
+             "stream inited incorrectly");
+
+  *result = 0;
+  while (mPos < mBufferLength) {
+    uint32_t remaining = mBufferLength - mPos;
+    MOZ_ASSERT(mArrayBuffer);
+
+    uint32_t count = std::min(aCount, remaining);
+    if (count == 0) {
+      break;
+    }
+
+    uint32_t written;
+    nsresult rv = writer(this, closure, &mArrayBuffer[0] + mPos, *result, count,
+                         &written);
+    if (NS_FAILED(rv)) {
+      // InputStreams do not propagate errors to caller.
+      return NS_OK;
+    }
+
+    NS_ASSERTION(written <= count,
+                 "writer should not write more than we asked it to write");
+    mPos += written;
+    *result += written;
+    aCount -= written;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ArrayBufferInputStream::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = true;
+  return NS_OK;
+}
diff --git a/netwerk/base/ArrayBufferInputStream.h b/netwerk/base/ArrayBufferInputStream.h
new file mode 100644
index 0000000000..3a4811373d
--- /dev/null
+++ b/netwerk/base/ArrayBufferInputStream.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ArrayBufferInputStream_h
+#define ArrayBufferInputStream_h
+
+#include "nsIArrayBufferInputStream.h"
+#include "js/Value.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/UniquePtr.h"
+#include "nsISupportsImpl.h"
+
+#define NS_ARRAYBUFFERINPUTSTREAM_CONTRACTID \
+  "@mozilla.org/io/arraybuffer-input-stream;1"
+#define NS_ARRAYBUFFERINPUTSTREAM_CID                \
+  { /* 3014dde6-aa1c-41db-87d0-48764a3710f6 */       \
+    0x3014dde6, 0xaa1c, 0x41db, {                    \
+      0x87, 0xd0, 0x48, 0x76, 0x4a, 0x37, 0x10, 0xf6 \
+    }                                                \
+  }
+
+class ArrayBufferInputStream : public nsIArrayBufferInputStream {
+ public:
+  ArrayBufferInputStream() = default;
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIARRAYBUFFERINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAM
+
+ private:
+  virtual ~ArrayBufferInputStream() = default;
+  mozilla::UniquePtr<char[]> mArrayBuffer;
+  uint32_t mBufferLength{0};
+  uint32_t mPos{0};
+  bool mClosed{false};
+};
+
+#endif  // ArrayBufferInputStream_h
diff --git a/netwerk/base/AutoClose.h b/netwerk/base/AutoClose.h
new file mode 100644
index 0000000000..a0e3a48e17
--- /dev/null
+++ b/netwerk/base/AutoClose.h
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_AutoClose_h
+#define mozilla_net_AutoClose_h
+
+#include "nsCOMPtr.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+// A container for XPCOM streams (e.g. nsIAsyncInputStream) and other
+// refcounted classes that need to have the Close() method called explicitly
+// before they are destroyed.
+template <typename T>
+class AutoClose {
+ public:
+  AutoClose() : mMutex("net::AutoClose.mMutex") {}
+  ~AutoClose() { CloseAndRelease(); }
+
+  explicit operator bool() {
+    MutexAutoLock lock(mMutex);
+    return mPtr;
+  }
+
+  already_AddRefed<T> forget() {
+    MutexAutoLock lock(mMutex);
+    return mPtr.forget();
+  }
+
+  void takeOver(nsCOMPtr<T>& rhs) { TakeOverInternal(rhs.forget()); }
+
+  void CloseAndRelease() { TakeOverInternal(nullptr); }
+
+ private:
+  void TakeOverInternal(already_AddRefed<T>&& aOther) {
+    nsCOMPtr<T> ptr(std::move(aOther));
+    {
+      MutexAutoLock lock(mMutex);
+      ptr.swap(mPtr);
+    }
+
+    if (ptr) {
+      ptr->Close();
+    }
+  }
+
+  void operator=(const AutoClose<T>&) = delete;
+  AutoClose(const AutoClose<T>&) = delete;
+
+  nsCOMPtr<T> mPtr;
+  Mutex mMutex MOZ_UNANNOTATED;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_AutoClose_h
diff --git a/netwerk/base/BackgroundFileSaver.cpp b/netwerk/base/BackgroundFileSaver.cpp
new file mode 100644
index 0000000000..bc52097da9
--- /dev/null
+++ b/netwerk/base/BackgroundFileSaver.cpp
@@ -0,0 +1,1121 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "BackgroundFileSaver.h"
+
+#include "ScopedNSSTypes.h"
+#include "mozilla/ArrayAlgorithm.h"
+#include "mozilla/Casting.h"
+#include "mozilla/Logging.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Telemetry.h"
+#include "nsCOMArray.h"
+#include "nsComponentManagerUtils.h"
+#include "nsDependentSubstring.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIFile.h"
+#include "nsIMutableArray.h"
+#include "nsIPipe.h"
+#include "nsNetUtil.h"
+#include "nsThreadUtils.h"
+#include "pk11pub.h"
+#include "secoidt.h"
+
+#ifdef XP_WIN
+#  include <windows.h>
+#  include <softpub.h>
+#  include <wintrust.h>
+#endif  // XP_WIN
+
+namespace mozilla {
+namespace net {
+
+// MOZ_LOG=BackgroundFileSaver:5
+static LazyLogModule prlog("BackgroundFileSaver");
+#define LOG(args) MOZ_LOG(prlog, mozilla::LogLevel::Debug, args)
+#define LOG_ENABLED() MOZ_LOG_TEST(prlog, mozilla::LogLevel::Debug)
+
+////////////////////////////////////////////////////////////////////////////////
+//// Globals
+
+/**
+ * Buffer size for writing to the output file or reading from the input file.
+ */
+#define BUFFERED_IO_SIZE (1024 * 32)
+
+/**
+ * When this upper limit is reached, the original request is suspended.
+ */
+#define REQUEST_SUSPEND_AT (1024 * 1024 * 4)
+
+/**
+ * When this lower limit is reached, the original request is resumed.
+ */
+#define REQUEST_RESUME_AT (1024 * 1024 * 2)
+
+////////////////////////////////////////////////////////////////////////////////
+//// NotifyTargetChangeRunnable
+
+/**
+ * Runnable object used to notify the control thread that file contents will now
+ * be saved to the specified file.
+ */
+class NotifyTargetChangeRunnable final : public Runnable {
+ public:
+  NotifyTargetChangeRunnable(BackgroundFileSaver* aSaver, nsIFile* aTarget)
+      : Runnable("net::NotifyTargetChangeRunnable"),
+        mSaver(aSaver),
+        mTarget(aTarget) {}
+
+  NS_IMETHOD Run() override { return mSaver->NotifyTargetChange(mTarget); }
+
+ private:
+  RefPtr<BackgroundFileSaver> mSaver;
+  nsCOMPtr<nsIFile> mTarget;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaver
+
+uint32_t BackgroundFileSaver::sThreadCount = 0;
+uint32_t BackgroundFileSaver::sTelemetryMaxThreadCount = 0;
+
+BackgroundFileSaver::BackgroundFileSaver() {
+  LOG(("Created BackgroundFileSaver [this = %p]", this));
+}
+
+BackgroundFileSaver::~BackgroundFileSaver() {
+  LOG(("Destroying BackgroundFileSaver [this = %p]", this));
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::Init() {
+  MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+  NS_NewPipe2(getter_AddRefs(mPipeInputStream),
+              getter_AddRefs(mPipeOutputStream), true, true, 0,
+              HasInfiniteBuffer() ? UINT32_MAX : 0);
+
+  mControlEventTarget = GetCurrentSerialEventTarget();
+  NS_ENSURE_TRUE(mControlEventTarget, NS_ERROR_NOT_INITIALIZED);
+
+  nsresult rv = NS_CreateBackgroundTaskQueue("BgFileSaver",
+                                             getter_AddRefs(mBackgroundET));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  sThreadCount++;
+  if (sThreadCount > sTelemetryMaxThreadCount) {
+    sTelemetryMaxThreadCount = sThreadCount;
+  }
+
+  return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::GetObserver(nsIBackgroundFileSaverObserver** aObserver) {
+  NS_ENSURE_ARG_POINTER(aObserver);
+  *aObserver = do_AddRef(mObserver).take();
+  return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::SetObserver(nsIBackgroundFileSaverObserver* aObserver) {
+  mObserver = aObserver;
+  return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::EnableAppend() {
+  MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+  MutexAutoLock lock(mLock);
+  mAppend = true;
+
+  return NS_OK;
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::SetTarget(nsIFile* aTarget, bool aKeepPartial) {
+  NS_ENSURE_ARG(aTarget);
+  {
+    MutexAutoLock lock(mLock);
+    if (!mInitialTarget) {
+      aTarget->Clone(getter_AddRefs(mInitialTarget));
+      mInitialTargetKeepPartial = aKeepPartial;
+    } else {
+      aTarget->Clone(getter_AddRefs(mRenamedTarget));
+      mRenamedTargetKeepPartial = aKeepPartial;
+    }
+  }
+
+  // After the worker thread wakes up because attention is requested, it will
+  // rename or create the target file as requested, and start copying data.
+  return GetWorkerThreadAttention(true);
+}
+
+// Called on the control thread.
+NS_IMETHODIMP
+BackgroundFileSaver::Finish(nsresult aStatus) {
+  nsresult rv;
+
+  // This will cause the NS_AsyncCopy operation, if it's in progress, to consume
+  // all the data that is still in the pipe, and then finish.
+  rv = mPipeOutputStream->Close();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Ensure that, when we get attention from the worker thread, if no pending
+  // rename operation is waiting, the operation will complete.
+  {
+    MutexAutoLock lock(mLock);
+    mFinishRequested = true;
+    if (NS_SUCCEEDED(mStatus)) {
+      mStatus = aStatus;
+    }
+  }
+
+  // After the worker thread wakes up because attention is requested, it will
+  // process the completion conditions, detect that completion is requested, and
+  // notify the main thread of the completion.  If this function was called with
+  // a success code, we wait for the copy to finish before processing the
+  // completion conditions, otherwise we interrupt the copy immediately.
+  return GetWorkerThreadAttention(NS_FAILED(aStatus));
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::EnableSha256() {
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Can't enable sha256 or initialize NSS off the main thread");
+  // Ensure Personal Security Manager is initialized. This is required for
+  // PK11_* operations to work.
+  nsresult rv;
+  nsCOMPtr<nsISupports> nssDummy = do_GetService("@mozilla.org/psm;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  MutexAutoLock lock(mLock);
+  mSha256Enabled = true;  // this will be read by the worker thread
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::GetSha256Hash(nsACString& aHash) {
+  MOZ_ASSERT(NS_IsMainThread(), "Can't inspect sha256 off the main thread");
+  // We acquire a lock because mSha256 is written on the worker thread.
+  MutexAutoLock lock(mLock);
+  if (mSha256.IsEmpty()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  aHash = mSha256;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::EnableSignatureInfo() {
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Can't enable signature extraction off the main thread");
+  // Ensure Personal Security Manager is initialized.
+  nsresult rv;
+  nsCOMPtr<nsISupports> nssDummy = do_GetService("@mozilla.org/psm;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  MutexAutoLock lock(mLock);
+  mSignatureInfoEnabled = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaver::GetSignatureInfo(
+    nsTArray<nsTArray<nsTArray<uint8_t>>>& aSignatureInfo) {
+  MOZ_ASSERT(NS_IsMainThread(), "Can't inspect signature off the main thread");
+  // We acquire a lock because mSignatureInfo is written on the worker thread.
+  MutexAutoLock lock(mLock);
+  if (!mComplete || !mSignatureInfoEnabled) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  for (const auto& signatureChain : mSignatureInfo) {
+    aSignatureInfo.AppendElement(TransformIntoNewArray(
+        signatureChain, [](const auto& element) { return element.Clone(); }));
+  }
+  return NS_OK;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::GetWorkerThreadAttention(
+    bool aShouldInterruptCopy) {
+  nsresult rv;
+
+  MutexAutoLock lock(mLock);
+
+  // We only require attention one time.  If this function is called two times
+  // before the worker thread wakes up, and the first has aShouldInterruptCopy
+  // false and the second true, we won't forcibly interrupt the copy from the
+  // control thread.  However, that never happens, because calling Finish with a
+  // success code is the only case that may result in aShouldInterruptCopy being
+  // false.  In that case, we won't call this function again, because consumers
+  // should not invoke other methods on the control thread after calling Finish.
+  // And in any case, Finish already closes one end of the pipe, causing the
+  // copy to finish properly on its own.
+  if (mWorkerThreadAttentionRequested) {
+    return NS_OK;
+  }
+
+  if (!mAsyncCopyContext) {
+    // Background event queues are not shutdown and could be called after
+    // the queue is reset to null.  To match the behavior of nsIThread
+    // return NS_ERROR_UNEXPECTED
+    if (!mBackgroundET) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    // Copy is not in progress, post an event to handle the change manually.
+    rv = mBackgroundET->Dispatch(
+        NewRunnableMethod("net::BackgroundFileSaver::ProcessAttention", this,
+                          &BackgroundFileSaver::ProcessAttention),
+        NS_DISPATCH_EVENT_MAY_BLOCK);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+  } else if (aShouldInterruptCopy) {
+    // Interrupt the copy.  The copy will be resumed, if needed, by the
+    // ProcessAttention function, invoked by the AsyncCopyCallback function.
+    NS_CancelAsyncCopy(mAsyncCopyContext, NS_ERROR_ABORT);
+  }
+
+  // Indicate that attention has been requested successfully, there is no need
+  // to post another event until the worker thread processes the current one.
+  mWorkerThreadAttentionRequested = true;
+
+  return NS_OK;
+}
+
+// Called on the worker thread.
+// static
+void BackgroundFileSaver::AsyncCopyCallback(void* aClosure, nsresult aStatus) {
+  // We called NS_ADDREF_THIS when NS_AsyncCopy started, to keep the object
+  // alive even if other references disappeared.  At the end of this method,
+  // we've finished using the object and can safely release our reference.
+  RefPtr<BackgroundFileSaver> self =
+      dont_AddRef((BackgroundFileSaver*)aClosure);
+  {
+    MutexAutoLock lock(self->mLock);
+
+    // Now that the copy was interrupted or terminated, any notification from
+    // the control thread requires an event to be posted to the worker thread.
+    self->mAsyncCopyContext = nullptr;
+
+    // When detecting failures, ignore the status code we use to interrupt.
+    if (NS_FAILED(aStatus) && aStatus != NS_ERROR_ABORT &&
+        NS_SUCCEEDED(self->mStatus)) {
+      self->mStatus = aStatus;
+    }
+  }
+
+  (void)self->ProcessAttention();
+}
+
+// Called on the worker thread.
+nsresult BackgroundFileSaver::ProcessAttention() {
+  nsresult rv;
+
+  // This function is called whenever the attention of the worker thread has
+  // been requested.  This may happen in these cases:
+  // * We are about to start the copy for the first time.  In this case, we are
+  //   called from an event posted on the worker thread from the control thread
+  //   by GetWorkerThreadAttention, and mAsyncCopyContext is null.
+  // * We have interrupted the copy for some reason.  In this case, we are
+  //   called by AsyncCopyCallback, and mAsyncCopyContext is null.
+  // * We are currently executing ProcessStateChange, and attention is requested
+  //   by the control thread, for example because SetTarget or Finish have been
+  //   called.  In this case, we are called from from an event posted through
+  //   GetWorkerThreadAttention.  While mAsyncCopyContext was always null when
+  //   the event was posted, at this point mAsyncCopyContext may not be null
+  //   anymore, because ProcessStateChange may have started the copy before the
+  //   event that called this function was processed on the worker thread.
+  // If mAsyncCopyContext is not null, we interrupt the copy and re-enter
+  // through AsyncCopyCallback.  This allows us to check if, for instance, we
+  // should rename the target file.  We will then restart the copy if needed.
+
+  // mAsyncCopyContext is only written on the worker thread (which we are on)
+  MOZ_ASSERT(!NS_IsMainThread());
+  {
+    // Even though we're the only thread that writes this, we have to take the
+    // lock
+    MutexAutoLock lock(mLock);
+    if (mAsyncCopyContext) {
+      NS_CancelAsyncCopy(mAsyncCopyContext, NS_ERROR_ABORT);
+      return NS_OK;
+    }
+  }
+  // Use the current shared state to determine the next operation to execute.
+  rv = ProcessStateChange();
+  if (NS_FAILED(rv)) {
+    // If something failed while processing, terminate the operation now.
+    {
+      MutexAutoLock lock(mLock);
+
+      if (NS_SUCCEEDED(mStatus)) {
+        mStatus = rv;
+      }
+    }
+    // Ensure we notify completion now that the operation failed.
+    CheckCompletion();
+  }
+
+  return NS_OK;
+}
+
+// Called on the worker thread.
+nsresult BackgroundFileSaver::ProcessStateChange() {
+  nsresult rv;
+
+  // We might have been notified because the operation is complete, verify.
+  if (CheckCompletion()) {
+    return NS_OK;
+  }
+
+  // Get a copy of the current shared state for the worker thread.
+  nsCOMPtr<nsIFile> initialTarget;
+  bool initialTargetKeepPartial;
+  nsCOMPtr<nsIFile> renamedTarget;
+  bool renamedTargetKeepPartial;
+  bool sha256Enabled;
+  bool append;
+  {
+    MutexAutoLock lock(mLock);
+
+    initialTarget = mInitialTarget;
+    initialTargetKeepPartial = mInitialTargetKeepPartial;
+    renamedTarget = mRenamedTarget;
+    renamedTargetKeepPartial = mRenamedTargetKeepPartial;
+    sha256Enabled = mSha256Enabled;
+    append = mAppend;
+
+    // From now on, another attention event needs to be posted if state changes.
+    mWorkerThreadAttentionRequested = false;
+  }
+
+  // The initial target can only be null if it has never been assigned.  In this
+  // case, there is nothing to do since we never created any output file.
+  if (!initialTarget) {
+    return NS_OK;
+  }
+
+  // Determine if we are processing the attention request for the first time.
+  bool isContinuation = !!mActualTarget;
+  if (!isContinuation) {
+    // Assign the target file for the first time.
+    mActualTarget = initialTarget;
+    mActualTargetKeepPartial = initialTargetKeepPartial;
+  }
+
+  // Verify whether we have actually been instructed to use a different file.
+  // This may happen the first time this function is executed, if SetTarget was
+  // called two times before the worker thread processed the attention request.
+  bool equalToCurrent = false;
+  if (renamedTarget) {
+    rv = mActualTarget->Equals(renamedTarget, &equalToCurrent);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!equalToCurrent) {
+      // If we were asked to rename the file but the initial file did not exist,
+      // we simply create the file in the renamed location.  We avoid this check
+      // if we have already started writing the output file ourselves.
+      bool exists = true;
+      if (!isContinuation) {
+        rv = mActualTarget->Exists(&exists);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      if (exists) {
+        // We are moving the previous target file to a different location.
+        nsCOMPtr<nsIFile> renamedTargetParentDir;
+        rv = renamedTarget->GetParent(getter_AddRefs(renamedTargetParentDir));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsAutoString renamedTargetName;
+        rv = renamedTarget->GetLeafName(renamedTargetName);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // We must delete any existing target file before moving the current
+        // one.
+        rv = renamedTarget->Exists(&exists);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (exists) {
+          rv = renamedTarget->Remove(false);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+
+        // Move the file.  If this fails, we still reference the original file
+        // in mActualTarget, so that it is deleted if requested.  If this
+        // succeeds, the nsIFile instance referenced by mActualTarget mutates
+        // and starts pointing to the new file, but we'll discard the reference.
+        rv = mActualTarget->MoveTo(renamedTargetParentDir, renamedTargetName);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      // We should not only update the mActualTarget with renameTarget when
+      // they point to the different files.
+      // In this way, if mActualTarget and renamedTarget point to the same file
+      // with different addresses, "CheckCompletion()" will return false
+      // forever.
+    }
+
+    // Update mActualTarget with renameTarget,
+    // even if they point to the same file.
+    mActualTarget = renamedTarget;
+    mActualTargetKeepPartial = renamedTargetKeepPartial;
+  }
+
+  // Notify if the target file name actually changed.
+  if (!equalToCurrent) {
+    // We must clone the nsIFile instance because mActualTarget is not
+    // immutable, it may change if the target is renamed later.
+    nsCOMPtr<nsIFile> actualTargetToNotify;
+    rv = mActualTarget->Clone(getter_AddRefs(actualTargetToNotify));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    RefPtr<NotifyTargetChangeRunnable> event =
+        new NotifyTargetChangeRunnable(this, actualTargetToNotify);
+    NS_ENSURE_TRUE(event, NS_ERROR_FAILURE);
+
+    rv = mControlEventTarget->Dispatch(event, NS_DISPATCH_NORMAL);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (isContinuation) {
+    // The pending rename operation might be the last task before finishing. We
+    // may return here only if we have already created the target file.
+    if (CheckCompletion()) {
+      return NS_OK;
+    }
+
+    // Even if the operation did not complete, the pipe input stream may be
+    // empty and may have been closed already.  We detect this case using the
+    // Available property, because it never returns an error if there is more
+    // data to be consumed.  If the pipe input stream is closed, we just exit
+    // and wait for more calls like SetTarget or Finish to be invoked on the
+    // control thread.  However, we still truncate the file or create the
+    // initial digest context if we are expected to do that.
+    uint64_t available;
+    rv = mPipeInputStream->Available(&available);
+    if (NS_FAILED(rv)) {
+      return NS_OK;
+    }
+  }
+
+  // Create the digest if requested and NSS hasn't been shut down.
+  if (sha256Enabled && mDigest.isNothing()) {
+    mDigest.emplace(Digest());
+    mDigest->Begin(SEC_OID_SHA256);
+  }
+
+  // When we are requested to append to an existing file, we should read the
+  // existing data and ensure we include it as part of the final hash.
+  if (mDigest.isSome() && append && !isContinuation) {
+    nsCOMPtr<nsIInputStream> inputStream;
+    rv = NS_NewLocalFileInputStream(getter_AddRefs(inputStream), mActualTarget,
+                                    PR_RDONLY | nsIFile::OS_READAHEAD);
+    if (rv != NS_ERROR_FILE_NOT_FOUND) {
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Try to clean up the inputStream if an error occurs.
+      auto closeGuard =
+          mozilla::MakeScopeExit([&] { Unused << inputStream->Close(); });
+
+      char buffer[BUFFERED_IO_SIZE];
+      while (true) {
+        uint32_t count;
+        rv = inputStream->Read(buffer, BUFFERED_IO_SIZE, &count);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        if (count == 0) {
+          // We reached the end of the file.
+          break;
+        }
+
+        rv = mDigest->Update(BitwiseCast<unsigned char*, char*>(buffer), count);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // The pending resume operation may have been cancelled by the control
+        // thread while the worker thread was reading in the existing file.
+        // Abort reading in the original file in that case, as the digest will
+        // be discarded anyway.
+        MutexAutoLock lock(mLock);
+        if (NS_FAILED(mStatus)) {
+          return NS_ERROR_ABORT;
+        }
+      }
+
+      // Close explicitly to handle any errors.
+      closeGuard.release();
+      rv = inputStream->Close();
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // We will append to the initial target file only if it was requested by the
+  // caller, but we'll always append on subsequent accesses to the target file.
+  int32_t creationIoFlags;
+  if (isContinuation) {
+    creationIoFlags = PR_APPEND;
+  } else {
+    creationIoFlags = (append ? PR_APPEND : PR_TRUNCATE) | PR_CREATE_FILE;
+  }
+
+  // Create the target file, or append to it if we already started writing it.
+  // The 0600 permissions are used while the file is being downloaded, and for
+  // interrupted downloads. Those may be located in the system temporary
+  // directory, as well as the target directory, and generally have a ".part"
+  // extension. Those part files should never be group or world-writable even
+  // if the umask allows it.
+  nsCOMPtr<nsIOutputStream> outputStream;
+  rv = NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mActualTarget,
+                                   PR_WRONLY | creationIoFlags, 0600);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIOutputStream> bufferedStream;
+  rv = NS_NewBufferedOutputStream(getter_AddRefs(bufferedStream),
+                                  outputStream.forget(), BUFFERED_IO_SIZE);
+  NS_ENSURE_SUCCESS(rv, rv);
+  outputStream = bufferedStream;
+
+  // Wrap the output stream so that it feeds the digest if needed.
+  if (mDigest.isSome()) {
+    // Constructing the DigestOutputStream cannot fail. Passing mDigest
+    // to DigestOutputStream is safe, because BackgroundFileSaver always
+    // outlives the outputStream. BackgroundFileSaver is reference-counted
+    // before the call to AsyncCopy, and mDigest is never destroyed
+    // before AsyncCopyCallback.
+    outputStream = new DigestOutputStream(outputStream, mDigest.ref());
+  }
+
+  // Start copying our input to the target file.  No errors can be raised past
+  // this point if the copy starts, since they should be handled by the thread.
+  {
+    MutexAutoLock lock(mLock);
+
+    rv = NS_AsyncCopy(mPipeInputStream, outputStream, mBackgroundET,
+                      NS_ASYNCCOPY_VIA_READSEGMENTS, 4096, AsyncCopyCallback,
+                      this, false, true, getter_AddRefs(mAsyncCopyContext),
+                      GetProgressCallback());
+    if (NS_FAILED(rv)) {
+      NS_WARNING("NS_AsyncCopy failed.");
+      mAsyncCopyContext = nullptr;
+      return rv;
+    }
+  }
+
+  // If the operation succeeded, we must ensure that we keep this object alive
+  // for the entire duration of the copy, since only the raw pointer will be
+  // provided as the argument of the AsyncCopyCallback function.  We can add the
+  // reference now, after NS_AsyncCopy returned, because it always starts
+  // processing asynchronously, and there is no risk that the callback is
+  // invoked before we reach this point.  If the operation failed instead, then
+  // AsyncCopyCallback will never be called.
+  NS_ADDREF_THIS();
+
+  return NS_OK;
+}
+
+// Called on the worker thread.
+bool BackgroundFileSaver::CheckCompletion() {
+  nsresult rv;
+
+  bool failed = true;
+  {
+    MutexAutoLock lock(mLock);
+    MOZ_ASSERT(!mAsyncCopyContext,
+               "Should not be copying when checking completion conditions.");
+
+    if (mComplete) {
+      return true;
+    }
+
+    // If an error occurred, we don't need to do the checks in this code block,
+    // and the operation can be completed immediately with a failure code.
+    if (NS_SUCCEEDED(mStatus)) {
+      failed = false;
+
+      // We did not incur in an error, so we must determine if we can stop now.
+      // If the Finish method has not been called, we can just continue now.
+      if (!mFinishRequested) {
+        return false;
+      }
+
+      // We can only stop when all the operations requested by the control
+      // thread have been processed.  First, we check whether we have processed
+      // the first SetTarget call, if any.  Then, we check whether we have
+      // processed any rename requested by subsequent SetTarget calls.
+      if ((mInitialTarget && !mActualTarget) ||
+          (mRenamedTarget && mRenamedTarget != mActualTarget)) {
+        return false;
+      }
+
+      // If we still have data to write to the output file, allow the copy
+      // operation to resume.  The Available getter may return an error if one
+      // of the pipe's streams has been already closed.
+      uint64_t available;
+      rv = mPipeInputStream->Available(&available);
+      if (NS_SUCCEEDED(rv) && available != 0) {
+        return false;
+      }
+    }
+
+    mComplete = true;
+  }
+
+  // Ensure we notify completion now that the operation finished.
+  // Do a best-effort attempt to remove the file if required.
+  if (failed && mActualTarget && !mActualTargetKeepPartial) {
+    (void)mActualTarget->Remove(false);
+  }
+
+  // Finish computing the hash
+  if (!failed && mDigest.isSome()) {
+    nsTArray<uint8_t> outArray;
+    rv = mDigest->End(outArray);
+    if (NS_SUCCEEDED(rv)) {
+      MutexAutoLock lock(mLock);
+      mSha256 = nsDependentCSubstring(
+          BitwiseCast<char*, uint8_t*>(outArray.Elements()), outArray.Length());
+    }
+  }
+
+  // Compute the signature of the binary. ExtractSignatureInfo doesn't do
+  // anything on non-Windows platforms except return an empty nsIArray.
+  if (!failed && mActualTarget) {
+    nsString filePath;
+    mActualTarget->GetTarget(filePath);
+    nsresult rv = ExtractSignatureInfo(filePath);
+    if (NS_FAILED(rv)) {
+      LOG(("Unable to extract signature information [this = %p].", this));
+    } else {
+      LOG(("Signature extraction success! [this = %p]", this));
+    }
+  }
+
+  // Post an event to notify that the operation completed.
+  if (NS_FAILED(mControlEventTarget->Dispatch(
+          NewRunnableMethod("BackgroundFileSaver::NotifySaveComplete", this,
+                            &BackgroundFileSaver::NotifySaveComplete),
+          NS_DISPATCH_NORMAL))) {
+    NS_WARNING("Unable to post completion event to the control thread.");
+  }
+
+  return true;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::NotifyTargetChange(nsIFile* aTarget) {
+  if (mObserver) {
+    (void)mObserver->OnTargetChange(this, aTarget);
+  }
+
+  return NS_OK;
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaver::NotifySaveComplete() {
+  MOZ_ASSERT(NS_IsMainThread(), "This should be called on the main thread");
+
+  nsresult status;
+  {
+    MutexAutoLock lock(mLock);
+    status = mStatus;
+  }
+
+  if (mObserver) {
+    (void)mObserver->OnSaveComplete(this, status);
+    // If mObserver keeps alive an enclosure that captures `this`, we'll have a
+    // cycle that won't be caught by the cycle-collector, so we need to break it
+    // when we're done here (see bug 1444265).
+    mObserver = nullptr;
+  }
+
+  // At this point, the worker thread will not process any more events, and we
+  // can shut it down.  Shutting down a thread may re-enter the event loop on
+  // this thread.  This is not a problem in this case, since this function is
+  // called by a top-level event itself, and we have already invoked the
+  // completion observer callback.  Re-entering the loop can only delay the
+  // final release and destruction of this saver object, since we are keeping a
+  // reference to it through the event object.
+  mBackgroundET = nullptr;
+
+  sThreadCount--;
+
+  // When there are no more active downloads, we consider the download session
+  // finished. We record the maximum number of concurrent downloads reached
+  // during the session in a telemetry histogram, and we reset the maximum
+  // thread counter for the next download session
+  if (sThreadCount == 0) {
+    Telemetry::Accumulate(Telemetry::BACKGROUNDFILESAVER_THREAD_COUNT,
+                          sTelemetryMaxThreadCount);
+    sTelemetryMaxThreadCount = 0;
+  }
+
+  return NS_OK;
+}
+
+nsresult BackgroundFileSaver::ExtractSignatureInfo(const nsAString& filePath) {
+  MOZ_ASSERT(!NS_IsMainThread(), "Cannot extract signature on main thread");
+  {
+    MutexAutoLock lock(mLock);
+    if (!mSignatureInfoEnabled) {
+      return NS_OK;
+    }
+  }
+#ifdef XP_WIN
+  // Setup the file to check.
+  WINTRUST_FILE_INFO fileToCheck = {0};
+  fileToCheck.cbStruct = sizeof(WINTRUST_FILE_INFO);
+  fileToCheck.pcwszFilePath = filePath.Data();
+  fileToCheck.hFile = nullptr;
+  fileToCheck.pgKnownSubject = nullptr;
+
+  // We want to check it is signed and trusted.
+  WINTRUST_DATA trustData = {0};
+  trustData.cbStruct = sizeof(trustData);
+  trustData.pPolicyCallbackData = nullptr;
+  trustData.pSIPClientData = nullptr;
+  trustData.dwUIChoice = WTD_UI_NONE;
+  trustData.fdwRevocationChecks = WTD_REVOKE_NONE;
+  trustData.dwUnionChoice = WTD_CHOICE_FILE;
+  trustData.dwStateAction = WTD_STATEACTION_VERIFY;
+  trustData.hWVTStateData = nullptr;
+  trustData.pwszURLReference = nullptr;
+  // Disallow revocation checks over the network
+  trustData.dwProvFlags = WTD_CACHE_ONLY_URL_RETRIEVAL;
+  // no UI
+  trustData.dwUIContext = 0;
+  trustData.pFile = &fileToCheck;
+
+  // The WINTRUST_ACTION_GENERIC_VERIFY_V2 policy verifies that the certificate
+  // chains up to a trusted root CA and has appropriate permissions to sign
+  // code.
+  GUID policyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2;
+  // Check if the file is signed by something that is trusted. If the file is
+  // not signed, this is a no-op.
+  LONG ret = WinVerifyTrust(nullptr, &policyGUID, &trustData);
+  CRYPT_PROVIDER_DATA* cryptoProviderData = nullptr;
+  // According to the Windows documentation, we should check against 0 instead
+  // of ERROR_SUCCESS, which is an HRESULT.
+  if (ret == 0) {
+    cryptoProviderData = WTHelperProvDataFromStateData(trustData.hWVTStateData);
+  }
+  if (cryptoProviderData) {
+    // Lock because signature information is read on the main thread.
+    MutexAutoLock lock(mLock);
+    LOG(("Downloaded trusted and signed file [this = %p].", this));
+    // A binary may have multiple signers. Each signer may have multiple certs
+    // in the chain.
+    for (DWORD i = 0; i < cryptoProviderData->csSigners; ++i) {
+      const CERT_CHAIN_CONTEXT* certChainContext =
+          cryptoProviderData->pasSigners[i].pChainContext;
+      if (!certChainContext) {
+        break;
+      }
+      for (DWORD j = 0; j < certChainContext->cChain; ++j) {
+        const CERT_SIMPLE_CHAIN* certSimpleChain =
+            certChainContext->rgpChain[j];
+        if (!certSimpleChain) {
+          break;
+        }
+
+        nsTArray<nsTArray<uint8_t>> certList;
+        bool extractionSuccess = true;
+        for (DWORD k = 0; k < certSimpleChain->cElement; ++k) {
+          CERT_CHAIN_ELEMENT* certChainElement = certSimpleChain->rgpElement[k];
+          if (certChainElement->pCertContext->dwCertEncodingType !=
+              X509_ASN_ENCODING) {
+            continue;
+          }
+          nsTArray<uint8_t> cert;
+          cert.AppendElements(certChainElement->pCertContext->pbCertEncoded,
+                              certChainElement->pCertContext->cbCertEncoded);
+          certList.AppendElement(std::move(cert));
+        }
+        if (extractionSuccess) {
+          mSignatureInfo.AppendElement(std::move(certList));
+        }
+      }
+    }
+    // Free the provider data if cryptoProviderData is not null.
+    trustData.dwStateAction = WTD_STATEACTION_CLOSE;
+    WinVerifyTrust(nullptr, &policyGUID, &trustData);
+  } else {
+    LOG(("Downloaded unsigned or untrusted file [this = %p].", this));
+  }
+#endif
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverOutputStream
+
+NS_IMPL_ISUPPORTS(BackgroundFileSaverOutputStream, nsIBackgroundFileSaver,
+                  nsIOutputStream, nsIAsyncOutputStream,
+                  nsIOutputStreamCallback)
+
+BackgroundFileSaverOutputStream::BackgroundFileSaverOutputStream()
+    : BackgroundFileSaver(), mAsyncWaitCallback(nullptr) {}
+
+bool BackgroundFileSaverOutputStream::HasInfiniteBuffer() { return false; }
+
+nsAsyncCopyProgressFun BackgroundFileSaverOutputStream::GetProgressCallback() {
+  return nullptr;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Close() { return mPipeOutputStream->Close(); }
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Flush() { return mPipeOutputStream->Flush(); }
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::StreamStatus() {
+  return mPipeOutputStream->StreamStatus();
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::Write(const char* aBuf, uint32_t aCount,
+                                       uint32_t* _retval) {
+  return mPipeOutputStream->Write(aBuf, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::WriteFrom(nsIInputStream* aFromStream,
+                                           uint32_t aCount, uint32_t* _retval) {
+  return mPipeOutputStream->WriteFrom(aFromStream, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::WriteSegments(nsReadSegmentFun aReader,
+                                               void* aClosure, uint32_t aCount,
+                                               uint32_t* _retval) {
+  return mPipeOutputStream->WriteSegments(aReader, aClosure, aCount, _retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::IsNonBlocking(bool* _retval) {
+  return mPipeOutputStream->IsNonBlocking(_retval);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::CloseWithStatus(nsresult reason) {
+  return mPipeOutputStream->CloseWithStatus(reason);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::AsyncWait(nsIOutputStreamCallback* aCallback,
+                                           uint32_t aFlags,
+                                           uint32_t aRequestedCount,
+                                           nsIEventTarget* aEventTarget) {
+  NS_ENSURE_STATE(!mAsyncWaitCallback);
+
+  mAsyncWaitCallback = aCallback;
+
+  return mPipeOutputStream->AsyncWait(this, aFlags, aRequestedCount,
+                                      aEventTarget);
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverOutputStream::OnOutputStreamReady(
+    nsIAsyncOutputStream* aStream) {
+  NS_ENSURE_STATE(mAsyncWaitCallback);
+
+  nsCOMPtr<nsIOutputStreamCallback> asyncWaitCallback = nullptr;
+  asyncWaitCallback.swap(mAsyncWaitCallback);
+
+  return asyncWaitCallback->OnOutputStreamReady(this);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverStreamListener
+
+NS_IMPL_ISUPPORTS(BackgroundFileSaverStreamListener, nsIBackgroundFileSaver,
+                  nsIRequestObserver, nsIStreamListener)
+
+bool BackgroundFileSaverStreamListener::HasInfiniteBuffer() { return true; }
+
+nsAsyncCopyProgressFun
+BackgroundFileSaverStreamListener::GetProgressCallback() {
+  return AsyncCopyProgressCallback;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnStartRequest(nsIRequest* aRequest) {
+  NS_ENSURE_ARG(aRequest);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnStopRequest(nsIRequest* aRequest,
+                                                 nsresult aStatusCode) {
+  // If an error occurred, cancel the operation immediately.  On success, wait
+  // until the caller has determined whether the file should be renamed.
+  if (NS_FAILED(aStatusCode)) {
+    Finish(aStatusCode);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+BackgroundFileSaverStreamListener::OnDataAvailable(nsIRequest* aRequest,
+                                                   nsIInputStream* aInputStream,
+                                                   uint64_t aOffset,
+                                                   uint32_t aCount) {
+  nsresult rv;
+
+  NS_ENSURE_ARG(aRequest);
+
+  // Read the requested data.  Since the pipe has an infinite buffer, we don't
+  // expect any write error to occur here.
+  uint32_t writeCount;
+  rv = mPipeOutputStream->WriteFrom(aInputStream, aCount, &writeCount);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // If reading from the input stream fails for any reason, the pipe will return
+  // a success code, but without reading all the data.  Since we should be able
+  // to read the requested data when OnDataAvailable is called, raise an error.
+  if (writeCount < aCount) {
+    NS_WARNING("Reading from the input stream should not have failed.");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  bool stateChanged = false;
+  {
+    MutexAutoLock lock(mSuspensionLock);
+
+    if (!mReceivedTooMuchData) {
+      uint64_t available;
+      nsresult rv = mPipeInputStream->Available(&available);
+      if (NS_SUCCEEDED(rv) && available > REQUEST_SUSPEND_AT) {
+        mReceivedTooMuchData = true;
+        mRequest = aRequest;
+        stateChanged = true;
+      }
+    }
+  }
+
+  if (stateChanged) {
+    NotifySuspendOrResume();
+  }
+
+  return NS_OK;
+}
+
+// Called on the worker thread.
+// static
+void BackgroundFileSaverStreamListener::AsyncCopyProgressCallback(
+    void* aClosure, uint32_t aCount) {
+  BackgroundFileSaverStreamListener* self =
+      (BackgroundFileSaverStreamListener*)aClosure;
+
+  // Wait if the control thread is in the process of suspending or resuming.
+  MutexAutoLock lock(self->mSuspensionLock);
+
+  // This function is called when some bytes are consumed by NS_AsyncCopy.  Each
+  // time this happens, verify if a suspended request should be resumed, because
+  // we have now consumed enough data.
+  if (self->mReceivedTooMuchData) {
+    uint64_t available;
+    nsresult rv = self->mPipeInputStream->Available(&available);
+    if (NS_FAILED(rv) || available < REQUEST_RESUME_AT) {
+      self->mReceivedTooMuchData = false;
+
+      // Post an event to verify if the request should be resumed.
+      if (NS_FAILED(self->mControlEventTarget->Dispatch(
+              NewRunnableMethod(
+                  "BackgroundFileSaverStreamListener::NotifySuspendOrResume",
+                  self,
+                  &BackgroundFileSaverStreamListener::NotifySuspendOrResume),
+              NS_DISPATCH_NORMAL))) {
+        NS_WARNING("Unable to post resume event to the control thread.");
+      }
+    }
+  }
+}
+
+// Called on the control thread.
+nsresult BackgroundFileSaverStreamListener::NotifySuspendOrResume() {
+  // Prevent the worker thread from changing state while processing.
+  MutexAutoLock lock(mSuspensionLock);
+
+  if (mReceivedTooMuchData) {
+    if (!mRequestSuspended) {
+      // Try to suspend the request.  If this fails, don't try to resume later.
+      if (NS_SUCCEEDED(mRequest->Suspend())) {
+        mRequestSuspended = true;
+      } else {
+        NS_WARNING("Unable to suspend the request.");
+      }
+    }
+  } else {
+    if (mRequestSuspended) {
+      // Resume the request only if we succeeded in suspending it.
+      if (NS_SUCCEEDED(mRequest->Resume())) {
+        mRequestSuspended = false;
+      } else {
+        NS_WARNING("Unable to resume the request.");
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//// DigestOutputStream
+NS_IMPL_ISUPPORTS(DigestOutputStream, nsIOutputStream)
+
+DigestOutputStream::DigestOutputStream(nsIOutputStream* aStream,
+                                       Digest& aDigest)
+    : mOutputStream(aStream), mDigest(aDigest) {
+  MOZ_ASSERT(mOutputStream, "Can't have null output stream");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::Close() { return mOutputStream->Close(); }
+
+NS_IMETHODIMP
+DigestOutputStream::Flush() { return mOutputStream->Flush(); }
+
+NS_IMETHODIMP
+DigestOutputStream::StreamStatus() { return mOutputStream->StreamStatus(); }
+
+NS_IMETHODIMP
+DigestOutputStream::Write(const char* aBuf, uint32_t aCount, uint32_t* retval) {
+  nsresult rv = mDigest.Update(
+      BitwiseCast<const unsigned char*, const char*>(aBuf), aCount);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return mOutputStream->Write(aBuf, aCount, retval);
+}
+
+NS_IMETHODIMP
+DigestOutputStream::WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
+                              uint32_t* retval) {
+  // Not supported. We could read the stream to a buf, call DigestOp on the
+  // result, seek back and pass the stream on, but it's not worth it since our
+  // application (NS_AsyncCopy) doesn't invoke this on the sink.
+  MOZ_CRASH("DigestOutputStream::WriteFrom not implemented");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::WriteSegments(nsReadSegmentFun aReader, void* aClosure,
+                                  uint32_t aCount, uint32_t* retval) {
+  MOZ_CRASH("DigestOutputStream::WriteSegments not implemented");
+}
+
+NS_IMETHODIMP
+DigestOutputStream::IsNonBlocking(bool* retval) {
+  return mOutputStream->IsNonBlocking(retval);
+}
+
+#undef LOG_ENABLED
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/BackgroundFileSaver.h b/netwerk/base/BackgroundFileSaver.h
new file mode 100644
index 0000000000..214aa31d10
--- /dev/null
+++ b/netwerk/base/BackgroundFileSaver.h
@@ -0,0 +1,397 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This file defines two implementations of the nsIBackgroundFileSaver
+ * interface.  See the "test_backgroundfilesaver.js" file for usage examples.
+ */
+
+#ifndef BackgroundFileSaver_h__
+#define BackgroundFileSaver_h__
+
+#include "ScopedNSSTypes.h"
+#include "mozilla/Mutex.h"
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIBackgroundFileSaver.h"
+#include "nsIStreamListener.h"
+#include "nsStreamUtils.h"
+#include "nsString.h"
+
+class nsIAsyncInputStream;
+class nsISerialEventTarget;
+
+namespace mozilla {
+namespace net {
+
+class DigestOutputStream;
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaver
+
+class BackgroundFileSaver : public nsIBackgroundFileSaver {
+ public:
+  NS_DECL_NSIBACKGROUNDFILESAVER
+
+  BackgroundFileSaver();
+
+  /**
+   * Initializes the pipe and the worker thread on XPCOM construction.
+   *
+   * This is called automatically by the XPCOM infrastructure, and if this
+   * fails, the factory will delete this object without returning a reference.
+   */
+  nsresult Init();
+
+  /**
+   * Number of worker threads that are currently running.
+   */
+  static uint32_t sThreadCount;
+
+  /**
+   * Maximum number of worker threads reached during the current download
+   * session, used for telemetry.
+   *
+   * When there are no more worker threads running, we consider the download
+   * session finished, and this counter is reset.
+   */
+  static uint32_t sTelemetryMaxThreadCount;
+
+ protected:
+  virtual ~BackgroundFileSaver();
+
+  /**
+   * Thread that constructed this object.
+   */
+  nsCOMPtr<nsIEventTarget> mControlEventTarget;
+
+  /**
+   * Thread to which the actual input/output is delegated.
+   */
+  nsCOMPtr<nsISerialEventTarget> mBackgroundET;
+
+  /**
+   * Stream that receives data from derived classes.  The received data will be
+   * available to the worker thread through mPipeInputStream. This is an
+   * instance of nsPipeOutputStream, not BackgroundFileSaverOutputStream.
+   */
+  nsCOMPtr<nsIAsyncOutputStream> mPipeOutputStream;
+
+  /**
+   * Used during initialization, determines if the pipe is created with an
+   * infinite buffer.  An infinite buffer is required if the derived class
+   * implements nsIStreamListener, because this interface requires all the
+   * provided data to be consumed synchronously.
+   */
+  virtual bool HasInfiniteBuffer() = 0;
+
+  /**
+   * Used by derived classes if they need to be called back while copying.
+   */
+  virtual nsAsyncCopyProgressFun GetProgressCallback() = 0;
+
+  /**
+   * Stream used by the worker thread to read the data to be saved.
+   */
+  nsCOMPtr<nsIAsyncInputStream> mPipeInputStream;
+
+ private:
+  friend class NotifyTargetChangeRunnable;
+
+  /**
+   * Matches the nsIBackgroundFileSaver::observer property.
+   *
+   * @remarks This is a strong reference so that JavaScript callers don't need
+   *          to worry about keeping another reference to the observer.
+   */
+  nsCOMPtr<nsIBackgroundFileSaverObserver> mObserver;
+
+  //////////////////////////////////////////////////////////////////////////////
+  //// Shared state between control and worker threads
+
+  /**
+   * Protects the shared state between control and worker threads.  This mutex
+   * is always locked for a very short time, never during input/output.
+   */
+  mozilla::Mutex mLock{"BackgroundFileSaver.mLock"};
+
+  /**
+   * True if the worker thread is already waiting to process a change in state.
+   */
+  bool mWorkerThreadAttentionRequested MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * True if the operation should finish as soon as possibile.
+   */
+  bool mFinishRequested MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * True if the operation completed, with either success or failure.
+   */
+  bool mComplete MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * Holds the current file saver status.  This is a success status while the
+   * object is working correctly, and remains such if the operation completes
+   * successfully.  This becomes an error status when an error occurs on the
+   * worker thread, or when the operation is canceled.
+   */
+  nsresult mStatus MOZ_GUARDED_BY(mLock){NS_OK};
+
+  /**
+   * True if we should append data to the initial target file, instead of
+   * overwriting it.
+   */
+  bool mAppend MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * This is set by the first SetTarget call on the control thread, and contains
+   * the target file name that will be used by the worker thread, as soon as it
+   * is possible to update mActualTarget and open the file.  This is null if no
+   * target was ever assigned to this object.
+   */
+  nsCOMPtr<nsIFile> mInitialTarget MOZ_GUARDED_BY(mLock);
+
+  /**
+   * This is set by the first SetTarget call on the control thread, and
+   * indicates whether mInitialTarget should be kept as partially completed,
+   * rather than deleted, if the operation fails or is canceled.
+   */
+  bool mInitialTargetKeepPartial MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * This is set by subsequent SetTarget calls on the control thread, and
+   * contains the new target file name to which the worker thread will move the
+   * target file, as soon as it can be done.  This is null if SetTarget was
+   * called only once, or no target was ever assigned to this object.
+   *
+   * The target file can be renamed multiple times, though only the most recent
+   * rename is guaranteed to be processed by the worker thread.
+   */
+  nsCOMPtr<nsIFile> mRenamedTarget MOZ_GUARDED_BY(mLock);
+
+  /**
+   * This is set by subsequent SetTarget calls on the control thread, and
+   * indicates whether mRenamedTarget should be kept as partially completed,
+   * rather than deleted, if the operation fails or is canceled.
+   */
+  bool mRenamedTargetKeepPartial MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * While NS_AsyncCopy is in progress, allows canceling it.  Null otherwise.
+   * This is read by both threads but only written by the worker thread.
+   */
+  nsCOMPtr<nsISupports> mAsyncCopyContext MOZ_GUARDED_BY(mLock);
+
+  /**
+   * The SHA 256 hash in raw bytes of the downloaded file. This is written
+   * by the worker thread but can be read on the main thread.
+   */
+  nsCString mSha256 MOZ_GUARDED_BY(mLock);
+
+  /**
+   * Whether or not to compute the hash. Must be set on the main thread before
+   * setTarget is called.
+   */
+  bool mSha256Enabled MOZ_GUARDED_BY(mLock){false};
+
+  /**
+   * Store the signature info.
+   */
+  nsTArray<nsTArray<nsTArray<uint8_t>>> mSignatureInfo MOZ_GUARDED_BY(mLock);
+
+  /**
+   * Whether or not to extract the signature. Must be set on the main thread
+   * before setTarget is called.
+   */
+  bool mSignatureInfoEnabled MOZ_GUARDED_BY(mLock){false};
+
+  //////////////////////////////////////////////////////////////////////////////
+  //// State handled exclusively by the worker thread
+
+  /**
+   * Current target file associated to the input and output streams.
+   */
+  nsCOMPtr<nsIFile> mActualTarget;
+
+  /**
+   * Indicates whether mActualTarget should be kept as partially completed,
+   * rather than deleted, if the operation fails or is canceled.
+   */
+  bool mActualTargetKeepPartial{false};
+
+  /**
+   * Used to calculate the file hash. This keeps state across file renames and
+   * is lazily initialized in ProcessStateChange.
+   */
+  Maybe<Digest> mDigest;
+
+  //////////////////////////////////////////////////////////////////////////////
+  //// Private methods
+
+  /**
+   * Called when NS_AsyncCopy completes.
+   *
+   * @param aClosure
+   *        Populated with a raw pointer to the BackgroundFileSaver object.
+   * @param aStatus
+   *        Success or failure status specified when the copy was interrupted.
+   */
+  static void AsyncCopyCallback(void* aClosure, nsresult aStatus);
+
+  /**
+   * Called on the control thread after state changes, to ensure that the worker
+   * thread will process the state change appropriately.
+   *
+   * @param aShouldInterruptCopy
+   *        If true, the current NS_AsyncCopy, if any, is canceled.
+   */
+  nsresult GetWorkerThreadAttention(bool aShouldInterruptCopy);
+
+  /**
+   * Event called on the worker thread to begin processing a state change.
+   */
+  nsresult ProcessAttention();
+
+  /**
+   * Called by ProcessAttention to execute the operations corresponding to the
+   * state change.  If this results in an error, ProcessAttention will force the
+   * entire operation to be aborted.
+   */
+  nsresult ProcessStateChange();
+
+  /**
+   * Returns true if completion conditions are met on the worker thread.  The
+   * first time this happens, posts the completion event to the control thread.
+   */
+  bool CheckCompletion();
+
+  /**
+   * Event called on the control thread to indicate that file contents will now
+   * be saved to the specified file.
+   */
+  nsresult NotifyTargetChange(nsIFile* aTarget);
+
+  /**
+   * Event called on the control thread to send the final notification.
+   */
+  nsresult NotifySaveComplete();
+
+  /**
+   * Verifies the signature of the binary at the specified file path and stores
+   * the signature data in mSignatureInfo. We extract only X.509 certificates,
+   * since that is what Google's Safebrowsing protocol specifies.
+   */
+  nsresult ExtractSignatureInfo(const nsAString& filePath);
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverOutputStream
+
+class BackgroundFileSaverOutputStream : public BackgroundFileSaver,
+                                        public nsIAsyncOutputStream,
+                                        public nsIOutputStreamCallback {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+  NS_DECL_NSIASYNCOUTPUTSTREAM
+  NS_DECL_NSIOUTPUTSTREAMCALLBACK
+
+  BackgroundFileSaverOutputStream();
+
+ protected:
+  virtual bool HasInfiniteBuffer() override;
+  virtual nsAsyncCopyProgressFun GetProgressCallback() override;
+
+ private:
+  ~BackgroundFileSaverOutputStream() = default;
+
+  /**
+   * Original callback provided to our AsyncWait wrapper.
+   */
+  nsCOMPtr<nsIOutputStreamCallback> mAsyncWaitCallback;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// BackgroundFileSaverStreamListener. This class is instantiated by
+// nsExternalHelperAppService, DownloadCore.sys.mjs, and possibly others.
+
+class BackgroundFileSaverStreamListener final : public BackgroundFileSaver,
+                                                public nsIStreamListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  BackgroundFileSaverStreamListener() = default;
+
+ protected:
+  virtual bool HasInfiniteBuffer() override;
+  virtual nsAsyncCopyProgressFun GetProgressCallback() override;
+
+ private:
+  ~BackgroundFileSaverStreamListener() = default;
+
+  /**
+   * Protects the state related to whether the request should be suspended.
+   */
+  mozilla::Mutex mSuspensionLock{
+      "BackgroundFileSaverStreamListener.mSuspensionLock"};
+
+  /**
+   * Whether we should suspend the request because we received too much data.
+   */
+  bool mReceivedTooMuchData MOZ_GUARDED_BY(mSuspensionLock){false};
+
+  /**
+   * Request for which we received too much data.  This is populated when
+   * mReceivedTooMuchData becomes true for the first time.
+   */
+  nsCOMPtr<nsIRequest> mRequest MOZ_GUARDED_BY(mSuspensionLock);
+
+  /**
+   * Whether mRequest is currently suspended.
+   */
+  bool mRequestSuspended MOZ_GUARDED_BY(mSuspensionLock){false};
+
+  /**
+   * Called while NS_AsyncCopy is copying data.
+   */
+  static void AsyncCopyProgressCallback(void* aClosure, uint32_t aCount);
+
+  /**
+   * Called on the control thread to suspend or resume the request.
+   */
+  nsresult NotifySuspendOrResume();
+};
+
+// A wrapper around nsIOutputStream, so that we can compute hashes on the
+// stream without copying and without polluting pristine NSS code with XPCOM
+// interfaces.
+class DigestOutputStream : public nsIOutputStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+  // Constructor. Neither parameter may be null. The caller owns both.
+  DigestOutputStream(nsIOutputStream* aStream, Digest& aDigest);
+
+ private:
+  virtual ~DigestOutputStream() = default;
+
+  // Calls to write are passed to this stream.
+  nsCOMPtr<nsIOutputStream> mOutputStream;
+  // Digest used to compute the hash, owned by the caller.
+  Digest& mDigest;
+
+  // Don't accidentally copy construct.
+  DigestOutputStream(const DigestOutputStream& d) = delete;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/CacheInfoIPCTypes.h b/netwerk/base/CacheInfoIPCTypes.h
new file mode 100644
index 0000000000..b3d2277335
--- /dev/null
+++ b/netwerk/base/CacheInfoIPCTypes.h
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_CacheInfoIPCTypes_h_
+#define mozilla_net_CacheInfoIPCTypes_h_
+
+#include "ipc/IPCMessageUtils.h"
+#include "ipc/IPCMessageUtilsSpecializations.h"
+#include "nsICacheInfoChannel.h"
+
+namespace IPC {
+
+template <>
+struct ParamTraits<nsICacheInfoChannel::PreferredAlternativeDataDeliveryType>
+    : public ContiguousEnumSerializerInclusive<
+          nsICacheInfoChannel::PreferredAlternativeDataDeliveryType,
+          nsICacheInfoChannel::PreferredAlternativeDataDeliveryType::NONE,
+          nsICacheInfoChannel::PreferredAlternativeDataDeliveryType::
+              SERIALIZE> {};
+
+}  // namespace IPC
+
+#endif  // mozilla_net_CacheInfoIPCTypes_h_
diff --git a/netwerk/base/CaptivePortalService.cpp b/netwerk/base/CaptivePortalService.cpp
new file mode 100644
index 0000000000..97a1dde929
--- /dev/null
+++ b/netwerk/base/CaptivePortalService.cpp
@@ -0,0 +1,428 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/net/CaptivePortalService.h"
+#include "mozilla/AppShutdown.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Services.h"
+#include "mozilla/Preferences.h"
+#include "nsIObserverService.h"
+#include "nsServiceManagerUtils.h"
+#include "nsXULAppAPI.h"
+#include "xpcpublic.h"
+#include "xpcprivate.h"
+
+static constexpr auto kInterfaceName = u"captive-portal-inteface"_ns;
+
+static const char kOpenCaptivePortalLoginEvent[] = "captive-portal-login";
+static const char kAbortCaptivePortalLoginEvent[] =
+    "captive-portal-login-abort";
+static const char kCaptivePortalLoginSuccessEvent[] =
+    "captive-portal-login-success";
+
+namespace mozilla {
+namespace net {
+
+static LazyLogModule gCaptivePortalLog("CaptivePortalService");
+#undef LOG
+#define LOG(args) MOZ_LOG(gCaptivePortalLog, mozilla::LogLevel::Debug, args)
+
+NS_IMPL_ISUPPORTS(CaptivePortalService, nsICaptivePortalService, nsIObserver,
+                  nsISupportsWeakReference, nsITimerCallback,
+                  nsICaptivePortalCallback, nsINamed)
+
+static StaticRefPtr<CaptivePortalService> gCPService;
+
+// static
+already_AddRefed<nsICaptivePortalService> CaptivePortalService::GetSingleton() {
+  if (gCPService) {
+    return do_AddRef(gCPService);
+  }
+
+  gCPService = new CaptivePortalService();
+  ClearOnShutdown(&gCPService);
+  return do_AddRef(gCPService);
+}
+
+CaptivePortalService::CaptivePortalService() {
+  mLastChecked = TimeStamp::Now();
+}
+
+CaptivePortalService::~CaptivePortalService() {
+  LOG(("CaptivePortalService::~CaptivePortalService isParentProcess:%d\n",
+       XRE_GetProcessType() == GeckoProcessType_Default));
+}
+
+nsresult CaptivePortalService::PerformCheck() {
+  LOG(
+      ("CaptivePortalService::PerformCheck mRequestInProgress:%d "
+       "mInitialized:%d mStarted:%d\n",
+       mRequestInProgress, mInitialized, mStarted));
+  // Don't issue another request if last one didn't complete
+  if (mRequestInProgress || !mInitialized || !mStarted) {
+    return NS_OK;
+  }
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+  // Instantiating CaptiveDetect.sys.mjs before the JS engine is ready will
+  // lead to a crash (see bug 1800603)
+  // We can remove this restriction when we rewrite the detector in
+  // C++ or rust (bug 1809886).
+  if (!XPCJSRuntime::Get()) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+  nsresult rv;
+  if (!mCaptivePortalDetector) {
+    mCaptivePortalDetector =
+        do_CreateInstance("@mozilla.org/toolkit/captive-detector;1", &rv);
+    if (NS_FAILED(rv)) {
+      LOG(("Unable to get a captive portal detector\n"));
+      return rv;
+    }
+  }
+
+  LOG(("CaptivePortalService::PerformCheck - Calling CheckCaptivePortal\n"));
+  mRequestInProgress = true;
+  mCaptivePortalDetector->CheckCaptivePortal(kInterfaceName, this);
+  return NS_OK;
+}
+
+nsresult CaptivePortalService::RearmTimer() {
+  LOG(("CaptivePortalService::RearmTimer\n"));
+  // Start a timer to recheck
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    mTimer = nullptr;
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  // If we have successfully determined the state, and we have never detected
+  // a captive portal, we don't need to keep polling, but will rely on events
+  // to trigger detection.
+  if (mState == NOT_CAPTIVE) {
+    return NS_OK;
+  }
+
+  if (!mTimer) {
+    mTimer = NS_NewTimer();
+  }
+
+  if (mTimer && mDelay > 0) {
+    LOG(("CaptivePortalService - Reloading timer with delay %u\n", mDelay));
+    return mTimer->InitWithCallback(this, mDelay, nsITimer::TYPE_ONE_SHOT);
+  }
+
+  return NS_OK;
+}
+
+nsresult CaptivePortalService::Initialize() {
+  if (mInitialized) {
+    return NS_OK;
+  }
+  mInitialized = true;
+
+  // Only the main process service should actually do anything. The service in
+  // the content process only mirrors the CP state in the main process.
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->AddObserver(this, kOpenCaptivePortalLoginEvent, true);
+    observerService->AddObserver(this, kAbortCaptivePortalLoginEvent, true);
+    observerService->AddObserver(this, kCaptivePortalLoginSuccessEvent, true);
+    observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
+  }
+
+  LOG(("Initialized CaptivePortalService\n"));
+  return NS_OK;
+}
+
+nsresult CaptivePortalService::Start() {
+  if (!mInitialized) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (xpc::AreNonLocalConnectionsDisabled() &&
+      !Preferences::GetBool("network.captive-portal-service.testMode", false)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    // Doesn't do anything if called in the content process.
+    return NS_OK;
+  }
+
+  if (mStarted) {
+    return NS_OK;
+  }
+
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  MOZ_ASSERT(mState == UNKNOWN, "Initial state should be UNKNOWN");
+  mStarted = true;
+  mEverBeenCaptive = false;
+
+  // Get the delay prefs
+  Preferences::GetUint("network.captive-portal-service.minInterval",
+                       &mMinInterval);
+  Preferences::GetUint("network.captive-portal-service.maxInterval",
+                       &mMaxInterval);
+  Preferences::GetFloat("network.captive-portal-service.backoffFactor",
+                        &mBackoffFactor);
+
+  LOG(("CaptivePortalService::Start min:%u max:%u backoff:%.2f\n", mMinInterval,
+       mMaxInterval, mBackoffFactor));
+
+  mSlackCount = 0;
+  mDelay = mMinInterval;
+
+  // When Start is called, perform a check immediately
+  PerformCheck();
+  RearmTimer();
+  return NS_OK;
+}
+
+nsresult CaptivePortalService::Stop() {
+  LOG(("CaptivePortalService::Stop\n"));
+
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    // Doesn't do anything when called in the content process.
+    return NS_OK;
+  }
+
+  if (!mStarted) {
+    return NS_OK;
+  }
+
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+  mTimer = nullptr;
+  mRequestInProgress = false;
+  mStarted = false;
+  mEverBeenCaptive = false;
+  if (mCaptivePortalDetector) {
+    mCaptivePortalDetector->Abort(kInterfaceName);
+  }
+  mCaptivePortalDetector = nullptr;
+
+  // Clear the state in case anyone queries the state while detection is off.
+  mState = UNKNOWN;
+  return NS_OK;
+}
+
+void CaptivePortalService::SetStateInChild(int32_t aState) {
+  // This should only be called in the content process, from ContentChild.cpp
+  // in order to mirror the captive portal state set in the chrome process.
+  MOZ_ASSERT(XRE_GetProcessType() != GeckoProcessType_Default);
+
+  mState = aState;
+  mLastChecked = TimeStamp::Now();
+}
+
+//-----------------------------------------------------------------------------
+// CaptivePortalService::nsICaptivePortalService
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+CaptivePortalService::GetState(int32_t* aState) {
+  *aState = mState;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CaptivePortalService::RecheckCaptivePortal() {
+  LOG(("CaptivePortalService::RecheckCaptivePortal\n"));
+
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    // Doesn't do anything if called in the content process.
+    return NS_OK;
+  }
+
+  // This is called for user activity. We need to reset the slack count,
+  // so the checks continue to be quite frequent.
+  mSlackCount = 0;
+  mDelay = mMinInterval;
+
+  PerformCheck();
+  RearmTimer();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CaptivePortalService::GetLastChecked(uint64_t* aLastChecked) {
+  double duration = (TimeStamp::Now() - mLastChecked).ToMilliseconds();
+  *aLastChecked = static_cast<uint64_t>(duration);
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// CaptivePortalService::nsITimer
+// This callback gets called every mDelay miliseconds
+// It issues a checkCaptivePortal operation if one isn't already in progress
+//-----------------------------------------------------------------------------
+NS_IMETHODIMP
+CaptivePortalService::Notify(nsITimer* aTimer) {
+  LOG(("CaptivePortalService::Notify\n"));
+  MOZ_ASSERT(aTimer == mTimer);
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+
+  PerformCheck();
+
+  // This is needed because we don't want to always make requests very often.
+  // Every 10 checks, we the delay is increased mBackoffFactor times
+  // to a maximum delay of mMaxInterval
+  mSlackCount++;
+  if (mSlackCount % 10 == 0) {
+    mDelay = mDelay * mBackoffFactor;
+  }
+  if (mDelay > mMaxInterval) {
+    mDelay = mMaxInterval;
+  }
+
+  // Note - if mDelay is 0, the timer will not be rearmed.
+  RearmTimer();
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// CaptivePortalService::nsINamed
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+CaptivePortalService::GetName(nsACString& aName) {
+  aName.AssignLiteral("CaptivePortalService");
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// CaptivePortalService::nsIObserver
+//-----------------------------------------------------------------------------
+NS_IMETHODIMP
+CaptivePortalService::Observe(nsISupports* aSubject, const char* aTopic,
+                              const char16_t* aData) {
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    // Doesn't do anything if called in the content process.
+    return NS_OK;
+  }
+
+  LOG(("CaptivePortalService::Observe() topic=%s\n", aTopic));
+  if (!strcmp(aTopic, kOpenCaptivePortalLoginEvent)) {
+    // A redirect or altered content has been detected.
+    // The user needs to log in. We are in a captive portal.
+    StateTransition(LOCKED_PORTAL);
+    mLastChecked = TimeStamp::Now();
+    mEverBeenCaptive = true;
+  } else if (!strcmp(aTopic, kCaptivePortalLoginSuccessEvent)) {
+    // The user has successfully logged in. We have connectivity.
+    StateTransition(UNLOCKED_PORTAL);
+    mLastChecked = TimeStamp::Now();
+    mSlackCount = 0;
+    mDelay = mMinInterval;
+
+    RearmTimer();
+  } else if (!strcmp(aTopic, kAbortCaptivePortalLoginEvent)) {
+    // The login has been aborted
+    StateTransition(UNKNOWN);
+    mLastChecked = TimeStamp::Now();
+    mSlackCount = 0;
+  } else if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    Stop();
+    return NS_OK;
+  }
+
+  // Send notification so that the captive portal state is mirrored in the
+  // content process.
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+  if (observerService) {
+    nsCOMPtr<nsICaptivePortalService> cps(this);
+    observerService->NotifyObservers(cps, NS_IPC_CAPTIVE_PORTAL_SET_STATE,
+                                     nullptr);
+  }
+
+  return NS_OK;
+}
+
+void CaptivePortalService::NotifyConnectivityAvailable(bool aCaptive) {
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+  if (observerService) {
+    nsCOMPtr<nsICaptivePortalService> cps(this);
+    observerService->NotifyObservers(cps, NS_CAPTIVE_PORTAL_CONNECTIVITY,
+                                     aCaptive ? u"captive" : u"clear");
+  }
+}
+
+//-----------------------------------------------------------------------------
+// CaptivePortalService::nsICaptivePortalCallback
+//-----------------------------------------------------------------------------
+NS_IMETHODIMP
+CaptivePortalService::Prepare() {
+  LOG(("CaptivePortalService::Prepare\n"));
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    return NS_OK;
+  }
+  // XXX: Finish preparation shouldn't be called until dns and routing is
+  // available.
+  if (mCaptivePortalDetector) {
+    mCaptivePortalDetector->FinishPreparation(kInterfaceName);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CaptivePortalService::Complete(bool success) {
+  LOG(("CaptivePortalService::Complete(success=%d) mState=%d\n", success,
+       mState));
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+  mLastChecked = TimeStamp::Now();
+
+  // Note: this callback gets called when:
+  // 1. the request is completed, and content is valid (success == true)
+  // 2. when the request is aborted or times out (success == false)
+
+  if (success) {
+    if (mEverBeenCaptive) {
+      StateTransition(UNLOCKED_PORTAL);
+      NotifyConnectivityAvailable(true);
+    } else {
+      StateTransition(NOT_CAPTIVE);
+      NotifyConnectivityAvailable(false);
+    }
+  }
+
+  mRequestInProgress = false;
+  return NS_OK;
+}
+
+void CaptivePortalService::StateTransition(int32_t aNewState) {
+  int32_t oldState = mState;
+  mState = aNewState;
+
+  if ((oldState == UNKNOWN && mState == NOT_CAPTIVE) ||
+      (oldState == LOCKED_PORTAL && mState == UNLOCKED_PORTAL)) {
+    nsCOMPtr<nsIObserverService> observerService =
+        services::GetObserverService();
+    if (observerService) {
+      nsCOMPtr<nsICaptivePortalService> cps(this);
+      observerService->NotifyObservers(
+          cps, NS_CAPTIVE_PORTAL_CONNECTIVITY_CHANGED, nullptr);
+    }
+  }
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/CaptivePortalService.h b/netwerk/base/CaptivePortalService.h
new file mode 100644
index 0000000000..f0a7200b4b
--- /dev/null
+++ b/netwerk/base/CaptivePortalService.h
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CaptivePortalService_h_
+#define CaptivePortalService_h_
+
+#include "nsICaptivePortalService.h"
+#include "nsICaptivePortalDetector.h"
+#include "nsINamed.h"
+#include "nsIObserver.h"
+#include "nsWeakReference.h"
+#include "nsITimer.h"
+#include "nsCOMArray.h"
+#include "mozilla/TimeStamp.h"
+
+namespace mozilla {
+namespace net {
+
+class CaptivePortalService : public nsICaptivePortalService,
+                             public nsIObserver,
+                             public nsSupportsWeakReference,
+                             public nsITimerCallback,
+                             public nsICaptivePortalCallback,
+                             public nsINamed {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICAPTIVEPORTALSERVICE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSICAPTIVEPORTALCALLBACK
+  NS_DECL_NSINAMED
+
+  nsresult Initialize();
+  nsresult Start();
+  nsresult Stop();
+
+  static already_AddRefed<nsICaptivePortalService> GetSingleton();
+
+  // This method is only called in the content process, in order to mirror
+  // the captive portal state in the parent process.
+  void SetStateInChild(int32_t aState);
+
+ private:
+  static const uint32_t kDefaultInterval = 60 * 1000;  // check every 60 seconds
+
+  CaptivePortalService();
+  virtual ~CaptivePortalService();
+  nsresult PerformCheck();
+  nsresult RearmTimer();
+  void NotifyConnectivityAvailable(bool aCaptive);
+
+  nsCOMPtr<nsICaptivePortalDetector> mCaptivePortalDetector;
+  int32_t mState{UNKNOWN};
+
+  nsCOMPtr<nsITimer> mTimer;
+  bool mStarted{false};
+  bool mInitialized{false};
+  bool mRequestInProgress{false};
+  bool mEverBeenCaptive{false};
+
+  uint32_t mDelay{kDefaultInterval};
+  int32_t mSlackCount{0};
+
+  uint32_t mMinInterval{kDefaultInterval};
+  uint32_t mMaxInterval{25 * kDefaultInterval};
+  float mBackoffFactor{5.0};
+
+  void StateTransition(int32_t aNewState);
+
+  // This holds a timestamp when the last time when the captive portal check
+  // has changed state.
+  mozilla::TimeStamp mLastChecked;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // CaptivePortalService_h_
diff --git a/netwerk/base/Dashboard.cpp b/netwerk/base/Dashboard.cpp
new file mode 100644
index 0000000000..bc1619ee60
--- /dev/null
+++ b/netwerk/base/Dashboard.cpp
@@ -0,0 +1,1182 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http:mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/NetDashboardBinding.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/ErrorNames.h"
+#include "mozilla/net/Dashboard.h"
+#include "mozilla/net/HttpInfo.h"
+#include "mozilla/net/HTTPSSVC.h"
+#include "mozilla/net/SocketProcessParent.h"
+#include "nsHttp.h"
+#include "nsICancelable.h"
+#include "nsIDNSListener.h"
+#include "nsIDNSService.h"
+#include "nsIDNSRecord.h"
+#include "nsIDNSByTypeRecord.h"
+#include "nsIInputStream.h"
+#include "nsINamed.h"
+#include "nsINetAddr.h"
+#include "nsISocketTransport.h"
+#include "nsProxyRelease.h"
+#include "nsSocketTransportService2.h"
+#include "nsThreadUtils.h"
+#include "nsURLHelper.h"
+#include "mozilla/Logging.h"
+#include "nsIOService.h"
+#include "../cache2/CacheFileUtils.h"
+
+using mozilla::AutoSafeJSContext;
+using mozilla::dom::Sequence;
+using mozilla::dom::ToJSValue;
+
+namespace mozilla {
+namespace net {
+
+class SocketData : public nsISupports {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  SocketData() = default;
+
+  uint64_t mTotalSent{0};
+  uint64_t mTotalRecv{0};
+  nsTArray<SocketInfo> mData;
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+
+ private:
+  virtual ~SocketData() = default;
+};
+
+static void GetErrorString(nsresult rv, nsAString& errorString);
+
+NS_IMPL_ISUPPORTS0(SocketData)
+
+class HttpData : public nsISupports {
+  virtual ~HttpData() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  HttpData() = default;
+
+  nsTArray<HttpRetParams> mData;
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+};
+
+NS_IMPL_ISUPPORTS0(HttpData)
+
+class WebSocketRequest : public nsISupports {
+  virtual ~WebSocketRequest() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  WebSocketRequest() = default;
+
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+};
+
+NS_IMPL_ISUPPORTS0(WebSocketRequest)
+
+class DnsData : public nsISupports {
+  virtual ~DnsData() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  DnsData() = default;
+
+  nsTArray<DNSCacheEntries> mData;
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+};
+
+NS_IMPL_ISUPPORTS0(DnsData)
+
+class ConnectionData : public nsITransportEventSink,
+                       public nsITimerCallback,
+                       public nsINamed {
+  virtual ~ConnectionData() {
+    if (mTimer) {
+      mTimer->Cancel();
+    }
+  }
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITRANSPORTEVENTSINK
+  NS_DECL_NSITIMERCALLBACK
+
+  NS_IMETHOD GetName(nsACString& aName) override {
+    aName.AssignLiteral("net::ConnectionData");
+    return NS_OK;
+  }
+
+  void StartTimer(uint32_t aTimeout);
+  void StopTimer();
+
+  explicit ConnectionData(Dashboard* target) { mDashboard = target; }
+
+  nsCOMPtr<nsISocketTransport> mSocket;
+  nsCOMPtr<nsIInputStream> mStreamIn;
+  nsCOMPtr<nsITimer> mTimer;
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+  Dashboard* mDashboard;
+
+  nsCString mHost;
+  uint32_t mPort{0};
+  nsCString mProtocol;
+  uint32_t mTimeout{0};
+
+  nsString mStatus;
+};
+
+NS_IMPL_ISUPPORTS(ConnectionData, nsITransportEventSink, nsITimerCallback,
+                  nsINamed)
+
+class RcwnData : public nsISupports {
+  virtual ~RcwnData() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  RcwnData() = default;
+
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+};
+
+NS_IMPL_ISUPPORTS0(RcwnData)
+
+NS_IMETHODIMP
+ConnectionData::OnTransportStatus(nsITransport* aTransport, nsresult aStatus,
+                                  int64_t aProgress, int64_t aProgressMax) {
+  if (aStatus == NS_NET_STATUS_CONNECTED_TO) {
+    StopTimer();
+  }
+
+  GetErrorString(aStatus, mStatus);
+  mEventTarget->Dispatch(NewRunnableMethod<RefPtr<ConnectionData>>(
+                             "net::Dashboard::GetConnectionStatus", mDashboard,
+                             &Dashboard::GetConnectionStatus, this),
+                         NS_DISPATCH_NORMAL);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ConnectionData::Notify(nsITimer* aTimer) {
+  MOZ_ASSERT(aTimer == mTimer);
+
+  if (mSocket) {
+    mSocket->Close(NS_ERROR_ABORT);
+    mSocket = nullptr;
+    mStreamIn = nullptr;
+  }
+
+  mTimer = nullptr;
+
+  mStatus.AssignLiteral(u"NS_ERROR_NET_TIMEOUT");
+  mEventTarget->Dispatch(NewRunnableMethod<RefPtr<ConnectionData>>(
+                             "net::Dashboard::GetConnectionStatus", mDashboard,
+                             &Dashboard::GetConnectionStatus, this),
+                         NS_DISPATCH_NORMAL);
+
+  return NS_OK;
+}
+
+void ConnectionData::StartTimer(uint32_t aTimeout) {
+  if (!mTimer) {
+    mTimer = NS_NewTimer();
+  }
+
+  mTimer->InitWithCallback(this, aTimeout * 1000, nsITimer::TYPE_ONE_SHOT);
+}
+
+void ConnectionData::StopTimer() {
+  if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nullptr;
+  }
+}
+
+class LookupHelper;
+
+class LookupArgument : public nsISupports {
+  virtual ~LookupArgument() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  LookupArgument(nsIDNSRecord* aRecord, LookupHelper* aHelper) {
+    mRecord = aRecord;
+    mHelper = aHelper;
+  }
+
+  nsCOMPtr<nsIDNSRecord> mRecord;
+  RefPtr<LookupHelper> mHelper;
+};
+
+NS_IMPL_ISUPPORTS0(LookupArgument)
+
+class LookupHelper final : public nsIDNSListener {
+  virtual ~LookupHelper() {
+    if (mCancel) {
+      mCancel->Cancel(NS_ERROR_ABORT);
+    }
+  }
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSLISTENER
+
+  LookupHelper() = default;
+
+  nsresult ConstructAnswer(LookupArgument* aArgument);
+  nsresult ConstructHTTPSRRAnswer(LookupArgument* aArgument);
+
+ public:
+  nsCOMPtr<nsICancelable> mCancel;
+  nsMainThreadPtrHandle<nsINetDashboardCallback> mCallback;
+  nsIEventTarget* mEventTarget{nullptr};
+  nsresult mStatus{NS_ERROR_NOT_INITIALIZED};
+};
+
+NS_IMPL_ISUPPORTS(LookupHelper, nsIDNSListener)
+
+NS_IMETHODIMP
+LookupHelper::OnLookupComplete(nsICancelable* aRequest, nsIDNSRecord* aRecord,
+                               nsresult aStatus) {
+  MOZ_ASSERT(aRequest == mCancel);
+  mCancel = nullptr;
+  mStatus = aStatus;
+
+  nsCOMPtr<nsIDNSHTTPSSVCRecord> httpsRecord = do_QueryInterface(aRecord);
+  if (httpsRecord) {
+    RefPtr<LookupArgument> arg = new LookupArgument(aRecord, this);
+    mEventTarget->Dispatch(
+        NewRunnableMethod<RefPtr<LookupArgument>>(
+            "net::LookupHelper::ConstructHTTPSRRAnswer", this,
+            &LookupHelper::ConstructHTTPSRRAnswer, arg),
+        NS_DISPATCH_NORMAL);
+    return NS_OK;
+  }
+
+  RefPtr<LookupArgument> arg = new LookupArgument(aRecord, this);
+  mEventTarget->Dispatch(NewRunnableMethod<RefPtr<LookupArgument>>(
+                             "net::LookupHelper::ConstructAnswer", this,
+                             &LookupHelper::ConstructAnswer, arg),
+                         NS_DISPATCH_NORMAL);
+
+  return NS_OK;
+}
+
+nsresult LookupHelper::ConstructAnswer(LookupArgument* aArgument) {
+  nsIDNSRecord* aRecord = aArgument->mRecord;
+  AutoSafeJSContext cx;
+
+  mozilla::dom::DNSLookupDict dict;
+  dict.mAddress.Construct();
+
+  Sequence<nsString>& addresses = dict.mAddress.Value();
+  nsCOMPtr<nsIDNSAddrRecord> record = do_QueryInterface(aRecord);
+  if (NS_SUCCEEDED(mStatus) && record) {
+    dict.mAnswer = true;
+    bool hasMore;
+    record->HasMore(&hasMore);
+    while (hasMore) {
+      nsString* nextAddress = addresses.AppendElement(fallible);
+      if (!nextAddress) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      nsCString nextAddressASCII;
+      record->GetNextAddrAsString(nextAddressASCII);
+      CopyASCIItoUTF16(nextAddressASCII, *nextAddress);
+      record->HasMore(&hasMore);
+    }
+  } else {
+    dict.mAnswer = false;
+    GetErrorString(mStatus, dict.mError);
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  this->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+static void CStringToHexString(const nsACString& aIn, nsAString& aOut) {
+  static const char* const lut = "0123456789ABCDEF";
+
+  size_t len = aIn.Length();
+
+  aOut.SetCapacity(2 * len);
+  for (size_t i = 0; i < aIn.Length(); ++i) {
+    const char c = static_cast<char>(aIn[i]);
+    aOut.Append(lut[(c >> 4) & 0x0F]);
+    aOut.Append(lut[c & 15]);
+  }
+}
+
+nsresult LookupHelper::ConstructHTTPSRRAnswer(LookupArgument* aArgument) {
+  nsCOMPtr<nsIDNSHTTPSSVCRecord> httpsRecord =
+      do_QueryInterface(aArgument->mRecord);
+
+  AutoSafeJSContext cx;
+
+  mozilla::dom::HTTPSRRLookupDict dict;
+  dict.mRecords.Construct();
+
+  Sequence<dom::HTTPSRecord>& records = dict.mRecords.Value();
+  if (NS_SUCCEEDED(mStatus) && httpsRecord) {
+    dict.mAnswer = true;
+    nsTArray<RefPtr<nsISVCBRecord>> svcbRecords;
+    httpsRecord->GetRecords(svcbRecords);
+
+    for (const auto& record : svcbRecords) {
+      dom::HTTPSRecord* nextRecord = records.AppendElement(fallible);
+      if (!nextRecord) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      Unused << record->GetPriority(&nextRecord->mPriority);
+      nsCString name;
+      Unused << record->GetName(name);
+      CopyASCIItoUTF16(name, nextRecord->mTargetName);
+
+      nsTArray<RefPtr<nsISVCParam>> values;
+      Unused << record->GetValues(values);
+      if (values.IsEmpty()) {
+        continue;
+      }
+
+      for (const auto& value : values) {
+        uint16_t type;
+        Unused << value->GetType(&type);
+        switch (type) {
+          case SvcParamKeyAlpn: {
+            nextRecord->mAlpn.Construct();
+            nextRecord->mAlpn.Value().mType = type;
+            nsCOMPtr<nsISVCParamAlpn> alpnParam = do_QueryInterface(value);
+            nsTArray<nsCString> alpn;
+            Unused << alpnParam->GetAlpn(alpn);
+            nsAutoCString alpnStr;
+            for (const auto& str : alpn) {
+              alpnStr.Append(str);
+              alpnStr.Append(',');
+            }
+            CopyASCIItoUTF16(Span(alpnStr.BeginReading(), alpnStr.Length() - 1),
+                             nextRecord->mAlpn.Value().mAlpn);
+            break;
+          }
+          case SvcParamKeyNoDefaultAlpn: {
+            nextRecord->mNoDefaultAlpn.Construct();
+            nextRecord->mNoDefaultAlpn.Value().mType = type;
+            break;
+          }
+          case SvcParamKeyPort: {
+            nextRecord->mPort.Construct();
+            nextRecord->mPort.Value().mType = type;
+            nsCOMPtr<nsISVCParamPort> portParam = do_QueryInterface(value);
+            Unused << portParam->GetPort(&nextRecord->mPort.Value().mPort);
+            break;
+          }
+          case SvcParamKeyIpv4Hint: {
+            nextRecord->mIpv4Hint.Construct();
+            nextRecord->mIpv4Hint.Value().mType = type;
+            nsCOMPtr<nsISVCParamIPv4Hint> ipv4Param = do_QueryInterface(value);
+            nsTArray<RefPtr<nsINetAddr>> ipv4Hint;
+            Unused << ipv4Param->GetIpv4Hint(ipv4Hint);
+            if (!ipv4Hint.IsEmpty()) {
+              nextRecord->mIpv4Hint.Value().mAddress.Construct();
+              for (const auto& address : ipv4Hint) {
+                nsString* nextAddress = nextRecord->mIpv4Hint.Value()
+                                            .mAddress.Value()
+                                            .AppendElement(fallible);
+                if (!nextAddress) {
+                  return NS_ERROR_OUT_OF_MEMORY;
+                }
+
+                nsCString addressASCII;
+                Unused << address->GetAddress(addressASCII);
+                CopyASCIItoUTF16(addressASCII, *nextAddress);
+              }
+            }
+            break;
+          }
+          case SvcParamKeyIpv6Hint: {
+            nextRecord->mIpv6Hint.Construct();
+            nextRecord->mIpv6Hint.Value().mType = type;
+            nsCOMPtr<nsISVCParamIPv6Hint> ipv6Param = do_QueryInterface(value);
+            nsTArray<RefPtr<nsINetAddr>> ipv6Hint;
+            Unused << ipv6Param->GetIpv6Hint(ipv6Hint);
+            if (!ipv6Hint.IsEmpty()) {
+              nextRecord->mIpv6Hint.Value().mAddress.Construct();
+              for (const auto& address : ipv6Hint) {
+                nsString* nextAddress = nextRecord->mIpv6Hint.Value()
+                                            .mAddress.Value()
+                                            .AppendElement(fallible);
+                if (!nextAddress) {
+                  return NS_ERROR_OUT_OF_MEMORY;
+                }
+
+                nsCString addressASCII;
+                Unused << address->GetAddress(addressASCII);
+                CopyASCIItoUTF16(addressASCII, *nextAddress);
+              }
+            }
+            break;
+          }
+          case SvcParamKeyEchConfig: {
+            nextRecord->mEchConfig.Construct();
+            nextRecord->mEchConfig.Value().mType = type;
+            nsCOMPtr<nsISVCParamEchConfig> echConfigParam =
+                do_QueryInterface(value);
+            nsCString echConfigStr;
+            Unused << echConfigParam->GetEchconfig(echConfigStr);
+            CStringToHexString(echConfigStr,
+                               nextRecord->mEchConfig.Value().mEchConfig);
+            break;
+          }
+          case SvcParamKeyODoHConfig: {
+            nextRecord->mODoHConfig.Construct();
+            nextRecord->mODoHConfig.Value().mType = type;
+            nsCOMPtr<nsISVCParamODoHConfig> ODoHConfigParam =
+                do_QueryInterface(value);
+            nsCString ODoHConfigStr;
+            Unused << ODoHConfigParam->GetODoHConfig(ODoHConfigStr);
+            CStringToHexString(ODoHConfigStr,
+                               nextRecord->mODoHConfig.Value().mODoHConfig);
+            break;
+          }
+          default:
+            break;
+        }
+      }
+    }
+  } else {
+    dict.mAnswer = false;
+    GetErrorString(mStatus, dict.mError);
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  this->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(Dashboard, nsIDashboard, nsIDashboardEventNotifier)
+
+Dashboard::Dashboard() { mEnableLogging = false; }
+
+NS_IMETHODIMP
+Dashboard::RequestSockets(nsINetDashboardCallback* aCallback) {
+  RefPtr<SocketData> socketData = new SocketData();
+  socketData->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+  socketData->mEventTarget = GetCurrentSerialEventTarget();
+
+  if (nsIOService::UseSocketProcess()) {
+    if (!gIOService->SocketProcessReady()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    RefPtr<Dashboard> self(this);
+    SocketProcessParent::GetSingleton()->SendGetSocketData()->Then(
+        GetMainThreadSerialEventTarget(), __func__,
+        [self{std::move(self)},
+         socketData{std::move(socketData)}](SocketDataArgs&& args) {
+          socketData->mData.Assign(args.info());
+          socketData->mTotalSent = args.totalSent();
+          socketData->mTotalRecv = args.totalRecv();
+          socketData->mEventTarget->Dispatch(
+              NewRunnableMethod<RefPtr<SocketData>>(
+                  "net::Dashboard::GetSockets", self, &Dashboard::GetSockets,
+                  socketData),
+              NS_DISPATCH_NORMAL);
+        },
+        [self](const mozilla::ipc::ResponseRejectReason) {});
+    return NS_OK;
+  }
+
+  gSocketTransportService->Dispatch(
+      NewRunnableMethod<RefPtr<SocketData>>(
+          "net::Dashboard::GetSocketsDispatch", this,
+          &Dashboard::GetSocketsDispatch, socketData),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetSocketsDispatch(SocketData* aSocketData) {
+  RefPtr<SocketData> socketData = aSocketData;
+  if (gSocketTransportService) {
+    gSocketTransportService->GetSocketConnections(&socketData->mData);
+    socketData->mTotalSent = gSocketTransportService->GetSentBytes();
+    socketData->mTotalRecv = gSocketTransportService->GetReceivedBytes();
+  }
+  socketData->mEventTarget->Dispatch(
+      NewRunnableMethod<RefPtr<SocketData>>("net::Dashboard::GetSockets", this,
+                                            &Dashboard::GetSockets, socketData),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetSockets(SocketData* aSocketData) {
+  RefPtr<SocketData> socketData = aSocketData;
+  AutoSafeJSContext cx;
+
+  mozilla::dom::SocketsDict dict;
+  dict.mSockets.Construct();
+  dict.mSent = 0;
+  dict.mReceived = 0;
+
+  Sequence<mozilla::dom::SocketElement>& sockets = dict.mSockets.Value();
+
+  uint32_t length = socketData->mData.Length();
+  if (!sockets.SetCapacity(length, fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < socketData->mData.Length(); i++) {
+    dom::SocketElement& mSocket = *sockets.AppendElement(fallible);
+    CopyASCIItoUTF16(socketData->mData[i].host, mSocket.mHost);
+    mSocket.mPort = socketData->mData[i].port;
+    mSocket.mActive = socketData->mData[i].active;
+    CopyASCIItoUTF16(socketData->mData[i].type, mSocket.mType);
+    mSocket.mSent = (double)socketData->mData[i].sent;
+    mSocket.mReceived = (double)socketData->mData[i].received;
+    dict.mSent += socketData->mData[i].sent;
+    dict.mReceived += socketData->mData[i].received;
+  }
+
+  dict.mSent += socketData->mTotalSent;
+  dict.mReceived += socketData->mTotalRecv;
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) return NS_ERROR_FAILURE;
+  socketData->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestHttpConnections(nsINetDashboardCallback* aCallback) {
+  RefPtr<HttpData> httpData = new HttpData();
+  httpData->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+  httpData->mEventTarget = GetCurrentSerialEventTarget();
+
+  if (nsIOService::UseSocketProcess()) {
+    if (!gIOService->SocketProcessReady()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    RefPtr<Dashboard> self(this);
+    SocketProcessParent::GetSingleton()->SendGetHttpConnectionData()->Then(
+        GetMainThreadSerialEventTarget(), __func__,
+        [self{std::move(self)}, httpData](nsTArray<HttpRetParams>&& params) {
+          httpData->mData.Assign(std::move(params));
+          self->GetHttpConnections(httpData);
+          httpData->mEventTarget->Dispatch(
+              NewRunnableMethod<RefPtr<HttpData>>(
+                  "net::Dashboard::GetHttpConnections", self,
+                  &Dashboard::GetHttpConnections, httpData),
+              NS_DISPATCH_NORMAL);
+        },
+        [self](const mozilla::ipc::ResponseRejectReason) {});
+    return NS_OK;
+  }
+
+  gSocketTransportService->Dispatch(NewRunnableMethod<RefPtr<HttpData>>(
+                                        "net::Dashboard::GetHttpDispatch", this,
+                                        &Dashboard::GetHttpDispatch, httpData),
+                                    NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetHttpDispatch(HttpData* aHttpData) {
+  RefPtr<HttpData> httpData = aHttpData;
+  HttpInfo::GetHttpConnectionData(&httpData->mData);
+  httpData->mEventTarget->Dispatch(
+      NewRunnableMethod<RefPtr<HttpData>>("net::Dashboard::GetHttpConnections",
+                                          this, &Dashboard::GetHttpConnections,
+                                          httpData),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetHttpConnections(HttpData* aHttpData) {
+  RefPtr<HttpData> httpData = aHttpData;
+  AutoSafeJSContext cx;
+
+  mozilla::dom::HttpConnDict dict;
+  dict.mConnections.Construct();
+
+  using mozilla::dom::DnsAndSockInfoDict;
+  using mozilla::dom::HttpConnectionElement;
+  using mozilla::dom::HttpConnInfo;
+  Sequence<HttpConnectionElement>& connections = dict.mConnections.Value();
+
+  uint32_t length = httpData->mData.Length();
+  if (!connections.SetCapacity(length, fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < httpData->mData.Length(); i++) {
+    HttpConnectionElement& connection = *connections.AppendElement(fallible);
+
+    CopyASCIItoUTF16(httpData->mData[i].host, connection.mHost);
+    connection.mPort = httpData->mData[i].port;
+    CopyASCIItoUTF16(httpData->mData[i].httpVersion, connection.mHttpVersion);
+    connection.mSsl = httpData->mData[i].ssl;
+
+    connection.mActive.Construct();
+    connection.mIdle.Construct();
+    connection.mDnsAndSocks.Construct();
+
+    Sequence<HttpConnInfo>& active = connection.mActive.Value();
+    Sequence<HttpConnInfo>& idle = connection.mIdle.Value();
+    Sequence<DnsAndSockInfoDict>& dnsAndSocks = connection.mDnsAndSocks.Value();
+
+    if (!active.SetCapacity(httpData->mData[i].active.Length(), fallible) ||
+        !idle.SetCapacity(httpData->mData[i].idle.Length(), fallible) ||
+        !dnsAndSocks.SetCapacity(httpData->mData[i].dnsAndSocks.Length(),
+                                 fallible)) {
+      JS_ReportOutOfMemory(cx);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    for (uint32_t j = 0; j < httpData->mData[i].active.Length(); j++) {
+      HttpConnInfo& info = *active.AppendElement(fallible);
+      info.mRtt = httpData->mData[i].active[j].rtt;
+      info.mTtl = httpData->mData[i].active[j].ttl;
+      info.mProtocolVersion = httpData->mData[i].active[j].protocolVersion;
+    }
+
+    for (uint32_t j = 0; j < httpData->mData[i].idle.Length(); j++) {
+      HttpConnInfo& info = *idle.AppendElement(fallible);
+      info.mRtt = httpData->mData[i].idle[j].rtt;
+      info.mTtl = httpData->mData[i].idle[j].ttl;
+      info.mProtocolVersion = httpData->mData[i].idle[j].protocolVersion;
+    }
+
+    for (uint32_t j = 0; j < httpData->mData[i].dnsAndSocks.Length(); j++) {
+      DnsAndSockInfoDict& info = *dnsAndSocks.AppendElement(fallible);
+      info.mSpeculative = httpData->mData[i].dnsAndSocks[j].speculative;
+    }
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  httpData->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::GetEnableLogging(bool* value) {
+  *value = mEnableLogging;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::SetEnableLogging(const bool value) {
+  mEnableLogging = value;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::AddHost(const nsACString& aHost, uint32_t aSerial, bool aEncrypted) {
+  if (mEnableLogging) {
+    mozilla::MutexAutoLock lock(mWs.lock);
+    LogData mData(nsCString(aHost), aSerial, aEncrypted);
+    if (mWs.data.Contains(mData)) {
+      return NS_OK;
+    }
+    // XXX(Bug 1631371) Check if this should use a fallible operation as it
+    // pretended earlier.
+    mWs.data.AppendElement(mData);
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+Dashboard::RemoveHost(const nsACString& aHost, uint32_t aSerial) {
+  if (mEnableLogging) {
+    mozilla::MutexAutoLock lock(mWs.lock);
+    int32_t index = mWs.IndexOf(nsCString(aHost), aSerial);
+    if (index == -1) return NS_ERROR_FAILURE;
+    mWs.data.RemoveElementAt(index);
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+Dashboard::NewMsgSent(const nsACString& aHost, uint32_t aSerial,
+                      uint32_t aLength) {
+  if (mEnableLogging) {
+    mozilla::MutexAutoLock lock(mWs.lock);
+    int32_t index = mWs.IndexOf(nsCString(aHost), aSerial);
+    if (index == -1) return NS_ERROR_FAILURE;
+    mWs.data[index].mMsgSent++;
+    mWs.data[index].mSizeSent += aLength;
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+Dashboard::NewMsgReceived(const nsACString& aHost, uint32_t aSerial,
+                          uint32_t aLength) {
+  if (mEnableLogging) {
+    mozilla::MutexAutoLock lock(mWs.lock);
+    int32_t index = mWs.IndexOf(nsCString(aHost), aSerial);
+    if (index == -1) return NS_ERROR_FAILURE;
+    mWs.data[index].mMsgReceived++;
+    mWs.data[index].mSizeReceived += aLength;
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestWebsocketConnections(nsINetDashboardCallback* aCallback) {
+  RefPtr<WebSocketRequest> wsRequest = new WebSocketRequest();
+  wsRequest->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+  wsRequest->mEventTarget = GetCurrentSerialEventTarget();
+
+  wsRequest->mEventTarget->Dispatch(
+      NewRunnableMethod<RefPtr<WebSocketRequest>>(
+          "net::Dashboard::GetWebSocketConnections", this,
+          &Dashboard::GetWebSocketConnections, wsRequest),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetWebSocketConnections(WebSocketRequest* aWsRequest) {
+  RefPtr<WebSocketRequest> wsRequest = aWsRequest;
+  AutoSafeJSContext cx;
+
+  mozilla::dom::WebSocketDict dict;
+  dict.mWebsockets.Construct();
+  Sequence<mozilla::dom::WebSocketElement>& websockets =
+      dict.mWebsockets.Value();
+
+  mozilla::MutexAutoLock lock(mWs.lock);
+  uint32_t length = mWs.data.Length();
+  if (!websockets.SetCapacity(length, fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < mWs.data.Length(); i++) {
+    dom::WebSocketElement& websocket = *websockets.AppendElement(fallible);
+    CopyASCIItoUTF16(mWs.data[i].mHost, websocket.mHostport);
+    websocket.mMsgsent = mWs.data[i].mMsgSent;
+    websocket.mMsgreceived = mWs.data[i].mMsgReceived;
+    websocket.mSentsize = mWs.data[i].mSizeSent;
+    websocket.mReceivedsize = mWs.data[i].mSizeReceived;
+    websocket.mEncrypted = mWs.data[i].mEncrypted;
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+  wsRequest->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestDNSInfo(nsINetDashboardCallback* aCallback) {
+  RefPtr<DnsData> dnsData = new DnsData();
+  dnsData->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+
+  nsresult rv;
+  dnsData->mData.Clear();
+  dnsData->mEventTarget = GetCurrentSerialEventTarget();
+
+  if (!mDnsService) {
+    mDnsService = do_GetService("@mozilla.org/network/dns-service;1", &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  if (nsIOService::UseSocketProcess()) {
+    if (!gIOService->SocketProcessReady()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    RefPtr<Dashboard> self(this);
+    SocketProcessParent::GetSingleton()->SendGetDNSCacheEntries()->Then(
+        GetMainThreadSerialEventTarget(), __func__,
+        [self{std::move(self)},
+         dnsData{std::move(dnsData)}](nsTArray<DNSCacheEntries>&& entries) {
+          dnsData->mData.Assign(std::move(entries));
+          dnsData->mEventTarget->Dispatch(
+              NewRunnableMethod<RefPtr<DnsData>>(
+                  "net::Dashboard::GetDNSCacheEntries", self,
+                  &Dashboard::GetDNSCacheEntries, dnsData),
+              NS_DISPATCH_NORMAL);
+        },
+        [self](const mozilla::ipc::ResponseRejectReason) {});
+    return NS_OK;
+  }
+
+  gSocketTransportService->Dispatch(
+      NewRunnableMethod<RefPtr<DnsData>>("net::Dashboard::GetDnsInfoDispatch",
+                                         this, &Dashboard::GetDnsInfoDispatch,
+                                         dnsData),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetDnsInfoDispatch(DnsData* aDnsData) {
+  RefPtr<DnsData> dnsData = aDnsData;
+  if (mDnsService) {
+    mDnsService->GetDNSCacheEntries(&dnsData->mData);
+  }
+  dnsData->mEventTarget->Dispatch(
+      NewRunnableMethod<RefPtr<DnsData>>("net::Dashboard::GetDNSCacheEntries",
+                                         this, &Dashboard::GetDNSCacheEntries,
+                                         dnsData),
+      NS_DISPATCH_NORMAL);
+  return NS_OK;
+}
+
+nsresult Dashboard::GetDNSCacheEntries(DnsData* dnsData) {
+  AutoSafeJSContext cx;
+
+  mozilla::dom::DNSCacheDict dict;
+  dict.mEntries.Construct();
+  Sequence<mozilla::dom::DnsCacheEntry>& entries = dict.mEntries.Value();
+
+  uint32_t length = dnsData->mData.Length();
+  if (!entries.SetCapacity(length, fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < dnsData->mData.Length(); i++) {
+    dom::DnsCacheEntry& entry = *entries.AppendElement(fallible);
+    entry.mHostaddr.Construct();
+
+    Sequence<nsString>& addrs = entry.mHostaddr.Value();
+    if (!addrs.SetCapacity(dnsData->mData[i].hostaddr.Length(), fallible)) {
+      JS_ReportOutOfMemory(cx);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    CopyASCIItoUTF16(dnsData->mData[i].hostname, entry.mHostname);
+    entry.mExpiration = dnsData->mData[i].expiration;
+    entry.mTrr = dnsData->mData[i].TRR;
+
+    for (uint32_t j = 0; j < dnsData->mData[i].hostaddr.Length(); j++) {
+      nsString* addr = addrs.AppendElement(fallible);
+      if (!addr) {
+        JS_ReportOutOfMemory(cx);
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+      CopyASCIItoUTF16(dnsData->mData[i].hostaddr[j], *addr);
+    }
+
+    if (dnsData->mData[i].family == PR_AF_INET6) {
+      entry.mFamily.AssignLiteral(u"ipv6");
+    } else {
+      entry.mFamily.AssignLiteral(u"ipv4");
+    }
+
+    entry.mOriginAttributesSuffix =
+        NS_ConvertUTF8toUTF16(dnsData->mData[i].originAttributesSuffix);
+    entry.mFlags = NS_ConvertUTF8toUTF16(dnsData->mData[i].flags);
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+  dnsData->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestDNSLookup(const nsACString& aHost,
+                            nsINetDashboardCallback* aCallback) {
+  nsresult rv;
+
+  if (!mDnsService) {
+    mDnsService = do_GetService("@mozilla.org/network/dns-service;1", &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  RefPtr<LookupHelper> helper = new LookupHelper();
+  helper->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+  helper->mEventTarget = GetCurrentSerialEventTarget();
+  OriginAttributes attrs;
+  rv = mDnsService->AsyncResolveNative(
+      aHost, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+      nsIDNSService::RESOLVE_DEFAULT_FLAGS, nullptr, helper.get(),
+      NS_GetCurrentThread(), attrs, getter_AddRefs(helper->mCancel));
+  return rv;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestDNSHTTPSRRLookup(const nsACString& aHost,
+                                   nsINetDashboardCallback* aCallback) {
+  nsresult rv;
+
+  if (!mDnsService) {
+    mDnsService = do_GetService("@mozilla.org/network/dns-service;1", &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  RefPtr<LookupHelper> helper = new LookupHelper();
+  helper->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+  helper->mEventTarget = GetCurrentSerialEventTarget();
+  OriginAttributes attrs;
+  rv = mDnsService->AsyncResolveNative(
+      aHost, nsIDNSService::RESOLVE_TYPE_HTTPSSVC,
+      nsIDNSService::RESOLVE_DEFAULT_FLAGS, nullptr, helper.get(),
+      NS_GetCurrentThread(), attrs, getter_AddRefs(helper->mCancel));
+  return rv;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestRcwnStats(nsINetDashboardCallback* aCallback) {
+  RefPtr<RcwnData> rcwnData = new RcwnData();
+  rcwnData->mEventTarget = GetCurrentSerialEventTarget();
+  rcwnData->mCallback = new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+      "nsINetDashboardCallback", aCallback, true);
+
+  return rcwnData->mEventTarget->Dispatch(
+      NewRunnableMethod<RefPtr<RcwnData>>("net::Dashboard::GetRcwnData", this,
+                                          &Dashboard::GetRcwnData, rcwnData),
+      NS_DISPATCH_NORMAL);
+}
+
+nsresult Dashboard::GetRcwnData(RcwnData* aData) {
+  AutoSafeJSContext cx;
+  mozilla::dom::RcwnStatus dict;
+
+  dict.mTotalNetworkRequests = gIOService->GetTotalRequestNumber();
+  dict.mRcwnCacheWonCount = gIOService->GetCacheWonRequestNumber();
+  dict.mRcwnNetWonCount = gIOService->GetNetWonRequestNumber();
+
+  uint32_t cacheSlow, cacheNotSlow;
+  CacheFileUtils::CachePerfStats::GetSlowStats(&cacheSlow, &cacheNotSlow);
+  dict.mCacheSlowCount = cacheSlow;
+  dict.mCacheNotSlowCount = cacheNotSlow;
+
+  dict.mPerfStats.Construct();
+  Sequence<mozilla::dom::RcwnPerfStats>& perfStats = dict.mPerfStats.Value();
+  uint32_t length = CacheFileUtils::CachePerfStats::LAST;
+  if (!perfStats.SetCapacity(length, fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < length; i++) {
+    CacheFileUtils::CachePerfStats::EDataType perfType =
+        static_cast<CacheFileUtils::CachePerfStats::EDataType>(i);
+    dom::RcwnPerfStats& elem = *perfStats.AppendElement(fallible);
+    elem.mAvgShort =
+        CacheFileUtils::CachePerfStats::GetAverage(perfType, false);
+    elem.mAvgLong = CacheFileUtils::CachePerfStats::GetAverage(perfType, true);
+    elem.mStddevLong =
+        CacheFileUtils::CachePerfStats::GetStdDev(perfType, true);
+  }
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  aData->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+void HttpConnInfo::SetHTTPProtocolVersion(HttpVersion pv) {
+  switch (pv) {
+    case HttpVersion::v0_9:
+      protocolVersion.AssignLiteral(u"http/0.9");
+      break;
+    case HttpVersion::v1_0:
+      protocolVersion.AssignLiteral(u"http/1.0");
+      break;
+    case HttpVersion::v1_1:
+      protocolVersion.AssignLiteral(u"http/1.1");
+      break;
+    case HttpVersion::v2_0:
+      protocolVersion.AssignLiteral(u"http/2");
+      break;
+    case HttpVersion::v3_0:
+      protocolVersion.AssignLiteral(u"http/3");
+      break;
+    default:
+      protocolVersion.AssignLiteral(u"unknown protocol version");
+  }
+}
+
+NS_IMETHODIMP
+Dashboard::GetLogPath(nsACString& aLogPath) {
+  aLogPath.SetLength(2048);
+  uint32_t len = LogModule::GetLogFile(aLogPath.BeginWriting(), 2048);
+  aLogPath.SetLength(len);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Dashboard::RequestConnection(const nsACString& aHost, uint32_t aPort,
+                             const char* aProtocol, uint32_t aTimeout,
+                             nsINetDashboardCallback* aCallback) {
+  nsresult rv;
+  RefPtr<ConnectionData> connectionData = new ConnectionData(this);
+  connectionData->mHost = aHost;
+  connectionData->mPort = aPort;
+  connectionData->mProtocol = aProtocol;
+  connectionData->mTimeout = aTimeout;
+
+  connectionData->mCallback =
+      new nsMainThreadPtrHolder<nsINetDashboardCallback>(
+          "nsINetDashboardCallback", aCallback, true);
+  connectionData->mEventTarget = GetCurrentSerialEventTarget();
+
+  rv = TestNewConnection(connectionData);
+  if (NS_FAILED(rv)) {
+    mozilla::net::GetErrorString(rv, connectionData->mStatus);
+    connectionData->mEventTarget->Dispatch(
+        NewRunnableMethod<RefPtr<ConnectionData>>(
+            "net::Dashboard::GetConnectionStatus", this,
+            &Dashboard::GetConnectionStatus, connectionData),
+        NS_DISPATCH_NORMAL);
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult Dashboard::GetConnectionStatus(ConnectionData* aConnectionData) {
+  RefPtr<ConnectionData> connectionData = aConnectionData;
+  AutoSafeJSContext cx;
+
+  mozilla::dom::ConnStatusDict dict;
+  dict.mStatus = connectionData->mStatus;
+
+  JS::Rooted<JS::Value> val(cx);
+  if (!ToJSValue(cx, dict, &val)) return NS_ERROR_FAILURE;
+
+  connectionData->mCallback->OnDashboardDataAvailable(val);
+
+  return NS_OK;
+}
+
+nsresult Dashboard::TestNewConnection(ConnectionData* aConnectionData) {
+  RefPtr<ConnectionData> connectionData = aConnectionData;
+
+  nsresult rv;
+  if (!connectionData->mHost.Length() ||
+      !net_IsValidHostName(connectionData->mHost)) {
+    return NS_ERROR_UNKNOWN_HOST;
+  }
+
+  if (connectionData->mProtocol.EqualsLiteral("ssl")) {
+    AutoTArray<nsCString, 1> socketTypes = {connectionData->mProtocol};
+    rv = gSocketTransportService->CreateTransport(
+        socketTypes, connectionData->mHost, connectionData->mPort, nullptr,
+        nullptr, getter_AddRefs(connectionData->mSocket));
+  } else {
+    rv = gSocketTransportService->CreateTransport(
+        nsTArray<nsCString>(), connectionData->mHost, connectionData->mPort,
+        nullptr, nullptr, getter_AddRefs(connectionData->mSocket));
+  }
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = connectionData->mSocket->SetEventSink(connectionData,
+                                             GetCurrentSerialEventTarget());
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = connectionData->mSocket->OpenInputStream(
+      nsITransport::OPEN_BLOCKING, 0, 0,
+      getter_AddRefs(connectionData->mStreamIn));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  connectionData->StartTimer(connectionData->mTimeout);
+
+  return rv;
+}
+
+using ErrorEntry = struct {
+  nsresult key;
+  const char* error;
+};
+
+#undef ERROR
+#define ERROR(key, val) \
+  { key, #key }
+
+ErrorEntry socketTransportStatuses[] = {
+    ERROR(NS_NET_STATUS_RESOLVING_HOST, FAILURE(3)),
+    ERROR(NS_NET_STATUS_RESOLVED_HOST, FAILURE(11)),
+    ERROR(NS_NET_STATUS_CONNECTING_TO, FAILURE(7)),
+    ERROR(NS_NET_STATUS_CONNECTED_TO, FAILURE(4)),
+    ERROR(NS_NET_STATUS_TLS_HANDSHAKE_STARTING, FAILURE(12)),
+    ERROR(NS_NET_STATUS_TLS_HANDSHAKE_ENDED, FAILURE(13)),
+    ERROR(NS_NET_STATUS_SENDING_TO, FAILURE(5)),
+    ERROR(NS_NET_STATUS_WAITING_FOR, FAILURE(10)),
+    ERROR(NS_NET_STATUS_RECEIVING_FROM, FAILURE(6)),
+};
+#undef ERROR
+
+static void GetErrorString(nsresult rv, nsAString& errorString) {
+  for (auto& socketTransportStatus : socketTransportStatuses) {
+    if (socketTransportStatus.key == rv) {
+      errorString.AssignASCII(socketTransportStatus.error);
+      return;
+    }
+  }
+  nsAutoCString errorCString;
+  mozilla::GetErrorName(rv, errorCString);
+  CopyUTF8toUTF16(errorCString, errorString);
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/Dashboard.h b/netwerk/base/Dashboard.h
new file mode 100644
index 0000000000..1112a013e9
--- /dev/null
+++ b/netwerk/base/Dashboard.h
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsDashboard_h__
+#define nsDashboard_h__
+
+#include "mozilla/Mutex.h"
+#include "mozilla/net/DashboardTypes.h"
+#include "nsIDashboard.h"
+#include "nsIDashboardEventNotifier.h"
+
+class nsIDNSService;
+
+namespace mozilla {
+namespace net {
+
+class SocketData;
+class HttpData;
+class DnsData;
+class WebSocketRequest;
+class ConnectionData;
+class RcwnData;
+
+class Dashboard final : public nsIDashboard, public nsIDashboardEventNotifier {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDASHBOARD
+  NS_DECL_NSIDASHBOARDEVENTNOTIFIER
+
+  Dashboard();
+  static const char* GetErrorString(nsresult rv);
+  nsresult GetConnectionStatus(ConnectionData* aConnectionData);
+
+ private:
+  struct LogData {
+    LogData(nsCString host, uint32_t serial, bool encryption)
+        : mHost(host),
+          mSerial(serial),
+          mMsgSent(0),
+          mMsgReceived(0),
+          mSizeSent(0),
+          mSizeReceived(0),
+          mEncrypted(encryption) {}
+    nsCString mHost;
+    uint32_t mSerial;
+    uint32_t mMsgSent;
+    uint32_t mMsgReceived;
+    uint64_t mSizeSent;
+    uint64_t mSizeReceived;
+    bool mEncrypted;
+    bool operator==(const LogData& a) const {
+      return mHost.Equals(a.mHost) && (mSerial == a.mSerial);
+    }
+  };
+
+  struct WebSocketData {
+    WebSocketData() : lock("Dashboard.webSocketData") {}
+    uint32_t IndexOf(const nsCString& hostname, uint32_t mSerial) {
+      LogData temp(hostname, mSerial, false);
+      return data.IndexOf(temp);
+    }
+    nsTArray<LogData> data;
+    mozilla::Mutex lock MOZ_UNANNOTATED;
+  };
+
+  bool mEnableLogging;
+  WebSocketData mWs;
+
+ private:
+  virtual ~Dashboard() = default;
+
+  nsresult GetSocketsDispatch(SocketData*);
+  nsresult GetHttpDispatch(HttpData*);
+  nsresult GetDnsInfoDispatch(DnsData*);
+  nsresult TestNewConnection(ConnectionData*);
+
+  /* Helper methods that pass the JSON to the callback function. */
+  nsresult GetSockets(SocketData*);
+  nsresult GetHttpConnections(HttpData*);
+  nsresult GetDNSCacheEntries(DnsData*);
+  nsresult GetWebSocketConnections(WebSocketRequest*);
+  nsresult GetRcwnData(RcwnData*);
+
+  nsCOMPtr<nsIDNSService> mDnsService;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsDashboard_h__
diff --git a/netwerk/base/DashboardTypes.h b/netwerk/base/DashboardTypes.h
new file mode 100644
index 0000000000..6dd901d02a
--- /dev/null
+++ b/netwerk/base/DashboardTypes.h
@@ -0,0 +1,175 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_DashboardTypes_h_
+#define mozilla_net_DashboardTypes_h_
+
+#include "ipc/IPCMessageUtils.h"
+#include "ipc/IPCMessageUtilsSpecializations.h"
+#include "nsHttp.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace net {
+
+struct SocketInfo {
+  nsCString host;
+  uint64_t sent;
+  uint64_t received;
+  uint16_t port;
+  bool active;
+  nsCString type;
+};
+
+inline bool operator==(const SocketInfo& a, const SocketInfo& b) {
+  return a.host == b.host && a.sent == b.sent && a.received == b.received &&
+         a.port == b.port && a.active == b.active && a.type == b.type;
+}
+
+struct DnsAndConnectSockets {
+  bool speculative;
+};
+
+struct DNSCacheEntries {
+  nsCString hostname;
+  nsTArray<nsCString> hostaddr;
+  uint16_t family;
+  int64_t expiration;
+  nsCString netInterface;
+  bool TRR;
+  nsCString originAttributesSuffix;
+  nsCString flags;
+};
+
+struct HttpConnInfo {
+  uint32_t ttl;
+  uint32_t rtt;
+  nsString protocolVersion;
+
+  void SetHTTPProtocolVersion(HttpVersion pv);
+};
+
+struct HttpRetParams {
+  nsCString host;
+  CopyableTArray<HttpConnInfo> active;
+  CopyableTArray<HttpConnInfo> idle;
+  CopyableTArray<DnsAndConnectSockets> dnsAndSocks;
+  uint32_t counter;
+  uint16_t port;
+  nsCString httpVersion;
+  bool ssl;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mozilla::net::SocketInfo> {
+  typedef mozilla::net::SocketInfo paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.host);
+    WriteParam(aWriter, aParam.sent);
+    WriteParam(aWriter, aParam.received);
+    WriteParam(aWriter, aParam.port);
+    WriteParam(aWriter, aParam.active);
+    WriteParam(aWriter, aParam.type);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->host) &&
+           ReadParam(aReader, &aResult->sent) &&
+           ReadParam(aReader, &aResult->received) &&
+           ReadParam(aReader, &aResult->port) &&
+           ReadParam(aReader, &aResult->active) &&
+           ReadParam(aReader, &aResult->type);
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::net::DNSCacheEntries> {
+  typedef mozilla::net::DNSCacheEntries paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.hostname);
+    WriteParam(aWriter, aParam.hostaddr);
+    WriteParam(aWriter, aParam.family);
+    WriteParam(aWriter, aParam.expiration);
+    WriteParam(aWriter, aParam.netInterface);
+    WriteParam(aWriter, aParam.TRR);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->hostname) &&
+           ReadParam(aReader, &aResult->hostaddr) &&
+           ReadParam(aReader, &aResult->family) &&
+           ReadParam(aReader, &aResult->expiration) &&
+           ReadParam(aReader, &aResult->netInterface) &&
+           ReadParam(aReader, &aResult->TRR);
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::net::DnsAndConnectSockets> {
+  typedef mozilla::net::DnsAndConnectSockets paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.speculative);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->speculative);
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::net::HttpConnInfo> {
+  typedef mozilla::net::HttpConnInfo paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.ttl);
+    WriteParam(aWriter, aParam.rtt);
+    WriteParam(aWriter, aParam.protocolVersion);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->ttl) &&
+           ReadParam(aReader, &aResult->rtt) &&
+           ReadParam(aReader, &aResult->protocolVersion);
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::net::HttpRetParams> {
+  typedef mozilla::net::HttpRetParams paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.host);
+    WriteParam(aWriter, aParam.active);
+    WriteParam(aWriter, aParam.idle);
+    WriteParam(aWriter, aParam.dnsAndSocks);
+    WriteParam(aWriter, aParam.counter);
+    WriteParam(aWriter, aParam.port);
+    WriteParam(aWriter, aParam.httpVersion);
+    WriteParam(aWriter, aParam.ssl);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->host) &&
+           ReadParam(aReader, &aResult->active) &&
+           ReadParam(aReader, &aResult->idle) &&
+           ReadParam(aReader, &aResult->dnsAndSocks) &&
+           ReadParam(aReader, &aResult->counter) &&
+           ReadParam(aReader, &aResult->port) &&
+           ReadParam(aReader, &aResult->httpVersion) &&
+           ReadParam(aReader, &aResult->ssl);
+  }
+};
+
+}  // namespace IPC
+
+#endif  // mozilla_net_DashboardTypes_h_
diff --git a/netwerk/base/DefaultURI.cpp b/netwerk/base/DefaultURI.cpp
new file mode 100644
index 0000000000..f6506e28fb
--- /dev/null
+++ b/netwerk/base/DefaultURI.cpp
@@ -0,0 +1,538 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DefaultURI.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "nsURLHelper.h"
+
+#include "mozilla/ipc/URIParams.h"
+
+namespace mozilla {
+namespace net {
+
+#define NS_DEFAULTURI_CID                            \
+  { /* 04445aa0-fd27-4c99-bd41-6be6318ae92c */       \
+    0x04445aa0, 0xfd27, 0x4c99, {                    \
+      0xbd, 0x41, 0x6b, 0xe6, 0x31, 0x8a, 0xe9, 0x2c \
+    }                                                \
+  }
+
+#define ASSIGN_AND_ADDREF_THIS(ptrToMutator)    \
+  do {                                          \
+    if (ptrToMutator) {                         \
+      *(ptrToMutator) = do_AddRef(this).take(); \
+    }                                           \
+  } while (0)
+
+static NS_DEFINE_CID(kDefaultURICID, NS_DEFAULTURI_CID);
+
+//----------------------------------------------------------------------------
+// nsIClassInfo
+//----------------------------------------------------------------------------
+
+NS_IMPL_CLASSINFO(DefaultURI, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_DEFAULTURI_CID)
+// Empty CI getter. We only need nsIClassInfo for Serialization
+NS_IMPL_CI_INTERFACE_GETTER0(DefaultURI)
+
+//----------------------------------------------------------------------------
+// nsISupports
+//----------------------------------------------------------------------------
+
+NS_IMPL_ADDREF(DefaultURI)
+NS_IMPL_RELEASE(DefaultURI)
+NS_INTERFACE_TABLE_HEAD(DefaultURI)
+  NS_INTERFACE_TABLE(DefaultURI, nsIURI, nsISerializable)
+  NS_INTERFACE_TABLE_TO_MAP_SEGUE
+  NS_IMPL_QUERY_CLASSINFO(DefaultURI)
+  if (aIID.Equals(kDefaultURICID)) {
+    foundInterface = static_cast<nsIURI*>(this);
+  } else
+    NS_INTERFACE_MAP_ENTRY(nsISizeOf)
+NS_INTERFACE_MAP_END
+
+//----------------------------------------------------------------------------
+// nsISerializable
+//----------------------------------------------------------------------------
+
+NS_IMETHODIMP DefaultURI::Read(nsIObjectInputStream* aInputStream) {
+  MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP DefaultURI::Write(nsIObjectOutputStream* aOutputStream) {
+  nsAutoCString spec(mURL->Spec());
+  return aOutputStream->WriteStringZ(spec.get());
+}
+
+//----------------------------------------------------------------------------
+// nsISizeOf
+//----------------------------------------------------------------------------
+
+size_t DefaultURI::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  return mURL->SizeOf();
+}
+
+size_t DefaultURI::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+//----------------------------------------------------------------------------
+// nsIURI
+//----------------------------------------------------------------------------
+
+NS_IMETHODIMP DefaultURI::GetSpec(nsACString& aSpec) {
+  aSpec = mURL->Spec();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetPrePath(nsACString& aPrePath) {
+  aPrePath = mURL->PrePath();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetScheme(nsACString& aScheme) {
+  aScheme = mURL->Scheme();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetUserPass(nsACString& aUserPass) {
+  aUserPass = mURL->Username();
+  nsAutoCString pass(mURL->Password());
+  if (pass.IsEmpty()) {
+    return NS_OK;
+  }
+  aUserPass.Append(':');
+  aUserPass.Append(pass);
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetUsername(nsACString& aUsername) {
+  aUsername = mURL->Username();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetPassword(nsACString& aPassword) {
+  aPassword = mURL->Password();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetHostPort(nsACString& aHostPort) {
+  aHostPort = mURL->HostPort();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetHost(nsACString& aHost) {
+  aHost = mURL->Host();
+
+  // Historically nsIURI.host has always returned an IPv6 address that isn't
+  // enclosed in brackets. Ideally we want to change that, but for the sake of
+  // consitency we'll leave it like that for the moment.
+  // Bug 1603199 should fix this.
+  if (StringBeginsWith(aHost, "["_ns) && StringEndsWith(aHost, "]"_ns) &&
+      aHost.FindChar(':') != kNotFound) {
+    aHost = Substring(aHost, 1, aHost.Length() - 2);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetPort(int32_t* aPort) {
+  *aPort = mURL->Port();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetPathQueryRef(nsACString& aPathQueryRef) {
+  aPathQueryRef = mURL->Path();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::Equals(nsIURI* other, bool* _retval) {
+  RefPtr<DefaultURI> otherUri;
+  nsresult rv = other->QueryInterface(kDefaultURICID, getter_AddRefs(otherUri));
+  if (NS_FAILED(rv)) {
+    *_retval = false;
+    return NS_OK;
+  }
+
+  *_retval = mURL->Spec() == otherUri->mURL->Spec();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::SchemeIs(const char* scheme, bool* _retval) {
+  *_retval = mURL->Scheme().Equals(scheme);
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::Resolve(const nsACString& aRelativePath,
+                                  nsACString& aResult) {
+  nsAutoCString scheme;
+  nsresult rv = net_ExtractURLScheme(aRelativePath, scheme);
+  if (NS_SUCCEEDED(rv)) {
+    aResult = aRelativePath;
+    return NS_OK;
+  }
+
+  // We try to create another URL with this one as its base.
+  RefPtr<MozURL> resolvedURL;
+  rv = MozURL::Init(getter_AddRefs(resolvedURL), aRelativePath, mURL);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    // If parsing the relative url fails, we revert to the previous behaviour
+    // and just return the relative path.
+    aResult = aRelativePath;
+    return NS_OK;
+  }
+
+  aResult = resolvedURL->Spec();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetAsciiSpec(nsACString& aAsciiSpec) {
+  return GetSpec(aAsciiSpec);
+}
+
+NS_IMETHODIMP DefaultURI::GetAsciiHostPort(nsACString& aAsciiHostPort) {
+  return GetHostPort(aAsciiHostPort);
+}
+
+NS_IMETHODIMP DefaultURI::GetAsciiHost(nsACString& aAsciiHost) {
+  return GetHost(aAsciiHost);
+}
+
+NS_IMETHODIMP DefaultURI::GetRef(nsACString& aRef) {
+  aRef = mURL->Ref();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::EqualsExceptRef(nsIURI* other, bool* _retval) {
+  RefPtr<DefaultURI> otherUri;
+  nsresult rv = other->QueryInterface(kDefaultURICID, getter_AddRefs(otherUri));
+  if (NS_FAILED(rv)) {
+    *_retval = false;
+    return NS_OK;
+  }
+
+  *_retval = mURL->SpecNoRef().Equals(otherUri->mURL->SpecNoRef());
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetSpecIgnoringRef(nsACString& aSpecIgnoringRef) {
+  aSpecIgnoringRef = mURL->SpecNoRef();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetHasRef(bool* aHasRef) {
+  *aHasRef = mURL->HasFragment();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetFilePath(nsACString& aFilePath) {
+  aFilePath = mURL->FilePath();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetQuery(nsACString& aQuery) {
+  aQuery = mURL->Query();
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::GetDisplayHost(nsACString& aDisplayHost) {
+  // At the moment it doesn't seem useful to decode the hostname if it happens
+  // to contain punycode.
+  return GetHost(aDisplayHost);
+}
+
+NS_IMETHODIMP DefaultURI::GetDisplayHostPort(nsACString& aDisplayHostPort) {
+  // At the moment it doesn't seem useful to decode the hostname if it happens
+  // to contain punycode.
+  return GetHostPort(aDisplayHostPort);
+}
+
+NS_IMETHODIMP DefaultURI::GetDisplaySpec(nsACString& aDisplaySpec) {
+  // At the moment it doesn't seem useful to decode the hostname if it happens
+  // to contain punycode.
+  return GetSpec(aDisplaySpec);
+}
+
+NS_IMETHODIMP DefaultURI::GetDisplayPrePath(nsACString& aDisplayPrePath) {
+  // At the moment it doesn't seem useful to decode the hostname if it happens
+  // to contain punycode.
+  return GetPrePath(aDisplayPrePath);
+}
+
+NS_IMETHODIMP DefaultURI::Mutate(nsIURIMutator** _retval) {
+  RefPtr<DefaultURI::Mutator> mutator = new DefaultURI::Mutator();
+  mutator->Init(this);
+  mutator.forget(_retval);
+  return NS_OK;
+}
+
+void DefaultURI::Serialize(ipc::URIParams& aParams) {
+  ipc::DefaultURIParams params;
+  params.spec() = mURL->Spec();
+  aParams = params;
+}
+
+//----------------------------------------------------------------------------
+// nsIURIMutator
+//----------------------------------------------------------------------------
+
+NS_IMPL_ADDREF(DefaultURI::Mutator)
+NS_IMPL_RELEASE(DefaultURI::Mutator)
+NS_IMETHODIMP DefaultURI::Mutator::QueryInterface(REFNSIID aIID,
+                                                  void** aInstancePtr) {
+  NS_ASSERTION(aInstancePtr, "QueryInterface requires a non-NULL destination!");
+  nsISupports* foundInterface = nullptr;
+  if (aIID.Equals(NS_GET_IID(nsIURI))) {
+    RefPtr<DefaultURI> defaultURI = new DefaultURI();
+    mMutator->Finalize(getter_AddRefs(defaultURI->mURL));
+    foundInterface =
+        static_cast<nsISupports*>(static_cast<nsIURI*>((defaultURI.get())));
+    NS_ADDREF(foundInterface);
+    *aInstancePtr = foundInterface;
+    return NS_OK;
+  }
+
+  if (aIID.Equals(NS_GET_IID(nsIURIMutator)) ||
+      aIID.Equals(NS_GET_IID(nsISupports))) {
+    foundInterface =
+        static_cast<nsISupports*>(static_cast<nsIURIMutator*>(this));
+  } else if (aIID.Equals(NS_GET_IID(nsIURISetters))) {
+    foundInterface =
+        static_cast<nsISupports*>(static_cast<nsIURISetters*>(this));
+  } else if (aIID.Equals(NS_GET_IID(nsIURISetSpec))) {
+    foundInterface =
+        static_cast<nsISupports*>(static_cast<nsIURISetSpec*>(this));
+  } else if (aIID.Equals(NS_GET_IID(nsISerializable))) {
+    foundInterface =
+        static_cast<nsISupports*>(static_cast<nsISerializable*>(this));
+  }
+
+  if (foundInterface) {
+    NS_ADDREF(foundInterface);
+    *aInstancePtr = foundInterface;
+    return NS_OK;
+  }
+
+  return NS_NOINTERFACE;
+}
+
+NS_IMETHODIMP DefaultURI::Mutator::Read(nsIObjectInputStream* aStream) {
+  nsAutoCString spec;
+  nsresult rv = aStream->ReadCString(spec);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return SetSpec(spec, nullptr);
+}
+
+NS_IMETHODIMP DefaultURI::Mutator::Deserialize(
+    const mozilla::ipc::URIParams& aParams) {
+  if (aParams.type() != ipc::URIParams::TDefaultURIParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return NS_ERROR_FAILURE;
+  }
+
+  const ipc::DefaultURIParams& params = aParams.get_DefaultURIParams();
+  auto result = MozURL::Mutator::FromSpec(params.spec());
+  if (result.isErr()) {
+    return result.unwrapErr();
+  }
+  mMutator = Some(result.unwrap());
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::Mutator::Finalize(nsIURI** aURI) {
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  RefPtr<DefaultURI> uri = new DefaultURI();
+  mMutator->Finalize(getter_AddRefs(uri->mURL));
+  mMutator = Nothing();
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP DefaultURI::Mutator::SetSpec(const nsACString& aSpec,
+                                           nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  auto result = MozURL::Mutator::FromSpec(aSpec);
+  if (result.isErr()) {
+    return result.unwrapErr();
+  }
+  mMutator = Some(result.unwrap());
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetScheme(const nsACString& aScheme,
+                               nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetScheme(aScheme);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetUserPass(const nsACString& aUserPass,
+                                 nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  int32_t index = aUserPass.FindChar(':');
+  if (index == kNotFound) {
+    mMutator->SetUsername(aUserPass);
+    mMutator->SetPassword(""_ns);
+    return mMutator->GetStatus();
+  }
+
+  mMutator->SetUsername(Substring(aUserPass, 0, index));
+  nsresult rv = mMutator->GetStatus();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mMutator->SetPassword(Substring(aUserPass, index + 1));
+  rv = mMutator->GetStatus();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetUsername(const nsACString& aUsername,
+                                 nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetUsername(aUsername);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetPassword(const nsACString& aPassword,
+                                 nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetPassword(aPassword);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetHostPort(const nsACString& aHostPort,
+                                 nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetHostPort(aHostPort);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetHost(const nsACString& aHost,
+                             nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetHostname(aHost);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetPort(int32_t aPort, nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetPort(aPort);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetPathQueryRef(const nsACString& aPathQueryRef,
+                                     nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  if (aPathQueryRef.IsEmpty()) {
+    mMutator->SetFilePath(""_ns);
+    mMutator->SetQuery(""_ns);
+    mMutator->SetRef(""_ns);
+    return mMutator->GetStatus();
+  }
+
+  nsAutoCString pathQueryRef(aPathQueryRef);
+  if (!StringBeginsWith(pathQueryRef, "/"_ns)) {
+    pathQueryRef.Insert('/', 0);
+  }
+
+  RefPtr<MozURL> url;
+  mMutator->Finalize(getter_AddRefs(url));
+  mMutator = Nothing();
+
+  auto result = MozURL::Mutator::FromSpec(pathQueryRef, url);
+  if (result.isErr()) {
+    return result.unwrapErr();
+  }
+  mMutator = Some(result.unwrap());
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetRef(const nsACString& aRef, nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetRef(aRef);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetFilePath(const nsACString& aFilePath,
+                                 nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetFilePath(aFilePath);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetQuery(const nsACString& aQuery,
+                              nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  mMutator->SetQuery(aQuery);
+  return mMutator->GetStatus();
+}
+
+NS_IMETHODIMP
+DefaultURI::Mutator::SetQueryWithEncoding(const nsACString& aQuery,
+                                          const mozilla::Encoding* aEncoding,
+                                          nsIURIMutator** aMutator) {
+  ASSIGN_AND_ADDREF_THIS(aMutator);
+  if (!mMutator.isSome()) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  // we only support UTF-8 for DefaultURI
+  mMutator->SetQuery(aQuery);
+  return mMutator->GetStatus();
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/DefaultURI.h b/netwerk/base/DefaultURI.h
new file mode 100644
index 0000000000..e737067565
--- /dev/null
+++ b/netwerk/base/DefaultURI.h
@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DefaultURI_h__
+#define DefaultURI_h__
+
+#include "nsIURI.h"
+#include "nsISerializable.h"
+#include "nsISizeOf.h"
+#include "nsIURIMutator.h"
+#include "mozilla/net/MozURL.h"
+
+namespace mozilla {
+namespace net {
+
+class DefaultURI : public nsIURI, public nsISerializable, public nsISizeOf {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIURI
+  NS_DECL_NSISERIALIZABLE
+
+  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override;
+  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override;
+
+  class Mutator final : public nsIURIMutator, public nsISerializable {
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIURISETSPEC
+    NS_DECL_NSIURISETTERS
+    NS_DECL_NSIURIMUTATOR
+
+    NS_IMETHOD
+    Write(nsIObjectOutputStream* aOutputStream) override {
+      MOZ_ASSERT_UNREACHABLE("nsIURIMutator.write() should never be called");
+      return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    [[nodiscard]] NS_IMETHOD Read(nsIObjectInputStream* aStream) override;
+
+    explicit Mutator() = default;
+
+   private:
+    virtual ~Mutator() = default;
+    void Init(DefaultURI* aFrom) { mMutator = Some(aFrom->mURL->Mutate()); }
+
+    Maybe<MozURL::Mutator> mMutator;
+
+    friend class DefaultURI;
+  };
+
+ private:
+  virtual ~DefaultURI() = default;
+  RefPtr<MozURL> mURL;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // DefaultURI_h__
diff --git a/netwerk/base/EventTokenBucket.cpp b/netwerk/base/EventTokenBucket.cpp
new file mode 100644
index 0000000000..87179d6732
--- /dev/null
+++ b/netwerk/base/EventTokenBucket.cpp
@@ -0,0 +1,410 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "EventTokenBucket.h"
+
+#include "nsICancelable.h"
+#include "nsIIOService.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsSocketTransportService2.h"
+#ifdef DEBUG
+#  include "MainThreadUtils.h"
+#endif
+
+#ifdef XP_WIN
+#  include <windows.h>
+#  include <mmsystem.h>
+#endif
+
+namespace mozilla {
+namespace net {
+
+////////////////////////////////////////////
+// EventTokenBucketCancelable
+////////////////////////////////////////////
+
+class TokenBucketCancelable : public nsICancelable {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICANCELABLE
+
+  explicit TokenBucketCancelable(class ATokenBucketEvent* event);
+  void Fire();
+
+ private:
+  virtual ~TokenBucketCancelable() = default;
+
+  friend class EventTokenBucket;
+  ATokenBucketEvent* mEvent;
+};
+
+NS_IMPL_ISUPPORTS(TokenBucketCancelable, nsICancelable)
+
+TokenBucketCancelable::TokenBucketCancelable(ATokenBucketEvent* event)
+    : mEvent(event) {}
+
+NS_IMETHODIMP
+TokenBucketCancelable::Cancel(nsresult reason) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  mEvent = nullptr;
+  return NS_OK;
+}
+
+void TokenBucketCancelable::Fire() {
+  if (!mEvent) return;
+
+  ATokenBucketEvent* event = mEvent;
+  mEvent = nullptr;
+  event->OnTokenBucketAdmitted();
+}
+
+////////////////////////////////////////////
+// EventTokenBucket
+////////////////////////////////////////////
+
+NS_IMPL_ISUPPORTS(EventTokenBucket, nsITimerCallback, nsINamed)
+
+// by default 1hz with no burst
+EventTokenBucket::EventTokenBucket(uint32_t eventsPerSecond, uint32_t burstSize)
+    : mUnitCost(kUsecPerSec),
+      mMaxCredit(kUsecPerSec),
+      mCredit(kUsecPerSec),
+      mPaused(false),
+      mStopped(false),
+      mTimerArmed(false)
+#ifdef XP_WIN
+      ,
+      mFineGrainTimerInUse(false),
+      mFineGrainResetTimerArmed(false)
+#endif
+{
+  mLastUpdate = TimeStamp::Now();
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsresult rv;
+  nsCOMPtr<nsIEventTarget> sts;
+  nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
+  if (NS_SUCCEEDED(rv)) {
+    sts = do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
+  }
+  if (NS_SUCCEEDED(rv)) mTimer = NS_NewTimer(sts);
+  SetRate(eventsPerSecond, burstSize);
+}
+
+EventTokenBucket::~EventTokenBucket() {
+  SOCKET_LOG(
+      ("EventTokenBucket::dtor %p events=%zu\n", this, mEvents.GetSize()));
+
+  CleanupTimers();
+
+  // Complete any queued events to prevent hangs
+  while (mEvents.GetSize()) {
+    RefPtr<TokenBucketCancelable> cancelable = mEvents.PopFront();
+    cancelable->Fire();
+  }
+}
+
+void EventTokenBucket::CleanupTimers() {
+  if (mTimer && mTimerArmed) {
+    mTimer->Cancel();
+  }
+  mTimer = nullptr;
+  mTimerArmed = false;
+
+#ifdef XP_WIN
+  NormalTimers();
+  if (mFineGrainResetTimer && mFineGrainResetTimerArmed) {
+    mFineGrainResetTimer->Cancel();
+  }
+  mFineGrainResetTimer = nullptr;
+  mFineGrainResetTimerArmed = false;
+#endif
+}
+
+void EventTokenBucket::SetRate(uint32_t eventsPerSecond, uint32_t burstSize) {
+  SOCKET_LOG(("EventTokenBucket::SetRate %p %u %u\n", this, eventsPerSecond,
+              burstSize));
+
+  if (eventsPerSecond > kMaxHz) {
+    eventsPerSecond = kMaxHz;
+    SOCKET_LOG(("  eventsPerSecond out of range\n"));
+  }
+
+  if (!eventsPerSecond) {
+    eventsPerSecond = 1;
+    SOCKET_LOG(("  eventsPerSecond out of range\n"));
+  }
+
+  mUnitCost = kUsecPerSec / eventsPerSecond;
+  mMaxCredit = mUnitCost * burstSize;
+  if (mMaxCredit > kUsecPerSec * 60 * 15) {
+    SOCKET_LOG(("  burstSize out of range\n"));
+    mMaxCredit = kUsecPerSec * 60 * 15;
+  }
+  mCredit = mMaxCredit;
+  mLastUpdate = TimeStamp::Now();
+}
+
+void EventTokenBucket::ClearCredits() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::ClearCredits %p\n", this));
+  mCredit = 0;
+}
+
+uint32_t EventTokenBucket::BurstEventsAvailable() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  return static_cast<uint32_t>(mCredit / mUnitCost);
+}
+
+uint32_t EventTokenBucket::QueuedEvents() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  return mEvents.GetSize();
+}
+
+void EventTokenBucket::Pause() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::Pause %p\n", this));
+  if (mPaused || mStopped) return;
+
+  mPaused = true;
+  if (mTimerArmed) {
+    mTimer->Cancel();
+    mTimerArmed = false;
+  }
+}
+
+void EventTokenBucket::UnPause() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::UnPause %p\n", this));
+  if (!mPaused || mStopped) return;
+
+  mPaused = false;
+  DispatchEvents();
+  UpdateTimer();
+}
+
+void EventTokenBucket::Stop() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::Stop %p armed=%d\n", this, mTimerArmed));
+  mStopped = true;
+  CleanupTimers();
+
+  // Complete any queued events to prevent hangs
+  while (mEvents.GetSize()) {
+    RefPtr<TokenBucketCancelable> cancelable = mEvents.PopFront();
+    cancelable->Fire();
+  }
+}
+
+nsresult EventTokenBucket::SubmitEvent(ATokenBucketEvent* event,
+                                       nsICancelable** cancelable) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::SubmitEvent %p\n", this));
+
+  if (mStopped || !mTimer) return NS_ERROR_FAILURE;
+
+  UpdateCredits();
+
+  RefPtr<TokenBucketCancelable> cancelEvent = new TokenBucketCancelable(event);
+  // When this function exits the cancelEvent needs 2 references, one for the
+  // mEvents queue and one for the caller of SubmitEvent()
+
+  *cancelable = do_AddRef(cancelEvent).take();
+
+  if (mPaused || !TryImmediateDispatch(cancelEvent.get())) {
+    // queue it
+    SOCKET_LOG(("   queued\n"));
+    mEvents.Push(cancelEvent.forget());
+    UpdateTimer();
+  } else {
+    SOCKET_LOG(("   dispatched synchronously\n"));
+  }
+
+  return NS_OK;
+}
+
+bool EventTokenBucket::TryImmediateDispatch(TokenBucketCancelable* cancelable) {
+  if (mCredit < mUnitCost) return false;
+
+  mCredit -= mUnitCost;
+  cancelable->Fire();
+  return true;
+}
+
+void EventTokenBucket::DispatchEvents() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("EventTokenBucket::DispatchEvents %p %d\n", this, mPaused));
+  if (mPaused || mStopped) return;
+
+  while (mEvents.GetSize() && mUnitCost <= mCredit) {
+    RefPtr<TokenBucketCancelable> cancelable = mEvents.PopFront();
+    if (cancelable->mEvent) {
+      SOCKET_LOG(
+          ("EventTokenBucket::DispachEvents [%p] "
+           "Dispatching queue token bucket event cost=%" PRIu64
+           " credit=%" PRIu64 "\n",
+           this, mUnitCost, mCredit));
+      mCredit -= mUnitCost;
+      cancelable->Fire();
+    }
+  }
+
+#ifdef XP_WIN
+  if (!mEvents.GetSize()) WantNormalTimers();
+#endif
+}
+
+void EventTokenBucket::UpdateTimer() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (mTimerArmed || mPaused || mStopped || !mEvents.GetSize() || !mTimer) {
+    return;
+  }
+
+  if (mCredit >= mUnitCost) return;
+
+  // determine the time needed to wait to accumulate enough credits to admit
+  // one more event and set the timer for that point. Always round it
+  // up because firing early doesn't help.
+  //
+  uint64_t deficit = mUnitCost - mCredit;
+  uint64_t msecWait = (deficit + (kUsecPerMsec - 1)) / kUsecPerMsec;
+
+  if (msecWait < 4) {  // minimum wait
+    msecWait = 4;
+  } else if (msecWait > 60000) {  // maximum wait
+    msecWait = 60000;
+  }
+
+#ifdef XP_WIN
+  FineGrainTimers();
+#endif
+
+  SOCKET_LOG(
+      ("EventTokenBucket::UpdateTimer %p for %" PRIu64 "ms\n", this, msecWait));
+  nsresult rv = mTimer->InitWithCallback(this, static_cast<uint32_t>(msecWait),
+                                         nsITimer::TYPE_ONE_SHOT);
+  mTimerArmed = NS_SUCCEEDED(rv);
+}
+
+NS_IMETHODIMP
+EventTokenBucket::Notify(nsITimer* timer) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+#ifdef XP_WIN
+  if (timer == mFineGrainResetTimer) {
+    FineGrainResetTimerNotify();
+    return NS_OK;
+  }
+#endif
+
+  SOCKET_LOG(("EventTokenBucket::Notify() %p\n", this));
+  mTimerArmed = false;
+  if (mStopped) return NS_OK;
+
+  UpdateCredits();
+  DispatchEvents();
+  UpdateTimer();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+EventTokenBucket::GetName(nsACString& aName) {
+  aName.AssignLiteral("EventTokenBucket");
+  return NS_OK;
+}
+
+void EventTokenBucket::UpdateCredits() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  TimeStamp now = TimeStamp::Now();
+  TimeDuration elapsed = now - mLastUpdate;
+  mLastUpdate = now;
+
+  mCredit += static_cast<uint64_t>(elapsed.ToMicroseconds());
+  if (mCredit > mMaxCredit) mCredit = mMaxCredit;
+  SOCKET_LOG(("EventTokenBucket::UpdateCredits %p to %" PRIu64 " (%" PRIu64
+              " each.. %3.2f)\n",
+              this, mCredit, mUnitCost, (double)mCredit / mUnitCost));
+}
+
+#ifdef XP_WIN
+void EventTokenBucket::FineGrainTimers() {
+  SOCKET_LOG(("EventTokenBucket::FineGrainTimers %p mFineGrainTimerInUse=%d\n",
+              this, mFineGrainTimerInUse));
+
+  mLastFineGrainTimerUse = TimeStamp::Now();
+
+  if (mFineGrainTimerInUse) return;
+
+  if (mUnitCost > kCostFineGrainThreshold) return;
+
+  SOCKET_LOG(
+      ("EventTokenBucket::FineGrainTimers %p timeBeginPeriod()\n", this));
+
+  mFineGrainTimerInUse = true;
+  timeBeginPeriod(1);
+}
+
+void EventTokenBucket::NormalTimers() {
+  if (!mFineGrainTimerInUse) return;
+  mFineGrainTimerInUse = false;
+
+  SOCKET_LOG(("EventTokenBucket::NormalTimers %p timeEndPeriod()\n", this));
+  timeEndPeriod(1);
+}
+
+void EventTokenBucket::WantNormalTimers() {
+  if (!mFineGrainTimerInUse) return;
+  if (mFineGrainResetTimerArmed) return;
+
+  TimeDuration elapsed(TimeStamp::Now() - mLastFineGrainTimerUse);
+  static const TimeDuration fiveSeconds = TimeDuration::FromSeconds(5);
+
+  if (elapsed >= fiveSeconds) {
+    NormalTimers();
+    return;
+  }
+
+  if (!mFineGrainResetTimer) mFineGrainResetTimer = NS_NewTimer();
+
+  // if we can't delay the reset, just do it now
+  if (!mFineGrainResetTimer) {
+    NormalTimers();
+    return;
+  }
+
+  // pad the callback out 100ms to avoid having to round trip this again if the
+  // timer calls back just a tad early.
+  SOCKET_LOG(
+      ("EventTokenBucket::WantNormalTimers %p "
+       "Will reset timer granularity after delay",
+       this));
+
+  mFineGrainResetTimer->InitWithCallback(
+      this,
+      static_cast<uint32_t>((fiveSeconds - elapsed).ToMilliseconds()) + 100,
+      nsITimer::TYPE_ONE_SHOT);
+  mFineGrainResetTimerArmed = true;
+}
+
+void EventTokenBucket::FineGrainResetTimerNotify() {
+  SOCKET_LOG(("EventTokenBucket::FineGrainResetTimerNotify(%p) events = %zd\n",
+              this, mEvents.GetSize()));
+  mFineGrainResetTimerArmed = false;
+
+  // If we are currently processing events then wait for the queue to drain
+  // before trying to reset back to normal timers again
+  if (!mEvents.GetSize()) WantNormalTimers();
+}
+
+#endif
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/EventTokenBucket.h b/netwerk/base/EventTokenBucket.h
new file mode 100644
index 0000000000..4206a622f5
--- /dev/null
+++ b/netwerk/base/EventTokenBucket.h
@@ -0,0 +1,155 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NetEventTokenBucket_h__
+#define NetEventTokenBucket_h__
+
+#include "ARefBase.h"
+#include "nsCOMPtr.h"
+#include "nsDeque.h"
+#include "nsINamed.h"
+#include "nsITimer.h"
+
+#include "mozilla/TimeStamp.h"
+
+class nsICancelable;
+
+namespace mozilla {
+namespace net {
+
+/* A token bucket is used to govern the maximum rate a series of events
+   can be executed at. For instance if your event was "eat a piece of cake"
+   then a token bucket configured to allow "1 piece per day" would spread
+   the eating of a 8 piece cake over 8 days even if you tried to eat the
+   whole thing up front. In a practical sense it 'costs' 1 token to execute
+   an event and tokens are 'earned' at a particular rate as time goes by.
+
+   The token bucket can be perfectly smooth or allow a configurable amount of
+   burstiness. A bursty token bucket allows you to save up unused credits, while
+   a perfectly smooth one would not. A smooth "1 per day" cake token bucket
+   would require 9 days to eat that cake if you skipped a slice on day 4
+   (use the token or lose it), while a token bucket configured with a burst
+   of 2 would just let you eat 2 slices on day 5 (the credits for day 4 and day
+   5) and finish the cake in the usual 8 days.
+
+   EventTokenBucket(hz=20, burst=5) creates a token bucket with the following
+   properties:
+
+  + events from an infinite stream will be admitted 20 times per second (i.e.
+    hz=20 means 1 event per 50 ms). Timers will be used to space things evenly
+    down to 5ms gaps (i.e. up to 200hz). Token buckets with rates greater than
+    200hz will admit multiple events with 5ms gaps between them. 10000hz is the
+    maximum rate and 1hz is the minimum rate.
+
+  + The burst size controls the limit of 'credits' that a token bucket can
+    accumulate when idle. For our (20,5) example each event requires 50ms of
+    credit (again, 20hz = 50ms per event). a burst size of 5 means that the
+    token bucket can accumulate a maximum of 250ms (5 * 50ms) for this bucket.
+    If no events have been admitted for the last full second the bucket can
+    still only accumulate 250ms of credit - but that credit means that 5 events
+    can be admitted without delay. A burst size of 1 is the minimum.  The
+    EventTokenBucket is created with maximum credits already applied, but they
+    can be cleared with the ClearCredits() method. The maximum burst size is 15
+    minutes worth of events.
+
+  + An event is submitted to the token bucket asynchronously through
+    SubmitEvent().  The OnTokenBucketAdmitted() method of the submitted event
+    is used as a callback when the event is ready to run. A cancelable event is
+    returned to the SubmitEvent() caller for use in the case they do not wish
+    to wait for the callback.
+*/
+
+class EventTokenBucket;
+
+class ATokenBucketEvent {
+ public:
+  virtual void OnTokenBucketAdmitted() = 0;
+};
+
+class TokenBucketCancelable;
+
+class EventTokenBucket : public nsITimerCallback,
+                         public nsINamed,
+                         public ARefBase {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSINAMED
+
+  // This should be constructed on the main thread
+  EventTokenBucket(uint32_t eventsPerSecond, uint32_t burstSize);
+
+  // These public methods are all meant to be called from the socket thread
+  void ClearCredits();
+  uint32_t BurstEventsAvailable();
+  uint32_t QueuedEvents();
+
+  // a paused token bucket will not process any events, but it will accumulate
+  // credits. ClearCredits can be used before unpausing if desired.
+  void Pause();
+  void UnPause();
+  void Stop();
+
+  // The returned cancelable event can only be canceled from the socket thread
+  nsresult SubmitEvent(ATokenBucketEvent* event, nsICancelable** cancelable);
+
+ private:
+  virtual ~EventTokenBucket();
+  void CleanupTimers();
+
+  friend class RunNotifyEvent;
+  friend class SetTimerEvent;
+
+  bool TryImmediateDispatch(TokenBucketCancelable* cancelable);
+  void SetRate(uint32_t eventsPerSecond, uint32_t burstSize);
+
+  void DispatchEvents();
+  void UpdateTimer();
+  void UpdateCredits();
+
+  const static uint64_t kUsecPerSec = 1000000;
+  const static uint64_t kUsecPerMsec = 1000;
+  const static uint64_t kMaxHz = 10000;
+
+  uint64_t
+      mUnitCost;  // usec of credit needed for 1 event (from eventsPerSecond)
+  uint64_t mMaxCredit;  // usec mCredit limit (from busrtSize)
+  uint64_t mCredit;     // usec of accumulated credit.
+
+  bool mPaused;
+  bool mStopped;
+  nsRefPtrDeque<TokenBucketCancelable> mEvents;
+  bool mTimerArmed;
+  TimeStamp mLastUpdate;
+
+  // The timer is created on the main thread, but is armed and executes Notify()
+  // callbacks on the socket thread in order to maintain low latency of event
+  // delivery.
+  nsCOMPtr<nsITimer> mTimer;
+
+#ifdef XP_WIN
+  // Windows timers are 15ms granularity by default. When we have active events
+  // that need to be dispatched at 50ms  or less granularity we change the OS
+  // granularity to 1ms. 90 seconds after that need has elapsed we will change
+  // it back
+  const static uint64_t kCostFineGrainThreshold = 50 * kUsecPerMsec;
+
+  void FineGrainTimers();   // get 1ms granularity
+  void NormalTimers();      // reset to default granularity
+  void WantNormalTimers();  // reset after 90 seconds if not needed in interim
+  void FineGrainResetTimerNotify();  // delayed callback to reset
+
+  TimeStamp mLastFineGrainTimerUse;
+  bool mFineGrainTimerInUse;
+  bool mFineGrainResetTimerArmed;
+  nsCOMPtr<nsITimer> mFineGrainResetTimer;
+#endif
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/FuzzyLayer.cpp b/netwerk/base/FuzzyLayer.cpp
new file mode 100644
index 0000000000..8a9ee694dd
--- /dev/null
+++ b/netwerk/base/FuzzyLayer.cpp
@@ -0,0 +1,407 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FuzzyLayer.h"
+#include "nsTHashMap.h"
+#include "nsDeque.h"
+#include "nsIRunnable.h"
+#include "nsSocketTransportService2.h"
+#include "nsThreadUtils.h"
+
+#include "prmem.h"
+#include "prio.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gFuzzingLog("nsFuzzingNecko");
+
+#define FUZZING_LOG(args) \
+  MOZ_LOG(mozilla::net::gFuzzingLog, mozilla::LogLevel::Verbose, args)
+
+// Mutex for modifying our hash tables
+Mutex gConnRecvMutex("ConnectRecvMutex");
+
+// This structure will be created by addNetworkFuzzingBuffer below
+// and then added to the gNetworkFuzzingBuffers structure.
+//
+// It is assigned on connect and associated with the socket it belongs to.
+typedef struct {
+  const uint8_t* buf;
+  size_t size;
+  bool allowRead;
+  bool allowUnused;
+  PRNetAddr* addr;
+} NetworkFuzzingBuffer;
+
+// This holds all connections we have currently open.
+static nsTHashMap<nsPtrHashKey<PRFileDesc>, NetworkFuzzingBuffer*>
+    gConnectedNetworkFuzzingBuffers;
+
+// This holds all buffers for connections we can still open.
+static nsDeque<NetworkFuzzingBuffer> gNetworkFuzzingBuffers;
+
+// This is `true` once all connections are closed and either there are
+// no buffers left to be used or all remaining buffers are marked optional.
+// Used by `signalNetworkFuzzingDone` to tell the main thread if it needs
+// to spin-wait for `gFuzzingConnClosed`.
+static Atomic<bool> fuzzingNoWaitRequired(false);
+
+// Used to memorize if the main thread has indicated that it is done with
+// its iteration and we don't expect more connections now.
+static Atomic<bool> fuzzingMainSignaledDone(false);
+
+/*
+ * The flag `gFuzzingConnClosed` is set by `FuzzyClose` when all connections
+ * are closed *and* there are no more buffers in `gNetworkFuzzingBuffers` that
+ * must be used. The main thread spins until this becomes true to synchronize
+ * the fuzzing iteration between the main thread and the socket thread, if
+ * the prior call to `signalNetworkFuzzingDone` returned `false`.
+ */
+Atomic<bool> gFuzzingConnClosed(true);
+
+void addNetworkFuzzingBuffer(const uint8_t* data, size_t size, bool readFirst,
+                             bool useIsOptional) {
+  if (size > INT32_MAX) {
+    MOZ_CRASH("Unsupported buffer size");
+  }
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* buf = new NetworkFuzzingBuffer();
+  buf->buf = data;
+  buf->size = size;
+  buf->allowRead = readFirst;
+  buf->allowUnused = useIsOptional;
+  buf->addr = nullptr;
+
+  gNetworkFuzzingBuffers.Push(buf);
+
+  fuzzingMainSignaledDone = false;
+  fuzzingNoWaitRequired = false;
+}
+
+/*
+ * This method should be called by fuzzing from the main thread to signal to
+ * the layer code that a fuzzing iteration is done. As a result, we can throw
+ * away any optional buffers and signal back once all connections have been
+ * closed. The main thread should synchronize on all connections being closed
+ * after the actual request/action is complete.
+ */
+bool signalNetworkFuzzingDone() {
+  FUZZING_LOG(("[signalNetworkFuzzingDone] Called."));
+  MutexAutoLock lock(gConnRecvMutex);
+  bool rv = false;
+
+  if (fuzzingNoWaitRequired) {
+    FUZZING_LOG(("[signalNetworkFuzzingDone] Purging remaining buffers."));
+    // Easy case, we already have no connections and non-optional buffers left.
+    gNetworkFuzzingBuffers.Erase();
+    gFuzzingConnClosed = true;
+    rv = true;
+  } else {
+    // We still have either connections left open or non-optional buffers left.
+    // In this case, FuzzyClose will handle the tear-down and signaling.
+    fuzzingMainSignaledDone = true;
+  }
+
+  return rv;
+}
+
+static PRDescIdentity sFuzzyLayerIdentity;
+static PRIOMethods sFuzzyLayerMethods;
+static PRIOMethods* sFuzzyLayerMethodsPtr = nullptr;
+
+static PRInt16 PR_CALLBACK FuzzyPoll(PRFileDesc* fd, PRInt16 in_flags,
+                                     PRInt16* out_flags) {
+  *out_flags = 0;
+
+  FUZZING_LOG(("[FuzzyPoll] Called with in_flags=%X.", in_flags));
+
+  NetworkFuzzingBuffer* fuzzBuf = gConnectedNetworkFuzzingBuffers.Get(fd);
+
+  if (in_flags & PR_POLL_READ && fuzzBuf && fuzzBuf->allowRead) {
+    *out_flags = PR_POLL_READ;
+    return PR_POLL_READ;
+  }
+
+  if (in_flags & PR_POLL_WRITE) {
+    *out_flags = PR_POLL_WRITE;
+    return PR_POLL_WRITE;
+  }
+
+  return in_flags;
+}
+
+static PRStatus FuzzyConnect(PRFileDesc* fd, const PRNetAddr* addr,
+                             PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sFuzzyLayerIdentity);
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* buf = gNetworkFuzzingBuffers.PopFront();
+  if (!buf) {
+    FUZZING_LOG(("[FuzzyConnect] Denying additional connection."));
+    return PR_FAILURE;
+  }
+
+  gConnectedNetworkFuzzingBuffers.InsertOrUpdate(fd, buf);
+  fuzzingNoWaitRequired = false;
+
+  FUZZING_LOG(("[FuzzyConnect] Successfully opened connection: %p", fd));
+
+  gFuzzingConnClosed = false;
+
+  return PR_SUCCESS;
+}
+
+static PRInt32 FuzzySendTo(PRFileDesc* fd, const void* buf, PRInt32 amount,
+                           PRIntn flags, const PRNetAddr* addr,
+                           PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sFuzzyLayerIdentity);
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* fuzzBuf = gConnectedNetworkFuzzingBuffers.Get(fd);
+  if (!fuzzBuf) {
+    NetworkFuzzingBuffer* buf = gNetworkFuzzingBuffers.PopFront();
+    if (!buf) {
+      FUZZING_LOG(("[FuzzySentTo] Denying additional connection."));
+      return 0;
+    }
+
+    gConnectedNetworkFuzzingBuffers.InsertOrUpdate(fd, buf);
+
+    // Store connection address
+    buf->addr = new PRNetAddr;
+    memcpy(buf->addr, addr, sizeof(PRNetAddr));
+
+    fuzzingNoWaitRequired = false;
+
+    FUZZING_LOG(("[FuzzySendTo] Successfully opened connection: %p", fd));
+
+    gFuzzingConnClosed = false;
+  }
+
+  // Allow reading once the implementation has written at least some data
+  if (fuzzBuf && !fuzzBuf->allowRead) {
+    FUZZING_LOG(("[FuzzySendTo] Write received, allowing further reads."));
+    fuzzBuf->allowRead = true;
+  }
+
+  FUZZING_LOG(("[FuzzySendTo] Sent %" PRIx32 " bytes of data.", amount));
+
+  return amount;
+}
+
+static PRInt32 FuzzySend(PRFileDesc* fd, const void* buf, PRInt32 amount,
+                         PRIntn flags, PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sFuzzyLayerIdentity);
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* fuzzBuf = gConnectedNetworkFuzzingBuffers.Get(fd);
+  if (!fuzzBuf) {
+    FUZZING_LOG(("[FuzzySend] Write on socket that is not connected."));
+    amount = 0;
+  }
+
+  // Allow reading once the implementation has written at least some data
+  if (fuzzBuf && !fuzzBuf->allowRead) {
+    FUZZING_LOG(("[FuzzySend] Write received, allowing further reads."));
+    fuzzBuf->allowRead = true;
+  }
+
+  FUZZING_LOG(("[FuzzySend] Sent %" PRIx32 " bytes of data.", amount));
+
+  return amount;
+}
+
+static PRInt32 FuzzyWrite(PRFileDesc* fd, const void* buf, PRInt32 amount) {
+  return FuzzySend(fd, buf, amount, 0, PR_INTERVAL_NO_WAIT);
+}
+
+static PRInt32 FuzzyRecv(PRFileDesc* fd, void* buf, PRInt32 amount,
+                         PRIntn flags, PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sFuzzyLayerIdentity);
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* fuzzBuf = gConnectedNetworkFuzzingBuffers.Get(fd);
+  if (!fuzzBuf) {
+    FUZZING_LOG(("[FuzzyRecv] Denying read, connection is closed."));
+    return 0;
+  }
+
+  // As long as we haven't written anything, act as if no data was there yet
+  if (!fuzzBuf->allowRead) {
+    FUZZING_LOG(("[FuzzyRecv] Denying read, nothing written before."));
+    PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
+    return -1;
+  }
+
+  if (gFuzzingConnClosed) {
+    FUZZING_LOG(("[FuzzyRecv] Denying read, connection is closed."));
+    return 0;
+  }
+
+  // No data left, act as if the connection was closed.
+  if (!fuzzBuf->size) {
+    FUZZING_LOG(("[FuzzyRecv] Read failed, no data left."));
+    return 0;
+  }
+
+  // Use the remains of fuzzing buffer, if too little is left
+  if (fuzzBuf->size < (PRUint32)amount) amount = fuzzBuf->size;
+
+  // Consume buffer, copy data
+  memcpy(buf, fuzzBuf->buf, amount);
+
+  if (!(flags & PR_MSG_PEEK)) {
+    fuzzBuf->buf += amount;
+    fuzzBuf->size -= amount;
+  }
+
+  FUZZING_LOG(("[FuzzyRecv] Read %" PRIx32 " bytes of data.", amount));
+
+  return amount;
+}
+
+static PRInt32 FuzzyRecvFrom(PRFileDesc* fd, void* buf, PRInt32 amount,
+                             PRIntn flags, PRNetAddr* addr,
+                             PRIntervalTime timeout) {
+  // Return the same address used for initial SendTo on this fd
+  if (addr) {
+    NetworkFuzzingBuffer* fuzzBuf = gConnectedNetworkFuzzingBuffers.Get(fd);
+    if (!fuzzBuf) {
+      FUZZING_LOG(("[FuzzyRecvFrom] Denying read, connection is closed."));
+      return 0;
+    }
+
+    if (fuzzBuf->addr) {
+      memcpy(addr, fuzzBuf->addr, sizeof(PRNetAddr));
+    } else {
+      FUZZING_LOG(("[FuzzyRecvFrom] No address found for connection"));
+    }
+  }
+  return FuzzyRecv(fd, buf, amount, flags, timeout);
+}
+
+static PRInt32 FuzzyRead(PRFileDesc* fd, void* buf, PRInt32 amount) {
+  return FuzzyRecv(fd, buf, amount, 0, PR_INTERVAL_NO_WAIT);
+}
+
+static PRStatus FuzzyClose(PRFileDesc* fd) {
+  if (!fd) {
+    return PR_FAILURE;
+  }
+  PRFileDesc* layer = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
+  MOZ_RELEASE_ASSERT(layer && layer->identity == sFuzzyLayerIdentity,
+                     "Fuzzy Layer not on top of stack");
+
+  layer->dtor(layer);
+
+  MutexAutoLock lock(gConnRecvMutex);
+
+  NetworkFuzzingBuffer* fuzzBuf = nullptr;
+  if (gConnectedNetworkFuzzingBuffers.Remove(fd, &fuzzBuf)) {
+    FUZZING_LOG(("[FuzzyClose] Received close on socket %p", fd));
+    if (fuzzBuf->addr) {
+      delete fuzzBuf->addr;
+    }
+    delete fuzzBuf;
+  } else {
+    /* Happens when close is called on a non-connected socket */
+    FUZZING_LOG(("[FuzzyClose] Received close on unknown socket %p.", fd));
+  }
+
+  PRStatus ret = fd->methods->close(fd);
+
+  if (!gConnectedNetworkFuzzingBuffers.Count()) {
+    // At this point, all connections are closed, but we might still have
+    // unused network buffers that were not marked as optional.
+    bool haveRemainingUnusedBuffers = false;
+    for (size_t i = 0; i < gNetworkFuzzingBuffers.GetSize(); ++i) {
+      NetworkFuzzingBuffer* buf = gNetworkFuzzingBuffers.ObjectAt(i);
+
+      if (!buf->allowUnused) {
+        haveRemainingUnusedBuffers = true;
+        break;
+      }
+    }
+
+    if (haveRemainingUnusedBuffers) {
+      FUZZING_LOG(
+          ("[FuzzyClose] All connections closed, waiting for remaining "
+           "connections."));
+    } else if (!fuzzingMainSignaledDone) {
+      // We have no connections left, but the main thread hasn't signaled us
+      // yet. For now, that means once the main thread signals us, we can tell
+      // it immediately that it won't have to wait for closing connections.
+      FUZZING_LOG(
+          ("[FuzzyClose] All connections closed, waiting for main thread."));
+      fuzzingNoWaitRequired = true;
+    } else {
+      // No connections left and main thread is already done. Perform cleanup
+      // and then signal the main thread to continue.
+      FUZZING_LOG(("[FuzzyClose] All connections closed, cleaning up."));
+
+      gNetworkFuzzingBuffers.Erase();
+      gFuzzingConnClosed = true;
+
+      // We need to dispatch this so the main thread is guaranteed to wake up
+      nsCOMPtr<nsIRunnable> r(new mozilla::Runnable("Dummy"));
+      NS_DispatchToMainThread(r.forget());
+    }
+  } else {
+    FUZZING_LOG(("[FuzzyClose] Connection closed."));
+  }
+
+  return ret;
+}
+
+nsresult AttachFuzzyIOLayer(PRFileDesc* fd) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  if (!sFuzzyLayerMethodsPtr) {
+    sFuzzyLayerIdentity = PR_GetUniqueIdentity("Fuzzy Layer");
+    sFuzzyLayerMethods = *PR_GetDefaultIOMethods();
+    sFuzzyLayerMethods.connect = FuzzyConnect;
+    sFuzzyLayerMethods.send = FuzzySend;
+    sFuzzyLayerMethods.sendto = FuzzySendTo;
+    sFuzzyLayerMethods.write = FuzzyWrite;
+    sFuzzyLayerMethods.recv = FuzzyRecv;
+    sFuzzyLayerMethods.recvfrom = FuzzyRecvFrom;
+    sFuzzyLayerMethods.read = FuzzyRead;
+    sFuzzyLayerMethods.close = FuzzyClose;
+    sFuzzyLayerMethods.poll = FuzzyPoll;
+    sFuzzyLayerMethodsPtr = &sFuzzyLayerMethods;
+  }
+
+  PRFileDesc* layer =
+      PR_CreateIOLayerStub(sFuzzyLayerIdentity, sFuzzyLayerMethodsPtr);
+
+  if (!layer) {
+    return NS_ERROR_FAILURE;
+  }
+
+  PRStatus status = PR_PushIOLayer(fd, PR_TOP_IO_LAYER, layer);
+
+  if (status == PR_FAILURE) {
+    PR_Free(layer);  // PR_CreateIOLayerStub() uses PR_Malloc().
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/FuzzyLayer.h b/netwerk/base/FuzzyLayer.h
new file mode 100644
index 0000000000..6b8109f949
--- /dev/null
+++ b/netwerk/base/FuzzyLayer.h
@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef FuzzyLayer_h__
+#define FuzzyLayer_h__
+
+#include "prerror.h"
+#include "nsError.h"
+#include "nsIFile.h"
+
+namespace mozilla {
+namespace net {
+
+nsresult AttachFuzzyIOLayer(PRFileDesc* fd);
+
+extern Atomic<bool> gFuzzingConnClosed;
+bool signalNetworkFuzzingDone();
+
+void addNetworkFuzzingBuffer(const uint8_t* data, size_t size,
+                             bool readFirst = false,
+                             bool useIsOptional = false);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // FuzzyLayer_h__
diff --git a/netwerk/base/FuzzySecurityInfo.cpp b/netwerk/base/FuzzySecurityInfo.cpp
new file mode 100644
index 0000000000..7a2405ab0a
--- /dev/null
+++ b/netwerk/base/FuzzySecurityInfo.cpp
@@ -0,0 +1,177 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FuzzySecurityInfo.h"
+
+#include "nsIWebProgressListener.h"
+#include "nsString.h"
+
+namespace mozilla {
+namespace net {
+
+FuzzySecurityInfo::FuzzySecurityInfo() {}
+
+FuzzySecurityInfo::~FuzzySecurityInfo() {}
+
+NS_IMPL_ISUPPORTS(FuzzySecurityInfo, nsITransportSecurityInfo)
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetSecurityState(uint32_t* state) {
+  *state = nsIWebProgressListener::STATE_IS_SECURE;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetErrorCode(int32_t* state) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetErrorCodeString(nsAString& aErrorString) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetFailedCertChain(
+    nsTArray<RefPtr<nsIX509Cert>>& aFailedCertChain) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetServerCert(nsIX509Cert** aServerCert) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetSucceededCertChain(
+    nsTArray<RefPtr<nsIX509Cert>>& aSucceededCertChain) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetCipherName(nsACString& aCipherName) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetKeyLength(uint32_t* aKeyLength) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetSecretKeyLength(uint32_t* aSecretKeyLength) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetKeaGroupName(nsACString& aKeaGroup) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetSignatureSchemeName(nsACString& aSignatureScheme) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetProtocolVersion(uint16_t* aProtocolVersion) {
+  NS_ENSURE_ARG_POINTER(aProtocolVersion);
+  // Must be >= TLS 1.2 for HTTP2
+  *aProtocolVersion = nsITransportSecurityInfo::TLS_VERSION_1_2;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetCertificateTransparencyStatus(
+    uint16_t* aCertificateTransparencyStatus) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetIsDelegatedCredential(bool* aIsDelegCred) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetIsAcceptedEch(bool* aIsAcceptedEch) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetOverridableErrorCategory(
+    OverridableErrorCategory* aOverridableErrorCode) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetMadeOCSPRequests(bool* aMadeOCSPRequests) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetUsedPrivateDNS(bool* aUsedPrivateDNS) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetIsExtendedValidation(bool* aIsEV) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::ToString(nsACString& aResult) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+void FuzzySecurityInfo::SerializeToIPC(IPC::MessageWriter* aWriter) {
+  MOZ_CRASH("Unused");
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetNegotiatedNPN(nsACString& aNegotiatedNPN) {
+  aNegotiatedNPN.Assign("h2");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetResumed(bool* aResumed) {
+  *aResumed = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP FuzzySecurityInfo::GetIsBuiltCertChainRootBuiltInRoot(
+    bool* aIsBuiltInRoot) {
+  *aIsBuiltInRoot = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySecurityInfo::GetPeerId(nsACString& aResult) {
+  aResult.Assign(""_ns);
+  return NS_OK;
+}
+
+}  // namespace net
+
+}  // namespace mozilla
diff --git a/netwerk/base/FuzzySecurityInfo.h b/netwerk/base/FuzzySecurityInfo.h
new file mode 100644
index 0000000000..121c6c8ba9
--- /dev/null
+++ b/netwerk/base/FuzzySecurityInfo.h
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef FuzzySecurityInfo_h__
+#define FuzzySecurityInfo_h__
+
+#include "nsCOMPtr.h"
+#include "nsITransportSecurityInfo.h"
+
+namespace mozilla {
+namespace net {
+
+class FuzzySecurityInfo final : public nsITransportSecurityInfo {
+ public:
+  FuzzySecurityInfo();
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITRANSPORTSECURITYINFO
+
+ protected:
+  virtual ~FuzzySecurityInfo();
+};  // class FuzzySecurityInfo
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // FuzzySecurityInfo_h__
diff --git a/netwerk/base/FuzzySocketControl.cpp b/netwerk/base/FuzzySocketControl.cpp
new file mode 100644
index 0000000000..ec24d1da6b
--- /dev/null
+++ b/netwerk/base/FuzzySocketControl.cpp
@@ -0,0 +1,185 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FuzzySocketControl.h"
+
+#include "FuzzySecurityInfo.h"
+#include "ipc/IPCMessageUtils.h"
+#include "nsITlsHandshakeListener.h"
+#include "sslt.h"
+
+namespace mozilla {
+namespace net {
+
+FuzzySocketControl::FuzzySocketControl() {}
+
+FuzzySocketControl::~FuzzySocketControl() {}
+
+NS_IMPL_ISUPPORTS(FuzzySocketControl, nsITLSSocketControl)
+
+NS_IMETHODIMP
+FuzzySocketControl::GetProviderFlags(uint32_t* aProviderFlags) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetKEAUsed(int16_t* aKea) {
+  // Can be ssl_kea_dh or ssl_kea_ecdh for HTTP2
+  *aKea = ssl_kea_ecdh;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetKEAKeyBits(uint32_t* aKeyBits) {
+  // Must be >= 224 for ecdh and >= 2048 for dh when using HTTP2
+  *aKeyBits = 256;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetSSLVersionUsed(int16_t* aSSLVersionUsed) {
+  // Must be >= TLS 1.2 for HTTP2
+  *aSSLVersionUsed = nsITLSSocketControl::TLS_VERSION_1_2;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetSSLVersionOffered(int16_t* aSSLVersionOffered) {
+  *aSSLVersionOffered = nsITLSSocketControl::TLS_VERSION_1_2;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetMACAlgorithmUsed(int16_t* aMac) {
+  // The only valid choice for HTTP2 is SSL_MAC_AEAD
+  *aMac = nsITLSSocketControl::SSL_MAC_AEAD;
+  return NS_OK;
+}
+
+bool FuzzySocketControl::GetDenyClientCert() { return false; }
+
+void FuzzySocketControl::SetDenyClientCert(bool aDenyClientCert) {
+  // Called by mozilla::net::nsHttpConnection::StartSpdy
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetClientCertSent(bool* arg) {
+  *arg = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetFailedVerification(bool* arg) {
+  *arg = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetAlpnEarlySelection(nsACString& aAlpnSelected) {
+  // TODO: For now we don't support early selection
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetEarlyDataAccepted(bool* aAccepted) {
+  *aAccepted = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::DriveHandshake() { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::IsAcceptableForHost(const nsACString& hostname,
+                                        bool* _retval) {
+  NS_ENSURE_ARG(_retval);
+  *_retval = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::TestJoinConnection(const nsACString& npnProtocol,
+                                       const nsACString& hostname, int32_t port,
+                                       bool* _retval) {
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::JoinConnection(const nsACString& npnProtocol,
+                                   const nsACString& hostname, int32_t port,
+                                   bool* _retval) {
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::ProxyStartSSL() { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::StartTLS() { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::SetNPNList(nsTArray<nsCString>& protocolArray) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetEsniTxt(nsACString& aEsniTxt) { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::SetEsniTxt(const nsACString& aEsniTxt) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetEchConfig(nsACString& aEchConfig) { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::SetEchConfig(const nsACString& aEchConfig) {
+  MOZ_CRASH("Unused");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::GetRetryEchConfig(nsACString& aEchConfig) { return NS_OK; }
+
+NS_IMETHODIMP
+FuzzySocketControl::GetPeerId(nsACString& aResult) {
+  aResult.Assign(""_ns);
+  return NS_OK;
+}
+
+NS_IMETHODIMP FuzzySocketControl::SetHandshakeCallbackListener(
+    nsITlsHandshakeCallbackListener* callback) {
+  if (callback) {
+    callback->HandshakeDone();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::DisableEarlyData(void) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP FuzzySocketControl::GetSecurityInfo(
+    nsITransportSecurityInfo** aSecurityInfo) {
+  nsCOMPtr<nsITransportSecurityInfo> securityInfo(new FuzzySecurityInfo());
+  securityInfo.forget(aSecurityInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FuzzySocketControl::AsyncGetSecurityInfo(JSContext* aCx,
+                                         mozilla::dom::Promise** aPromise) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP FuzzySocketControl::Claim() { return NS_OK; }
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/FuzzySocketControl.h b/netwerk/base/FuzzySocketControl.h
new file mode 100644
index 0000000000..9debbe32e8
--- /dev/null
+++ b/netwerk/base/FuzzySocketControl.h
@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef FuzzySocketControl_h__
+#define FuzzySocketControl_h__
+
+#include "nsITLSSocketControl.h"
+
+namespace mozilla {
+namespace net {
+
+class FuzzySocketControl final : public nsITLSSocketControl {
+ public:
+  FuzzySocketControl();
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITLSSOCKETCONTROL
+
+ protected:
+  virtual ~FuzzySocketControl();
+};  // class FuzzySocketControl
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // FuzzySocketControl_h__
diff --git a/netwerk/base/IOActivityMonitor.cpp b/netwerk/base/IOActivityMonitor.cpp
new file mode 100644
index 0000000000..76047a7a00
--- /dev/null
+++ b/netwerk/base/IOActivityMonitor.cpp
@@ -0,0 +1,495 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "IOActivityMonitor.h"
+#include "nsPrintfCString.h"
+#include "nsSocketTransport2.h"
+#include "nsSocketTransportService2.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/Promise.h"
+#include "prerror.h"
+#include "prio.h"
+#include "prmem.h"
+#include <vector>
+
+using namespace mozilla;
+using namespace mozilla::net;
+
+mozilla::StaticRefPtr<IOActivityMonitor> gInstance;
+static Atomic<bool> gActivated(false);
+static PRDescIdentity sNetActivityMonitorLayerIdentity;
+static PRIOMethods sNetActivityMonitorLayerMethods;
+static PRIOMethods* sNetActivityMonitorLayerMethodsPtr = nullptr;
+
+// Maximum number of activities entries in the monitoring class
+#define MAX_ACTIVITY_ENTRIES 1000
+
+// ActivityMonitorSecret is stored in the activity monitor layer
+// and provides a method to get the location.
+//
+// A location can be :
+// - a TCP or UDP socket. The form will be socket://ip:port
+// - a File. The form will be file://path
+//
+// For other cases, the location will be fd://number
+class ActivityMonitorSecret final {
+ public:
+  // constructor used for sockets
+  explicit ActivityMonitorSecret(PRFileDesc* aFd) {
+    mFd = aFd;
+    mLocationSet = false;
+  }
+
+  // constructor used for files
+  explicit ActivityMonitorSecret(PRFileDesc* aFd, const char* aLocation) {
+    mFd = aFd;
+    mLocation.AppendPrintf("file://%s", aLocation);
+    mLocationSet = true;
+  }
+
+  nsCString getLocation() {
+    if (!mLocationSet) {
+      LazySetLocation();
+    }
+    return mLocation;
+  }
+
+ private:
+  // Called to set the location using the FD on the first getLocation() usage
+  // which is typically when a socket is opened. If done earlier, at
+  // construction time, the host won't be bound yet.
+  //
+  // If the location is a file, it needs to be initialized in the
+  // constructor.
+  void LazySetLocation() {
+    mLocationSet = true;
+    PRFileDesc* extract = mFd;
+    while (PR_GetDescType(extract) == PR_DESC_LAYERED) {
+      if (!extract->lower) {
+        break;
+      }
+      extract = extract->lower;
+    }
+
+    PRDescType fdType = PR_GetDescType(extract);
+    // we should not use LazySetLocation for files
+    MOZ_ASSERT(fdType != PR_DESC_FILE);
+
+    switch (fdType) {
+      case PR_DESC_SOCKET_TCP:
+      case PR_DESC_SOCKET_UDP: {
+        mLocation.AppendPrintf("socket://");
+        PRNetAddr addr;
+        PRStatus status = PR_GetSockName(mFd, &addr);
+        if (NS_WARN_IF(status == PR_FAILURE)) {
+          mLocation.AppendPrintf("unknown");
+          break;
+        }
+
+        // grabbing the host
+        char netAddr[mozilla::net::kNetAddrMaxCStrBufSize] = {0};
+        status = PR_NetAddrToString(&addr, netAddr, sizeof(netAddr) - 1);
+        if (NS_WARN_IF(status == PR_FAILURE) || netAddr[0] == 0) {
+          mLocation.AppendPrintf("unknown");
+          break;
+        }
+        mLocation.Append(netAddr);
+
+        // adding the port
+        uint16_t port;
+        if (addr.raw.family == PR_AF_INET) {
+          port = addr.inet.port;
+        } else {
+          port = addr.ipv6.port;
+        }
+        mLocation.AppendPrintf(":%d", port);
+      } break;
+
+      // for all other cases, we just send back fd://<value>
+      default: {
+        mLocation.AppendLiteral("fd://");
+        mLocation.AppendInt(PR_FileDesc2NativeHandle(mFd));
+      }
+    }  // end switch
+  }
+
+ private:
+  nsCString mLocation;
+  bool mLocationSet;
+  PRFileDesc* mFd;
+};
+
+// FileDesc2Location converts a PRFileDesc into a "location" by
+// grabbing the ActivityMonitorSecret in layer->secret
+static nsAutoCString FileDesc2Location(PRFileDesc* fd) {
+  nsAutoCString location;
+  PRFileDesc* monitorLayer =
+      PR_GetIdentitiesLayer(fd, sNetActivityMonitorLayerIdentity);
+  if (!monitorLayer) {
+    location.AppendPrintf("unknown");
+    return location;
+  }
+
+  ActivityMonitorSecret* secret = (ActivityMonitorSecret*)monitorLayer->secret;
+  location.AppendPrintf("%s", secret->getLocation().get());
+  return location;
+}
+
+//
+// Wrappers around the socket APIS
+//
+static PRStatus nsNetMon_Connect(PRFileDesc* fd, const PRNetAddr* addr,
+                                 PRIntervalTime timeout) {
+  return fd->lower->methods->connect(fd->lower, addr, timeout);
+}
+
+static PRStatus nsNetMon_Close(PRFileDesc* fd) {
+  if (!fd) {
+    return PR_FAILURE;
+  }
+  PRFileDesc* layer = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
+  MOZ_RELEASE_ASSERT(
+      layer && layer->identity == sNetActivityMonitorLayerIdentity,
+      "NetActivityMonitor Layer not on top of stack");
+
+  if (layer->secret) {
+    delete (ActivityMonitorSecret*)layer->secret;
+    layer->secret = nullptr;
+  }
+  layer->dtor(layer);
+  return fd->methods->close(fd);
+}
+
+static int32_t nsNetMon_Read(PRFileDesc* fd, void* buf, int32_t len) {
+  int32_t ret = fd->lower->methods->read(fd->lower, buf, len);
+  if (ret >= 0) {
+    IOActivityMonitor::Read(fd, len);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_Write(PRFileDesc* fd, const void* buf, int32_t len) {
+  int32_t ret = fd->lower->methods->write(fd->lower, buf, len);
+  if (ret > 0) {
+    IOActivityMonitor::Write(fd, len);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_Writev(PRFileDesc* fd, const PRIOVec* iov, int32_t size,
+                               PRIntervalTime timeout) {
+  int32_t ret = fd->lower->methods->writev(fd->lower, iov, size, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Write(fd, size);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_Recv(PRFileDesc* fd, void* buf, int32_t amount,
+                             int flags, PRIntervalTime timeout) {
+  int32_t ret =
+      fd->lower->methods->recv(fd->lower, buf, amount, flags, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Read(fd, amount);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_Send(PRFileDesc* fd, const void* buf, int32_t amount,
+                             int flags, PRIntervalTime timeout) {
+  int32_t ret =
+      fd->lower->methods->send(fd->lower, buf, amount, flags, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Write(fd, amount);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_RecvFrom(PRFileDesc* fd, void* buf, int32_t amount,
+                                 int flags, PRNetAddr* addr,
+                                 PRIntervalTime timeout) {
+  int32_t ret = fd->lower->methods->recvfrom(fd->lower, buf, amount, flags,
+                                             addr, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Read(fd, amount);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_SendTo(PRFileDesc* fd, const void* buf, int32_t amount,
+                               int flags, const PRNetAddr* addr,
+                               PRIntervalTime timeout) {
+  int32_t ret =
+      fd->lower->methods->sendto(fd->lower, buf, amount, flags, addr, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Write(fd, amount);
+  }
+  return ret;
+}
+
+static int32_t nsNetMon_AcceptRead(PRFileDesc* listenSock,
+                                   PRFileDesc** acceptedSock,
+                                   PRNetAddr** peerAddr, void* buf,
+                                   int32_t amount, PRIntervalTime timeout) {
+  int32_t ret = listenSock->lower->methods->acceptread(
+      listenSock->lower, acceptedSock, peerAddr, buf, amount, timeout);
+  if (ret > 0) {
+    IOActivityMonitor::Read(listenSock, amount);
+  }
+  return ret;
+}
+
+//
+// Class IOActivityMonitor
+//
+NS_IMPL_ISUPPORTS(IOActivityMonitor, nsINamed)
+
+IOActivityMonitor::IOActivityMonitor() : mLock("IOActivityMonitor::mLock") {
+  RefPtr<IOActivityMonitor> mon(gInstance);
+  MOZ_ASSERT(!mon, "multiple IOActivityMonitor instances!");
+}
+
+// static
+void IOActivityMonitor::RequestActivities(dom::Promise* aPromise) {
+  MOZ_ASSERT(aPromise);
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    aPromise->MaybeReject(NS_ERROR_FAILURE);
+    return;
+  }
+
+  mon->RequestActivitiesInternal(aPromise);
+}
+
+void IOActivityMonitor::RequestActivitiesInternal(dom::Promise* aPromise) {
+  nsresult result = NS_OK;
+  FallibleTArray<dom::IOActivityDataDictionary> activities;
+
+  {
+    mozilla::MutexAutoLock lock(mLock);
+    // Remove inactive activities
+    for (auto iter = mActivities.Iter(); !iter.Done(); iter.Next()) {
+      dom::IOActivityDataDictionary* activity = &iter.Data();
+      if (activity->mRx == 0 && activity->mTx == 0) {
+        iter.Remove();
+      } else {
+        if (NS_WARN_IF(!activities.AppendElement(iter.Data(), fallible))) {
+          result = NS_ERROR_OUT_OF_MEMORY;
+          break;
+        }
+      }
+    }
+  }
+
+  if (NS_WARN_IF(NS_FAILED(result))) {
+    aPromise->MaybeReject(result);
+    return;
+  }
+  aPromise->MaybeResolve(activities);
+}
+
+NS_IMETHODIMP
+IOActivityMonitor::GetName(nsACString& aName) {
+  aName.AssignLiteral("IOActivityMonitor");
+  return NS_OK;
+}
+
+// static
+bool IOActivityMonitor::IsActive() { return gActivated; }
+
+// static
+already_AddRefed<IOActivityMonitor> IOActivityMonitor::Get() {
+  if (!gActivated) {
+    return nullptr;
+  }
+
+  RefPtr<IOActivityMonitor> mon = gInstance;
+  return mon.forget();
+}
+
+nsresult IOActivityMonitor::Init() {
+  if (IsActive()) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+  RefPtr<IOActivityMonitor> mon = new IOActivityMonitor();
+  nsresult rv = mon->InitInternal();
+  if (NS_SUCCEEDED(rv)) {
+    gInstance = mon;
+    ClearOnShutdown(&gInstance);
+    gActivated = true;
+  }
+  return rv;
+}
+
+nsresult IOActivityMonitor::InitInternal() {
+  // wraps the socket APIs
+  if (!sNetActivityMonitorLayerMethodsPtr) {
+    sNetActivityMonitorLayerIdentity =
+        PR_GetUniqueIdentity("network activity monitor layer");
+    sNetActivityMonitorLayerMethods = *PR_GetDefaultIOMethods();
+    sNetActivityMonitorLayerMethods.connect = nsNetMon_Connect;
+    sNetActivityMonitorLayerMethods.read = nsNetMon_Read;
+    sNetActivityMonitorLayerMethods.write = nsNetMon_Write;
+    sNetActivityMonitorLayerMethods.writev = nsNetMon_Writev;
+    sNetActivityMonitorLayerMethods.recv = nsNetMon_Recv;
+    sNetActivityMonitorLayerMethods.send = nsNetMon_Send;
+    sNetActivityMonitorLayerMethods.recvfrom = nsNetMon_RecvFrom;
+    sNetActivityMonitorLayerMethods.sendto = nsNetMon_SendTo;
+    sNetActivityMonitorLayerMethods.acceptread = nsNetMon_AcceptRead;
+    sNetActivityMonitorLayerMethods.close = nsNetMon_Close;
+    sNetActivityMonitorLayerMethodsPtr = &sNetActivityMonitorLayerMethods;
+  }
+
+  return NS_OK;
+}
+
+nsresult IOActivityMonitor::Shutdown() {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  return mon->ShutdownInternal();
+}
+
+nsresult IOActivityMonitor::ShutdownInternal() {
+  mozilla::MutexAutoLock lock(mLock);
+  mActivities.Clear();
+  gActivated = false;
+  return NS_OK;
+}
+
+nsresult IOActivityMonitor::MonitorSocket(PRFileDesc* aFd) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_OK;
+  }
+  PRFileDesc* layer;
+  PRStatus status;
+  layer = PR_CreateIOLayerStub(sNetActivityMonitorLayerIdentity,
+                               sNetActivityMonitorLayerMethodsPtr);
+  if (!layer) {
+    return NS_ERROR_FAILURE;
+  }
+
+  ActivityMonitorSecret* secret = new ActivityMonitorSecret(aFd);
+  layer->secret = reinterpret_cast<PRFilePrivate*>(secret);
+  status = PR_PushIOLayer(aFd, PR_NSPR_IO_LAYER, layer);
+
+  if (status == PR_FAILURE) {
+    delete secret;
+    PR_Free(layer);  // PR_CreateIOLayerStub() uses PR_Malloc().
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult IOActivityMonitor::MonitorFile(PRFileDesc* aFd, const char* aPath) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_OK;
+  }
+  PRFileDesc* layer;
+  PRStatus status;
+  layer = PR_CreateIOLayerStub(sNetActivityMonitorLayerIdentity,
+                               sNetActivityMonitorLayerMethodsPtr);
+  if (!layer) {
+    return NS_ERROR_FAILURE;
+  }
+
+  ActivityMonitorSecret* secret = new ActivityMonitorSecret(aFd, aPath);
+  layer->secret = reinterpret_cast<PRFilePrivate*>(secret);
+
+  status = PR_PushIOLayer(aFd, PR_NSPR_IO_LAYER, layer);
+  if (status == PR_FAILURE) {
+    delete secret;
+    PR_Free(layer);  // PR_CreateIOLayerStub() uses PR_Malloc().
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+bool IOActivityMonitor::IncrementActivity(const nsACString& aLocation,
+                                          uint32_t aRx, uint32_t aTx) {
+  mLock.AssertCurrentThreadOwns();
+  return mActivities.WithEntryHandle(aLocation, fallible, [&](auto&& entry) {
+    if (!entry) return false;
+
+    if (*entry) {
+      // already registered
+      entry->Data().mTx += aTx;
+      entry->Data().mRx += aRx;
+    } else {
+      // Creating a new IOActivity. Notice that mActivities
+      // will grow indefinitely, which is OK since we won't
+      // have but a few hundreds entries at the most, but we
+      // want to assert we have at the most 1000 entries
+      MOZ_ASSERT(mActivities.Count() <= MAX_ACTIVITY_ENTRIES);
+
+      dom::IOActivityDataDictionary activity;
+      activity.mLocation.Assign(aLocation);
+      activity.mTx = aTx;
+      activity.mRx = aRx;
+
+      entry->Insert(std::move(activity));
+    }
+
+    return true;
+  });
+}
+
+nsresult IOActivityMonitor::Write(const nsACString& aLocation,
+                                  uint32_t aAmount) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_ERROR_FAILURE;
+  }
+  return mon->WriteInternal(aLocation, aAmount);
+}
+
+nsresult IOActivityMonitor::Write(PRFileDesc* fd, uint32_t aAmount) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_ERROR_FAILURE;
+  }
+  return mon->Write(FileDesc2Location(fd), aAmount);
+}
+
+nsresult IOActivityMonitor::WriteInternal(const nsACString& aLocation,
+                                          uint32_t aAmount) {
+  mozilla::MutexAutoLock lock(mLock);
+  if (!IncrementActivity(aLocation, aAmount, 0)) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult IOActivityMonitor::Read(PRFileDesc* fd, uint32_t aAmount) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_ERROR_FAILURE;
+  }
+  return mon->Read(FileDesc2Location(fd), aAmount);
+}
+
+nsresult IOActivityMonitor::Read(const nsACString& aLocation,
+                                 uint32_t aAmount) {
+  RefPtr<IOActivityMonitor> mon = IOActivityMonitor::Get();
+  if (!mon) {
+    return NS_ERROR_FAILURE;
+  }
+  return mon->ReadInternal(aLocation, aAmount);
+}
+
+nsresult IOActivityMonitor::ReadInternal(const nsACString& aLocation,
+                                         uint32_t aAmount) {
+  mozilla::MutexAutoLock lock(mLock);
+  if (!IncrementActivity(aLocation, 0, aAmount)) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
diff --git a/netwerk/base/IOActivityMonitor.h b/netwerk/base/IOActivityMonitor.h
new file mode 100644
index 0000000000..5e46bc9bfc
--- /dev/null
+++ b/netwerk/base/IOActivityMonitor.h
@@ -0,0 +1,83 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef IOActivityMonitor_h___
+#define IOActivityMonitor_h___
+
+#include "mozilla/dom/ChromeUtilsBinding.h"
+#include "mozilla/Mutex.h"
+#include "nsCOMPtr.h"
+#include "nscore.h"
+#include "nsClassHashtable.h"
+#include "nsTHashMap.h"
+#include "nsHashKeys.h"
+#include "nsINamed.h"
+#include "nsISupports.h"
+#include "prinrval.h"
+#include "prio.h"
+#include "private/pprio.h"
+#include <stdint.h>
+
+namespace mozilla {
+
+namespace dom {
+class Promise;
+}
+
+namespace net {
+
+#define IO_ACTIVITY_ENABLED_PREF "io.activity.enabled"
+
+using Activities = nsTHashMap<nsCStringHashKey, dom::IOActivityDataDictionary>;
+
+// IOActivityMonitor has several roles:
+// - maintains an IOActivity per resource and updates it
+// - sends a dump of the activities to a promise via RequestActivities
+class IOActivityMonitor final : public nsINamed {
+ public:
+  IOActivityMonitor();
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSINAMED
+
+  // initializes and destroys the singleton
+  static nsresult Init();
+  static nsresult Shutdown();
+
+  // collect amounts of data that are written/read by location
+  static nsresult Read(const nsACString& location, uint32_t aAmount);
+  static nsresult Write(const nsACString& location, uint32_t aAmount);
+
+  static nsresult MonitorFile(PRFileDesc* aFd, const char* aPath);
+  static nsresult MonitorSocket(PRFileDesc* aFd);
+  static nsresult Read(PRFileDesc* fd, uint32_t aAmount);
+  static nsresult Write(PRFileDesc* fd, uint32_t aAmount);
+
+  static bool IsActive();
+  static void RequestActivities(dom::Promise* aPromise);
+
+ private:
+  ~IOActivityMonitor() = default;
+
+  static already_AddRefed<IOActivityMonitor> Get();
+
+  nsresult InitInternal();
+  nsresult ShutdownInternal();
+  bool IncrementActivity(const nsACString& location, uint32_t aRx,
+                         uint32_t aTx);
+  nsresult WriteInternal(const nsACString& location, uint32_t aAmount);
+  nsresult ReadInternal(const nsACString& location, uint32_t aAmount);
+  void RequestActivitiesInternal(dom::Promise* aPromise);
+
+  Activities mActivities;
+  // protects mActivities accesses
+  Mutex mLock MOZ_UNANNOTATED;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif /* IOActivityMonitor_h___ */
diff --git a/netwerk/base/IPv6Utils.h b/netwerk/base/IPv6Utils.h
new file mode 100644
index 0000000000..437c0befec
--- /dev/null
+++ b/netwerk/base/IPv6Utils.h
@@ -0,0 +1,50 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NETWORK_IPV6_UTILS_H_
+#define NETWORK_IPV6_UTILS_H_
+
+namespace mozilla {
+namespace net {
+namespace utils {
+
+// IPv6 address scopes.
+#define IPV6_SCOPE_GLOBAL 0       // Global scope.
+#define IPV6_SCOPE_LINKLOCAL 1    // Link-local scope.
+#define IPV6_SCOPE_SITELOCAL 2    // Site-local scope (deprecated).
+#define IPV6_SCOPE_UNIQUELOCAL 3  // Unique local
+#define IPV6_SCOPE_NODELOCAL 4    // Loopback
+
+// Return the scope of the given address.
+static int ipv6_scope(const unsigned char addr[16]) {
+  const unsigned char* b = addr;
+  unsigned short w = (unsigned short)((b[0] << 8) | b[1]);
+
+  if ((b[0] & 0xFE) == 0xFC) {
+    return IPV6_SCOPE_UNIQUELOCAL;
+  }
+  switch (w & 0xFFC0) {
+    case 0xFE80:
+      return IPV6_SCOPE_LINKLOCAL;
+    case 0xFEC0:
+      return IPV6_SCOPE_SITELOCAL;
+    case 0x0000:
+      w = b[1] | b[2] | b[3] | b[4] | b[5] | b[6] | b[7] | b[8] | b[9] | b[10] |
+          b[11] | b[12] | b[13] | b[14];
+      if (w || b[15] != 0x01) {
+        break;
+      }
+      return IPV6_SCOPE_NODELOCAL;
+    default:
+      break;
+  }
+
+  return IPV6_SCOPE_GLOBAL;
+}
+
+}  // namespace utils
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // NETWORK_IPV6_UTILS_H_
diff --git a/netwerk/base/InterceptionInfo.cpp b/netwerk/base/InterceptionInfo.cpp
new file mode 100644
index 0000000000..977ec02e47
--- /dev/null
+++ b/netwerk/base/InterceptionInfo.cpp
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/net/InterceptionInfo.h"
+#include "nsContentUtils.h"
+
+namespace mozilla::net {
+
+NS_IMPL_ISUPPORTS(InterceptionInfo, nsIInterceptionInfo)
+
+InterceptionInfo::InterceptionInfo(nsIPrincipal* aTriggeringPrincipal,
+                                   nsContentPolicyType aContentPolicyType,
+                                   const RedirectHistoryArray& aRedirectChain,
+                                   bool aFromThirdParty)
+    : mTriggeringPrincipal(aTriggeringPrincipal),
+      mContentPolicyType(aContentPolicyType),
+      mFromThirdParty(aFromThirdParty) {
+  SetRedirectChain(aRedirectChain);
+}
+
+nsIPrincipal* InterceptionInfo::TriggeringPrincipal() {
+  return mTriggeringPrincipal;
+}
+
+void InterceptionInfo::SetTriggeringPrincipal(nsIPrincipal* aPrincipal) {
+  mTriggeringPrincipal = aPrincipal;
+}
+
+nsContentPolicyType InterceptionInfo::ContentPolicyType() {
+  return mContentPolicyType;
+}
+
+nsContentPolicyType InterceptionInfo::ExternalContentPolicyType() {
+  return static_cast<nsContentPolicyType>(
+      nsContentUtils::InternalContentPolicyTypeToExternal(mContentPolicyType));
+}
+
+void InterceptionInfo::SetContentPolicyType(
+    const nsContentPolicyType aContentPolicyType) {
+  mContentPolicyType = aContentPolicyType;
+}
+
+const RedirectHistoryArray& InterceptionInfo::RedirectChain() {
+  return mRedirectChain;
+}
+
+void InterceptionInfo::SetRedirectChain(
+    const RedirectHistoryArray& aRedirectChain) {
+  for (auto entry : aRedirectChain) {
+    mRedirectChain.AppendElement(entry);
+  }
+}
+
+bool InterceptionInfo::FromThirdParty() { return mFromThirdParty; }
+
+void InterceptionInfo::SetFromThirdParty(bool aFromThirdParty) {
+  mFromThirdParty = aFromThirdParty;
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/InterceptionInfo.h b/netwerk/base/InterceptionInfo.h
new file mode 100644
index 0000000000..ad2f2a4499
--- /dev/null
+++ b/netwerk/base/InterceptionInfo.h
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_InterceptionInfo_h
+#define mozilla_net_InterceptionInfo_h
+
+#include "nsIContentSecurityPolicy.h"
+#include "nsIInterceptionInfo.h"
+#include "nsIPrincipal.h"
+#include "nsIRedirectHistoryEntry.h"
+#include "nsTArray.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla::net {
+
+using RedirectHistoryArray = nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>;
+
+class InterceptionInfo final : public nsIInterceptionInfo {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINTERCEPTIONINFO
+
+  InterceptionInfo(nsIPrincipal* aTriggeringPrincipal,
+                   nsContentPolicyType aContentPolicyType,
+                   const RedirectHistoryArray& aRedirectChain,
+                   bool aFromThirdParty);
+
+  using nsIInterceptionInfo::GetExtContentPolicyType;
+
+ private:
+  ~InterceptionInfo() = default;
+
+  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+  nsContentPolicyType mContentPolicyType{nsIContentPolicy::TYPE_INVALID};
+  RedirectHistoryArray mRedirectChain;
+  bool mFromThirdParty = false;
+};
+
+}  // namespace mozilla::net
+
+#endif
diff --git a/netwerk/base/LoadContextInfo.cpp b/netwerk/base/LoadContextInfo.cpp
new file mode 100644
index 0000000000..d544bf7275
--- /dev/null
+++ b/netwerk/base/LoadContextInfo.cpp
@@ -0,0 +1,168 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "LoadContextInfo.h"
+
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/StoragePrincipalHelper.h"
+#include "nsDocShell.h"
+#include "nsIChannel.h"
+#include "nsILoadContext.h"
+#include "nsIWebNavigation.h"
+#include "nsNetUtil.h"
+
+using namespace mozilla::dom;
+namespace mozilla {
+namespace net {
+
+// LoadContextInfo
+
+NS_IMPL_ISUPPORTS(LoadContextInfo, nsILoadContextInfo)
+
+LoadContextInfo::LoadContextInfo(bool aIsAnonymous,
+                                 OriginAttributes aOriginAttributes)
+    : mIsAnonymous(aIsAnonymous),
+      mOriginAttributes(std::move(aOriginAttributes)) {}
+
+NS_IMETHODIMP LoadContextInfo::GetIsPrivate(bool* aIsPrivate) {
+  *aIsPrivate = mOriginAttributes.mPrivateBrowsingId > 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfo::GetIsAnonymous(bool* aIsAnonymous) {
+  *aIsAnonymous = mIsAnonymous;
+  return NS_OK;
+}
+
+OriginAttributes const* LoadContextInfo::OriginAttributesPtr() {
+  return &mOriginAttributes;
+}
+
+NS_IMETHODIMP LoadContextInfo::GetOriginAttributes(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aVal) {
+  if (NS_WARN_IF(!ToJSValue(aCx, mOriginAttributes, aVal))) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+// LoadContextInfoFactory
+
+NS_IMPL_ISUPPORTS(LoadContextInfoFactory, nsILoadContextInfoFactory)
+
+NS_IMETHODIMP LoadContextInfoFactory::GetDefault(
+    nsILoadContextInfo** aDefault) {
+  nsCOMPtr<nsILoadContextInfo> info =
+      GetLoadContextInfo(false, OriginAttributes());
+  info.forget(aDefault);
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfoFactory::GetPrivate(
+    nsILoadContextInfo** aPrivate) {
+  OriginAttributes attrs;
+  attrs.SyncAttributesWithPrivateBrowsing(true);
+  nsCOMPtr<nsILoadContextInfo> info = GetLoadContextInfo(false, attrs);
+  info.forget(aPrivate);
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfoFactory::GetAnonymous(
+    nsILoadContextInfo** aAnonymous) {
+  nsCOMPtr<nsILoadContextInfo> info =
+      GetLoadContextInfo(true, OriginAttributes());
+  info.forget(aAnonymous);
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfoFactory::Custom(
+    bool aAnonymous, JS::Handle<JS::Value> aOriginAttributes, JSContext* cx,
+    nsILoadContextInfo** _retval) {
+  OriginAttributes attrs;
+  bool status = attrs.Init(cx, aOriginAttributes);
+  NS_ENSURE_TRUE(status, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsILoadContextInfo> info = GetLoadContextInfo(aAnonymous, attrs);
+  info.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfoFactory::FromLoadContext(
+    nsILoadContext* aLoadContext, bool aAnonymous,
+    nsILoadContextInfo** _retval) {
+  nsCOMPtr<nsILoadContextInfo> info =
+      GetLoadContextInfo(aLoadContext, aAnonymous);
+  info.forget(_retval);
+  return NS_OK;
+}
+
+NS_IMETHODIMP LoadContextInfoFactory::FromWindow(nsIDOMWindow* aWindow,
+                                                 bool aAnonymous,
+                                                 nsILoadContextInfo** _retval) {
+  nsCOMPtr<nsILoadContextInfo> info = GetLoadContextInfo(aWindow, aAnonymous);
+  info.forget(_retval);
+  return NS_OK;
+}
+
+// Helper functions
+
+LoadContextInfo* GetLoadContextInfo(nsIChannel* aChannel) {
+  nsresult rv;
+
+  DebugOnly<bool> pb = NS_UsePrivateBrowsing(aChannel);
+
+  bool anon = false;
+  nsLoadFlags loadFlags;
+  rv = aChannel->GetLoadFlags(&loadFlags);
+  if (NS_SUCCEEDED(rv)) {
+    anon = !!(loadFlags & nsIChannel::LOAD_ANONYMOUS);
+  }
+
+  OriginAttributes oa;
+  StoragePrincipalHelper::GetOriginAttributesForNetworkState(aChannel, oa);
+  MOZ_ASSERT(pb == (oa.mPrivateBrowsingId > 0));
+
+  return new LoadContextInfo(anon, oa);
+}
+
+LoadContextInfo* GetLoadContextInfo(nsILoadContext* aLoadContext,
+                                    bool aIsAnonymous) {
+  if (!aLoadContext) {
+    return new LoadContextInfo(aIsAnonymous, OriginAttributes());
+  }
+
+  OriginAttributes oa;
+  aLoadContext->GetOriginAttributes(oa);
+
+#ifdef DEBUG
+  nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(aLoadContext);
+  if (!docShell ||
+      nsDocShell::Cast(docShell)->GetBrowsingContext()->IsContent()) {
+    MOZ_ASSERT(aLoadContext->UsePrivateBrowsing() ==
+               (oa.mPrivateBrowsingId > 0));
+  }
+#endif
+
+  return new LoadContextInfo(aIsAnonymous, oa);
+}
+
+LoadContextInfo* GetLoadContextInfo(nsIDOMWindow* aWindow, bool aIsAnonymous) {
+  nsCOMPtr<nsIWebNavigation> webNav = do_GetInterface(aWindow);
+  nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(webNav);
+
+  return GetLoadContextInfo(loadContext, aIsAnonymous);
+}
+
+LoadContextInfo* GetLoadContextInfo(nsILoadContextInfo* aInfo) {
+  return new LoadContextInfo(aInfo->IsAnonymous(),
+                             *aInfo->OriginAttributesPtr());
+}
+
+LoadContextInfo* GetLoadContextInfo(bool const aIsAnonymous,
+                                    OriginAttributes const& aOriginAttributes) {
+  return new LoadContextInfo(aIsAnonymous, aOriginAttributes);
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/LoadContextInfo.h b/netwerk/base/LoadContextInfo.h
new file mode 100644
index 0000000000..efaf912db4
--- /dev/null
+++ b/netwerk/base/LoadContextInfo.h
@@ -0,0 +1,54 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsLoadContextInfo_h__
+#define nsLoadContextInfo_h__
+
+#include "nsILoadContextInfo.h"
+
+class nsIChannel;
+class nsILoadContext;
+
+namespace mozilla {
+namespace net {
+
+class LoadContextInfo final : public nsILoadContextInfo {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSILOADCONTEXTINFO
+
+  LoadContextInfo(bool aIsAnonymous, OriginAttributes aOriginAttributes);
+
+ private:
+  virtual ~LoadContextInfo() = default;
+
+ protected:
+  bool mIsAnonymous : 1;
+  OriginAttributes mOriginAttributes;
+};
+
+class LoadContextInfoFactory : public nsILoadContextInfoFactory {
+  virtual ~LoadContextInfoFactory() = default;
+
+ public:
+  NS_DECL_ISUPPORTS  // deliberately not thread-safe
+      NS_DECL_NSILOADCONTEXTINFOFACTORY
+};
+
+LoadContextInfo* GetLoadContextInfo(nsIChannel* aChannel);
+
+LoadContextInfo* GetLoadContextInfo(nsILoadContext* aLoadContext,
+                                    bool aIsAnonymous);
+
+LoadContextInfo* GetLoadContextInfo(nsIDOMWindow* aWindow, bool aIsAnonymous);
+
+LoadContextInfo* GetLoadContextInfo(nsILoadContextInfo* aInfo);
+
+LoadContextInfo* GetLoadContextInfo(bool const aIsAnonymous,
+                                    OriginAttributes const& aOriginAttributes);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/LoadInfo.cpp b/netwerk/base/LoadInfo.cpp
new file mode 100644
index 0000000000..e840a708fd
--- /dev/null
+++ b/netwerk/base/LoadInfo.cpp
@@ -0,0 +1,2282 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/LoadInfo.h"
+
+#include "js/Array.h"               // JS::NewArrayObject
+#include "js/PropertyAndElement.h"  // JS_DefineElement
+#include "mozilla/Assertions.h"
+#include "mozilla/ExpandedPrincipal.h"
+#include "mozilla/dom/CanonicalBrowsingContext.h"
+#include "mozilla/dom/ClientIPCTypes.h"
+#include "mozilla/dom/ClientSource.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/Performance.h"
+#include "mozilla/dom/PerformanceStorage.h"
+#include "mozilla/dom/BrowserChild.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/dom/BrowsingContext.h"
+#include "mozilla/dom/WindowGlobalParent.h"
+#include "mozilla/net/CookieJarSettings.h"
+#include "mozilla/NullPrincipal.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StaticPrefs_security.h"
+#include "mozIThirdPartyUtil.h"
+#include "ThirdPartyUtil.h"
+#include "nsFrameLoader.h"
+#include "nsFrameLoaderOwner.h"
+#include "nsIContentSecurityPolicy.h"
+#include "nsIDocShell.h"
+#include "mozilla/dom/Document.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIScriptElement.h"
+#include "nsISupportsImpl.h"
+#include "nsISupportsUtils.h"
+#include "nsIXPConnect.h"
+#include "nsDocShell.h"
+#include "nsGlobalWindow.h"
+#include "nsMixedContentBlocker.h"
+#include "nsQueryObject.h"
+#include "nsRedirectHistoryEntry.h"
+#include "nsSandboxFlags.h"
+#include "nsICookieService.h"
+
+using namespace mozilla::dom;
+
+namespace mozilla::net {
+
+static nsCString CurrentRemoteType() {
+  MOZ_ASSERT(XRE_IsParentProcess() || XRE_IsContentProcess());
+  if (ContentChild* cc = ContentChild::GetSingleton()) {
+    return nsCString(cc->GetRemoteType());
+  }
+  return NOT_REMOTE_TYPE;
+}
+
+static nsContentPolicyType InternalContentPolicyTypeForFrame(
+    CanonicalBrowsingContext* aBrowsingContext) {
+  const auto& maybeEmbedderElementType =
+      aBrowsingContext->GetEmbedderElementType();
+  MOZ_ASSERT(maybeEmbedderElementType.isSome());
+  auto embedderElementType = maybeEmbedderElementType.value();
+
+  // Assign same type as in nsDocShell::DetermineContentType.
+  // N.B. internal content policy type will never be TYPE_DOCUMENT
+  return embedderElementType.EqualsLiteral("iframe")
+             ? nsIContentPolicy::TYPE_INTERNAL_IFRAME
+             : nsIContentPolicy::TYPE_INTERNAL_FRAME;
+}
+
+/* static */ already_AddRefed<LoadInfo> LoadInfo::CreateForDocument(
+    dom::CanonicalBrowsingContext* aBrowsingContext, nsIURI* aURI,
+    nsIPrincipal* aTriggeringPrincipal, const nsACString& aTriggeringRemoteType,
+    const OriginAttributes& aOriginAttributes, nsSecurityFlags aSecurityFlags,
+    uint32_t aSandboxFlags) {
+  return MakeAndAddRef<LoadInfo>(aBrowsingContext, aURI, aTriggeringPrincipal,
+                                 aTriggeringRemoteType, aOriginAttributes,
+                                 aSecurityFlags, aSandboxFlags);
+}
+
+/* static */ already_AddRefed<LoadInfo> LoadInfo::CreateForFrame(
+    dom::CanonicalBrowsingContext* aBrowsingContext,
+    nsIPrincipal* aTriggeringPrincipal, const nsACString& aTriggeringRemoteType,
+    nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags) {
+  return MakeAndAddRef<LoadInfo>(aBrowsingContext, aTriggeringPrincipal,
+                                 aTriggeringRemoteType, aSecurityFlags,
+                                 aSandboxFlags);
+}
+
+/* static */ already_AddRefed<LoadInfo> LoadInfo::CreateForNonDocument(
+    dom::WindowGlobalParent* aParentWGP, nsIPrincipal* aTriggeringPrincipal,
+    nsContentPolicyType aContentPolicyType, nsSecurityFlags aSecurityFlags,
+    uint32_t aSandboxFlags) {
+  return MakeAndAddRef<LoadInfo>(
+      aParentWGP, aTriggeringPrincipal, aParentWGP->GetRemoteType(),
+      aContentPolicyType, aSecurityFlags, aSandboxFlags);
+}
+
+LoadInfo::LoadInfo(
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsINode* aLoadingContext, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    const Maybe<mozilla::dom::ClientInfo>& aLoadingClientInfo,
+    const Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+    uint32_t aSandboxFlags, bool aSkipCheckForBrokenURLOrZeroSized)
+    : mLoadingPrincipal(aLoadingContext ? aLoadingContext->NodePrincipal()
+                                        : aLoadingPrincipal),
+      mTriggeringPrincipal(aTriggeringPrincipal ? aTriggeringPrincipal
+                                                : mLoadingPrincipal.get()),
+      mTriggeringRemoteType(CurrentRemoteType()),
+      mSandboxedNullPrincipalID(nsID::GenerateUUID()),
+      mClientInfo(aLoadingClientInfo),
+      mController(aController),
+      mLoadingContext(do_GetWeakReference(aLoadingContext)),
+      mSecurityFlags(aSecurityFlags),
+      mSandboxFlags(aSandboxFlags),
+      mInternalContentPolicyType(aContentPolicyType),
+      mSkipCheckForBrokenURLOrZeroSized(aSkipCheckForBrokenURLOrZeroSized) {
+  MOZ_ASSERT(mLoadingPrincipal);
+  MOZ_ASSERT(mTriggeringPrincipal);
+
+#ifdef DEBUG
+  // TYPE_DOCUMENT loads initiated by javascript tests will go through
+  // nsIOService and use the wrong constructor.  Don't enforce the
+  // !TYPE_DOCUMENT check in those cases
+  bool skipContentTypeCheck = false;
+  skipContentTypeCheck =
+      Preferences::GetBool("network.loadinfo.skip_type_assertion");
+#endif
+
+  // This constructor shouldn't be used for TYPE_DOCUMENT loads that don't
+  // have a loadingPrincipal
+  MOZ_ASSERT(skipContentTypeCheck || mLoadingPrincipal ||
+             mInternalContentPolicyType != nsIContentPolicy::TYPE_DOCUMENT);
+
+  // We should only get an explicit controller for subresource requests.
+  MOZ_DIAGNOSTIC_ASSERT(aController.isNothing() ||
+                        !nsContentUtils::IsNonSubresourceInternalPolicyType(
+                            mInternalContentPolicyType));
+
+  // TODO(bug 1259873): Above, we initialize mIsThirdPartyContext to false
+  // meaning that consumers of LoadInfo that don't pass a context or pass a
+  // context from which we can't find a window will default to assuming that
+  // they're 1st party. It would be nice if we could default "safe" and assume
+  // that we are 3rd party until proven otherwise.
+
+  // if consumers pass both, aLoadingContext and aLoadingPrincipal
+  // then the loadingPrincipal must be the same as the node's principal
+  MOZ_ASSERT(!aLoadingContext || !aLoadingPrincipal ||
+             aLoadingContext->NodePrincipal() == aLoadingPrincipal);
+
+  // if the load is sandboxed, we can not also inherit the principal
+  if (mSandboxFlags & SANDBOXED_ORIGIN) {
+    mForceInheritPrincipalDropped =
+        (mSecurityFlags & nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL);
+    mSecurityFlags &= ~nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  }
+
+  ExtContentPolicyType externalType =
+      nsContentUtils::InternalContentPolicyTypeToExternal(aContentPolicyType);
+
+  if (aLoadingContext) {
+    // Ensure that all network requests for a window client have the ClientInfo
+    // properly set.  Workers must currently pass the loading ClientInfo
+    // explicitly. We allow main thread requests to explicitly pass the value as
+    // well.
+    if (mClientInfo.isNothing()) {
+      mClientInfo = aLoadingContext->OwnerDoc()->GetClientInfo();
+    }
+
+    // For subresource loads set the service worker based on the calling
+    // context's controller.  Workers must currently pass the controller in
+    // explicitly.  We allow main thread requests to explicitly pass the value
+    // as well, but otherwise extract from the loading context here.
+    if (mController.isNothing() &&
+        !nsContentUtils::IsNonSubresourceInternalPolicyType(
+            mInternalContentPolicyType)) {
+      mController = aLoadingContext->OwnerDoc()->GetController();
+    }
+
+    nsCOMPtr<nsPIDOMWindowOuter> contextOuter =
+        aLoadingContext->OwnerDoc()->GetWindow();
+    if (contextOuter) {
+      ComputeIsThirdPartyContext(contextOuter);
+      RefPtr<dom::BrowsingContext> bc = contextOuter->GetBrowsingContext();
+      MOZ_ASSERT(bc);
+      mBrowsingContextID = bc->Id();
+
+      nsGlobalWindowInner* innerWindow =
+          nsGlobalWindowInner::Cast(contextOuter->GetCurrentInnerWindow());
+      if (innerWindow) {
+        mTopLevelPrincipal = innerWindow->GetTopLevelAntiTrackingPrincipal();
+
+        if (!mTopLevelPrincipal &&
+            externalType == ExtContentPolicy::TYPE_SUBDOCUMENT && bc->IsTop()) {
+          // If this is the first level iframe, innerWindow is our top-level
+          // principal.
+          mTopLevelPrincipal = innerWindow->GetPrincipal();
+        }
+      }
+
+      // Let's inherit the cookie behavior and permission from the parent
+      // document.
+      mCookieJarSettings = aLoadingContext->OwnerDoc()->CookieJarSettings();
+    }
+
+    mInnerWindowID = aLoadingContext->OwnerDoc()->InnerWindowID();
+    RefPtr<WindowContext> ctx = WindowContext::GetById(mInnerWindowID);
+    if (ctx) {
+      mLoadingEmbedderPolicy = ctx->GetEmbedderPolicy();
+    }
+    mDocumentHasUserInteracted =
+        aLoadingContext->OwnerDoc()->UserHasInteracted();
+
+    // Inherit HTTPS-Only Mode flags from parent document
+    mHttpsOnlyStatus |= aLoadingContext->OwnerDoc()->HttpsOnlyStatus();
+
+    // When the element being loaded is a frame, we choose the frame's window
+    // for the window ID and the frame element's window as the parent
+    // window. This is the behavior that Chrome exposes to add-ons.
+    // NB: If the frameLoaderOwner doesn't have a frame loader, then the load
+    // must be coming from an object (such as a plugin) that's loaded into it
+    // instead of a document being loaded. In that case, treat this object like
+    // any other non-document-loading element.
+    RefPtr<nsFrameLoaderOwner> frameLoaderOwner =
+        do_QueryObject(aLoadingContext);
+    RefPtr<nsFrameLoader> fl =
+        frameLoaderOwner ? frameLoaderOwner->GetFrameLoader() : nullptr;
+    if (fl) {
+      nsCOMPtr<nsIDocShell> docShell = fl->GetDocShell(IgnoreErrors());
+      if (docShell) {
+        nsCOMPtr<nsPIDOMWindowOuter> outerWindow = do_GetInterface(docShell);
+        if (outerWindow) {
+          RefPtr<dom::BrowsingContext> bc = outerWindow->GetBrowsingContext();
+          mFrameBrowsingContextID = bc ? bc->Id() : 0;
+        }
+      }
+    }
+
+    // if the document forces all mixed content to be blocked, then we
+    // store that bit for all requests on the loadinfo.
+    mBlockAllMixedContent =
+        aLoadingContext->OwnerDoc()->GetBlockAllMixedContent(false) ||
+        (nsContentUtils::IsPreloadType(mInternalContentPolicyType) &&
+         aLoadingContext->OwnerDoc()->GetBlockAllMixedContent(true));
+
+    if (mLoadingPrincipal && BasePrincipal::Cast(mTriggeringPrincipal)
+                                 ->OverridesCSP(mLoadingPrincipal)) {
+      // if the load is triggered by an addon which potentially overrides the
+      // CSP of the document, then do not force insecure requests to be
+      // upgraded.
+      mUpgradeInsecureRequests = false;
+    } else {
+      // if the document forces all requests to be upgraded from http to https,
+      // then we should do that for all requests. If it only forces preloads to
+      // be upgraded then we should enforce upgrade insecure requests only for
+      // preloads.
+      mUpgradeInsecureRequests =
+          aLoadingContext->OwnerDoc()->GetUpgradeInsecureRequests(false) ||
+          (nsContentUtils::IsPreloadType(mInternalContentPolicyType) &&
+           aLoadingContext->OwnerDoc()->GetUpgradeInsecureRequests(true));
+    }
+
+    if (nsMixedContentBlocker::IsUpgradableContentType(
+            mInternalContentPolicyType)) {
+      if (mLoadingPrincipal->SchemeIs("https")) {
+        if (StaticPrefs::security_mixed_content_upgrade_display_content()) {
+          mBrowserUpgradeInsecureRequests = true;
+        } else {
+          mBrowserWouldUpgradeInsecureRequests = true;
+        }
+      }
+    }
+  }
+  mOriginAttributes = mLoadingPrincipal->OriginAttributesRef();
+
+  // We need to do this after inheriting the document's origin attributes
+  // above, in case the loading principal ends up being the system principal.
+  if (aLoadingContext) {
+    nsCOMPtr<nsILoadContext> loadContext =
+        aLoadingContext->OwnerDoc()->GetLoadContext();
+    nsCOMPtr<nsIDocShell> docShell = aLoadingContext->OwnerDoc()->GetDocShell();
+    if (loadContext && docShell &&
+        docShell->GetBrowsingContext()->IsContent()) {
+      bool usePrivateBrowsing;
+      nsresult rv = loadContext->GetUsePrivateBrowsing(&usePrivateBrowsing);
+      if (NS_SUCCEEDED(rv)) {
+        mOriginAttributes.SyncAttributesWithPrivateBrowsing(usePrivateBrowsing);
+      }
+    }
+  }
+
+  // For chrome docshell, the mPrivateBrowsingId remains 0 even its
+  // UsePrivateBrowsing() is true, so we only update the mPrivateBrowsingId in
+  // origin attributes if the type of the docshell is content.
+  if (aLoadingContext) {
+    nsCOMPtr<nsIDocShell> docShell = aLoadingContext->OwnerDoc()->GetDocShell();
+    if (docShell) {
+      if (docShell->GetBrowsingContext()->IsChrome()) {
+        MOZ_ASSERT(mOriginAttributes.mPrivateBrowsingId == 0,
+                   "chrome docshell shouldn't have mPrivateBrowsingId set.");
+      }
+    }
+  }
+
+  // in case this is a loadinfo for a parser generated script, then we store
+  // that bit of information so CSP strict-dynamic can query it.
+  if (!nsContentUtils::IsPreloadType(mInternalContentPolicyType)) {
+    nsCOMPtr<nsIScriptElement> script = do_QueryInterface(aLoadingContext);
+    if (script && script->GetParserCreated() != mozilla::dom::NOT_FROM_PARSER) {
+      mParserCreatedScript = true;
+    }
+  }
+}
+
+/* Constructor takes an outer window, but no loadingNode or loadingPrincipal.
+ * This constructor should only be used for TYPE_DOCUMENT loads, since they
+ * have a null loadingNode and loadingPrincipal.
+ */
+LoadInfo::LoadInfo(nsPIDOMWindowOuter* aOuterWindow, nsIURI* aURI,
+                   nsIPrincipal* aTriggeringPrincipal,
+                   nsISupports* aContextForTopLevelLoad,
+                   nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags)
+    : mTriggeringPrincipal(aTriggeringPrincipal),
+      mTriggeringRemoteType(CurrentRemoteType()),
+      mSandboxedNullPrincipalID(nsID::GenerateUUID()),
+      mContextForTopLevelLoad(do_GetWeakReference(aContextForTopLevelLoad)),
+      mSecurityFlags(aSecurityFlags),
+      mSandboxFlags(aSandboxFlags),
+      mInternalContentPolicyType(nsIContentPolicy::TYPE_DOCUMENT) {
+  // Top-level loads are never third-party
+  // Grab the information we can out of the window.
+  MOZ_ASSERT(aOuterWindow);
+  MOZ_ASSERT(mTriggeringPrincipal);
+
+  // if the load is sandboxed, we can not also inherit the principal
+  if (mSandboxFlags & SANDBOXED_ORIGIN) {
+    mForceInheritPrincipalDropped =
+        (mSecurityFlags & nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL);
+    mSecurityFlags &= ~nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  }
+
+  RefPtr<BrowsingContext> bc = aOuterWindow->GetBrowsingContext();
+  mBrowsingContextID = bc ? bc->Id() : 0;
+
+  // This should be removed in bug 1618557
+  nsGlobalWindowInner* innerWindow =
+      nsGlobalWindowInner::Cast(aOuterWindow->GetCurrentInnerWindow());
+  if (innerWindow) {
+    mTopLevelPrincipal = innerWindow->GetTopLevelAntiTrackingPrincipal();
+  }
+
+  // get the docshell from the outerwindow, and then get the originattributes
+  nsCOMPtr<nsIDocShell> docShell = aOuterWindow->GetDocShell();
+  MOZ_ASSERT(docShell);
+  mOriginAttributes = nsDocShell::Cast(docShell)->GetOriginAttributes();
+
+  // We sometimes use this constructor for security checks for outer windows
+  // that aren't top level.
+  if (aSecurityFlags != nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK) {
+    MOZ_ASSERT(aOuterWindow->GetBrowsingContext()->IsTop());
+  }
+
+#ifdef DEBUG
+  if (docShell->GetBrowsingContext()->IsChrome()) {
+    MOZ_ASSERT(mOriginAttributes.mPrivateBrowsingId == 0,
+               "chrome docshell shouldn't have mPrivateBrowsingId set.");
+  }
+#endif
+
+  // Let's take the current cookie behavior and current cookie permission
+  // for the documents' loadInfo. Note that for any other loadInfos,
+  // cookieBehavior will be BEHAVIOR_REJECT for security reasons.
+  bool isPrivate = mOriginAttributes.mPrivateBrowsingId > 0;
+  bool shouldResistFingerprinting =
+      nsContentUtils::ShouldResistFingerprinting_dangerous(
+          aURI, mOriginAttributes,
+          "We are creating CookieJarSettings, so we can't have one already.");
+  mCookieJarSettings = CookieJarSettings::Create(
+      isPrivate ? CookieJarSettings::ePrivate : CookieJarSettings::eRegular,
+      shouldResistFingerprinting);
+}
+
+LoadInfo::LoadInfo(dom::CanonicalBrowsingContext* aBrowsingContext,
+                   nsIURI* aURI, nsIPrincipal* aTriggeringPrincipal,
+                   const nsACString& aTriggeringRemoteType,
+                   const OriginAttributes& aOriginAttributes,
+                   nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags)
+    : mTriggeringPrincipal(aTriggeringPrincipal),
+      mTriggeringRemoteType(aTriggeringRemoteType),
+      mSandboxedNullPrincipalID(nsID::GenerateUUID()),
+      mSecurityFlags(aSecurityFlags),
+      mSandboxFlags(aSandboxFlags),
+      mInternalContentPolicyType(nsIContentPolicy::TYPE_DOCUMENT) {
+  // Top-level loads are never third-party
+  // Grab the information we can out of the window.
+  MOZ_ASSERT(aBrowsingContext);
+  MOZ_ASSERT(mTriggeringPrincipal);
+  MOZ_ASSERT(aSecurityFlags !=
+             nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK);
+
+  // if the load is sandboxed, we can not also inherit the principal
+  if (mSandboxFlags & SANDBOXED_ORIGIN) {
+    mForceInheritPrincipalDropped =
+        (mSecurityFlags & nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL);
+    mSecurityFlags &= ~nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  }
+
+  mBrowsingContextID = aBrowsingContext->Id();
+  mOriginAttributes = aOriginAttributes;
+
+#ifdef DEBUG
+  if (aBrowsingContext->IsChrome()) {
+    MOZ_ASSERT(mOriginAttributes.mPrivateBrowsingId == 0,
+               "chrome docshell shouldn't have mPrivateBrowsingId set.");
+  }
+#endif
+
+  // If we think we should not resist fingerprinting, defer to the opener's
+  // RFP bit (if there is an opener.)  If the opener is also exempted, it stays
+  // true, otherwise we will put a false into the CJS and that will be respected
+  // on this document.
+  bool shouldResistFingerprinting =
+      nsContentUtils::ShouldResistFingerprinting_dangerous(
+          aURI, mOriginAttributes,
+          "We are creating CookieJarSettings, so we can't have one already.");
+
+  RefPtr<BrowsingContext> opener = aBrowsingContext->GetOpener();
+  if (!shouldResistFingerprinting && opener &&
+      opener->GetCurrentWindowContext()) {
+    shouldResistFingerprinting =
+        opener->GetCurrentWindowContext()->ShouldResistFingerprinting();
+  }
+
+  const bool isPrivate = mOriginAttributes.mPrivateBrowsingId > 0;
+
+  // Let's take the current cookie behavior and current cookie permission
+  // for the documents' loadInfo. Note that for any other loadInfos,
+  // cookieBehavior will be BEHAVIOR_REJECT for security reasons.
+  mCookieJarSettings = CookieJarSettings::Create(
+      isPrivate ? CookieJarSettings::ePrivate : CookieJarSettings::eRegular,
+      shouldResistFingerprinting);
+}
+
+LoadInfo::LoadInfo(dom::WindowGlobalParent* aParentWGP,
+                   nsIPrincipal* aTriggeringPrincipal,
+                   const nsACString& aTriggeringRemoteType,
+                   nsContentPolicyType aContentPolicyType,
+                   nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags)
+    : mTriggeringPrincipal(aTriggeringPrincipal),
+      mTriggeringRemoteType(aTriggeringRemoteType),
+      mSandboxedNullPrincipalID(nsID::GenerateUUID()),
+      mSecurityFlags(aSecurityFlags),
+      mSandboxFlags(aSandboxFlags),
+      mInternalContentPolicyType(aContentPolicyType) {
+  CanonicalBrowsingContext* parentBC = aParentWGP->BrowsingContext();
+  MOZ_ASSERT(parentBC);
+  ComputeAncestors(parentBC, mAncestorPrincipals, mAncestorBrowsingContextIDs);
+
+  RefPtr<WindowGlobalParent> topLevelWGP = aParentWGP->TopWindowContext();
+
+  // if the load is sandboxed, we can not also inherit the principal
+  if (mSandboxFlags & SANDBOXED_ORIGIN) {
+    mForceInheritPrincipalDropped =
+        (mSecurityFlags & nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL);
+    mSecurityFlags &= ~nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  }
+
+  // Ensure that all network requests for a window client have the ClientInfo
+  // properly set.
+  mClientInfo = aParentWGP->GetClientInfo();
+  mLoadingPrincipal = aParentWGP->DocumentPrincipal();
+  ComputeIsThirdPartyContext(aParentWGP);
+
+  mBrowsingContextID = parentBC->Id();
+
+  // Let's inherit the cookie behavior and permission from the embedder
+  // document.
+  mCookieJarSettings = aParentWGP->CookieJarSettings();
+  if (topLevelWGP->BrowsingContext()->IsTop()) {
+    if (mCookieJarSettings) {
+      bool stopAtOurLevel = mCookieJarSettings->GetCookieBehavior() ==
+                            nsICookieService::BEHAVIOR_REJECT_TRACKER;
+      if (!stopAtOurLevel ||
+          topLevelWGP->OuterWindowId() != aParentWGP->OuterWindowId()) {
+        mTopLevelPrincipal = topLevelWGP->DocumentPrincipal();
+      }
+    }
+  }
+
+  if (!mTopLevelPrincipal && parentBC->IsTop()) {
+    // If this is the first level iframe, embedder WindowGlobalParent's document
+    // principal is our top-level principal.
+    mTopLevelPrincipal = aParentWGP->DocumentPrincipal();
+  }
+
+  mInnerWindowID = aParentWGP->InnerWindowId();
+  mDocumentHasUserInteracted = aParentWGP->DocumentHasUserInteracted();
+
+  // if the document forces all mixed content to be blocked, then we
+  // store that bit for all requests on the loadinfo.
+  mBlockAllMixedContent = aParentWGP->GetDocumentBlockAllMixedContent();
+
+  if (mTopLevelPrincipal && BasePrincipal::Cast(mTriggeringPrincipal)
+                                ->OverridesCSP(mTopLevelPrincipal)) {
+    // if the load is triggered by an addon which potentially overrides the
+    // CSP of the document, then do not force insecure requests to be
+    // upgraded.
+    mUpgradeInsecureRequests = false;
+  } else {
+    // if the document forces all requests to be upgraded from http to https,
+    // then we should do that for all requests. If it only forces preloads to
+    // be upgraded then we should enforce upgrade insecure requests only for
+    // preloads.
+    mUpgradeInsecureRequests = aParentWGP->GetDocumentUpgradeInsecureRequests();
+  }
+  mOriginAttributes = mLoadingPrincipal->OriginAttributesRef();
+
+  // We need to do this after inheriting the document's origin attributes
+  // above, in case the loading principal ends up being the system principal.
+  if (parentBC->IsContent()) {
+    mOriginAttributes.SyncAttributesWithPrivateBrowsing(
+        parentBC->UsePrivateBrowsing());
+  }
+
+  mHttpsOnlyStatus |= aParentWGP->HttpsOnlyStatus();
+
+  // For chrome BC, the mPrivateBrowsingId remains 0 even its
+  // UsePrivateBrowsing() is true, so we only update the mPrivateBrowsingId in
+  // origin attributes if the type of the BC is content.
+  if (parentBC->IsChrome()) {
+    MOZ_ASSERT(mOriginAttributes.mPrivateBrowsingId == 0,
+               "chrome docshell shouldn't have mPrivateBrowsingId set.");
+  }
+
+  RefPtr<WindowContext> ctx = WindowContext::GetById(mInnerWindowID);
+  if (ctx) {
+    mLoadingEmbedderPolicy = ctx->GetEmbedderPolicy();
+
+    if (Document* document = ctx->GetDocument()) {
+      mIsOriginTrialCoepCredentiallessEnabledForTopLevel =
+          document->Trials().IsEnabled(OriginTrial::CoepCredentialless);
+    }
+  }
+}
+
+// Used for TYPE_FRAME or TYPE_IFRAME load.
+LoadInfo::LoadInfo(dom::CanonicalBrowsingContext* aBrowsingContext,
+                   nsIPrincipal* aTriggeringPrincipal,
+                   const nsACString& aTriggeringRemoteType,
+                   nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags)
+    : LoadInfo(aBrowsingContext->GetParentWindowContext(), aTriggeringPrincipal,
+               aTriggeringRemoteType,
+               InternalContentPolicyTypeForFrame(aBrowsingContext),
+               aSecurityFlags, aSandboxFlags) {
+  mFrameBrowsingContextID = aBrowsingContext->Id();
+}
+
+LoadInfo::LoadInfo(const LoadInfo& rhs)
+    : mLoadingPrincipal(rhs.mLoadingPrincipal),
+      mTriggeringPrincipal(rhs.mTriggeringPrincipal),
+      mPrincipalToInherit(rhs.mPrincipalToInherit),
+      mTopLevelPrincipal(rhs.mTopLevelPrincipal),
+      mResultPrincipalURI(rhs.mResultPrincipalURI),
+      mChannelCreationOriginalURI(rhs.mChannelCreationOriginalURI),
+      mCookieJarSettings(rhs.mCookieJarSettings),
+      mCspToInherit(rhs.mCspToInherit),
+      mTriggeringRemoteType(rhs.mTriggeringRemoteType),
+      mSandboxedNullPrincipalID(rhs.mSandboxedNullPrincipalID),
+      mClientInfo(rhs.mClientInfo),
+      // mReservedClientSource must be handled specially during redirect
+      // mReservedClientInfo must be handled specially during redirect
+      // mInitialClientInfo must be handled specially during redirect
+      mController(rhs.mController),
+      mPerformanceStorage(rhs.mPerformanceStorage),
+      mLoadingContext(rhs.mLoadingContext),
+      mContextForTopLevelLoad(rhs.mContextForTopLevelLoad),
+      mSecurityFlags(rhs.mSecurityFlags),
+      mSandboxFlags(rhs.mSandboxFlags),
+      mTriggeringSandboxFlags(rhs.mTriggeringSandboxFlags),
+      mInternalContentPolicyType(rhs.mInternalContentPolicyType),
+      mTainting(rhs.mTainting),
+      mBlockAllMixedContent(rhs.mBlockAllMixedContent),
+      mUpgradeInsecureRequests(rhs.mUpgradeInsecureRequests),
+      mBrowserUpgradeInsecureRequests(rhs.mBrowserUpgradeInsecureRequests),
+      mBrowserDidUpgradeInsecureRequests(
+          rhs.mBrowserDidUpgradeInsecureRequests),
+      mBrowserWouldUpgradeInsecureRequests(
+          rhs.mBrowserWouldUpgradeInsecureRequests),
+      mForceAllowDataURI(rhs.mForceAllowDataURI),
+      mAllowInsecureRedirectToDataURI(rhs.mAllowInsecureRedirectToDataURI),
+      mSkipContentPolicyCheckForWebRequest(
+          rhs.mSkipContentPolicyCheckForWebRequest),
+      mOriginalFrameSrcLoad(rhs.mOriginalFrameSrcLoad),
+      mForceInheritPrincipalDropped(rhs.mForceInheritPrincipalDropped),
+      mInnerWindowID(rhs.mInnerWindowID),
+      mBrowsingContextID(rhs.mBrowsingContextID),
+      mWorkerAssociatedBrowsingContextID(
+          rhs.mWorkerAssociatedBrowsingContextID),
+      mFrameBrowsingContextID(rhs.mFrameBrowsingContextID),
+      mInitialSecurityCheckDone(rhs.mInitialSecurityCheckDone),
+      mIsThirdPartyContext(rhs.mIsThirdPartyContext),
+      mIsThirdPartyContextToTopWindow(rhs.mIsThirdPartyContextToTopWindow),
+      mIsFormSubmission(rhs.mIsFormSubmission),
+      mSendCSPViolationEvents(rhs.mSendCSPViolationEvents),
+      mOriginAttributes(rhs.mOriginAttributes),
+      mRedirectChainIncludingInternalRedirects(
+          rhs.mRedirectChainIncludingInternalRedirects.Clone()),
+      mRedirectChain(rhs.mRedirectChain.Clone()),
+      mAncestorPrincipals(rhs.mAncestorPrincipals.Clone()),
+      mAncestorBrowsingContextIDs(rhs.mAncestorBrowsingContextIDs.Clone()),
+      mCorsUnsafeHeaders(rhs.mCorsUnsafeHeaders.Clone()),
+      mRequestBlockingReason(rhs.mRequestBlockingReason),
+      mForcePreflight(rhs.mForcePreflight),
+      mIsPreflight(rhs.mIsPreflight),
+      mLoadTriggeredFromExternal(rhs.mLoadTriggeredFromExternal),
+      mDocumentHasUserInteracted(rhs.mDocumentHasUserInteracted),
+      mAllowListFutureDocumentsCreatedFromThisRedirectChain(
+          rhs.mAllowListFutureDocumentsCreatedFromThisRedirectChain),
+      mNeedForCheckingAntiTrackingHeuristic(
+          rhs.mNeedForCheckingAntiTrackingHeuristic),
+      mCspNonce(rhs.mCspNonce),
+      mSkipContentSniffing(rhs.mSkipContentSniffing),
+      mHttpsOnlyStatus(rhs.mHttpsOnlyStatus),
+      mHstsStatus(rhs.mHstsStatus),
+      mHasValidUserGestureActivation(rhs.mHasValidUserGestureActivation),
+      mAllowDeprecatedSystemRequests(rhs.mAllowDeprecatedSystemRequests),
+      mIsInDevToolsContext(rhs.mIsInDevToolsContext),
+      mParserCreatedScript(rhs.mParserCreatedScript),
+      mStoragePermission(rhs.mStoragePermission),
+      mIsMetaRefresh(rhs.mIsMetaRefresh),
+      mIsFromProcessingFrameAttributes(rhs.mIsFromProcessingFrameAttributes),
+      mIsMediaRequest(rhs.mIsMediaRequest),
+      mIsMediaInitialRequest(rhs.mIsMediaInitialRequest),
+      mIsFromObjectOrEmbed(rhs.mIsFromObjectOrEmbed),
+      mLoadingEmbedderPolicy(rhs.mLoadingEmbedderPolicy),
+      mIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+          rhs.mIsOriginTrialCoepCredentiallessEnabledForTopLevel),
+      mUnstrippedURI(rhs.mUnstrippedURI),
+      mInterceptionInfo(rhs.mInterceptionInfo),
+      mHasInjectedCookieForCookieBannerHandling(
+          rhs.mHasInjectedCookieForCookieBannerHandling) {}
+
+LoadInfo::LoadInfo(
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsIPrincipal* aPrincipalToInherit, nsIPrincipal* aTopLevelPrincipal,
+    nsIURI* aResultPrincipalURI, nsICookieJarSettings* aCookieJarSettings,
+    nsIContentSecurityPolicy* aCspToInherit,
+    const nsACString& aTriggeringRemoteType,
+    const nsID& aSandboxedNullPrincipalID, const Maybe<ClientInfo>& aClientInfo,
+    const Maybe<ClientInfo>& aReservedClientInfo,
+    const Maybe<ClientInfo>& aInitialClientInfo,
+    const Maybe<ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags,
+    uint32_t aTriggeringSandboxFlags, nsContentPolicyType aContentPolicyType,
+    LoadTainting aTainting, bool aBlockAllMixedContent,
+    bool aUpgradeInsecureRequests, bool aBrowserUpgradeInsecureRequests,
+    bool aBrowserDidUpgradeInsecureRequests,
+    bool aBrowserWouldUpgradeInsecureRequests, bool aForceAllowDataURI,
+    bool aAllowInsecureRedirectToDataURI,
+    bool aSkipContentPolicyCheckForWebRequest, bool aOriginalFrameSrcLoad,
+    bool aForceInheritPrincipalDropped, uint64_t aInnerWindowID,
+    uint64_t aBrowsingContextID, uint64_t aFrameBrowsingContextID,
+    bool aInitialSecurityCheckDone, bool aIsThirdPartyContext,
+    const Maybe<bool>& aIsThirdPartyContextToTopWindow, bool aIsFormSubmission,
+    bool aSendCSPViolationEvents, const OriginAttributes& aOriginAttributes,
+    RedirectHistoryArray&& aRedirectChainIncludingInternalRedirects,
+    RedirectHistoryArray&& aRedirectChain,
+    nsTArray<nsCOMPtr<nsIPrincipal>>&& aAncestorPrincipals,
+    const nsTArray<uint64_t>& aAncestorBrowsingContextIDs,
+    const nsTArray<nsCString>& aCorsUnsafeHeaders, bool aForcePreflight,
+    bool aIsPreflight, bool aLoadTriggeredFromExternal,
+    bool aServiceWorkerTaintingSynthesized, bool aDocumentHasUserInteracted,
+    bool aAllowListFutureDocumentsCreatedFromThisRedirectChain,
+    bool aNeedForCheckingAntiTrackingHeuristic, const nsAString& aCspNonce,
+    bool aSkipContentSniffing, uint32_t aHttpsOnlyStatus, bool aHstsStatus,
+    bool aHasValidUserGestureActivation, bool aAllowDeprecatedSystemRequests,
+    bool aIsInDevToolsContext, bool aParserCreatedScript,
+    nsILoadInfo::StoragePermissionState aStoragePermission, bool aIsMetaRefresh,
+    uint32_t aRequestBlockingReason, nsINode* aLoadingContext,
+    nsILoadInfo::CrossOriginEmbedderPolicy aLoadingEmbedderPolicy,
+    bool aIsOriginTrialCoepCredentiallessEnabledForTopLevel,
+    nsIURI* aUnstrippedURI, nsIInterceptionInfo* aInterceptionInfo,
+    bool aHasInjectedCookieForCookieBannerHandling)
+    : mLoadingPrincipal(aLoadingPrincipal),
+      mTriggeringPrincipal(aTriggeringPrincipal),
+      mPrincipalToInherit(aPrincipalToInherit),
+      mTopLevelPrincipal(aTopLevelPrincipal),
+      mResultPrincipalURI(aResultPrincipalURI),
+      mCookieJarSettings(aCookieJarSettings),
+      mCspToInherit(aCspToInherit),
+      mTriggeringRemoteType(aTriggeringRemoteType),
+      mSandboxedNullPrincipalID(aSandboxedNullPrincipalID),
+      mClientInfo(aClientInfo),
+      mReservedClientInfo(aReservedClientInfo),
+      mInitialClientInfo(aInitialClientInfo),
+      mController(aController),
+      mLoadingContext(do_GetWeakReference(aLoadingContext)),
+      mSecurityFlags(aSecurityFlags),
+      mSandboxFlags(aSandboxFlags),
+      mTriggeringSandboxFlags(aTriggeringSandboxFlags),
+      mInternalContentPolicyType(aContentPolicyType),
+      mTainting(aTainting),
+      mBlockAllMixedContent(aBlockAllMixedContent),
+      mUpgradeInsecureRequests(aUpgradeInsecureRequests),
+      mBrowserUpgradeInsecureRequests(aBrowserUpgradeInsecureRequests),
+      mBrowserDidUpgradeInsecureRequests(aBrowserDidUpgradeInsecureRequests),
+      mBrowserWouldUpgradeInsecureRequests(
+          aBrowserWouldUpgradeInsecureRequests),
+      mForceAllowDataURI(aForceAllowDataURI),
+      mAllowInsecureRedirectToDataURI(aAllowInsecureRedirectToDataURI),
+      mSkipContentPolicyCheckForWebRequest(
+          aSkipContentPolicyCheckForWebRequest),
+      mOriginalFrameSrcLoad(aOriginalFrameSrcLoad),
+      mForceInheritPrincipalDropped(aForceInheritPrincipalDropped),
+      mInnerWindowID(aInnerWindowID),
+      mBrowsingContextID(aBrowsingContextID),
+      mFrameBrowsingContextID(aFrameBrowsingContextID),
+      mInitialSecurityCheckDone(aInitialSecurityCheckDone),
+      mIsThirdPartyContext(aIsThirdPartyContext),
+      mIsThirdPartyContextToTopWindow(aIsThirdPartyContextToTopWindow),
+      mIsFormSubmission(aIsFormSubmission),
+      mSendCSPViolationEvents(aSendCSPViolationEvents),
+      mOriginAttributes(aOriginAttributes),
+      mRedirectChainIncludingInternalRedirects(
+          std::move(aRedirectChainIncludingInternalRedirects)),
+      mRedirectChain(std::move(aRedirectChain)),
+      mAncestorPrincipals(std::move(aAncestorPrincipals)),
+      mAncestorBrowsingContextIDs(aAncestorBrowsingContextIDs.Clone()),
+      mCorsUnsafeHeaders(aCorsUnsafeHeaders.Clone()),
+      mRequestBlockingReason(aRequestBlockingReason),
+      mForcePreflight(aForcePreflight),
+      mIsPreflight(aIsPreflight),
+      mLoadTriggeredFromExternal(aLoadTriggeredFromExternal),
+      mServiceWorkerTaintingSynthesized(aServiceWorkerTaintingSynthesized),
+      mDocumentHasUserInteracted(aDocumentHasUserInteracted),
+      mAllowListFutureDocumentsCreatedFromThisRedirectChain(
+          aAllowListFutureDocumentsCreatedFromThisRedirectChain),
+      mNeedForCheckingAntiTrackingHeuristic(
+          aNeedForCheckingAntiTrackingHeuristic),
+      mCspNonce(aCspNonce),
+      mSkipContentSniffing(aSkipContentSniffing),
+      mHttpsOnlyStatus(aHttpsOnlyStatus),
+      mHstsStatus(aHstsStatus),
+      mHasValidUserGestureActivation(aHasValidUserGestureActivation),
+      mAllowDeprecatedSystemRequests(aAllowDeprecatedSystemRequests),
+      mIsInDevToolsContext(aIsInDevToolsContext),
+      mParserCreatedScript(aParserCreatedScript),
+      mStoragePermission(aStoragePermission),
+      mIsMetaRefresh(aIsMetaRefresh),
+      mLoadingEmbedderPolicy(aLoadingEmbedderPolicy),
+      mIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+          aIsOriginTrialCoepCredentiallessEnabledForTopLevel),
+      mUnstrippedURI(aUnstrippedURI),
+      mInterceptionInfo(aInterceptionInfo),
+      mHasInjectedCookieForCookieBannerHandling(
+          aHasInjectedCookieForCookieBannerHandling) {
+  // Only top level TYPE_DOCUMENT loads can have a null loadingPrincipal
+  MOZ_ASSERT(mLoadingPrincipal ||
+             aContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT);
+  MOZ_ASSERT(mTriggeringPrincipal);
+}
+
+// static
+void LoadInfo::ComputeAncestors(
+    CanonicalBrowsingContext* aBC,
+    nsTArray<nsCOMPtr<nsIPrincipal>>& aAncestorPrincipals,
+    nsTArray<uint64_t>& aBrowsingContextIDs) {
+  MOZ_ASSERT(aAncestorPrincipals.IsEmpty());
+  MOZ_ASSERT(aBrowsingContextIDs.IsEmpty());
+  CanonicalBrowsingContext* ancestorBC = aBC;
+  // Iterate over ancestor WindowGlobalParents, collecting principals and outer
+  // window IDs.
+  while (WindowGlobalParent* ancestorWGP =
+             ancestorBC->GetParentWindowContext()) {
+    ancestorBC = ancestorWGP->BrowsingContext();
+
+    nsCOMPtr<nsIPrincipal> parentPrincipal = ancestorWGP->DocumentPrincipal();
+    MOZ_ASSERT(parentPrincipal, "Ancestor principal is null");
+    aAncestorPrincipals.AppendElement(parentPrincipal.forget());
+    aBrowsingContextIDs.AppendElement(ancestorBC->Id());
+  }
+}
+void LoadInfo::ComputeIsThirdPartyContext(nsPIDOMWindowOuter* aOuterWindow) {
+  ExtContentPolicyType type =
+      nsContentUtils::InternalContentPolicyTypeToExternal(
+          mInternalContentPolicyType);
+  if (type == ExtContentPolicy::TYPE_DOCUMENT) {
+    // Top-level loads are never third-party.
+    mIsThirdPartyContext = false;
+    return;
+  }
+
+  nsCOMPtr<mozIThirdPartyUtil> util(do_GetService(THIRDPARTYUTIL_CONTRACTID));
+  if (NS_WARN_IF(!util)) {
+    return;
+  }
+
+  util->IsThirdPartyWindow(aOuterWindow, nullptr, &mIsThirdPartyContext);
+}
+
+void LoadInfo::ComputeIsThirdPartyContext(dom::WindowGlobalParent* aGlobal) {
+  if (nsILoadInfo::GetExternalContentPolicyType() ==
+      ExtContentPolicy::TYPE_DOCUMENT) {
+    // Top-level loads are never third-party.
+    mIsThirdPartyContext = false;
+    return;
+  }
+
+  ThirdPartyUtil* thirdPartyUtil = ThirdPartyUtil::GetInstance();
+  if (!thirdPartyUtil) {
+    return;
+  }
+  thirdPartyUtil->IsThirdPartyGlobal(aGlobal, &mIsThirdPartyContext);
+}
+
+NS_IMPL_ISUPPORTS(LoadInfo, nsILoadInfo)
+
+LoadInfo::~LoadInfo() { MOZ_RELEASE_ASSERT(NS_IsMainThread()); }
+
+already_AddRefed<nsILoadInfo> LoadInfo::Clone() const {
+  RefPtr<LoadInfo> copy(new LoadInfo(*this));
+  return copy.forget();
+}
+
+already_AddRefed<nsILoadInfo> LoadInfo::CloneWithNewSecFlags(
+    nsSecurityFlags aSecurityFlags) const {
+  RefPtr<LoadInfo> copy(new LoadInfo(*this));
+  copy->mSecurityFlags = aSecurityFlags;
+  return copy.forget();
+}
+
+already_AddRefed<nsILoadInfo> LoadInfo::CloneForNewRequest() const {
+  RefPtr<LoadInfo> copy(new LoadInfo(*this));
+  copy->mInitialSecurityCheckDone = false;
+  copy->mRedirectChainIncludingInternalRedirects.Clear();
+  copy->mRedirectChain.Clear();
+  copy->mResultPrincipalURI = nullptr;
+  return copy.forget();
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadingPrincipal(nsIPrincipal** aLoadingPrincipal) {
+  *aLoadingPrincipal = do_AddRef(mLoadingPrincipal).take();
+  return NS_OK;
+}
+
+nsIPrincipal* LoadInfo::VirtualGetLoadingPrincipal() {
+  return mLoadingPrincipal;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetTriggeringPrincipal(nsIPrincipal** aTriggeringPrincipal) {
+  *aTriggeringPrincipal = do_AddRef(mTriggeringPrincipal).take();
+  return NS_OK;
+}
+
+nsIPrincipal* LoadInfo::TriggeringPrincipal() { return mTriggeringPrincipal; }
+
+NS_IMETHODIMP
+LoadInfo::GetPrincipalToInherit(nsIPrincipal** aPrincipalToInherit) {
+  *aPrincipalToInherit = do_AddRef(mPrincipalToInherit).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetPrincipalToInherit(nsIPrincipal* aPrincipalToInherit) {
+  MOZ_ASSERT(aPrincipalToInherit, "must be a valid principal to inherit");
+  mPrincipalToInherit = aPrincipalToInherit;
+  return NS_OK;
+}
+
+nsIPrincipal* LoadInfo::PrincipalToInherit() { return mPrincipalToInherit; }
+
+nsIPrincipal* LoadInfo::FindPrincipalToInherit(nsIChannel* aChannel) {
+  if (mPrincipalToInherit) {
+    return mPrincipalToInherit;
+  }
+
+  nsCOMPtr<nsIURI> uri = mResultPrincipalURI;
+  if (!uri) {
+    Unused << aChannel->GetOriginalURI(getter_AddRefs(uri));
+  }
+
+  auto* prin = BasePrincipal::Cast(mTriggeringPrincipal);
+  return prin->PrincipalToInherit(uri);
+}
+
+const nsID& LoadInfo::GetSandboxedNullPrincipalID() {
+  MOZ_ASSERT(!mSandboxedNullPrincipalID.Equals(nsID{}),
+             "mSandboxedNullPrincipalID wasn't initialized?");
+  return mSandboxedNullPrincipalID;
+}
+
+void LoadInfo::ResetSandboxedNullPrincipalID() {
+  mSandboxedNullPrincipalID = nsID::GenerateUUID();
+}
+
+nsIPrincipal* LoadInfo::GetTopLevelPrincipal() { return mTopLevelPrincipal; }
+
+NS_IMETHODIMP
+LoadInfo::GetTriggeringRemoteType(nsACString& aTriggeringRemoteType) {
+  aTriggeringRemoteType = mTriggeringRemoteType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetTriggeringRemoteType(const nsACString& aTriggeringRemoteType) {
+  mTriggeringRemoteType = aTriggeringRemoteType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadingDocument(Document** aResult) {
+  if (nsCOMPtr<nsINode> node = do_QueryReferent(mLoadingContext)) {
+    RefPtr<Document> context = node->OwnerDoc();
+    context.forget(aResult);
+  }
+  return NS_OK;
+}
+
+nsINode* LoadInfo::LoadingNode() {
+  nsCOMPtr<nsINode> node = do_QueryReferent(mLoadingContext);
+  return node;
+}
+
+already_AddRefed<nsISupports> LoadInfo::ContextForTopLevelLoad() {
+  // Most likely you want to query LoadingNode() instead of
+  // ContextForTopLevelLoad() if this assertion fires.
+  MOZ_ASSERT(mInternalContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+             "should only query this context for top level document loads");
+  nsCOMPtr<nsISupports> context = do_QueryReferent(mContextForTopLevelLoad);
+  return context.forget();
+}
+
+already_AddRefed<nsISupports> LoadInfo::GetLoadingContext() {
+  nsCOMPtr<nsISupports> context;
+  if (mInternalContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT) {
+    context = ContextForTopLevelLoad();
+  } else {
+    context = LoadingNode();
+  }
+  return context.forget();
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadingContextXPCOM(nsISupports** aResult) {
+  nsCOMPtr<nsISupports> context = GetLoadingContext();
+  context.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSecurityFlags(nsSecurityFlags* aResult) {
+  *aResult = mSecurityFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSandboxFlags(uint32_t* aResult) {
+  *aResult = mSandboxFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetTriggeringSandboxFlags(uint32_t* aResult) {
+  *aResult = mTriggeringSandboxFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetTriggeringSandboxFlags(uint32_t aFlags) {
+  mTriggeringSandboxFlags = aFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSecurityMode(uint32_t* aFlags) {
+  *aFlags = (mSecurityFlags &
+             (nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_INHERITS_SEC_CONTEXT |
+              nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED |
+              nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_INHERITS_SEC_CONTEXT |
+              nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL |
+              nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsInThirdPartyContext(bool* aIsInThirdPartyContext) {
+  *aIsInThirdPartyContext = mIsThirdPartyContext;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsInThirdPartyContext(bool aIsInThirdPartyContext) {
+  mIsThirdPartyContext = aIsInThirdPartyContext;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsThirdPartyContextToTopWindow(
+    bool* aIsThirdPartyContextToTopWindow) {
+  *aIsThirdPartyContextToTopWindow =
+      mIsThirdPartyContextToTopWindow.valueOr(true);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsThirdPartyContextToTopWindow(
+    bool aIsThirdPartyContextToTopWindow) {
+  mIsThirdPartyContextToTopWindow = Some(aIsThirdPartyContextToTopWindow);
+  return NS_OK;
+}
+
+static const uint32_t sCookiePolicyMask =
+    nsILoadInfo::SEC_COOKIES_DEFAULT | nsILoadInfo::SEC_COOKIES_INCLUDE |
+    nsILoadInfo::SEC_COOKIES_SAME_ORIGIN | nsILoadInfo::SEC_COOKIES_OMIT;
+
+NS_IMETHODIMP
+LoadInfo::GetCookiePolicy(uint32_t* aResult) {
+  uint32_t policy = mSecurityFlags & sCookiePolicyMask;
+  if (policy == nsILoadInfo::SEC_COOKIES_DEFAULT) {
+    policy = (mSecurityFlags & SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT)
+                 ? nsILoadInfo::SEC_COOKIES_SAME_ORIGIN
+                 : nsILoadInfo::SEC_COOKIES_INCLUDE;
+  }
+
+  *aResult = policy;
+  return NS_OK;
+}
+
+namespace {
+
+already_AddRefed<nsICookieJarSettings> CreateCookieJarSettings(
+    nsContentPolicyType aContentPolicyType, bool aIsPrivate,
+    bool shouldResistFingerprinting) {
+  if (StaticPrefs::network_cookieJarSettings_unblocked_for_testing()) {
+    return aIsPrivate ? CookieJarSettings::Create(CookieJarSettings::ePrivate,
+                                                  shouldResistFingerprinting)
+                      : CookieJarSettings::Create(CookieJarSettings::eRegular,
+                                                  shouldResistFingerprinting);
+  }
+
+  // These contentPolictTypes require a real CookieJarSettings because favicon
+  // and save-as requests must send cookies. Anything else should not
+  // send/receive cookies.
+  if (aContentPolicyType == nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON ||
+      aContentPolicyType == nsIContentPolicy::TYPE_SAVEAS_DOWNLOAD) {
+    return aIsPrivate ? CookieJarSettings::Create(CookieJarSettings::ePrivate,
+                                                  shouldResistFingerprinting)
+                      : CookieJarSettings::Create(CookieJarSettings::eRegular,
+                                                  shouldResistFingerprinting);
+  }
+
+  return CookieJarSettings::GetBlockingAll(shouldResistFingerprinting);
+}
+
+}  // namespace
+
+NS_IMETHODIMP
+LoadInfo::GetCookieJarSettings(nsICookieJarSettings** aCookieJarSettings) {
+  if (!mCookieJarSettings) {
+    bool isPrivate = mOriginAttributes.mPrivateBrowsingId > 0;
+    nsCOMPtr<nsIPrincipal> loadingPrincipal;
+    Unused << this->GetLoadingPrincipal(getter_AddRefs(loadingPrincipal));
+    bool shouldResistFingerprinting =
+        nsContentUtils::ShouldResistFingerprinting_dangerous(
+            loadingPrincipal,
+            "CookieJarSettings can't exist yet, we're creating it");
+    mCookieJarSettings = CreateCookieJarSettings(
+        mInternalContentPolicyType, isPrivate, shouldResistFingerprinting);
+  }
+
+  nsCOMPtr<nsICookieJarSettings> cookieJarSettings = mCookieJarSettings;
+  cookieJarSettings.forget(aCookieJarSettings);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetCookieJarSettings(nsICookieJarSettings* aCookieJarSettings) {
+  MOZ_ASSERT(aCookieJarSettings);
+  // We allow the overwrite of CookieJarSettings.
+  mCookieJarSettings = aCookieJarSettings;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetStoragePermission(
+    nsILoadInfo::StoragePermissionState* aStoragePermission) {
+  *aStoragePermission = mStoragePermission;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetStoragePermission(
+    nsILoadInfo::StoragePermissionState aStoragePermission) {
+  mStoragePermission = aStoragePermission;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsMetaRefresh(bool* aIsMetaRefresh) {
+  *aIsMetaRefresh = mIsMetaRefresh;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsMetaRefresh(bool aIsMetaRefresh) {
+  mIsMetaRefresh = aIsMetaRefresh;
+  return NS_OK;
+}
+
+void LoadInfo::SetIncludeCookiesSecFlag() {
+  MOZ_ASSERT((mSecurityFlags & sCookiePolicyMask) ==
+             nsILoadInfo::SEC_COOKIES_DEFAULT);
+  mSecurityFlags =
+      (mSecurityFlags & ~sCookiePolicyMask) | nsILoadInfo::SEC_COOKIES_INCLUDE;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetForceInheritPrincipal(bool* aInheritPrincipal) {
+  *aInheritPrincipal =
+      (mSecurityFlags & nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetForceInheritPrincipalOverruleOwner(bool* aInheritPrincipal) {
+  *aInheritPrincipal =
+      (mSecurityFlags &
+       nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL_OVERRULE_OWNER);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadingSandboxed(bool* aLoadingSandboxed) {
+  *aLoadingSandboxed = (mSandboxFlags & SANDBOXED_ORIGIN);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetAboutBlankInherits(bool* aResult) {
+  *aResult = (mSecurityFlags & nsILoadInfo::SEC_ABOUT_BLANK_INHERITS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetAllowChrome(bool* aResult) {
+  *aResult = (mSecurityFlags & nsILoadInfo::SEC_ALLOW_CHROME);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetDisallowScript(bool* aResult) {
+  *aResult = (mSecurityFlags & nsILoadInfo::SEC_DISALLOW_SCRIPT);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetDontFollowRedirects(bool* aResult) {
+  *aResult = (mSecurityFlags & nsILoadInfo::SEC_DONT_FOLLOW_REDIRECTS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadErrorPage(bool* aResult) {
+  *aResult = (mSecurityFlags & nsILoadInfo::SEC_LOAD_ERROR_PAGE);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsFormSubmission(bool* aResult) {
+  *aResult = mIsFormSubmission;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsFormSubmission(bool aValue) {
+  mIsFormSubmission = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSendCSPViolationEvents(bool* aResult) {
+  *aResult = mSendCSPViolationEvents;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetSendCSPViolationEvents(bool aValue) {
+  mSendCSPViolationEvents = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetExternalContentPolicyType(nsContentPolicyType* aResult) {
+  // We have to use nsContentPolicyType because ExtContentPolicyType is not
+  // visible from xpidl.
+  *aResult = static_cast<nsContentPolicyType>(
+      nsContentUtils::InternalContentPolicyTypeToExternal(
+          mInternalContentPolicyType));
+  return NS_OK;
+}
+
+nsContentPolicyType LoadInfo::InternalContentPolicyType() {
+  return mInternalContentPolicyType;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBlockAllMixedContent(bool* aResult) {
+  *aResult = mBlockAllMixedContent;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetUpgradeInsecureRequests(bool* aResult) {
+  *aResult = mUpgradeInsecureRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBrowserUpgradeInsecureRequests(bool* aResult) {
+  *aResult = mBrowserUpgradeInsecureRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBrowserDidUpgradeInsecureRequests(bool* aResult) {
+  *aResult = mBrowserDidUpgradeInsecureRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBrowserWouldUpgradeInsecureRequests(bool* aResult) {
+  *aResult = mBrowserWouldUpgradeInsecureRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetForceAllowDataURI(bool aForceAllowDataURI) {
+  MOZ_ASSERT(!mForceAllowDataURI ||
+                 mInternalContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+             "can only allow data URI navigation for TYPE_DOCUMENT");
+  mForceAllowDataURI = aForceAllowDataURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetForceAllowDataURI(bool* aForceAllowDataURI) {
+  *aForceAllowDataURI = mForceAllowDataURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetAllowInsecureRedirectToDataURI(
+    bool aAllowInsecureRedirectToDataURI) {
+  mAllowInsecureRedirectToDataURI = aAllowInsecureRedirectToDataURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetAllowInsecureRedirectToDataURI(
+    bool* aAllowInsecureRedirectToDataURI) {
+  *aAllowInsecureRedirectToDataURI = mAllowInsecureRedirectToDataURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetSkipContentPolicyCheckForWebRequest(bool aSkip) {
+  mSkipContentPolicyCheckForWebRequest = aSkip;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSkipContentPolicyCheckForWebRequest(bool* aSkip) {
+  *aSkip = mSkipContentPolicyCheckForWebRequest;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetOriginalFrameSrcLoad(bool aOriginalFrameSrcLoad) {
+  mOriginalFrameSrcLoad = aOriginalFrameSrcLoad;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetOriginalFrameSrcLoad(bool* aOriginalFrameSrcLoad) {
+  *aOriginalFrameSrcLoad = mOriginalFrameSrcLoad;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetForceInheritPrincipalDropped(bool* aResult) {
+  *aResult = mForceInheritPrincipalDropped;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetInnerWindowID(uint64_t* aResult) {
+  *aResult = mInnerWindowID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBrowsingContextID(uint64_t* aResult) {
+  *aResult = mBrowsingContextID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetWorkerAssociatedBrowsingContextID(uint64_t* aResult) {
+  *aResult = mWorkerAssociatedBrowsingContextID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetWorkerAssociatedBrowsingContextID(uint64_t aID) {
+  mWorkerAssociatedBrowsingContextID = aID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetFrameBrowsingContextID(uint64_t* aResult) {
+  *aResult = mFrameBrowsingContextID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetTargetBrowsingContextID(uint64_t* aResult) {
+  return (nsILoadInfo::GetExternalContentPolicyType() ==
+          ExtContentPolicy::TYPE_SUBDOCUMENT)
+             ? GetFrameBrowsingContextID(aResult)
+             : GetBrowsingContextID(aResult);
+}
+
+NS_IMETHODIMP
+LoadInfo::GetBrowsingContext(dom::BrowsingContext** aResult) {
+  *aResult = BrowsingContext::Get(mBrowsingContextID).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetWorkerAssociatedBrowsingContext(dom::BrowsingContext** aResult) {
+  *aResult = BrowsingContext::Get(mWorkerAssociatedBrowsingContextID).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetFrameBrowsingContext(dom::BrowsingContext** aResult) {
+  *aResult = BrowsingContext::Get(mFrameBrowsingContextID).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetTargetBrowsingContext(dom::BrowsingContext** aResult) {
+  uint64_t targetBrowsingContextID = 0;
+  MOZ_ALWAYS_SUCCEEDS(GetTargetBrowsingContextID(&targetBrowsingContextID));
+  *aResult = BrowsingContext::Get(targetBrowsingContextID).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetScriptableOriginAttributes(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aOriginAttributes) {
+  if (NS_WARN_IF(!ToJSValue(aCx, mOriginAttributes, aOriginAttributes))) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::ResetPrincipalToInheritToNullPrincipal() {
+  // take the originAttributes from the LoadInfo and create
+  // a new NullPrincipal using those origin attributes.
+  nsCOMPtr<nsIPrincipal> newNullPrincipal =
+      NullPrincipal::Create(mOriginAttributes);
+
+  mPrincipalToInherit = newNullPrincipal;
+
+  // setting SEC_FORCE_INHERIT_PRINCIPAL_OVERRULE_OWNER will overrule
+  // any non null owner set on the channel and will return the principal
+  // form the loadinfo instead.
+  mSecurityFlags |= SEC_FORCE_INHERIT_PRINCIPAL_OVERRULE_OWNER;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetScriptableOriginAttributes(
+    JSContext* aCx, JS::Handle<JS::Value> aOriginAttributes) {
+  OriginAttributes attrs;
+  if (!aOriginAttributes.isObject() || !attrs.Init(aCx, aOriginAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mOriginAttributes = attrs;
+  return NS_OK;
+}
+
+nsresult LoadInfo::GetOriginAttributes(
+    mozilla::OriginAttributes* aOriginAttributes) {
+  NS_ENSURE_ARG(aOriginAttributes);
+  *aOriginAttributes = mOriginAttributes;
+  return NS_OK;
+}
+
+nsresult LoadInfo::SetOriginAttributes(
+    const mozilla::OriginAttributes& aOriginAttributes) {
+  mOriginAttributes = aOriginAttributes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetInitialSecurityCheckDone(bool aInitialSecurityCheckDone) {
+  // Indicates whether the channel was ever evaluated by the
+  // ContentSecurityManager. Once set to true, this flag must
+  // remain true throughout the lifetime of the channel.
+  // Setting it to anything else than true will be discarded.
+  MOZ_ASSERT(aInitialSecurityCheckDone,
+             "aInitialSecurityCheckDone must be true");
+  mInitialSecurityCheckDone =
+      mInitialSecurityCheckDone || aInitialSecurityCheckDone;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetInitialSecurityCheckDone(bool* aResult) {
+  *aResult = mInitialSecurityCheckDone;
+  return NS_OK;
+}
+
+// To prevent unintenional credential and information leaks in content
+// processes we can use this function to truncate a Principal's URI as much as
+// possible.
+already_AddRefed<nsIPrincipal> CreateTruncatedPrincipal(
+    nsIPrincipal* aPrincipal) {
+  nsCOMPtr<nsIPrincipal> truncatedPrincipal;
+  // System Principal URIs don't need to be truncated as they don't contain any
+  // sensitive browsing history information.
+  if (aPrincipal->IsSystemPrincipal()) {
+    truncatedPrincipal = aPrincipal;
+    return truncatedPrincipal.forget();
+  }
+
+  // Content Principal URIs are the main location of the information we need to
+  // truncate.
+  if (aPrincipal->GetIsContentPrincipal()) {
+    // Certain URIs (chrome, resource, about) don't need to be truncated as they
+    // should be free of any sensitive user browsing history.
+    if (aPrincipal->SchemeIs("chrome") || aPrincipal->SchemeIs("resource") ||
+        aPrincipal->SchemeIs("about")) {
+      truncatedPrincipal = aPrincipal;
+      return truncatedPrincipal.forget();
+    }
+
+    // Different parts of the URI are preserved due to being vital to the
+    // browser's operation.
+    // Scheme for differentiating between different types of URIs and how to
+    // truncate them and later on utilize them.
+    // Host and Port to retain the redirect chain's core functionality.
+    // Path would ideally be removed but needs to be retained to ensure that
+    // http/https redirect loops can be detected.
+    // The entirety of the Query String, Reference Fragment, and User Info
+    // subcomponents must be stripped to avoid leaking Oauth tokens, user
+    // identifiers, and similar bits of information that these subcomponents may
+    // contain.
+    nsAutoCString scheme;
+    nsAutoCString separator("://");
+    nsAutoCString hostPort;
+    nsAutoCString path;
+    nsAutoCString uriString("");
+    if (aPrincipal->SchemeIs("view-source")) {
+      // The path portion of the view-source URI will be the URI whose source is
+      // being viewed, so we create a new URI object with a truncated form of
+      // the path and append the view-source scheme to the front again.
+      nsAutoCString viewSourcePath;
+      aPrincipal->GetFilePath(viewSourcePath);
+
+      nsCOMPtr<nsIURI> nestedURI;
+      nsresult rv = NS_NewURI(getter_AddRefs(nestedURI), viewSourcePath);
+
+      if (NS_FAILED(rv)) {
+        // Since the path here should be an already validated URI this should
+        // never happen.
+        NS_WARNING(viewSourcePath.get());
+        MOZ_ASSERT(false,
+                   "Failed to create truncated form of URI with NS_NewURI.");
+        truncatedPrincipal = aPrincipal;
+        return truncatedPrincipal.forget();
+      }
+
+      nestedURI->GetScheme(scheme);
+      nestedURI->GetHostPort(hostPort);
+      nestedURI->GetFilePath(path);
+      uriString += "view-source:";
+    } else {
+      aPrincipal->GetScheme(scheme);
+      aPrincipal->GetHostPort(hostPort);
+      aPrincipal->GetFilePath(path);
+    }
+    uriString += scheme + separator + hostPort + path;
+
+    nsCOMPtr<nsIURI> truncatedURI;
+    nsresult rv = NS_NewURI(getter_AddRefs(truncatedURI), uriString);
+    if (NS_FAILED(rv)) {
+      NS_WARNING(uriString.get());
+      MOZ_ASSERT(false,
+                 "Failed to create truncated form of URI with NS_NewURI.");
+      truncatedPrincipal = aPrincipal;
+      return truncatedPrincipal.forget();
+    }
+
+    return BasePrincipal::CreateContentPrincipal(
+        truncatedURI, aPrincipal->OriginAttributesRef());
+  }
+
+  // Null Principal Precursor URIs can also contain information that needs to
+  // be truncated.
+  if (aPrincipal->GetIsNullPrincipal()) {
+    nsCOMPtr<nsIPrincipal> precursorPrincipal =
+        aPrincipal->GetPrecursorPrincipal();
+    // If there is no precursor then nothing needs to be truncated.
+    if (!precursorPrincipal) {
+      truncatedPrincipal = aPrincipal;
+      return truncatedPrincipal.forget();
+    }
+
+    // Otherwise we return a new Null Principal with the original's Origin
+    // Attributes and a truncated version of the original's precursor URI.
+    nsCOMPtr<nsIPrincipal> truncatedPrecursor =
+        CreateTruncatedPrincipal(precursorPrincipal);
+    return NullPrincipal::CreateWithInheritedAttributes(truncatedPrecursor);
+  }
+
+  // Expanded Principals shouldn't contain sensitive information but their
+  // allowlists might so we truncate that information here.
+  if (aPrincipal->GetIsExpandedPrincipal()) {
+    nsTArray<nsCOMPtr<nsIPrincipal>> truncatedAllowList;
+
+    for (const auto& allowedPrincipal : BasePrincipal::Cast(aPrincipal)
+                                            ->As<ExpandedPrincipal>()
+                                            ->AllowList()) {
+      nsCOMPtr<nsIPrincipal> truncatedPrincipal =
+          CreateTruncatedPrincipal(allowedPrincipal);
+
+      truncatedAllowList.AppendElement(truncatedPrincipal);
+    }
+
+    return ExpandedPrincipal::Create(truncatedAllowList,
+                                     aPrincipal->OriginAttributesRef());
+  }
+
+  // If we hit this assertion we need to update this function to add the
+  // Principals and URIs seen as new corner cases to handle.
+  MOZ_ASSERT(false, "Unhandled Principal or URI type encountered.");
+
+  truncatedPrincipal = aPrincipal;
+  return truncatedPrincipal.forget();
+}
+
+NS_IMETHODIMP
+LoadInfo::AppendRedirectHistoryEntry(nsIChannel* aChannel,
+                                     bool aIsInternalRedirect) {
+  NS_ENSURE_ARG(aChannel);
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIPrincipal> uriPrincipal;
+  nsIScriptSecurityManager* sm = nsContentUtils::GetSecurityManager();
+  sm->GetChannelURIPrincipal(aChannel, getter_AddRefs(uriPrincipal));
+
+  nsCOMPtr<nsIURI> referrer;
+  nsCString remoteAddress;
+
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aChannel));
+  if (httpChannel) {
+    nsCOMPtr<nsIReferrerInfo> referrerInfo;
+    Unused << httpChannel->GetReferrerInfo(getter_AddRefs(referrerInfo));
+    if (referrerInfo) {
+      referrer = referrerInfo->GetComputedReferrer();
+    }
+
+    nsCOMPtr<nsIHttpChannelInternal> intChannel(do_QueryInterface(aChannel));
+    if (intChannel) {
+      Unused << intChannel->GetRemoteAddress(remoteAddress);
+    }
+  }
+
+  nsCOMPtr<nsIPrincipal> truncatedPrincipal =
+      CreateTruncatedPrincipal(uriPrincipal);
+
+  nsCOMPtr<nsIRedirectHistoryEntry> entry =
+      new nsRedirectHistoryEntry(truncatedPrincipal, referrer, remoteAddress);
+
+  mRedirectChainIncludingInternalRedirects.AppendElement(entry);
+  if (!aIsInternalRedirect) {
+    mRedirectChain.AppendElement(entry);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetRedirects(JSContext* aCx, JS::MutableHandle<JS::Value> aRedirects,
+                       const RedirectHistoryArray& aArray) {
+  JS::Rooted<JSObject*> redirects(aCx,
+                                  JS::NewArrayObject(aCx, aArray.Length()));
+  NS_ENSURE_TRUE(redirects, NS_ERROR_OUT_OF_MEMORY);
+
+  JS::Rooted<JSObject*> global(aCx, JS::CurrentGlobalOrNull(aCx));
+  NS_ENSURE_TRUE(global, NS_ERROR_UNEXPECTED);
+
+  nsCOMPtr<nsIXPConnect> xpc = nsIXPConnect::XPConnect();
+
+  for (size_t idx = 0; idx < aArray.Length(); idx++) {
+    JS::Rooted<JSObject*> jsobj(aCx);
+    nsresult rv =
+        xpc->WrapNative(aCx, global, aArray[idx],
+                        NS_GET_IID(nsIRedirectHistoryEntry), jsobj.address());
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_STATE(jsobj);
+
+    bool rc = JS_DefineElement(aCx, redirects, idx, jsobj, JSPROP_ENUMERATE);
+    NS_ENSURE_TRUE(rc, NS_ERROR_UNEXPECTED);
+  }
+
+  aRedirects.setObject(*redirects);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetRedirectChainIncludingInternalRedirects(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aChain) {
+  return GetRedirects(aCx, aChain, mRedirectChainIncludingInternalRedirects);
+}
+
+const RedirectHistoryArray&
+LoadInfo::RedirectChainIncludingInternalRedirects() {
+  return mRedirectChainIncludingInternalRedirects;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetRedirectChain(JSContext* aCx,
+                           JS::MutableHandle<JS::Value> aChain) {
+  return GetRedirects(aCx, aChain, mRedirectChain);
+}
+
+const RedirectHistoryArray& LoadInfo::RedirectChain() { return mRedirectChain; }
+
+const nsTArray<nsCOMPtr<nsIPrincipal>>& LoadInfo::AncestorPrincipals() {
+  return mAncestorPrincipals;
+}
+
+const nsTArray<uint64_t>& LoadInfo::AncestorBrowsingContextIDs() {
+  return mAncestorBrowsingContextIDs;
+}
+
+void LoadInfo::SetCorsPreflightInfo(const nsTArray<nsCString>& aHeaders,
+                                    bool aForcePreflight) {
+  MOZ_ASSERT(GetSecurityMode() ==
+             nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT);
+  MOZ_ASSERT(!mInitialSecurityCheckDone);
+  mCorsUnsafeHeaders = aHeaders.Clone();
+  mForcePreflight = aForcePreflight;
+}
+
+const nsTArray<nsCString>& LoadInfo::CorsUnsafeHeaders() {
+  return mCorsUnsafeHeaders;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetForcePreflight(bool* aForcePreflight) {
+  *aForcePreflight = mForcePreflight;
+  return NS_OK;
+}
+
+void LoadInfo::SetIsPreflight() {
+  MOZ_ASSERT(GetSecurityMode() ==
+             nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT);
+  MOZ_ASSERT(!mInitialSecurityCheckDone);
+  mIsPreflight = true;
+}
+
+void LoadInfo::SetUpgradeInsecureRequests(bool aValue) {
+  mUpgradeInsecureRequests = aValue;
+}
+
+void LoadInfo::SetBrowserUpgradeInsecureRequests() {
+  mBrowserUpgradeInsecureRequests = true;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetBrowserDidUpgradeInsecureRequests(
+    bool aBrowserDidUpgradeInsecureRequests) {
+  mBrowserDidUpgradeInsecureRequests = aBrowserDidUpgradeInsecureRequests;
+  return NS_OK;
+}
+
+void LoadInfo::SetBrowserWouldUpgradeInsecureRequests() {
+  mBrowserWouldUpgradeInsecureRequests = true;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsPreflight(bool* aIsPreflight) {
+  *aIsPreflight = mIsPreflight;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetLoadTriggeredFromExternal(bool aLoadTriggeredFromExternal) {
+  MOZ_ASSERT(!aLoadTriggeredFromExternal ||
+                 mInternalContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+             "can only set load triggered from external for TYPE_DOCUMENT");
+  mLoadTriggeredFromExternal = aLoadTriggeredFromExternal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadTriggeredFromExternal(bool* aLoadTriggeredFromExternal) {
+  *aLoadTriggeredFromExternal = mLoadTriggeredFromExternal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetServiceWorkerTaintingSynthesized(
+    bool* aServiceWorkerTaintingSynthesized) {
+  MOZ_ASSERT(aServiceWorkerTaintingSynthesized);
+  *aServiceWorkerTaintingSynthesized = mServiceWorkerTaintingSynthesized;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetTainting(uint32_t* aTaintingOut) {
+  MOZ_ASSERT(aTaintingOut);
+  *aTaintingOut = static_cast<uint32_t>(mTainting);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::MaybeIncreaseTainting(uint32_t aTainting) {
+  NS_ENSURE_ARG(aTainting <= TAINTING_OPAQUE);
+
+  // Skip if the tainting has been set by the service worker.
+  if (mServiceWorkerTaintingSynthesized) {
+    return NS_OK;
+  }
+
+  LoadTainting tainting = static_cast<LoadTainting>(aTainting);
+  if (tainting > mTainting) {
+    mTainting = tainting;
+  }
+  return NS_OK;
+}
+
+void LoadInfo::SynthesizeServiceWorkerTainting(LoadTainting aTainting) {
+  MOZ_DIAGNOSTIC_ASSERT(aTainting <= LoadTainting::Opaque);
+  mTainting = aTainting;
+
+  // Flag to prevent the tainting from being increased.
+  mServiceWorkerTaintingSynthesized = true;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetDocumentHasUserInteracted(bool* aDocumentHasUserInteracted) {
+  MOZ_ASSERT(aDocumentHasUserInteracted);
+  *aDocumentHasUserInteracted = mDocumentHasUserInteracted;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetDocumentHasUserInteracted(bool aDocumentHasUserInteracted) {
+  mDocumentHasUserInteracted = aDocumentHasUserInteracted;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetAllowListFutureDocumentsCreatedFromThisRedirectChain(
+    bool* aValue) {
+  MOZ_ASSERT(aValue);
+  *aValue = mAllowListFutureDocumentsCreatedFromThisRedirectChain;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetAllowListFutureDocumentsCreatedFromThisRedirectChain(bool aValue) {
+  mAllowListFutureDocumentsCreatedFromThisRedirectChain = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetNeedForCheckingAntiTrackingHeuristic(bool* aValue) {
+  MOZ_ASSERT(aValue);
+  *aValue = mNeedForCheckingAntiTrackingHeuristic;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetNeedForCheckingAntiTrackingHeuristic(bool aValue) {
+  mNeedForCheckingAntiTrackingHeuristic = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetCspNonce(nsAString& aCspNonce) {
+  aCspNonce = mCspNonce;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetCspNonce(const nsAString& aCspNonce) {
+  MOZ_ASSERT(!mInitialSecurityCheckDone,
+             "setting the nonce is only allowed before any sec checks");
+  mCspNonce = aCspNonce;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetSkipContentSniffing(bool* aSkipContentSniffing) {
+  *aSkipContentSniffing = mSkipContentSniffing;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetSkipContentSniffing(bool aSkipContentSniffing) {
+  mSkipContentSniffing = aSkipContentSniffing;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetHttpsOnlyStatus(uint32_t* aHttpsOnlyStatus) {
+  *aHttpsOnlyStatus = mHttpsOnlyStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetHttpsOnlyStatus(uint32_t aHttpsOnlyStatus) {
+  mHttpsOnlyStatus = aHttpsOnlyStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetHstsStatus(bool* aHstsStatus) {
+  *aHstsStatus = mHstsStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetHstsStatus(bool aHstsStatus) {
+  mHstsStatus = aHstsStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetHasValidUserGestureActivation(
+    bool* aHasValidUserGestureActivation) {
+  *aHasValidUserGestureActivation = mHasValidUserGestureActivation;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetHasValidUserGestureActivation(
+    bool aHasValidUserGestureActivation) {
+  mHasValidUserGestureActivation = aHasValidUserGestureActivation;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetAllowDeprecatedSystemRequests(
+    bool* aAllowDeprecatedSystemRequests) {
+  *aAllowDeprecatedSystemRequests = mAllowDeprecatedSystemRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetAllowDeprecatedSystemRequests(
+    bool aAllowDeprecatedSystemRequests) {
+  mAllowDeprecatedSystemRequests = aAllowDeprecatedSystemRequests;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsUserTriggeredSave(bool* aIsUserTriggeredSave) {
+  *aIsUserTriggeredSave =
+      mIsUserTriggeredSave ||
+      mInternalContentPolicyType == nsIContentPolicy::TYPE_SAVEAS_DOWNLOAD;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsUserTriggeredSave(bool aIsUserTriggeredSave) {
+  mIsUserTriggeredSave = aIsUserTriggeredSave;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsInDevToolsContext(bool* aIsInDevToolsContext) {
+  *aIsInDevToolsContext = mIsInDevToolsContext;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsInDevToolsContext(bool aIsInDevToolsContext) {
+  mIsInDevToolsContext = aIsInDevToolsContext;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetParserCreatedScript(bool* aParserCreatedScript) {
+  *aParserCreatedScript = mParserCreatedScript;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetParserCreatedScript(bool aParserCreatedScript) {
+  mParserCreatedScript = aParserCreatedScript;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsTopLevelLoad(bool* aResult) {
+  RefPtr<dom::BrowsingContext> bc;
+  GetTargetBrowsingContext(getter_AddRefs(bc));
+  *aResult = !bc || bc->IsTop();
+  return NS_OK;
+}
+
+void LoadInfo::SetIsFromProcessingFrameAttributes() {
+  mIsFromProcessingFrameAttributes = true;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsFromProcessingFrameAttributes(
+    bool* aIsFromProcessingFrameAttributes) {
+  MOZ_ASSERT(aIsFromProcessingFrameAttributes);
+  *aIsFromProcessingFrameAttributes = mIsFromProcessingFrameAttributes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsMediaRequest(bool aIsMediaRequest) {
+  mIsMediaRequest = aIsMediaRequest;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsMediaRequest(bool* aIsMediaRequest) {
+  MOZ_ASSERT(aIsMediaRequest);
+  *aIsMediaRequest = mIsMediaRequest;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsMediaInitialRequest(bool aIsMediaInitialRequest) {
+  mIsMediaInitialRequest = aIsMediaInitialRequest;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsMediaInitialRequest(bool* aIsMediaInitialRequest) {
+  MOZ_ASSERT(aIsMediaInitialRequest);
+  *aIsMediaInitialRequest = mIsMediaInitialRequest;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsFromObjectOrEmbed(bool aIsFromObjectOrEmbed) {
+  mIsFromObjectOrEmbed = aIsFromObjectOrEmbed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsFromObjectOrEmbed(bool* aIsFromObjectOrEmbed) {
+  MOZ_ASSERT(aIsFromObjectOrEmbed);
+  *aIsFromObjectOrEmbed = mIsFromObjectOrEmbed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetShouldSkipCheckForBrokenURLOrZeroSized(
+    bool* aShouldSkipCheckForBrokenURLOrZeroSized) {
+  MOZ_ASSERT(aShouldSkipCheckForBrokenURLOrZeroSized);
+  *aShouldSkipCheckForBrokenURLOrZeroSized = mSkipCheckForBrokenURLOrZeroSized;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetResultPrincipalURI(nsIURI** aURI) {
+  *aURI = do_AddRef(mResultPrincipalURI).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetResultPrincipalURI(nsIURI* aURI) {
+  mResultPrincipalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetChannelCreationOriginalURI(nsIURI** aURI) {
+  *aURI = do_AddRef(mChannelCreationOriginalURI).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetChannelCreationOriginalURI(nsIURI* aURI) {
+  mChannelCreationOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetRequestBlockingReason(uint32_t aReason) {
+  mRequestBlockingReason = aReason;
+  return NS_OK;
+}
+NS_IMETHODIMP
+LoadInfo::GetRequestBlockingReason(uint32_t* aReason) {
+  *aReason = mRequestBlockingReason;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetUnstrippedURI(nsIURI** aURI) {
+  *aURI = do_AddRef(mUnstrippedURI).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetUnstrippedURI(nsIURI* aURI) {
+  mUnstrippedURI = aURI;
+  return NS_OK;
+}
+
+void LoadInfo::SetClientInfo(const ClientInfo& aClientInfo) {
+  mClientInfo.emplace(aClientInfo);
+}
+
+const Maybe<ClientInfo>& LoadInfo::GetClientInfo() { return mClientInfo; }
+
+void LoadInfo::GiveReservedClientSource(
+    UniquePtr<ClientSource>&& aClientSource) {
+  MOZ_DIAGNOSTIC_ASSERT(aClientSource);
+  mReservedClientSource = std::move(aClientSource);
+  SetReservedClientInfo(mReservedClientSource->Info());
+}
+
+UniquePtr<ClientSource> LoadInfo::TakeReservedClientSource() {
+  if (mReservedClientSource) {
+    // If the reserved ClientInfo was set due to a ClientSource being present,
+    // then clear that info object when the ClientSource is taken.
+    mReservedClientInfo.reset();
+  }
+  return std::move(mReservedClientSource);
+}
+
+void LoadInfo::SetReservedClientInfo(const ClientInfo& aClientInfo) {
+  MOZ_DIAGNOSTIC_ASSERT(mInitialClientInfo.isNothing());
+  // Treat assignments of the same value as a no-op.  The emplace below
+  // will normally assert when overwriting an existing value.
+  if (mReservedClientInfo.isSome()) {
+    if (mReservedClientInfo.ref() == aClientInfo) {
+      return;
+    }
+    MOZ_DIAGNOSTIC_ASSERT(false, "mReservedClientInfo already set");
+    mReservedClientInfo.reset();
+  }
+  mReservedClientInfo.emplace(aClientInfo);
+}
+
+void LoadInfo::OverrideReservedClientInfoInParent(
+    const ClientInfo& aClientInfo) {
+  // This should only be called to handle redirects in the parent process.
+  MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
+
+  mInitialClientInfo.reset();
+  mReservedClientInfo.reset();
+  mReservedClientInfo.emplace(aClientInfo);
+}
+
+const Maybe<ClientInfo>& LoadInfo::GetReservedClientInfo() {
+  return mReservedClientInfo;
+}
+
+void LoadInfo::SetInitialClientInfo(const ClientInfo& aClientInfo) {
+  MOZ_DIAGNOSTIC_ASSERT(!mReservedClientSource);
+  MOZ_DIAGNOSTIC_ASSERT(mReservedClientInfo.isNothing());
+  // Treat assignments of the same value as a no-op.  The emplace below
+  // will normally assert when overwriting an existing value.
+  if (mInitialClientInfo.isSome() && mInitialClientInfo.ref() == aClientInfo) {
+    return;
+  }
+  mInitialClientInfo.emplace(aClientInfo);
+}
+
+const Maybe<ClientInfo>& LoadInfo::GetInitialClientInfo() {
+  return mInitialClientInfo;
+}
+
+void LoadInfo::SetController(const ServiceWorkerDescriptor& aServiceWorker) {
+  mController.emplace(aServiceWorker);
+}
+
+void LoadInfo::ClearController() { mController.reset(); }
+
+const Maybe<ServiceWorkerDescriptor>& LoadInfo::GetController() {
+  return mController;
+}
+
+void LoadInfo::SetPerformanceStorage(PerformanceStorage* aPerformanceStorage) {
+  mPerformanceStorage = aPerformanceStorage;
+}
+
+PerformanceStorage* LoadInfo::GetPerformanceStorage() {
+  if (mPerformanceStorage) {
+    return mPerformanceStorage;
+  }
+
+  auto* innerWindow = nsGlobalWindowInner::GetInnerWindowWithId(mInnerWindowID);
+  if (!innerWindow) {
+    return nullptr;
+  }
+
+  if (!TriggeringPrincipal()->Equals(innerWindow->GetPrincipal())) {
+    return nullptr;
+  }
+
+  if (nsILoadInfo::GetExternalContentPolicyType() ==
+          ExtContentPolicy::TYPE_SUBDOCUMENT &&
+      !GetIsFromProcessingFrameAttributes()) {
+    // We only report loads caused by processing the attributes of the
+    // browsing context container.
+    return nullptr;
+  }
+
+  mozilla::dom::Performance* performance = innerWindow->GetPerformance();
+  if (!performance) {
+    return nullptr;
+  }
+
+  return performance->AsPerformanceStorage();
+}
+
+NS_IMETHODIMP
+LoadInfo::GetCspEventListener(nsICSPEventListener** aCSPEventListener) {
+  *aCSPEventListener = do_AddRef(mCSPEventListener).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetCspEventListener(nsICSPEventListener* aCSPEventListener) {
+  mCSPEventListener = aCSPEventListener;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetInternalContentPolicyType(nsContentPolicyType* aResult) {
+  *aResult = mInternalContentPolicyType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadingEmbedderPolicy(
+    nsILoadInfo::CrossOriginEmbedderPolicy* aOutPolicy) {
+  *aOutPolicy = mLoadingEmbedderPolicy;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetLoadingEmbedderPolicy(
+    nsILoadInfo::CrossOriginEmbedderPolicy aPolicy) {
+  mLoadingEmbedderPolicy = aPolicy;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+    bool* aIsOriginTrialCoepCredentiallessEnabledForTopLevel) {
+  *aIsOriginTrialCoepCredentiallessEnabledForTopLevel =
+      mIsOriginTrialCoepCredentiallessEnabledForTopLevel;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+    bool aIsOriginTrialCoepCredentiallessEnabledForTopLevel) {
+  mIsOriginTrialCoepCredentiallessEnabledForTopLevel =
+      aIsOriginTrialCoepCredentiallessEnabledForTopLevel;
+  return NS_OK;
+}
+
+already_AddRefed<nsIContentSecurityPolicy> LoadInfo::GetCsp() {
+  // Before querying the CSP from the client we have to check if the
+  // triggeringPrincipal originates from an addon and potentially
+  // overrides the CSP stored within the client.
+  if (mLoadingPrincipal && BasePrincipal::Cast(mTriggeringPrincipal)
+                               ->OverridesCSP(mLoadingPrincipal)) {
+    nsCOMPtr<nsIExpandedPrincipal> ep = do_QueryInterface(mTriggeringPrincipal);
+    nsCOMPtr<nsIContentSecurityPolicy> addonCSP;
+    if (ep) {
+      addonCSP = ep->GetCsp();
+    }
+    return addonCSP.forget();
+  }
+
+  if (mClientInfo.isNothing()) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsINode> node = do_QueryReferent(mLoadingContext);
+  RefPtr<Document> doc = node ? node->OwnerDoc() : nullptr;
+
+  // If the client is of type window, then we return the cached CSP
+  // stored on the document instead of having to deserialize the CSP
+  // from the ClientInfo.
+  if (doc && mClientInfo->Type() == ClientType::Window) {
+    nsCOMPtr<nsIContentSecurityPolicy> docCSP = doc->GetCsp();
+    return docCSP.forget();
+  }
+
+  Maybe<mozilla::ipc::CSPInfo> cspInfo = mClientInfo->GetCspInfo();
+  if (cspInfo.isNothing()) {
+    return nullptr;
+  }
+  nsCOMPtr<nsIContentSecurityPolicy> clientCSP =
+      CSPInfoToCSP(cspInfo.ref(), doc);
+  return clientCSP.forget();
+}
+
+already_AddRefed<nsIContentSecurityPolicy> LoadInfo::GetPreloadCsp() {
+  if (mClientInfo.isNothing()) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsINode> node = do_QueryReferent(mLoadingContext);
+  RefPtr<Document> doc = node ? node->OwnerDoc() : nullptr;
+
+  // If the client is of type window, then we return the cached CSP
+  // stored on the document instead of having to deserialize the CSP
+  // from the ClientInfo.
+  if (doc && mClientInfo->Type() == ClientType::Window) {
+    nsCOMPtr<nsIContentSecurityPolicy> preloadCsp = doc->GetPreloadCsp();
+    return preloadCsp.forget();
+  }
+
+  Maybe<mozilla::ipc::CSPInfo> cspInfo = mClientInfo->GetPreloadCspInfo();
+  if (cspInfo.isNothing()) {
+    return nullptr;
+  }
+  nsCOMPtr<nsIContentSecurityPolicy> preloadCSP =
+      CSPInfoToCSP(cspInfo.ref(), doc);
+  return preloadCSP.forget();
+}
+
+already_AddRefed<nsIContentSecurityPolicy> LoadInfo::GetCspToInherit() {
+  nsCOMPtr<nsIContentSecurityPolicy> cspToInherit = mCspToInherit;
+  return cspToInherit.forget();
+}
+
+nsIInterceptionInfo* LoadInfo::InterceptionInfo() { return mInterceptionInfo; }
+
+void LoadInfo::SetInterceptionInfo(nsIInterceptionInfo* aInfo) {
+  mInterceptionInfo = aInfo;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetHasInjectedCookieForCookieBannerHandling(
+    bool* aHasInjectedCookieForCookieBannerHandling) {
+  *aHasInjectedCookieForCookieBannerHandling =
+      mHasInjectedCookieForCookieBannerHandling;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::SetHasInjectedCookieForCookieBannerHandling(
+    bool aHasInjectedCookieForCookieBannerHandling) {
+  mHasInjectedCookieForCookieBannerHandling =
+      aHasInjectedCookieForCookieBannerHandling;
+  return NS_OK;
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/LoadInfo.h b/netwerk/base/LoadInfo.h
new file mode 100644
index 0000000000..8e9424a2d2
--- /dev/null
+++ b/netwerk/base/LoadInfo.h
@@ -0,0 +1,392 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_LoadInfo_h
+#define mozilla_LoadInfo_h
+
+#include "nsIContentSecurityPolicy.h"
+#include "nsIInterceptionInfo.h"
+#include "nsILoadInfo.h"
+#include "nsIPrincipal.h"
+#include "nsIWeakReferenceUtils.h"  // for nsWeakPtr
+#include "nsIURI.h"
+#include "nsContentUtils.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/dom/ClientInfo.h"
+#include "mozilla/dom/ServiceWorkerDescriptor.h"
+
+class nsDocShell;
+class nsICookieJarSettings;
+class nsINode;
+class nsPIDOMWindowOuter;
+
+namespace mozilla {
+
+namespace dom {
+class PerformanceStorage;
+class XMLHttpRequestMainThread;
+class CanonicalBrowsingContext;
+class WindowGlobalParent;
+}  // namespace dom
+
+namespace net {
+class LoadInfoArgs;
+class LoadInfo;
+}  // namespace net
+
+namespace ipc {
+// we have to forward declare that function so we can use it as a friend.
+nsresult LoadInfoArgsToLoadInfo(
+    const Maybe<mozilla::net::LoadInfoArgs>& aLoadInfoArgs,
+    const nsACString& aOriginRemoteType, nsINode* aCspToInheritLoadingContext,
+    net::LoadInfo** outLoadInfo);
+}  // namespace ipc
+
+namespace net {
+
+using RedirectHistoryArray = nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>;
+
+/**
+ * Class that provides an nsILoadInfo implementation.
+ */
+class LoadInfo final : public nsILoadInfo {
+  template <typename T, typename... Args>
+  friend already_AddRefed<T> mozilla::MakeAndAddRef(Args&&... aArgs);
+
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSILOADINFO
+
+  // Used for TYPE_DOCUMENT load.
+  static already_AddRefed<LoadInfo> CreateForDocument(
+      dom::CanonicalBrowsingContext* aBrowsingContext, nsIURI* aURI,
+      nsIPrincipal* aTriggeringPrincipal,
+      const nsACString& aTriggeringRemoteType,
+      const OriginAttributes& aOriginAttributes, nsSecurityFlags aSecurityFlags,
+      uint32_t aSandboxFlags);
+
+  // Used for TYPE_FRAME or TYPE_IFRAME load.
+  static already_AddRefed<LoadInfo> CreateForFrame(
+      dom::CanonicalBrowsingContext* aBrowsingContext,
+      nsIPrincipal* aTriggeringPrincipal,
+      const nsACString& aTriggeringRemoteType, nsSecurityFlags aSecurityFlags,
+      uint32_t aSandboxFlags);
+
+  // Use for non-{TYPE_DOCUMENT|TYPE_FRAME|TYPE_IFRAME} load.
+  static already_AddRefed<LoadInfo> CreateForNonDocument(
+      dom::WindowGlobalParent* aParentWGP, nsIPrincipal* aTriggeringPrincipal,
+      nsContentPolicyType aContentPolicyType, nsSecurityFlags aSecurityFlags,
+      uint32_t aSandboxFlags);
+
+  // aLoadingPrincipal MUST NOT BE NULL.
+  LoadInfo(nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+           nsINode* aLoadingContext, nsSecurityFlags aSecurityFlags,
+           nsContentPolicyType aContentPolicyType,
+           const Maybe<mozilla::dom::ClientInfo>& aLoadingClientInfo =
+               Maybe<mozilla::dom::ClientInfo>(),
+           const Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController =
+               Maybe<mozilla::dom::ServiceWorkerDescriptor>(),
+           uint32_t aSandboxFlags = 0,
+           bool aSkipCheckForBrokenURLOrZeroSized = 0);
+
+  // Constructor used for TYPE_DOCUMENT loads which have a different
+  // loadingContext than other loads. This ContextForTopLevelLoad is
+  // only used for content policy checks.
+  LoadInfo(nsPIDOMWindowOuter* aOuterWindow, nsIURI* aURI,
+           nsIPrincipal* aTriggeringPrincipal,
+           nsISupports* aContextForTopLevelLoad, nsSecurityFlags aSecurityFlags,
+           uint32_t aSandboxFlags);
+
+ private:
+  // Use factory function CreateForDocument
+  // Used for TYPE_DOCUMENT load.
+  LoadInfo(dom::CanonicalBrowsingContext* aBrowsingContext, nsIURI* aURI,
+           nsIPrincipal* aTriggeringPrincipal,
+           const nsACString& aTriggeringRemoteType,
+           const OriginAttributes& aOriginAttributes,
+           nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags);
+
+  // Use factory function CreateForFrame
+  // Used for TYPE_FRAME or TYPE_IFRAME load.
+  LoadInfo(dom::CanonicalBrowsingContext* aBrowsingContext,
+           nsIPrincipal* aTriggeringPrincipal,
+           const nsACString& aTriggeringRemoteType,
+           nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags);
+
+  // Used for loads initiated by DocumentLoadListener that are not TYPE_DOCUMENT
+  // | TYPE_FRAME | TYPE_FRAME.
+  LoadInfo(dom::WindowGlobalParent* aParentWGP,
+           nsIPrincipal* aTriggeringPrincipal,
+           const nsACString& aTriggeringRemoteType,
+           nsContentPolicyType aContentPolicyType,
+           nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags);
+
+ public:
+  // Compute a list of ancestor principals and BrowsingContext IDs.
+  // See methods AncestorPrincipals and AncestorBrowsingContextIDs
+  // in nsILoadInfo.idl for details.
+  static void ComputeAncestors(
+      dom::CanonicalBrowsingContext* aBC,
+      nsTArray<nsCOMPtr<nsIPrincipal>>& aAncestorPrincipals,
+      nsTArray<uint64_t>& aBrowsingContextIDs);
+
+  // create an exact copy of the loadinfo
+  already_AddRefed<nsILoadInfo> Clone() const;
+
+  // hands off!!! don't use CloneWithNewSecFlags unless you know
+  // exactly what you are doing - it should only be used within
+  // nsBaseChannel::Redirect()
+  already_AddRefed<nsILoadInfo> CloneWithNewSecFlags(
+      nsSecurityFlags aSecurityFlags) const;
+  // creates a copy of the loadinfo which is appropriate to use for a
+  // separate request. I.e. not for a redirect or an inner channel, but
+  // when a separate request is made with the same security properties.
+  already_AddRefed<nsILoadInfo> CloneForNewRequest() const;
+
+  // The `nsContentPolicyType GetExternalContentPolicyType()` version in the
+  // base class is hidden by the implementation of
+  // `GetExternalContentPolicyType(nsContentPolicyType* aResult)` in
+  // LoadInfo.cpp. Explicit mark it visible.
+  using nsILoadInfo::GetExternalContentPolicyType;
+
+  void SetIsPreflight();
+  void SetUpgradeInsecureRequests(bool aValue);
+  void SetBrowserUpgradeInsecureRequests();
+  void SetBrowserWouldUpgradeInsecureRequests();
+  void SetIsFromProcessingFrameAttributes();
+
+  // Hands off from the cspToInherit functionality!
+  //
+  // For navigations, GetCSPToInherit returns what the spec calls the
+  // "request's client's global object's CSP list", or more precisely
+  // a snapshot of it taken when the navigation starts.  For navigations
+  // that need to inherit their CSP, this is the right CSP to use for
+  // the new document.  We need a way to transfer the CSP from the
+  // docshell (where the navigation starts) to the point where the new
+  // document is created and decides whether to inherit its CSP, and
+  // this is the mechanism we use for that.
+  //
+  // For example:
+  // A document with a CSP triggers a new top-level data: URI load.
+  // We pass the CSP of the document that triggered the load all the
+  // way to docshell. Within docshell we call SetCSPToInherit() on the
+  // loadinfo. Within Document::InitCSP() we check if the newly created
+  // document needs to inherit the CSP. If so, we call GetCSPToInherit()
+  // and set the inherited CSP as the CSP for the new document. Please
+  // note that any additonal Meta CSP in that document will be merged
+  // into that CSP. Any subresource loads within that document
+  // subesquently will receive the correct CSP by querying
+  // loadinfo->GetCsp() from that point on.
+  void SetCSPToInherit(nsIContentSecurityPolicy* aCspToInherit) {
+    mCspToInherit = aCspToInherit;
+  }
+
+  bool HasIsThirdPartyContextToTopWindowSet() {
+    return mIsThirdPartyContextToTopWindow.isSome();
+  }
+  void ClearIsThirdPartyContextToTopWindow() {
+    mIsThirdPartyContextToTopWindow.reset();
+  }
+
+ private:
+  // private constructor that is only allowed to be called from within
+  // HttpChannelParent and FTPChannelParent declared as friends undeneath.
+  // In e10s we can not serialize nsINode, hence we store the innerWindowID.
+  // Please note that aRedirectChain uses swapElements.
+  LoadInfo(
+      nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+      nsIPrincipal* aPrincipalToInherit, nsIPrincipal* aTopLevelPrincipal,
+      nsIURI* aResultPrincipalURI, nsICookieJarSettings* aCookieJarSettings,
+      nsIContentSecurityPolicy* aCspToInherit,
+      const nsACString& aTriggeringRemoteType,
+      const nsID& aSandboxedNullPrincipalID,
+      const Maybe<mozilla::dom::ClientInfo>& aClientInfo,
+      const Maybe<mozilla::dom::ClientInfo>& aReservedClientInfo,
+      const Maybe<mozilla::dom::ClientInfo>& aInitialClientInfo,
+      const Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+      nsSecurityFlags aSecurityFlags, uint32_t aSandboxFlags,
+      uint32_t aTriggeringSandboxFlags, nsContentPolicyType aContentPolicyType,
+      LoadTainting aTainting, bool aBlockAllMixedContent,
+      bool aUpgradeInsecureRequests, bool aBrowserUpgradeInsecureRequests,
+      bool aBrowserDidUpgradeInsecureRequests,
+      bool aBrowserWouldUpgradeInsecureRequests, bool aForceAllowDataURI,
+      bool aAllowInsecureRedirectToDataURI,
+      bool aSkipContentPolicyCheckForWebRequest, bool aOriginalFrameSrcLoad,
+      bool aForceInheritPrincipalDropped, uint64_t aInnerWindowID,
+      uint64_t aBrowsingContextID, uint64_t aFrameBrowsingContextID,
+      bool aInitialSecurityCheckDone, bool aIsThirdPartyContext,
+      const Maybe<bool>& aIsThirdPartyContextToTopWindow,
+      bool aIsFormSubmission, bool aSendCSPViolationEvents,
+      const OriginAttributes& aOriginAttributes,
+      RedirectHistoryArray&& aRedirectChainIncludingInternalRedirects,
+      RedirectHistoryArray&& aRedirectChain,
+      nsTArray<nsCOMPtr<nsIPrincipal>>&& aAncestorPrincipals,
+      const nsTArray<uint64_t>& aAncestorBrowsingContextIDs,
+      const nsTArray<nsCString>& aCorsUnsafeHeaders, bool aForcePreflight,
+      bool aIsPreflight, bool aLoadTriggeredFromExternal,
+      bool aServiceWorkerTaintingSynthesized, bool aDocumentHasUserInteracted,
+      bool aAllowListFutureDocumentsCreatedFromThisRedirectChain,
+      bool aNeedForCheckingAntiTrackingHeuristic, const nsAString& aCspNonce,
+      bool aSkipContentSniffing, uint32_t aHttpsOnlyStatus, bool aHstsStatus,
+      bool aHasValidUserGestureActivation, bool aAllowDeprecatedSystemRequests,
+      bool aIsInDevToolsContext, bool aParserCreatedScript,
+      nsILoadInfo::StoragePermissionState aStoragePermission,
+      bool aIsMetaRefresh, uint32_t aRequestBlockingReason,
+      nsINode* aLoadingContext,
+      nsILoadInfo::CrossOriginEmbedderPolicy aLoadingEmbedderPolicy,
+      bool aIsOriginTrialCoepCredentiallessEnabledForTopLevel,
+      nsIURI* aUnstrippedURI, nsIInterceptionInfo* aInterceptionInfo,
+      bool aHasInjectedCookieForCookieBannerHandling);
+  LoadInfo(const LoadInfo& rhs);
+
+  NS_IMETHOD GetRedirects(JSContext* aCx,
+                          JS::MutableHandle<JS::Value> aRedirects,
+                          const RedirectHistoryArray& aArra);
+
+  friend nsresult mozilla::ipc::LoadInfoArgsToLoadInfo(
+      const Maybe<mozilla::net::LoadInfoArgs>& aLoadInfoArgs,
+      const nsACString& aOriginRemoteType, nsINode* aCspToInheritLoadingContext,
+      net::LoadInfo** outLoadInfo);
+
+  ~LoadInfo();
+
+  void ComputeIsThirdPartyContext(nsPIDOMWindowOuter* aOuterWindow);
+  void ComputeIsThirdPartyContext(dom::WindowGlobalParent* aGlobal);
+
+  // This function is the *only* function which can change the securityflags
+  // of a loadinfo. It only exists because of the XHR code. Don't call it
+  // from anywhere else!
+  void SetIncludeCookiesSecFlag();
+  friend class mozilla::dom::XMLHttpRequestMainThread;
+
+  // nsDocShell::OpenInitializedChannel needs to update the loadInfo with
+  // the correct browsingContext.
+  friend class ::nsDocShell;
+  void UpdateBrowsingContextID(uint64_t aBrowsingContextID) {
+    mBrowsingContextID = aBrowsingContextID;
+  }
+  void UpdateFrameBrowsingContextID(uint64_t aFrameBrowsingContextID) {
+    mFrameBrowsingContextID = aFrameBrowsingContextID;
+  }
+  MOZ_NEVER_INLINE void ReleaseMembers();
+
+  // if you add a member, please also update the copy constructor and consider
+  // if it should be merged from parent channel through
+  // ParentLoadInfoForwarderArgs.
+  nsCOMPtr<nsIPrincipal> mLoadingPrincipal;
+  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+  nsCOMPtr<nsIPrincipal> mPrincipalToInherit;
+  nsCOMPtr<nsIPrincipal> mTopLevelPrincipal;
+  nsCOMPtr<nsIURI> mResultPrincipalURI;
+  nsCOMPtr<nsIURI> mChannelCreationOriginalURI;
+  nsCOMPtr<nsICSPEventListener> mCSPEventListener;
+  nsCOMPtr<nsICookieJarSettings> mCookieJarSettings;
+  nsCOMPtr<nsIContentSecurityPolicy> mCspToInherit;
+  nsCString mTriggeringRemoteType;
+  nsID mSandboxedNullPrincipalID;
+
+  Maybe<mozilla::dom::ClientInfo> mClientInfo;
+  UniquePtr<mozilla::dom::ClientSource> mReservedClientSource;
+  Maybe<mozilla::dom::ClientInfo> mReservedClientInfo;
+  Maybe<mozilla::dom::ClientInfo> mInitialClientInfo;
+  Maybe<mozilla::dom::ServiceWorkerDescriptor> mController;
+  RefPtr<mozilla::dom::PerformanceStorage> mPerformanceStorage;
+
+  nsWeakPtr mLoadingContext;
+  nsWeakPtr mContextForTopLevelLoad;
+  nsSecurityFlags mSecurityFlags;
+  uint32_t mSandboxFlags;
+  uint32_t mTriggeringSandboxFlags = 0;
+  nsContentPolicyType mInternalContentPolicyType;
+  LoadTainting mTainting = LoadTainting::Basic;
+  bool mBlockAllMixedContent = false;
+  bool mUpgradeInsecureRequests = false;
+  bool mBrowserUpgradeInsecureRequests = false;
+  bool mBrowserDidUpgradeInsecureRequests = false;
+  bool mBrowserWouldUpgradeInsecureRequests = false;
+  bool mForceAllowDataURI = false;
+  bool mAllowInsecureRedirectToDataURI = false;
+  bool mSkipContentPolicyCheckForWebRequest = false;
+  bool mOriginalFrameSrcLoad = false;
+  bool mForceInheritPrincipalDropped = false;
+  uint64_t mInnerWindowID = 0;
+  uint64_t mBrowsingContextID = 0;
+  uint64_t mWorkerAssociatedBrowsingContextID = 0;
+  uint64_t mFrameBrowsingContextID = 0;
+  bool mInitialSecurityCheckDone = false;
+  // NB: TYPE_DOCUMENT implies !third-party.
+  bool mIsThirdPartyContext = false;
+  Maybe<bool> mIsThirdPartyContextToTopWindow;
+  bool mIsFormSubmission = false;
+  bool mSendCSPViolationEvents = true;
+  OriginAttributes mOriginAttributes;
+  RedirectHistoryArray mRedirectChainIncludingInternalRedirects;
+  RedirectHistoryArray mRedirectChain;
+  nsTArray<nsCOMPtr<nsIPrincipal>> mAncestorPrincipals;
+  nsTArray<uint64_t> mAncestorBrowsingContextIDs;
+  nsTArray<nsCString> mCorsUnsafeHeaders;
+  uint32_t mRequestBlockingReason = BLOCKING_REASON_NONE;
+  bool mForcePreflight = false;
+  bool mIsPreflight = false;
+  bool mLoadTriggeredFromExternal = false;
+  bool mServiceWorkerTaintingSynthesized = false;
+  bool mDocumentHasUserInteracted = false;
+  bool mAllowListFutureDocumentsCreatedFromThisRedirectChain = false;
+  bool mNeedForCheckingAntiTrackingHeuristic = false;
+  nsString mCspNonce;
+  bool mSkipContentSniffing = false;
+  uint32_t mHttpsOnlyStatus = nsILoadInfo::HTTPS_ONLY_UNINITIALIZED;
+  bool mHstsStatus = false;
+  bool mHasValidUserGestureActivation = false;
+  bool mAllowDeprecatedSystemRequests = false;
+  bool mIsUserTriggeredSave = false;
+  bool mIsInDevToolsContext = false;
+  bool mParserCreatedScript = false;
+  nsILoadInfo::StoragePermissionState mStoragePermission =
+      nsILoadInfo::NoStoragePermission;
+  bool mIsMetaRefresh = false;
+
+  // Is true if this load was triggered by processing the attributes of the
+  // browsing context container.
+  // See nsILoadInfo.isFromProcessingFrameAttributes
+  bool mIsFromProcessingFrameAttributes = false;
+
+  // See nsILoadInfo.isMediaRequest and nsILoadInfo.isMediaInitialRequest.
+  bool mIsMediaRequest = false;
+  bool mIsMediaInitialRequest = false;
+
+  // See nsILoadInfo.isFromObjectOrEmbed
+  bool mIsFromObjectOrEmbed = false;
+
+  bool mSkipCheckForBrokenURLOrZeroSized = false;
+
+  // The cross origin embedder policy that the loading need to respect.
+  // If the value is nsILoadInfo::EMBEDDER_POLICY_REQUIRE_CORP, CORP checking
+  // must be performed for the loading.
+  // See https://wicg.github.io/cross-origin-embedder-policy/#corp-check.
+  nsILoadInfo::CrossOriginEmbedderPolicy mLoadingEmbedderPolicy =
+      nsILoadInfo::EMBEDDER_POLICY_NULL;
+
+  bool mIsOriginTrialCoepCredentiallessEnabledForTopLevel = false;
+
+  nsCOMPtr<nsIURI> mUnstrippedURI;
+
+  nsCOMPtr<nsIInterceptionInfo> mInterceptionInfo;
+
+  bool mHasInjectedCookieForCookieBannerHandling = false;
+};
+
+// This is exposed solely for testing purposes and should not be used outside of
+// LoadInfo
+already_AddRefed<nsIPrincipal> CreateTruncatedPrincipal(nsIPrincipal*);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_LoadInfo_h
diff --git a/netwerk/base/LoadTainting.h b/netwerk/base/LoadTainting.h
new file mode 100644
index 0000000000..11dc8a304f
--- /dev/null
+++ b/netwerk/base/LoadTainting.h
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_LoadTainting_h
+#define mozilla_LoadTainting_h
+
+#include <stdint.h>
+
+namespace mozilla {
+
+// Define an enumeration to reflect the concept of response tainting from the
+// the fetch spec:
+//
+//  https://fetch.spec.whatwg.org/#concept-request-response-tainting
+//
+// Roughly the tainting means:
+//
+//  * Basic: the request resulted in a same-origin or non-http load
+//  * CORS: the request resulted in a cross-origin load with CORS headers
+//  * Opaque: the request resulted in a cross-origin load without CORS headers
+//
+// The enumeration is purposefully designed such that more restrictive tainting
+// corresponds to a higher integral value.
+enum class LoadTainting : uint8_t { Basic = 0, CORS = 1, Opaque = 2 };
+
+}  // namespace mozilla
+
+#endif  // mozilla_LoadTainting_h
diff --git a/netwerk/base/MemoryDownloader.cpp b/netwerk/base/MemoryDownloader.cpp
new file mode 100644
index 0000000000..afb4552cca
--- /dev/null
+++ b/netwerk/base/MemoryDownloader.cpp
@@ -0,0 +1,71 @@
+/* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MemoryDownloader.h"
+
+#include "mozilla/Assertions.h"
+#include "nsIInputStream.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(MemoryDownloader, nsIStreamListener, nsIRequestObserver)
+
+MemoryDownloader::MemoryDownloader(IObserver* aObserver)
+    : mObserver(aObserver), mStatus(NS_ERROR_NOT_INITIALIZED) {}
+
+NS_IMETHODIMP
+MemoryDownloader::OnStartRequest(nsIRequest* aRequest) {
+  MOZ_ASSERT(!mData);
+  mData.reset(new FallibleTArray<uint8_t>());
+  mStatus = NS_OK;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+MemoryDownloader::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  MOZ_ASSERT_IF(NS_FAILED(mStatus), NS_FAILED(aStatus));
+  MOZ_ASSERT(!mData == NS_FAILED(mStatus));
+  Data data;
+  data.swap(mData);
+  RefPtr<IObserver> observer;
+  observer.swap(mObserver);
+  observer->OnDownloadComplete(this, aRequest, aStatus, std::move(data));
+  return NS_OK;
+}
+
+nsresult MemoryDownloader::ConsumeData(nsIInputStream* aIn, void* aClosure,
+                                       const char* aFromRawSegment,
+                                       uint32_t aToOffset, uint32_t aCount,
+                                       uint32_t* aWriteCount) {
+  MemoryDownloader* self = static_cast<MemoryDownloader*>(aClosure);
+  if (!self->mData->AppendElements(aFromRawSegment, aCount, fallible)) {
+    // The error returned by ConsumeData isn't propagated to the
+    // return of ReadSegments, so it has to be passed as state.
+    self->mStatus = NS_ERROR_OUT_OF_MEMORY;
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  *aWriteCount = aCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+MemoryDownloader::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aInStr,
+                                  uint64_t aSourceOffset, uint32_t aCount) {
+  uint32_t n;
+  MOZ_ASSERT(mData);
+  nsresult rv = aInStr->ReadSegments(ConsumeData, this, aCount, &n);
+  if (NS_SUCCEEDED(mStatus) && NS_FAILED(rv)) {
+    mStatus = rv;
+  }
+  if (NS_WARN_IF(NS_FAILED(mStatus))) {
+    mData.reset(nullptr);
+    return mStatus;
+  }
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/MemoryDownloader.h b/netwerk/base/MemoryDownloader.h
new file mode 100644
index 0000000000..8b5700f5bf
--- /dev/null
+++ b/netwerk/base/MemoryDownloader.h
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_MemoryDownloader_h__
+#define mozilla_net_MemoryDownloader_h__
+
+#include "mozilla/UniquePtr.h"
+#include "nsCOMPtr.h"
+#include "nsIStreamListener.h"
+#include "nsTArray.h"
+
+/**
+ * mozilla::net::MemoryDownloader
+ *
+ * This class is similar to nsIDownloader, but stores the downloaded
+ * stream in memory instead of a file.  Ownership of the temporary
+ * memory is transferred to the observer when download is complete;
+ * there is no need to retain a reference to the downloader.
+ */
+
+namespace mozilla {
+namespace net {
+
+class MemoryDownloader final : public nsIStreamListener {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  using Data = mozilla::UniquePtr<FallibleTArray<uint8_t>>;
+
+  class IObserver : public nsISupports {
+   public:
+    // Note: aData may be null if (and only if) aStatus indicates failure.
+    virtual void OnDownloadComplete(MemoryDownloader* aDownloader,
+                                    nsIRequest* aRequest, nsresult aStatus,
+                                    Data aData) = 0;
+  };
+
+  explicit MemoryDownloader(IObserver* aObserver);
+
+ private:
+  virtual ~MemoryDownloader() = default;
+
+  static nsresult ConsumeData(nsIInputStream* in, void* closure,
+                              const char* fromRawSegment, uint32_t toOffset,
+                              uint32_t count, uint32_t* writeCount);
+
+  RefPtr<IObserver> mObserver;
+  Data mData;
+  nsresult mStatus;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_MemoryDownloader_h__
diff --git a/netwerk/base/NetUtil.sys.mjs b/netwerk/base/NetUtil.sys.mjs
new file mode 100644
index 0000000000..679c9979a7
--- /dev/null
+++ b/netwerk/base/NetUtil.sys.mjs
@@ -0,0 +1,453 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 4 -*-
+ * vim: sw=4 ts=4 sts=4 et filetype=javascript
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Necko utilities
+ */
+
+// //////////////////////////////////////////////////////////////////////////////
+// // Constants
+
+const PR_UINT32_MAX = 0xffffffff;
+
+const BinaryInputStream = Components.Constructor(
+  "@mozilla.org/binaryinputstream;1",
+  "nsIBinaryInputStream",
+  "setInputStream"
+);
+
+// //////////////////////////////////////////////////////////////////////////////
+// // NetUtil Object
+
+export var NetUtil = {
+  /**
+   * Function to perform simple async copying from aSource (an input stream)
+   * to aSink (an output stream).  The copy will happen on some background
+   * thread.  Both streams will be closed when the copy completes.
+   *
+   * @param aSource
+   *        The input stream to read from
+   * @param aSink
+   *        The output stream to write to
+   * @param aCallback [optional]
+   *        A function that will be called at copy completion with a single
+   *        argument: the nsresult status code for the copy operation.
+   *
+   * @return An nsIRequest representing the copy operation (for example, this
+   *         can be used to cancel the copying).  The consumer can ignore the
+   *         return value if desired.
+   */
+  asyncCopy: function NetUtil_asyncCopy(aSource, aSink, aCallback = null) {
+    if (!aSource || !aSink) {
+      let exception = new Components.Exception(
+        "Must have a source and a sink",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    // make a stream copier
+    var copier = Cc[
+      "@mozilla.org/network/async-stream-copier;1"
+    ].createInstance(Ci.nsIAsyncStreamCopier2);
+    copier.init(
+      aSource,
+      aSink,
+      null /* Default event target */,
+      0 /* Default length */,
+      true,
+      true /* Auto-close */
+    );
+
+    var observer;
+    if (aCallback) {
+      observer = {
+        onStartRequest(aRequest) {},
+        onStopRequest(aRequest, aStatusCode) {
+          aCallback(aStatusCode);
+        },
+      };
+    } else {
+      observer = null;
+    }
+
+    // start the copying
+    copier.QueryInterface(Ci.nsIAsyncStreamCopier).asyncCopy(observer, null);
+    return copier;
+  },
+
+  /**
+   * Asynchronously opens a source and fetches the response.  While the fetch
+   * is asynchronous, I/O may happen on the main thread.  When reading from
+   * a local file, prefer using IOUtils methods instead.
+   *
+   * @param aSource
+   *        This argument can be one of the following:
+   *         - An options object that will be passed to NetUtil.newChannel.
+   *         - An existing nsIChannel.
+   *         - An existing nsIInputStream.
+   *        Using an nsIURI, nsIFile, or string spec directly is deprecated.
+   * @param aCallback
+   *        The callback function that will be notified upon completion.  It
+   *        will get these arguments:
+   *        1) An nsIInputStream containing the data from aSource, if any.
+   *        2) The status code from opening the source.
+   *        3) Reference to the nsIRequest.
+   */
+  asyncFetch: function NetUtil_asyncFetch(aSource, aCallback) {
+    if (!aSource || !aCallback) {
+      let exception = new Components.Exception(
+        "Must have a source and a callback",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    // Create a pipe that will create our output stream that we can use once
+    // we have gotten all the data.
+    let pipe = Cc["@mozilla.org/pipe;1"].createInstance(Ci.nsIPipe);
+    pipe.init(true, true, 0, PR_UINT32_MAX, null);
+
+    // Create a listener that will give data to the pipe's output stream.
+    let listener = Cc[
+      "@mozilla.org/network/simple-stream-listener;1"
+    ].createInstance(Ci.nsISimpleStreamListener);
+    listener.init(pipe.outputStream, {
+      onStartRequest(aRequest) {},
+      onStopRequest(aRequest, aStatusCode) {
+        pipe.outputStream.close();
+        aCallback(pipe.inputStream, aStatusCode, aRequest);
+      },
+    });
+
+    // Input streams are handled slightly differently from everything else.
+    if (aSource instanceof Ci.nsIInputStream) {
+      let pump = Cc["@mozilla.org/network/input-stream-pump;1"].createInstance(
+        Ci.nsIInputStreamPump
+      );
+      pump.init(aSource, 0, 0, true);
+      pump.asyncRead(listener, null);
+      return;
+    }
+
+    let channel = aSource;
+    if (!(channel instanceof Ci.nsIChannel)) {
+      channel = this.newChannel(aSource);
+    }
+
+    try {
+      channel.asyncOpen(listener);
+    } catch (e) {
+      let exception = new Components.Exception(
+        "Failed to open input source '" + channel.originalURI.spec + "'",
+        e.result,
+        Components.stack.caller,
+        aSource,
+        e
+      );
+      throw exception;
+    }
+  },
+
+  /**
+   * Constructs a new URI for the given spec, character set, and base URI, or
+   * an nsIFile.
+   *
+   * @param aTarget
+   *        The string spec for the desired URI or an nsIFile.
+   * @param aOriginCharset [optional]
+   *        The character set for the URI.  Only used if aTarget is not an
+   *        nsIFile.
+   * @param aBaseURI [optional]
+   *        The base URI for the spec.  Only used if aTarget is not an
+   *        nsIFile.
+   *
+   * @return an nsIURI object.
+   */
+  newURI: function NetUtil_newURI(aTarget, aOriginCharset, aBaseURI) {
+    if (!aTarget) {
+      let exception = new Components.Exception(
+        "Must have a non-null string spec or nsIFile object",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    if (aTarget instanceof Ci.nsIFile) {
+      return Services.io.newFileURI(aTarget);
+    }
+
+    return Services.io.newURI(aTarget, aOriginCharset, aBaseURI);
+  },
+
+  /**
+   * Constructs a new channel for the given source.
+   *
+   * Keep in mind that URIs coming from a webpage should *never* use the
+   * systemPrincipal as the loadingPrincipal.
+   *
+   * @param aWhatToLoad
+   *        This argument used to be a string spec for the desired URI, an
+   *        nsIURI, or an nsIFile.  Now it should be an options object with
+   *        the following properties:
+   *        {
+   *          uri:
+   *            The full URI spec string, nsIURI or nsIFile to create the
+   *            channel for.
+   *            Note that this cannot be an nsIFile if you have to specify a
+   *            non-default charset or base URI.  Call NetUtil.newURI first if
+   *            you need to construct an URI using those options.
+   *          loadingNode:
+   *          loadingPrincipal:
+   *          triggeringPrincipal:
+   *          securityFlags:
+   *          contentPolicyType:
+   *            These will be used as values for the nsILoadInfo object on the
+   *            created channel. For details, see nsILoadInfo in nsILoadInfo.idl
+   *          loadUsingSystemPrincipal:
+   *            Set this to true to use the system principal as
+   *            loadingPrincipal.  This must be omitted if loadingPrincipal or
+   *            loadingNode are present.
+   *            This should be used with care as it skips security checks.
+   *        }
+   * @return an nsIChannel object.
+   */
+  newChannel: function NetUtil_newChannel(aWhatToLoad) {
+    // Make sure the API is called using only the options object.
+    if (typeof aWhatToLoad != "object" || arguments.length != 1) {
+      throw new Components.Exception(
+        "newChannel requires a single object argument",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+    }
+
+    let {
+      uri,
+      loadingNode,
+      loadingPrincipal,
+      loadUsingSystemPrincipal,
+      triggeringPrincipal,
+      securityFlags,
+      contentPolicyType,
+    } = aWhatToLoad;
+
+    if (!uri) {
+      throw new Components.Exception(
+        "newChannel requires the 'uri' property on the options object.",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+    }
+
+    if (typeof uri == "string" || uri instanceof Ci.nsIFile) {
+      uri = this.newURI(uri);
+    }
+
+    if (!loadingNode && !loadingPrincipal && !loadUsingSystemPrincipal) {
+      throw new Components.Exception(
+        "newChannel requires at least one of the 'loadingNode'," +
+          " 'loadingPrincipal', or 'loadUsingSystemPrincipal'" +
+          " properties on the options object.",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+    }
+
+    if (loadUsingSystemPrincipal === true) {
+      if (loadingNode || loadingPrincipal) {
+        throw new Components.Exception(
+          "newChannel does not accept 'loadUsingSystemPrincipal'" +
+            " if the 'loadingNode' or 'loadingPrincipal' properties" +
+            " are present on the options object.",
+          Cr.NS_ERROR_INVALID_ARG,
+          Components.stack.caller
+        );
+      }
+      loadingPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+    } else if (loadUsingSystemPrincipal !== undefined) {
+      throw new Components.Exception(
+        "newChannel requires the 'loadUsingSystemPrincipal'" +
+          " property on the options object to be 'true' or 'undefined'.",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+    }
+
+    if (securityFlags === undefined) {
+      if (!loadUsingSystemPrincipal) {
+        throw new Components.Exception(
+          "newChannel requires the 'securityFlags' property on" +
+            " the options object unless loading from system principal.",
+          Cr.NS_ERROR_INVALID_ARG,
+          Components.stack.caller
+        );
+      }
+      securityFlags = Ci.nsILoadInfo.SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL;
+    }
+
+    if (contentPolicyType === undefined) {
+      if (!loadUsingSystemPrincipal) {
+        throw new Components.Exception(
+          "newChannel requires the 'contentPolicyType' property on" +
+            " the options object unless loading from system principal.",
+          Cr.NS_ERROR_INVALID_ARG,
+          Components.stack.caller
+        );
+      }
+      contentPolicyType = Ci.nsIContentPolicy.TYPE_OTHER;
+    }
+
+    let channel = Services.io.newChannelFromURI(
+      uri,
+      loadingNode || null,
+      loadingPrincipal || null,
+      triggeringPrincipal || null,
+      securityFlags,
+      contentPolicyType
+    );
+    if (loadUsingSystemPrincipal) {
+      channel.loadInfo.allowDeprecatedSystemRequests = true;
+    }
+    return channel;
+  },
+
+  newWebTransport: function NetUtil_newWebTransport() {
+    return Services.io.newWebTransport();
+  },
+
+  /**
+   * Reads aCount bytes from aInputStream into a string.
+   *
+   * @param aInputStream
+   *        The input stream to read from.
+   * @param aCount
+   *        The number of bytes to read from the stream.
+   * @param aOptions [optional]
+   *        charset
+   *          The character encoding of stream data.
+   *        replacement
+   *          The character to replace unknown byte sequences.
+   *          If unset, it causes an exceptions to be thrown.
+   *
+   * @return the bytes from the input stream in string form.
+   *
+   * @throws NS_ERROR_INVALID_ARG if aInputStream is not an nsIInputStream.
+   * @throws NS_BASE_STREAM_WOULD_BLOCK if reading from aInputStream would
+   *         block the calling thread (non-blocking mode only).
+   * @throws NS_ERROR_FAILURE if there are not enough bytes available to read
+   *         aCount amount of data.
+   * @throws NS_ERROR_ILLEGAL_INPUT if aInputStream has invalid sequences
+   */
+  readInputStreamToString: function NetUtil_readInputStreamToString(
+    aInputStream,
+    aCount,
+    aOptions
+  ) {
+    if (!(aInputStream instanceof Ci.nsIInputStream)) {
+      let exception = new Components.Exception(
+        "First argument should be an nsIInputStream",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    if (!aCount) {
+      let exception = new Components.Exception(
+        "Non-zero amount of bytes must be specified",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    if (aOptions && "charset" in aOptions) {
+      let cis = Cc["@mozilla.org/intl/converter-input-stream;1"].createInstance(
+        Ci.nsIConverterInputStream
+      );
+      try {
+        // When replacement is set, the character that is unknown sequence
+        // replaces with aOptions.replacement character.
+        if (!("replacement" in aOptions)) {
+          // aOptions.replacement isn't set.
+          // If input stream has unknown sequences for aOptions.charset,
+          // throw NS_ERROR_ILLEGAL_INPUT.
+          aOptions.replacement = 0;
+        }
+
+        cis.init(aInputStream, aOptions.charset, aCount, aOptions.replacement);
+        let str = {};
+        cis.readString(-1, str);
+        cis.close();
+        return str.value;
+      } catch (e) {
+        // Adjust the stack so it throws at the caller's location.
+        throw new Components.Exception(
+          e.message,
+          e.result,
+          Components.stack.caller,
+          e.data
+        );
+      }
+    }
+
+    let sis = Cc["@mozilla.org/scriptableinputstream;1"].createInstance(
+      Ci.nsIScriptableInputStream
+    );
+    sis.init(aInputStream);
+    try {
+      return sis.readBytes(aCount);
+    } catch (e) {
+      // Adjust the stack so it throws at the caller's location.
+      throw new Components.Exception(
+        e.message,
+        e.result,
+        Components.stack.caller,
+        e.data
+      );
+    }
+  },
+
+  /**
+   * Reads aCount bytes from aInputStream into a string.
+   *
+   * @param {nsIInputStream} aInputStream
+   *        The input stream to read from.
+   * @param {integer} [aCount = aInputStream.available()]
+   *        The number of bytes to read from the stream.
+   *
+   * @return the bytes from the input stream in string form.
+   *
+   * @throws NS_ERROR_INVALID_ARG if aInputStream is not an nsIInputStream.
+   * @throws NS_BASE_STREAM_WOULD_BLOCK if reading from aInputStream would
+   *         block the calling thread (non-blocking mode only).
+   * @throws NS_ERROR_FAILURE if there are not enough bytes available to read
+   *         aCount amount of data.
+   */
+  readInputStream(aInputStream, aCount) {
+    if (!(aInputStream instanceof Ci.nsIInputStream)) {
+      let exception = new Components.Exception(
+        "First argument should be an nsIInputStream",
+        Cr.NS_ERROR_INVALID_ARG,
+        Components.stack.caller
+      );
+      throw exception;
+    }
+
+    if (!aCount) {
+      aCount = aInputStream.available();
+    }
+
+    let stream = new BinaryInputStream(aInputStream);
+    let result = new ArrayBuffer(aCount);
+    stream.readArrayBuffer(result.byteLength, result);
+    return result;
+  },
+};
diff --git a/netwerk/base/NetworkConnectivityService.cpp b/netwerk/base/NetworkConnectivityService.cpp
new file mode 100644
index 0000000000..f68728db7b
--- /dev/null
+++ b/netwerk/base/NetworkConnectivityService.cpp
@@ -0,0 +1,552 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DNSUtils.h"
+#include "NetworkConnectivityService.h"
+#include "mozilla/net/SocketProcessParent.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Services.h"
+#include "nsCOMPtr.h"
+#include "nsIOService.h"
+#include "nsICancelable.h"
+#include "xpcpublic.h"
+#include "nsSocketTransport2.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsINetworkLinkService.h"
+#include "mozilla/StaticPrefs_network.h"
+
+static mozilla::LazyLogModule gNCSLog("NetworkConnectivityService");
+#undef LOG
+#define LOG(args) MOZ_LOG(gNCSLog, mozilla::LogLevel::Debug, args)
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(NetworkConnectivityService, nsIDNSListener, nsIObserver,
+                  nsINetworkConnectivityService, nsIStreamListener)
+
+static StaticRefPtr<NetworkConnectivityService> gConnService;
+
+NetworkConnectivityService::NetworkConnectivityService()
+    : mDNSv4(UNKNOWN),
+      mDNSv6(UNKNOWN),
+      mIPv4(UNKNOWN),
+      mIPv6(UNKNOWN),
+      mNAT64(UNKNOWN),
+      mLock("nat64prefixes") {}
+
+// static
+already_AddRefed<NetworkConnectivityService>
+NetworkConnectivityService::GetSingleton() {
+  if (gConnService) {
+    return do_AddRef(gConnService);
+  }
+
+  RefPtr<NetworkConnectivityService> service = new NetworkConnectivityService();
+  service->Init();
+
+  gConnService = std::move(service);
+  ClearOnShutdown(&gConnService);
+  return do_AddRef(gConnService);
+}
+
+nsresult NetworkConnectivityService::Init() {
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+  observerService->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
+  observerService->AddObserver(this, "network:captive-portal-connectivity",
+                               false);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::GetDNSv4(ConnectivityState* aState) {
+  NS_ENSURE_ARG(aState);
+  *aState = mDNSv4;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::GetDNSv6(ConnectivityState* aState) {
+  NS_ENSURE_ARG(aState);
+  *aState = mDNSv6;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::GetIPv4(ConnectivityState* aState) {
+  NS_ENSURE_ARG(aState);
+  *aState = mIPv4;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::GetIPv6(ConnectivityState* aState) {
+  NS_ENSURE_ARG(aState);
+  *aState = mIPv6;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::GetNAT64(ConnectivityState* aState) {
+  NS_ENSURE_ARG(aState);
+  *aState = mNAT64;
+  return NS_OK;
+}
+
+already_AddRefed<AddrInfo> NetworkConnectivityService::MapNAT64IPs(
+    AddrInfo* aNewRRSet) {
+  // Add prefixes only if there are no IPv6 addresses.
+  // Expect that if aNewRRSet has IPv6 addresses, they must come
+  // before IPv4 addresses.
+  if (aNewRRSet->Addresses().IsEmpty() ||
+      aNewRRSet->Addresses()[0].raw.family == PR_AF_INET6) {
+    return do_AddRef(aNewRRSet);
+  }
+
+  // Currently we only add prefixes to the first IP's clones.
+  uint32_t ip = aNewRRSet->Addresses()[0].inet.ip;
+  nsTArray<NetAddr> addresses = aNewRRSet->Addresses().Clone();
+
+  {
+    MutexAutoLock lock(mLock);
+    for (const auto& prefix : mNAT64Prefixes) {
+      NetAddr addr = NetAddr(prefix);
+
+      // Copy the IPv4 address to the end
+      addr.inet6.ip.u32[3] = ip;
+
+      // If we have both IPv4 and NAT64, we be could insourcing NAT64
+      // to avoid double NAT and improve performance. However, this
+      // breaks WebRTC, so we push it to the back.
+      addresses.AppendElement(addr);
+    }
+  }
+
+  auto builder = aNewRRSet->Build();
+  builder.SetAddresses(std::move(addresses));
+  return builder.Finish();
+}
+
+// Returns true if a prefix was read and saved to the argument
+static inline bool NAT64PrefixFromPref(NetAddr* prefix) {
+  nsAutoCString nat64PrefixPref;
+
+  nsresult rv = Preferences::GetCString(
+      "network.connectivity-service.nat64-prefix", nat64PrefixPref);
+  return !(NS_FAILED(rv) || nat64PrefixPref.IsEmpty() ||
+           NS_FAILED(prefix->InitFromString(nat64PrefixPref)) ||
+           prefix->raw.family != PR_AF_INET6);
+}
+
+static inline bool NAT64PrefixCompare(const NetAddr& prefix1,
+                                      const NetAddr& prefix2) {
+  // Compare the first 96 bits as 64 + 32
+  return prefix1.inet6.ip.u64[0] == prefix2.inet6.ip.u64[0] &&
+         prefix1.inet6.ip.u32[2] == prefix2.inet6.ip.u32[2];
+}
+
+void NetworkConnectivityService::PerformChecks() {
+  mDNSv4 = UNKNOWN;
+  mDNSv6 = UNKNOWN;
+
+  mIPv4 = UNKNOWN;
+  mIPv6 = UNKNOWN;
+
+  mNAT64 = UNKNOWN;
+
+  {
+    MutexAutoLock lock(mLock);
+    mNAT64Prefixes.Clear();
+
+    // NAT64 checks might be disabled.
+    // Since We can't guarantee a DNS response, we should set up
+    // NAT64 manually now if needed.
+
+    NetAddr priorityPrefix{};
+    bool havePrefix = NAT64PrefixFromPref(&priorityPrefix);
+    if (havePrefix) {
+      mNAT64Prefixes.AppendElement(priorityPrefix);
+      mNAT64 = OK;
+    }
+  }
+
+  RecheckDNS();
+  RecheckIPConnectivity();
+}
+
+static inline void NotifyObservers(const char* aTopic) {
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  obs->NotifyObservers(nullptr, aTopic, nullptr);
+}
+
+void NetworkConnectivityService::SaveNAT64Prefixes(nsIDNSRecord* aRecord) {
+  nsCOMPtr<nsIDNSAddrRecord> rec = do_QueryInterface(aRecord);
+  MutexAutoLock lock(mLock);
+  mNAT64Prefixes.Clear();
+
+  NetAddr priorityPrefix{};
+  bool havePrefix = NAT64PrefixFromPref(&priorityPrefix);
+  if (havePrefix) {
+    mNAT64 = OK;
+    mNAT64Prefixes.AppendElement(priorityPrefix);
+  }
+
+  if (!rec) {
+    if (!havePrefix) {
+      mNAT64 = NOT_AVAILABLE;
+    }
+    return;
+  }
+
+  mNAT64 = UNKNOWN;
+  NetAddr addr{};
+
+  // use port 80 as dummy value for NetAddr
+  while (NS_SUCCEEDED(rec->GetNextAddr(80, &addr))) {
+    if (addr.raw.family != AF_INET6 || addr.IsIPAddrV4Mapped()) {
+      // These are not the kind of addresses we are looking for.
+      continue;
+    }
+
+    // RFC 7050 does not require the embedded IPv4 to be
+    // at the end of IPv6. In practice, and as we assume,
+    // it is always at the end.
+    // The embedded IP must be 192.0.0.170 or 192.0.0.171
+
+    // Clear the last bit to compare with the next one.
+    addr.inet6.ip.u8[15] &= ~(uint32_t)1;
+    if ((addr.inet6.ip.u8[12] != 192) || (addr.inet6.ip.u8[13] != 0) ||
+        (addr.inet6.ip.u8[14] != 0) || (addr.inet6.ip.u8[15] != 170)) {
+      continue;
+    }
+
+    mNAT64Prefixes.AppendElement(addr);
+  }
+
+  size_t length = mNAT64Prefixes.Length();
+  if (length == 0) {
+    mNAT64 = NOT_AVAILABLE;
+    return;
+  }
+
+  // Remove duplicates. Typically a DNS64 resolver sends every
+  // prefix twice with address with different last bits. We want
+  // a list of unique prefixes while reordering is not allowed.
+  // We must not handle the case with an element in-between
+  // two identical ones, which is never the case for a properly
+  // configured DNS64 resolver.
+
+  NetAddr prev = mNAT64Prefixes[0];
+
+  for (size_t i = 1; i < length; i++) {
+    if (NAT64PrefixCompare(prev, mNAT64Prefixes[i])) {
+      mNAT64Prefixes.RemoveElementAt(i);
+      i--;
+      length--;
+    } else {
+      prev = mNAT64Prefixes[i];
+    }
+  }
+
+  // The prioritized address might also appear in the record we received.
+
+  if (havePrefix) {
+    for (size_t i = 1; i < length; i++) {
+      if (NAT64PrefixCompare(priorityPrefix, mNAT64Prefixes[i])) {
+        mNAT64Prefixes.RemoveElementAt(i);
+        // It wouldn't appear more than once.
+        break;
+      }
+    }
+  }
+
+  mNAT64 = OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::OnLookupComplete(nsICancelable* aRequest,
+                                             nsIDNSRecord* aRecord,
+                                             nsresult aStatus) {
+  ConnectivityState state = NS_SUCCEEDED(aStatus) ? OK : NOT_AVAILABLE;
+
+  if (aRequest == mDNSv4Request) {
+    mDNSv4 = state;
+    mDNSv4Request = nullptr;
+  } else if (aRequest == mDNSv6Request) {
+    mDNSv6 = state;
+    mDNSv6Request = nullptr;
+  } else if (aRequest == mNAT64Request) {
+    mNAT64Request = nullptr;
+    SaveNAT64Prefixes(aRecord);
+  }
+
+  if (!mDNSv4Request && !mDNSv6Request && !mNAT64Request) {
+    NotifyObservers("network:connectivity-service:dns-checks-complete");
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::RecheckDNS() {
+  bool enabled =
+      Preferences::GetBool("network.connectivity-service.enabled", false);
+  if (!enabled) {
+    return NS_OK;
+  }
+
+  if (nsIOService::UseSocketProcess()) {
+    SocketProcessParent* parent = SocketProcessParent::GetSingleton();
+    if (parent) {
+      Unused << parent->SendRecheckDNS();
+    }
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
+  OriginAttributes attrs;
+  nsAutoCString host;
+  Preferences::GetCString("network.connectivity-service.DNSv4.domain", host);
+
+  rv = dns->AsyncResolveNative(host, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+                               nsIDNSService::RESOLVE_DISABLE_IPV6 |
+                                   nsIDNSService::RESOLVE_TRR_DISABLED_MODE,
+                               nullptr, this, NS_GetCurrentThread(), attrs,
+                               getter_AddRefs(mDNSv4Request));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  Preferences::GetCString("network.connectivity-service.DNSv6.domain", host);
+  rv = dns->AsyncResolveNative(host, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+                               nsIDNSService::RESOLVE_DISABLE_IPV4 |
+                                   nsIDNSService::RESOLVE_TRR_DISABLED_MODE,
+                               nullptr, this, NS_GetCurrentThread(), attrs,
+                               getter_AddRefs(mDNSv6Request));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (StaticPrefs::network_connectivity_service_nat64_check()) {
+    rv = dns->AsyncResolveNative("ipv4only.arpa"_ns,
+                                 nsIDNSService::RESOLVE_TYPE_DEFAULT,
+                                 nsIDNSService::RESOLVE_DISABLE_IPV4 |
+                                     nsIDNSService::RESOLVE_TRR_DISABLED_MODE,
+                                 nullptr, this, NS_GetCurrentThread(), attrs,
+                                 getter_AddRefs(mNAT64Request));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::Observe(nsISupports* aSubject, const char* aTopic,
+                                    const char16_t* aData) {
+  if (!strcmp(aTopic, "network:captive-portal-connectivity")) {
+    // Captive portal is cleared, so we redo the checks.
+    PerformChecks();
+  } else if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    if (mDNSv4Request) {
+      mDNSv4Request->Cancel(NS_ERROR_ABORT);
+      mDNSv4Request = nullptr;
+    }
+    if (mDNSv6Request) {
+      mDNSv6Request->Cancel(NS_ERROR_ABORT);
+      mDNSv6Request = nullptr;
+    }
+    if (mNAT64Request) {
+      mNAT64Request->Cancel(NS_ERROR_ABORT);
+      mNAT64Request = nullptr;
+    }
+
+    nsCOMPtr<nsIObserverService> observerService =
+        mozilla::services::GetObserverService();
+    observerService->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+    observerService->RemoveObserver(this,
+                                    "network:captive-portal-connectivity");
+    observerService->RemoveObserver(this, NS_NETWORK_LINK_TOPIC);
+  } else if (!strcmp(aTopic, NS_NETWORK_LINK_TOPIC) &&
+             !NS_LITERAL_STRING_FROM_CSTRING(NS_NETWORK_LINK_DATA_UNKNOWN)
+                  .Equals(aData)) {
+    PerformChecks();
+  }
+
+  return NS_OK;
+}
+
+already_AddRefed<nsIChannel> NetworkConnectivityService::SetupIPCheckChannel(
+    bool ipv4) {
+  nsresult rv;
+  nsAutoCString url;
+
+  if (ipv4) {
+    rv = Preferences::GetCString("network.connectivity-service.IPv4.url", url);
+  } else {
+    rv = Preferences::GetCString("network.connectivity-service.IPv6.url", url);
+  }
+  NS_ENSURE_SUCCESS(rv, nullptr);
+
+  nsCOMPtr<nsIURI> uri;
+  rv = NS_NewURI(getter_AddRefs(uri), url);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+
+  nsCOMPtr<nsIChannel> channel;
+  if (XRE_IsSocketProcess()) {
+    rv = DNSUtils::CreateChannelHelper(uri, getter_AddRefs(channel));
+    if (NS_FAILED(rv)) {
+      return nullptr;
+    }
+    channel->SetLoadFlags(
+        nsIRequest::LOAD_BYPASS_CACHE |  // don't read from the cache
+        nsIRequest::INHIBIT_CACHING |    // don't write the response to cache
+        nsIRequest::LOAD_ANONYMOUS);
+  } else {
+    rv = NS_NewChannel(
+        getter_AddRefs(channel), uri, nsContentUtils::GetSystemPrincipal(),
+        nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+        nsIContentPolicy::TYPE_OTHER,
+        nullptr,  // nsICookieJarSettings
+        nullptr,  // aPerformanceStorage
+        nullptr,  // aLoadGroup
+        nullptr,
+        nsIRequest::LOAD_BYPASS_CACHE |    // don't read from the cache
+            nsIRequest::INHIBIT_CACHING |  // don't write the response to cache
+            nsIRequest::LOAD_ANONYMOUS);   // prevent privacy leaks
+    NS_ENSURE_SUCCESS(rv, nullptr);
+
+    {
+      // Prevent HTTPS-Only Mode from upgrading the OCSP request.
+      nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+      uint32_t httpsOnlyStatus = loadInfo->GetHttpsOnlyStatus();
+      httpsOnlyStatus |= nsILoadInfo::HTTPS_ONLY_EXEMPT;
+      loadInfo->SetHttpsOnlyStatus(httpsOnlyStatus);
+
+      // allow deprecated HTTP request from SystemPrincipal
+      loadInfo->SetAllowDeprecatedSystemRequests(true);
+    }
+  }
+
+  rv = channel->SetTRRMode(nsIRequest::TRR_DISABLED_MODE);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+
+  nsCOMPtr<nsIHttpChannelInternal> internalChan = do_QueryInterface(channel);
+  NS_ENSURE_TRUE(internalChan, nullptr);
+
+  if (ipv4) {
+    internalChan->SetIPv6Disabled();
+  } else {
+    internalChan->SetIPv4Disabled();
+  }
+
+  return channel.forget();
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::RecheckIPConnectivity() {
+  bool enabled =
+      Preferences::GetBool("network.connectivity-service.enabled", false);
+  if (!enabled) {
+    return NS_OK;
+  }
+
+  if (nsIOService::UseSocketProcess()) {
+    SocketProcessParent* parent = SocketProcessParent::GetSingleton();
+    if (parent) {
+      Unused << parent->SendRecheckIPConnectivity();
+    }
+  }
+
+  if (xpc::AreNonLocalConnectionsDisabled() &&
+      !Preferences::GetBool("network.captive-portal-service.testMode", false)) {
+    return NS_OK;
+  }
+
+  if (mIPv4Channel) {
+    mIPv4Channel->Cancel(NS_ERROR_ABORT);
+    mIPv4Channel = nullptr;
+  }
+  if (mIPv6Channel) {
+    mIPv6Channel->Cancel(NS_ERROR_ABORT);
+    mIPv6Channel = nullptr;
+  }
+
+  nsresult rv;
+  mHasNetworkId = false;
+  mCheckedNetworkId = false;
+  mIPv4Channel = SetupIPCheckChannel(/* ipv4 = */ true);
+  if (mIPv4Channel) {
+    rv = mIPv4Channel->AsyncOpen(this);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  mIPv6Channel = SetupIPCheckChannel(/* ipv4 = */ false);
+  if (mIPv6Channel) {
+    rv = mIPv6Channel->AsyncOpen(this);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::OnStartRequest(nsIRequest* aRequest) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::OnStopRequest(nsIRequest* aRequest,
+                                          nsresult aStatusCode) {
+  if (aStatusCode == NS_ERROR_ABORT) {
+    return NS_OK;
+  }
+
+  ConnectivityState status = NS_FAILED(aStatusCode) ? NOT_AVAILABLE : OK;
+
+  if (aRequest == mIPv4Channel) {
+    mIPv4 = status;
+    mIPv4Channel = nullptr;
+
+    if (mIPv4 == nsINetworkConnectivityService::OK) {
+      Telemetry::AccumulateCategorical(
+          mHasNetworkId ? Telemetry::LABELS_NETWORK_ID_ONLINE::present
+                        : Telemetry::LABELS_NETWORK_ID_ONLINE::absent);
+      LOG(("mHasNetworkId : %d\n", mHasNetworkId));
+    }
+  } else if (aRequest == mIPv6Channel) {
+    mIPv6 = status;
+    mIPv6Channel = nullptr;
+  }
+
+  if (!mIPv6Channel && !mIPv4Channel) {
+    NotifyObservers("network:connectivity-service:ip-checks-complete");
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+NetworkConnectivityService::OnDataAvailable(nsIRequest* aRequest,
+                                            nsIInputStream* aInputStream,
+                                            uint64_t aOffset, uint32_t aCount) {
+  nsAutoCString data;
+
+  // We perform this check here, instead of doing it in OnStopRequest in case
+  // a network down event occurs after the data has arrived but before we fire
+  // OnStopRequest. That would cause us to report a missing networkID, even
+  // though it was not empty while receiving data.
+  if (aRequest == mIPv4Channel && !mCheckedNetworkId) {
+    nsCOMPtr<nsINetworkLinkService> nls =
+        do_GetService(NS_NETWORK_LINK_SERVICE_CONTRACTID);
+    nsAutoCString networkId;
+    if (nls) {
+      nls->GetNetworkID(networkId);
+    }
+    mHasNetworkId = !networkId.IsEmpty();
+    mCheckedNetworkId = true;
+  }
+
+  Unused << NS_ReadInputStreamToString(aInputStream, data, aCount);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/NetworkConnectivityService.h b/netwerk/base/NetworkConnectivityService.h
new file mode 100644
index 0000000000..6315fb192b
--- /dev/null
+++ b/netwerk/base/NetworkConnectivityService.h
@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NetworkConnectivityService_h_
+#define NetworkConnectivityService_h_
+
+#include "nsINetworkConnectivityService.h"
+#include "nsCOMPtr.h"
+#include "nsIObserver.h"
+#include "nsIDNSListener.h"
+#include "nsIStreamListener.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+class NetworkConnectivityService : public nsINetworkConnectivityService,
+                                   public nsIObserver,
+                                   public nsIDNSListener,
+                                   public nsIStreamListener {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSINETWORKCONNECTIVITYSERVICE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIDNSLISTENER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSIREQUESTOBSERVER
+
+  already_AddRefed<AddrInfo> MapNAT64IPs(AddrInfo* aNewRRSet);
+
+  static already_AddRefed<NetworkConnectivityService> GetSingleton();
+
+ private:
+  NetworkConnectivityService();
+  virtual ~NetworkConnectivityService() = default;
+
+  nsresult Init();
+  // Calls all the check methods
+  void PerformChecks();
+
+  void SaveNAT64Prefixes(nsIDNSRecord* aRecord);
+
+  already_AddRefed<nsIChannel> SetupIPCheckChannel(bool ipv4);
+
+  // Will be set to OK if the DNS request returned in IP of this type,
+  //                NOT_AVAILABLE if that type of resolution is not available
+  //                UNKNOWN if the check wasn't performed
+  Atomic<ConnectivityState, Relaxed> mDNSv4;
+  Atomic<ConnectivityState, Relaxed> mDNSv6;
+
+  Atomic<ConnectivityState, Relaxed> mIPv4;
+  Atomic<ConnectivityState, Relaxed> mIPv6;
+
+  Atomic<ConnectivityState, Relaxed> mNAT64;
+
+  nsTArray<NetAddr> mNAT64Prefixes;
+
+  nsCOMPtr<nsICancelable> mDNSv4Request;
+  nsCOMPtr<nsICancelable> mDNSv6Request;
+  nsCOMPtr<nsICancelable> mNAT64Request;
+
+  nsCOMPtr<nsIChannel> mIPv4Channel;
+  nsCOMPtr<nsIChannel> mIPv6Channel;
+
+  bool mCheckedNetworkId = false;
+  bool mHasNetworkId = false;
+
+  Mutex mLock MOZ_UNANNOTATED;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // NetworkConnectivityService_h_
diff --git a/netwerk/base/NetworkDataCountLayer.cpp b/netwerk/base/NetworkDataCountLayer.cpp
new file mode 100644
index 0000000000..bee8bd1ee5
--- /dev/null
+++ b/netwerk/base/NetworkDataCountLayer.cpp
@@ -0,0 +1,138 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "NetworkDataCountLayer.h"
+#include "nsSocketTransportService2.h"
+#include "prmem.h"
+#include "prio.h"
+
+namespace mozilla {
+namespace net {
+
+static PRDescIdentity sNetworkDataCountLayerIdentity;
+static PRIOMethods sNetworkDataCountLayerMethods;
+static PRIOMethods* sNetworkDataCountLayerMethodsPtr = nullptr;
+
+class NetworkDataCountSecret {
+ public:
+  NetworkDataCountSecret() = default;
+
+  uint64_t mSentBytes = 0;
+  uint64_t mReceivedBytes = 0;
+};
+
+static PRInt32 NetworkDataCountSend(PRFileDesc* fd, const void* buf,
+                                    PRInt32 amount, PRIntn flags,
+                                    PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sNetworkDataCountLayerIdentity);
+
+  NetworkDataCountSecret* secret =
+      reinterpret_cast<NetworkDataCountSecret*>(fd->secret);
+
+  PRInt32 rv =
+      (fd->lower->methods->send)(fd->lower, buf, amount, flags, timeout);
+  if (rv > 0) {
+    secret->mSentBytes += rv;
+  }
+  return rv;
+}
+
+static PRInt32 NetworkDataCountWrite(PRFileDesc* fd, const void* buf,
+                                     PRInt32 amount) {
+  return NetworkDataCountSend(fd, buf, amount, 0, PR_INTERVAL_NO_WAIT);
+}
+
+static PRInt32 NetworkDataCountRecv(PRFileDesc* fd, void* buf, PRInt32 amount,
+                                    PRIntn flags, PRIntervalTime timeout) {
+  MOZ_RELEASE_ASSERT(fd->identity == sNetworkDataCountLayerIdentity);
+
+  NetworkDataCountSecret* secret =
+      reinterpret_cast<NetworkDataCountSecret*>(fd->secret);
+
+  PRInt32 rv =
+      (fd->lower->methods->recv)(fd->lower, buf, amount, flags, timeout);
+  if (rv > 0) {
+    secret->mReceivedBytes += rv;
+  }
+  return rv;
+}
+
+static PRInt32 NetworkDataCountRead(PRFileDesc* fd, void* buf, PRInt32 amount) {
+  return NetworkDataCountRecv(fd, buf, amount, 0, PR_INTERVAL_NO_WAIT);
+}
+
+static PRStatus NetworkDataCountClose(PRFileDesc* fd) {
+  if (!fd) {
+    return PR_FAILURE;
+  }
+
+  PRFileDesc* layer = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
+
+  MOZ_RELEASE_ASSERT(layer && layer->identity == sNetworkDataCountLayerIdentity,
+                     "NetworkDataCount Layer not on top of stack");
+
+  NetworkDataCountSecret* secret =
+      reinterpret_cast<NetworkDataCountSecret*>(layer->secret);
+  layer->secret = nullptr;
+  layer->dtor(layer);
+  delete secret;
+  return fd->methods->close(fd);
+}
+
+nsresult AttachNetworkDataCountLayer(PRFileDesc* fd) {
+  if (!sNetworkDataCountLayerMethodsPtr) {
+    sNetworkDataCountLayerIdentity =
+        PR_GetUniqueIdentity("NetworkDataCount Layer");
+    sNetworkDataCountLayerMethods = *PR_GetDefaultIOMethods();
+    sNetworkDataCountLayerMethods.send = NetworkDataCountSend;
+    sNetworkDataCountLayerMethods.write = NetworkDataCountWrite;
+    sNetworkDataCountLayerMethods.recv = NetworkDataCountRecv;
+    sNetworkDataCountLayerMethods.read = NetworkDataCountRead;
+    sNetworkDataCountLayerMethods.close = NetworkDataCountClose;
+    sNetworkDataCountLayerMethodsPtr = &sNetworkDataCountLayerMethods;
+  }
+
+  PRFileDesc* layer = PR_CreateIOLayerStub(sNetworkDataCountLayerIdentity,
+                                           sNetworkDataCountLayerMethodsPtr);
+
+  if (!layer) {
+    return NS_ERROR_FAILURE;
+  }
+
+  NetworkDataCountSecret* secret = new NetworkDataCountSecret();
+
+  layer->secret = reinterpret_cast<PRFilePrivate*>(secret);
+
+  PRStatus status = PR_PushIOLayer(fd, PR_NSPR_IO_LAYER, layer);
+
+  if (status == PR_FAILURE) {
+    delete secret;
+    PR_Free(layer);  // PR_CreateIOLayerStub() uses PR_Malloc().
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+void NetworkDataCountSent(PRFileDesc* fd, uint64_t& sentBytes) {
+  PRFileDesc* ndcFd = PR_GetIdentitiesLayer(fd, sNetworkDataCountLayerIdentity);
+  MOZ_RELEASE_ASSERT(ndcFd);
+
+  NetworkDataCountSecret* secret =
+      reinterpret_cast<NetworkDataCountSecret*>(ndcFd->secret);
+  sentBytes = secret->mSentBytes;
+}
+
+void NetworkDataCountReceived(PRFileDesc* fd, uint64_t& receivedBytes) {
+  PRFileDesc* ndcFd = PR_GetIdentitiesLayer(fd, sNetworkDataCountLayerIdentity);
+  MOZ_RELEASE_ASSERT(ndcFd);
+
+  NetworkDataCountSecret* secret =
+      reinterpret_cast<NetworkDataCountSecret*>(ndcFd->secret);
+  receivedBytes = secret->mReceivedBytes;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/NetworkDataCountLayer.h b/netwerk/base/NetworkDataCountLayer.h
new file mode 100644
index 0000000000..a5a0d8f0dc
--- /dev/null
+++ b/netwerk/base/NetworkDataCountLayer.h
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NetworkDataCountLayer_h__
+#define NetworkDataCountLayer_h__
+
+#include "prerror.h"
+#include "prio.h"
+#include "ErrorList.h"
+
+namespace mozilla {
+namespace net {
+
+nsresult AttachNetworkDataCountLayer(PRFileDesc* fd);
+
+// Get amount of sent bytes.
+void NetworkDataCountSent(PRFileDesc* fd, uint64_t& sentBytes);
+
+// Get amount of received bytes.
+void NetworkDataCountReceived(PRFileDesc* fd, uint64_t& receivedBytes);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // NetworkDataCountLayer_h__
diff --git a/netwerk/base/NetworkInfoServiceCocoa.cpp b/netwerk/base/NetworkInfoServiceCocoa.cpp
new file mode 100644
index 0000000000..554557c809
--- /dev/null
+++ b/netwerk/base/NetworkInfoServiceCocoa.cpp
@@ -0,0 +1,100 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <net/if.h>
+#include <netdb.h>
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/ScopeExit.h"
+
+#include "NetworkInfoServiceImpl.h"
+
+namespace mozilla {
+namespace net {
+
+static nsresult ListInterfaceAddresses(int aFd, const char* aIface,
+                                       AddrMapType& aAddrMap);
+
+nsresult DoListAddresses(AddrMapType& aAddrMap) {
+  int fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (fd < 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto autoCloseSocket = MakeScopeExit([&] { close(fd); });
+
+  struct ifconf ifconf;
+  /* 16k of space should be enough to list all interfaces.  Worst case, if it's
+   * not then we will error out and fail to list addresses.  This should only
+   * happen on pathological machines with way too many interfaces.
+   */
+  char buf[16384];
+
+  ifconf.ifc_len = sizeof(buf);
+  ifconf.ifc_buf = buf;
+  if (ioctl(fd, SIOCGIFCONF, &ifconf) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  struct ifreq* ifreq = ifconf.ifc_req;
+  int i = 0;
+  while (i < ifconf.ifc_len) {
+    size_t len = IFNAMSIZ + ifreq->ifr_addr.sa_len;
+
+    DebugOnly<nsresult> rv =
+        ListInterfaceAddresses(fd, ifreq->ifr_name, aAddrMap);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "ListInterfaceAddresses failed");
+
+    ifreq = (struct ifreq*)((char*)ifreq + len);
+    i += len;
+  }
+
+  autoCloseSocket.release();
+  return NS_OK;
+}
+
+static nsresult ListInterfaceAddresses(int aFd, const char* aInterface,
+                                       AddrMapType& aAddrMap) {
+  struct ifreq ifreq;
+  memset(&ifreq, 0, sizeof(struct ifreq));
+  strncpy(ifreq.ifr_name, aInterface, IFNAMSIZ - 1);
+  if (ioctl(aFd, SIOCGIFADDR, &ifreq) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  char host[128];
+  int family;
+  switch (family = ifreq.ifr_addr.sa_family) {
+    case AF_INET:
+    case AF_INET6:
+      getnameinfo(&ifreq.ifr_addr, sizeof(ifreq.ifr_addr), host, sizeof(host),
+                  nullptr, 0, NI_NUMERICHOST);
+      break;
+    case AF_UNSPEC:
+      return NS_OK;
+    default:
+      // Unknown family.
+      return NS_OK;
+  }
+
+  nsCString ifaceStr;
+  ifaceStr.AssignASCII(aInterface);
+
+  nsCString addrStr;
+  addrStr.AssignASCII(host);
+
+  aAddrMap.InsertOrUpdate(ifaceStr, addrStr);
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/NetworkInfoServiceImpl.h b/netwerk/base/NetworkInfoServiceImpl.h
new file mode 100644
index 0000000000..218f31cb0c
--- /dev/null
+++ b/netwerk/base/NetworkInfoServiceImpl.h
@@ -0,0 +1,18 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsString.h"
+#include "nsTHashMap.h"
+
+namespace mozilla {
+namespace net {
+
+using AddrMapType = nsTHashMap<nsCStringHashKey, nsCString>;
+
+nsresult DoListAddresses(AddrMapType& aAddrMap);
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/NetworkInfoServiceLinux.cpp b/netwerk/base/NetworkInfoServiceLinux.cpp
new file mode 100644
index 0000000000..8b365e4028
--- /dev/null
+++ b/netwerk/base/NetworkInfoServiceLinux.cpp
@@ -0,0 +1,95 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netdb.h>
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/ScopeExit.h"
+
+#include "NetworkInfoServiceImpl.h"
+
+namespace mozilla::net {
+
+static nsresult ListInterfaceAddresses(int aFd, const char* aInterface,
+                                       AddrMapType& aAddrMap);
+
+nsresult DoListAddresses(AddrMapType& aAddrMap) {
+  int fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (fd < 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto autoCloseSocket = MakeScopeExit([&] { close(fd); });
+
+  struct ifconf ifconf {};
+  /* 16k of space should be enough to list all interfaces.  Worst case, if it's
+   * not then we will error out and fail to list addresses.  This should only
+   * happen on pathological machines with way too many interfaces.
+   */
+  char buf[16384];
+
+  ifconf.ifc_len = sizeof(buf);
+  ifconf.ifc_buf = buf;
+  if (ioctl(fd, SIOCGIFCONF, &ifconf) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  struct ifreq* ifreq = ifconf.ifc_req;
+  int i = 0;
+  while (i < ifconf.ifc_len) {
+    size_t len = sizeof(struct ifreq);
+
+    DebugOnly<nsresult> rv =
+        ListInterfaceAddresses(fd, ifreq->ifr_name, aAddrMap);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "ListInterfaceAddresses failed");
+
+    ifreq = (struct ifreq*)((char*)ifreq + len);
+    i += len;
+  }
+
+  return NS_OK;
+}
+
+static nsresult ListInterfaceAddresses(int aFd, const char* aInterface,
+                                       AddrMapType& aAddrMap) {
+  struct ifreq ifreq {};
+  memset(&ifreq, 0, sizeof(struct ifreq));
+  strncpy(ifreq.ifr_name, aInterface, IFNAMSIZ - 1);
+  if (ioctl(aFd, SIOCGIFADDR, &ifreq) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  char host[128];
+  switch (ifreq.ifr_addr.sa_family) {
+    case AF_INET:
+    case AF_INET6:
+      getnameinfo(&ifreq.ifr_addr, sizeof(ifreq.ifr_addr), host, sizeof(host),
+                  nullptr, 0, NI_NUMERICHOST);
+      break;
+    case AF_UNSPEC:
+      return NS_OK;
+    default:
+      // Unknown family.
+      return NS_OK;
+  }
+
+  nsCString ifaceStr;
+  ifaceStr.AssignASCII(aInterface);
+
+  nsCString addrStr;
+  addrStr.AssignASCII(host);
+
+  aAddrMap.InsertOrUpdate(ifaceStr, addrStr);
+
+  return NS_OK;
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/NetworkInfoServiceWindows.cpp b/netwerk/base/NetworkInfoServiceWindows.cpp
new file mode 100644
index 0000000000..943226cd5f
--- /dev/null
+++ b/netwerk/base/NetworkInfoServiceWindows.cpp
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <winsock2.h>
+#include <ws2ipdef.h>
+#include <iphlpapi.h>
+
+#include "mozilla/UniquePtr.h"
+
+#include "NetworkInfoServiceImpl.h"
+
+namespace mozilla {
+namespace net {
+
+nsresult DoListAddresses(AddrMapType& aAddrMap) {
+  UniquePtr<MIB_IPADDRTABLE> ipAddrTable;
+  DWORD size = sizeof(MIB_IPADDRTABLE);
+
+  ipAddrTable.reset((MIB_IPADDRTABLE*)malloc(size));
+  if (!ipAddrTable) {
+    return NS_ERROR_FAILURE;
+  }
+
+  DWORD retVal = GetIpAddrTable(ipAddrTable.get(), &size, 0);
+  if (retVal == ERROR_INSUFFICIENT_BUFFER) {
+    ipAddrTable.reset((MIB_IPADDRTABLE*)malloc(size));
+    if (!ipAddrTable) {
+      return NS_ERROR_FAILURE;
+    }
+    retVal = GetIpAddrTable(ipAddrTable.get(), &size, 0);
+  }
+  if (retVal != NO_ERROR) {
+    return NS_ERROR_FAILURE;
+  }
+
+  for (DWORD i = 0; i < ipAddrTable->dwNumEntries; i++) {
+    int index = ipAddrTable->table[i].dwIndex;
+    uint32_t addrVal = (uint32_t)ipAddrTable->table[i].dwAddr;
+
+    nsCString indexString;
+    indexString.AppendInt(index, 10);
+
+    nsCString addrString;
+    addrString.AppendPrintf("%d.%d.%d.%d", (addrVal >> 0) & 0xff,
+                            (addrVal >> 8) & 0xff, (addrVal >> 16) & 0xff,
+                            (addrVal >> 24) & 0xff);
+
+    aAddrMap.InsertOrUpdate(indexString, addrString);
+  }
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/PollableEvent.cpp b/netwerk/base/PollableEvent.cpp
new file mode 100644
index 0000000000..a99d6d88f5
--- /dev/null
+++ b/netwerk/base/PollableEvent.cpp
@@ -0,0 +1,399 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsSocketTransportService2.h"
+#include "PollableEvent.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Logging.h"
+#include "mozilla/net/DNS.h"
+#include "prerror.h"
+#include "prio.h"
+#include "private/pprio.h"
+#include "prnetdb.h"
+
+#ifdef XP_WIN
+#  include "ShutdownLayer.h"
+#else
+#  include <fcntl.h>
+#  define USEPIPE 1
+#endif
+
+namespace mozilla {
+namespace net {
+
+#ifndef USEPIPE
+static PRDescIdentity sPollableEventLayerIdentity;
+static PRIOMethods sPollableEventLayerMethods;
+static PRIOMethods* sPollableEventLayerMethodsPtr = nullptr;
+
+static void LazyInitSocket() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (sPollableEventLayerMethodsPtr) {
+    return;
+  }
+  sPollableEventLayerIdentity = PR_GetUniqueIdentity("PollableEvent Layer");
+  sPollableEventLayerMethods = *PR_GetDefaultIOMethods();
+  sPollableEventLayerMethodsPtr = &sPollableEventLayerMethods;
+}
+
+static bool NewTCPSocketPair(PRFileDesc* fd[], bool aSetRecvBuff) {
+  // this is a replacement for PR_NewTCPSocketPair that manually
+  // sets the recv buffer to 64K. A windows bug (1248358)
+  // can result in using an incompatible rwin and window
+  // scale option on localhost pipes if not set before connect.
+
+  SOCKET_LOG(("NewTCPSocketPair %s a recv buffer tuning\n",
+              aSetRecvBuff ? "with" : "without"));
+
+  PRFileDesc* listener = nullptr;
+  PRFileDesc* writer = nullptr;
+  PRFileDesc* reader = nullptr;
+  PRSocketOptionData recvBufferOpt;
+  recvBufferOpt.option = PR_SockOpt_RecvBufferSize;
+  recvBufferOpt.value.recv_buffer_size = 65535;
+
+  PRSocketOptionData nodelayOpt;
+  nodelayOpt.option = PR_SockOpt_NoDelay;
+  nodelayOpt.value.no_delay = true;
+
+  PRSocketOptionData noblockOpt;
+  noblockOpt.option = PR_SockOpt_Nonblocking;
+  noblockOpt.value.non_blocking = true;
+
+  listener = PR_OpenTCPSocket(PR_AF_INET);
+  if (!listener) {
+    goto failed;
+  }
+
+  if (aSetRecvBuff) {
+    PR_SetSocketOption(listener, &recvBufferOpt);
+  }
+  PR_SetSocketOption(listener, &nodelayOpt);
+
+  PRNetAddr listenAddr;
+  memset(&listenAddr, 0, sizeof(listenAddr));
+  if ((PR_InitializeNetAddr(PR_IpAddrLoopback, 0, &listenAddr) == PR_FAILURE) ||
+      (PR_Bind(listener, &listenAddr) == PR_FAILURE) ||
+      (PR_GetSockName(listener, &listenAddr) ==
+       PR_FAILURE) ||  // learn the dynamic port
+      (PR_Listen(listener, 5) == PR_FAILURE)) {
+    goto failed;
+  }
+
+  writer = PR_OpenTCPSocket(PR_AF_INET);
+  if (!writer) {
+    goto failed;
+  }
+  if (aSetRecvBuff) {
+    PR_SetSocketOption(writer, &recvBufferOpt);
+  }
+  PR_SetSocketOption(writer, &nodelayOpt);
+  PR_SetSocketOption(writer, &noblockOpt);
+  PRNetAddr writerAddr;
+  if (PR_InitializeNetAddr(PR_IpAddrLoopback, ntohs(listenAddr.inet.port),
+                           &writerAddr) == PR_FAILURE) {
+    goto failed;
+  }
+
+  if (PR_Connect(writer, &writerAddr, PR_INTERVAL_NO_TIMEOUT) == PR_FAILURE) {
+    if ((PR_GetError() != PR_IN_PROGRESS_ERROR) ||
+        (PR_ConnectContinue(writer, PR_POLL_WRITE) == PR_FAILURE)) {
+      goto failed;
+    }
+  }
+  PR_SetFDInheritable(writer, false);
+
+  reader = PR_Accept(listener, &listenAddr, PR_MillisecondsToInterval(200));
+  if (!reader) {
+    goto failed;
+  }
+  PR_SetFDInheritable(reader, false);
+  if (aSetRecvBuff) {
+    PR_SetSocketOption(reader, &recvBufferOpt);
+  }
+  PR_SetSocketOption(reader, &nodelayOpt);
+  PR_SetSocketOption(reader, &noblockOpt);
+  PR_Close(listener);
+
+  fd[0] = reader;
+  fd[1] = writer;
+  return true;
+
+failed:
+  if (listener) {
+    PR_Close(listener);
+  }
+  if (reader) {
+    PR_Close(reader);
+  }
+  if (writer) {
+    PR_Close(writer);
+  }
+  return false;
+}
+
+#endif
+
+PollableEvent::PollableEvent()
+
+{
+  MOZ_COUNT_CTOR(PollableEvent);
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  // create pair of prfiledesc that can be used as a poll()ble
+  // signal. on windows use a localhost socket pair, and on
+  // unix use a pipe.
+#ifdef USEPIPE
+  SOCKET_LOG(("PollableEvent() using pipe\n"));
+  if (PR_CreatePipe(&mReadFD, &mWriteFD) == PR_SUCCESS) {
+    // make the pipe non blocking. NSPR asserts at
+    // trying to use SockOpt here
+    PROsfd fd = PR_FileDesc2NativeHandle(mReadFD);
+    int flags = fcntl(fd, F_GETFL, 0);
+    (void)fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+    fd = PR_FileDesc2NativeHandle(mWriteFD);
+    flags = fcntl(fd, F_GETFL, 0);
+    (void)fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+  } else {
+    mReadFD = nullptr;
+    mWriteFD = nullptr;
+    SOCKET_LOG(("PollableEvent() pipe failed\n"));
+  }
+#else
+  SOCKET_LOG(("PollableEvent() using socket pair\n"));
+  PRFileDesc* fd[2];
+  LazyInitSocket();
+
+  // Try with a increased recv buffer first (bug 1248358).
+  if (NewTCPSocketPair(fd, true)) {
+    mReadFD = fd[0];
+    mWriteFD = fd[1];
+    // If the previous fails try without recv buffer increase (bug 1305436).
+  } else if (NewTCPSocketPair(fd, false)) {
+    mReadFD = fd[0];
+    mWriteFD = fd[1];
+    // If both fail, try the old version.
+  } else if (PR_NewTCPSocketPair(fd) == PR_SUCCESS) {
+    mReadFD = fd[0];
+    mWriteFD = fd[1];
+
+    PRSocketOptionData socket_opt;
+    DebugOnly<PRStatus> status;
+    socket_opt.option = PR_SockOpt_NoDelay;
+    socket_opt.value.no_delay = true;
+    PR_SetSocketOption(mWriteFD, &socket_opt);
+    PR_SetSocketOption(mReadFD, &socket_opt);
+    socket_opt.option = PR_SockOpt_Nonblocking;
+    socket_opt.value.non_blocking = true;
+    status = PR_SetSocketOption(mWriteFD, &socket_opt);
+    MOZ_ASSERT(status == PR_SUCCESS);
+    status = PR_SetSocketOption(mReadFD, &socket_opt);
+    MOZ_ASSERT(status == PR_SUCCESS);
+  }
+
+  if (mReadFD && mWriteFD) {
+    // compatibility with LSPs such as McAfee that assume a NSPR
+    // layer for read ala the nspr Pollable Event - Bug 698882. This layer is a
+    // nop.
+    PRFileDesc* topLayer = PR_CreateIOLayerStub(sPollableEventLayerIdentity,
+                                                sPollableEventLayerMethodsPtr);
+    if (topLayer) {
+      if (PR_PushIOLayer(fd[0], PR_TOP_IO_LAYER, topLayer) == PR_FAILURE) {
+        topLayer->dtor(topLayer);
+      } else {
+        SOCKET_LOG(("PollableEvent() nspr layer ok\n"));
+        mReadFD = topLayer;
+      }
+    }
+
+  } else {
+    SOCKET_LOG(("PollableEvent() socketpair failed\n"));
+  }
+#endif
+
+  if (mReadFD && mWriteFD) {
+    // prime the system to deal with races invovled in [dc]tor cycle
+    SOCKET_LOG(("PollableEvent() ctor ok\n"));
+    mSignaled = true;
+    MarkFirstSignalTimestamp();
+    PR_Write(mWriteFD, "I", 1);
+  }
+}
+
+PollableEvent::~PollableEvent() {
+  MOZ_COUNT_DTOR(PollableEvent);
+  if (mWriteFD) {
+#if defined(XP_WIN)
+    AttachShutdownLayer(mWriteFD);
+#endif
+    PR_Close(mWriteFD);
+  }
+  if (mReadFD) {
+#if defined(XP_WIN)
+    AttachShutdownLayer(mReadFD);
+#endif
+    PR_Close(mReadFD);
+  }
+}
+
+// we do not record signals on the socket thread
+// because the socket thread can reliably look at its
+// own runnable queue before selecting a poll time
+// this is the "service the network without blocking" comment in
+// nsSocketTransportService2.cpp
+bool PollableEvent::Signal() {
+  SOCKET_LOG(("PollableEvent::Signal\n"));
+
+  if (!mWriteFD) {
+    SOCKET_LOG(("PollableEvent::Signal Failed on no FD\n"));
+    return false;
+  }
+#ifndef XP_WIN
+  // On windows poll can hang and this became worse when we introduced the
+  // patch for bug 698882 (see also bug 1292181), therefore we reverted the
+  // behavior on windows to be as before bug 698882, e.g. write to the socket
+  // also if an event dispatch is on the socket thread and writing to the
+  // socket for each event. See bug 1292181.
+  if (OnSocketThread()) {
+    SOCKET_LOG(("PollableEvent::Signal OnSocketThread nop\n"));
+    return true;
+  }
+#endif
+
+#ifndef XP_WIN
+  // To wake up the poll writing once is enough, but for Windows that can cause
+  // hangs so we will write for every event.
+  // For non-Windows systems it is enough to write just once.
+  if (mSignaled) {
+    return true;
+  }
+#endif
+
+  if (!mSignaled) {
+    mSignaled = true;
+    MarkFirstSignalTimestamp();
+  }
+
+  int32_t status = PR_Write(mWriteFD, "M", 1);
+  SOCKET_LOG(("PollableEvent::Signal PR_Write %d\n", status));
+  if (status != 1) {
+    NS_WARNING("PollableEvent::Signal Failed\n");
+    SOCKET_LOG(("PollableEvent::Signal Failed\n"));
+    mSignaled = false;
+    mWriteFailed = true;
+  } else {
+    mWriteFailed = false;
+  }
+  return (status == 1);
+}
+
+bool PollableEvent::Clear() {
+  // necessary because of the "dont signal on socket thread" optimization
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  SOCKET_LOG(("PollableEvent::Clear\n"));
+
+  if (!mFirstSignalAfterClear.IsNull()) {
+    SOCKET_LOG(("PollableEvent::Clear time to signal %ums",
+                (uint32_t)(TimeStamp::NowLoRes() - mFirstSignalAfterClear)
+                    .ToMilliseconds()));
+  }
+
+  mFirstSignalAfterClear = TimeStamp();
+  mSignalTimestampAdjusted = false;
+  mSignaled = false;
+
+  if (!mReadFD) {
+    SOCKET_LOG(("PollableEvent::Clear mReadFD is null\n"));
+    return false;
+  }
+
+  char buf[2048];
+  int32_t status;
+#ifdef XP_WIN
+  // On Windows we are writing to the socket for each event, to be sure that we
+  // do not have any deadlock read from the socket as much as we can.
+  while (true) {
+    status = PR_Read(mReadFD, buf, 2048);
+    SOCKET_LOG(("PollableEvent::Clear PR_Read %d\n", status));
+    if (status == 0) {
+      SOCKET_LOG(("PollableEvent::Clear EOF!\n"));
+      return false;
+    }
+    if (status < 0) {
+      PRErrorCode code = PR_GetError();
+      if (code == PR_WOULD_BLOCK_ERROR) {
+        return true;
+      } else {
+        SOCKET_LOG(("PollableEvent::Clear unexpected error %d\n", code));
+        return false;
+      }
+    }
+  }
+#else
+  status = PR_Read(mReadFD, buf, 2048);
+  SOCKET_LOG(("PollableEvent::Clear PR_Read %d\n", status));
+
+  if (status == 1) {
+    return true;
+  }
+  if (status == 0) {
+    SOCKET_LOG(("PollableEvent::Clear EOF!\n"));
+    return false;
+  }
+  if (status > 1) {
+    MOZ_ASSERT(false);
+    SOCKET_LOG(("PollableEvent::Clear Unexpected events\n"));
+    Clear();
+    return true;
+  }
+  PRErrorCode code = PR_GetError();
+  if (code == PR_WOULD_BLOCK_ERROR) {
+    return true;
+  }
+  SOCKET_LOG(("PollableEvent::Clear unexpected error %d\n", code));
+  return false;
+#endif  // XP_WIN
+}
+
+void PollableEvent::MarkFirstSignalTimestamp() {
+  if (mFirstSignalAfterClear.IsNull()) {
+    SOCKET_LOG(("PollableEvent::MarkFirstSignalTimestamp"));
+    mFirstSignalAfterClear = TimeStamp::NowLoRes();
+  }
+}
+
+void PollableEvent::AdjustFirstSignalTimestamp() {
+  if (!mSignalTimestampAdjusted && !mFirstSignalAfterClear.IsNull()) {
+    SOCKET_LOG(("PollableEvent::AdjustFirstSignalTimestamp"));
+    mFirstSignalAfterClear = TimeStamp::NowLoRes();
+    mSignalTimestampAdjusted = true;
+  }
+}
+
+bool PollableEvent::IsSignallingAlive(TimeDuration const& timeout) {
+  if (mWriteFailed) {
+    return false;
+  }
+
+#ifdef DEBUG
+  // The timeout would be just a disturbance in a debug build.
+  return true;
+#else
+  if (!mSignaled || mFirstSignalAfterClear.IsNull() ||
+      timeout == TimeDuration()) {
+    return true;
+  }
+
+  TimeDuration delay = (TimeStamp::NowLoRes() - mFirstSignalAfterClear);
+  bool timedOut = delay > timeout;
+
+  return !timedOut;
+#endif  // DEBUG
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/PollableEvent.h b/netwerk/base/PollableEvent.h
new file mode 100644
index 0000000000..6a17cd909d
--- /dev/null
+++ b/netwerk/base/PollableEvent.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef PollableEvent_h__
+#define PollableEvent_h__
+
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+
+struct PRFileDesc;
+
+namespace mozilla {
+namespace net {
+
+// class must be called locked
+class PollableEvent {
+ public:
+  PollableEvent();
+  ~PollableEvent();
+
+  // Signal/Clear return false only if they fail
+  bool Signal();
+  // This is called only when we get non-null out_flags for the socket pair
+  bool Clear();
+  bool Valid() { return mWriteFD && mReadFD; }
+
+  // We want to detect if writing to one of the socket pair sockets takes
+  // too long to be received by the other socket from the pair.
+  // Hence, we remember the timestamp of the earliest write by a call to
+  // MarkFirstSignalTimestamp() from Signal().  After waking up from poll()
+  // we check how long it took get the 'readable' signal on the socket pair.
+  void MarkFirstSignalTimestamp();
+  // Called right before we enter poll() to exclude any possible delay between
+  // the earlist call to Signal() and entering poll() caused by processing
+  // of events dispatched to the socket transport thread.
+  void AdjustFirstSignalTimestamp();
+  // This returns false on following conditions:
+  // - PR_Write has failed
+  // - no out_flags were signalled on the socket pair for too long after
+  //   the earliest Signal()
+  bool IsSignallingAlive(TimeDuration const& timeout);
+
+  PRFileDesc* PollableFD() { return mReadFD; }
+
+ private:
+  PRFileDesc* mWriteFD{nullptr};
+  PRFileDesc* mReadFD{nullptr};
+  bool mSignaled{false};
+  // true when PR_Write to the socket pair has failed (status < 1)
+  bool mWriteFailed{false};
+  // Set true after AdjustFirstSignalTimestamp() was called
+  // Set false after Clear() was called
+  // Ensures shifting the timestamp before entering poll() only once
+  // between Clear()'ings.
+  bool mSignalTimestampAdjusted{false};
+  // Timestamp of the first call to Signal() (or time we enter poll())
+  // that happened after the last Clear() call
+  TimeStamp mFirstSignalAfterClear;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/Predictor.cpp b/netwerk/base/Predictor.cpp
new file mode 100644
index 0000000000..ac3176dddf
--- /dev/null
+++ b/netwerk/base/Predictor.cpp
@@ -0,0 +1,2439 @@
+/* vim: set ts=2 sts=2 et sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <algorithm>
+
+#include "Predictor.h"
+
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsICacheStorage.h"
+#include "nsICachingChannel.h"
+#include "nsICancelable.h"
+#include "nsIChannel.h"
+#include "nsContentUtils.h"
+#include "nsIDNSService.h"
+#include "mozilla/dom/Document.h"
+#include "nsIFile.h"
+#include "nsIHttpChannel.h"
+#include "nsIInputStream.h"
+#include "nsILoadContext.h"
+#include "nsILoadContextInfo.h"
+#include "nsILoadGroup.h"
+#include "nsINetworkPredictorVerifier.h"
+#include "nsIObserverService.h"
+#include "nsISpeculativeConnect.h"
+#include "nsITimer.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsStreamUtils.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Logging.h"
+
+#include "mozilla/OriginAttributes.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/SchedulerGroup.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Telemetry.h"
+
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/net/NeckoParent.h"
+
+#include "LoadContextInfo.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "SerializedLoadContext.h"
+#include "mozilla/net/NeckoChild.h"
+
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/ClearOnShutdown.h"
+
+#include "CacheControlParser.h"
+#include "ReferrerInfo.h"
+
+using namespace mozilla;
+
+namespace mozilla {
+namespace net {
+
+Predictor* Predictor::sSelf = nullptr;
+
+static LazyLogModule gPredictorLog("NetworkPredictor");
+
+#define PREDICTOR_LOG(args) \
+  MOZ_LOG(gPredictorLog, mozilla::LogLevel::Debug, args)
+
+#define NOW_IN_SECONDS() static_cast<uint32_t>(PR_Now() / PR_USEC_PER_SEC)
+
+// All these time values are in sec
+static const uint32_t ONE_DAY = 86400U;
+static const uint32_t ONE_WEEK = 7U * ONE_DAY;
+static const uint32_t ONE_MONTH = 30U * ONE_DAY;
+static const uint32_t ONE_YEAR = 365U * ONE_DAY;
+
+// Version of metadata entries we expect
+static const uint32_t METADATA_VERSION = 1;
+
+// Flags available in entries
+// FLAG_PREFETCHABLE - we have determined that this item is eligible for
+// prefetch
+static const uint32_t FLAG_PREFETCHABLE = 1 << 0;
+
+// We save 12 bits in the "flags" section of our metadata for actual flags, the
+// rest are to keep track of a rolling count of which loads a resource has been
+// used on to determine if we can prefetch that resource or not;
+static const uint8_t kRollingLoadOffset = 12;
+static const int32_t kMaxPrefetchRollingLoadCount = 20;
+static const uint32_t kFlagsMask = ((1 << kRollingLoadOffset) - 1);
+
+// ID Extensions for cache entries
+#define PREDICTOR_ORIGIN_EXTENSION "predictor-origin"
+
+// Get the full origin (scheme, host, port) out of a URI (maybe should be part
+// of nsIURI instead?)
+static nsresult ExtractOrigin(nsIURI* uri, nsIURI** originUri) {
+  nsAutoCString s;
+  nsresult rv = nsContentUtils::GetASCIIOrigin(uri, s);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_NewURI(originUri, s);
+}
+
+// All URIs we get passed *must* be http or https if they're not null. This
+// helps ensure that.
+static bool IsNullOrHttp(nsIURI* uri) {
+  if (!uri) {
+    return true;
+  }
+
+  return uri->SchemeIs("http") || uri->SchemeIs("https");
+}
+
+// Listener for the speculative DNS requests we'll fire off, which just ignores
+// the result (since we're just trying to warm the cache). This also exists to
+// reduce round-trips to the main thread, by being something threadsafe the
+// Predictor can use.
+
+NS_IMPL_ISUPPORTS(Predictor::DNSListener, nsIDNSListener);
+
+NS_IMETHODIMP
+Predictor::DNSListener::OnLookupComplete(nsICancelable* request,
+                                         nsIDNSRecord* rec, nsresult status) {
+  return NS_OK;
+}
+
+// Class to proxy important information from the initial predictor call through
+// the cache API and back into the internals of the predictor. We can't use the
+// predictor itself, as it may have multiple actions in-flight, and each action
+// has different parameters.
+NS_IMPL_ISUPPORTS(Predictor::Action, nsICacheEntryOpenCallback);
+
+Predictor::Action::Action(bool fullUri, bool predict, Predictor::Reason reason,
+                          nsIURI* targetURI, nsIURI* sourceURI,
+                          nsINetworkPredictorVerifier* verifier,
+                          Predictor* predictor)
+    : mFullUri(fullUri),
+      mPredict(predict),
+      mTargetURI(targetURI),
+      mSourceURI(sourceURI),
+      mVerifier(verifier),
+      mStackCount(0),
+      mPredictor(predictor) {
+  mStartTime = TimeStamp::Now();
+  if (mPredict) {
+    mPredictReason = reason.mPredict;
+  } else {
+    mLearnReason = reason.mLearn;
+  }
+}
+
+Predictor::Action::Action(bool fullUri, bool predict, Predictor::Reason reason,
+                          nsIURI* targetURI, nsIURI* sourceURI,
+                          nsINetworkPredictorVerifier* verifier,
+                          Predictor* predictor, uint8_t stackCount)
+    : mFullUri(fullUri),
+      mPredict(predict),
+      mTargetURI(targetURI),
+      mSourceURI(sourceURI),
+      mVerifier(verifier),
+      mStackCount(stackCount),
+      mPredictor(predictor) {
+  mStartTime = TimeStamp::Now();
+  if (mPredict) {
+    mPredictReason = reason.mPredict;
+  } else {
+    mLearnReason = reason.mLearn;
+  }
+}
+
+NS_IMETHODIMP
+Predictor::Action::OnCacheEntryCheck(nsICacheEntry* entry, uint32_t* result) {
+  *result = nsICacheEntryOpenCallback::ENTRY_WANTED;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Action::OnCacheEntryAvailable(nsICacheEntry* entry, bool isNew,
+                                         nsresult result) {
+  MOZ_ASSERT(NS_IsMainThread(), "Got cache entry off main thread!");
+
+  nsAutoCString targetURI, sourceURI;
+  mTargetURI->GetAsciiSpec(targetURI);
+  if (mSourceURI) {
+    mSourceURI->GetAsciiSpec(sourceURI);
+  }
+  PREDICTOR_LOG(
+      ("OnCacheEntryAvailable %p called. entry=%p mFullUri=%d mPredict=%d "
+       "mPredictReason=%d mLearnReason=%d mTargetURI=%s "
+       "mSourceURI=%s mStackCount=%d isNew=%d result=0x%08" PRIx32,
+       this, entry, mFullUri, mPredict, mPredictReason, mLearnReason,
+       targetURI.get(), sourceURI.get(), mStackCount, isNew,
+       static_cast<uint32_t>(result)));
+  if (NS_FAILED(result)) {
+    PREDICTOR_LOG(
+        ("OnCacheEntryAvailable %p FAILED to get cache entry (0x%08" PRIX32
+         "). Aborting.",
+         this, static_cast<uint32_t>(result)));
+    return NS_OK;
+  }
+  Telemetry::AccumulateTimeDelta(Telemetry::PREDICTOR_WAIT_TIME, mStartTime);
+  if (mPredict) {
+    bool predicted =
+        mPredictor->PredictInternal(mPredictReason, entry, isNew, mFullUri,
+                                    mTargetURI, mVerifier, mStackCount);
+    Telemetry::AccumulateTimeDelta(Telemetry::PREDICTOR_PREDICT_WORK_TIME,
+                                   mStartTime);
+    if (predicted) {
+      Telemetry::AccumulateTimeDelta(
+          Telemetry::PREDICTOR_PREDICT_TIME_TO_ACTION, mStartTime);
+    } else {
+      Telemetry::AccumulateTimeDelta(
+          Telemetry::PREDICTOR_PREDICT_TIME_TO_INACTION, mStartTime);
+    }
+  } else {
+    mPredictor->LearnInternal(mLearnReason, entry, isNew, mFullUri, mTargetURI,
+                              mSourceURI);
+    Telemetry::AccumulateTimeDelta(Telemetry::PREDICTOR_LEARN_WORK_TIME,
+                                   mStartTime);
+  }
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(Predictor, nsINetworkPredictor, nsIObserver,
+                  nsISpeculativeConnectionOverrider, nsIInterfaceRequestor,
+                  nsICacheEntryMetaDataVisitor, nsINetworkPredictorVerifier)
+
+Predictor::Predictor()
+
+{
+  MOZ_ASSERT(!sSelf, "multiple Predictor instances!");
+  sSelf = this;
+}
+
+Predictor::~Predictor() {
+  if (mInitialized) Shutdown();
+
+  sSelf = nullptr;
+}
+
+// Predictor::nsIObserver
+
+nsresult Predictor::InstallObserver() {
+  MOZ_ASSERT(NS_IsMainThread(), "Installing observer off main thread");
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (!obs) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  rv = obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return rv;
+}
+
+void Predictor::RemoveObserver() {
+  MOZ_ASSERT(NS_IsMainThread(), "Removing observer off main thread");
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) {
+    obs->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+  }
+}
+
+NS_IMETHODIMP
+Predictor::Observe(nsISupports* subject, const char* topic,
+                   const char16_t* data_unicode) {
+  nsresult rv = NS_OK;
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Predictor observing something off main thread!");
+
+  if (!strcmp(NS_XPCOM_SHUTDOWN_OBSERVER_ID, topic)) {
+    Shutdown();
+  }
+
+  return rv;
+}
+
+// Predictor::nsISpeculativeConnectionOverrider
+
+NS_IMETHODIMP
+Predictor::GetIgnoreIdle(bool* ignoreIdle) {
+  *ignoreIdle = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::GetParallelSpeculativeConnectLimit(
+    uint32_t* parallelSpeculativeConnectLimit) {
+  *parallelSpeculativeConnectLimit = 6;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::GetIsFromPredictor(bool* isFromPredictor) {
+  *isFromPredictor = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::GetAllow1918(bool* allow1918) {
+  *allow1918 = false;
+  return NS_OK;
+}
+
+// Predictor::nsIInterfaceRequestor
+
+NS_IMETHODIMP
+Predictor::GetInterface(const nsIID& iid, void** result) {
+  return QueryInterface(iid, result);
+}
+
+// Predictor::nsICacheEntryMetaDataVisitor
+
+#define SEEN_META_DATA "predictor::seen"
+#define RESOURCE_META_DATA "predictor::resource-count"
+#define META_DATA_PREFIX "predictor::"
+
+static bool IsURIMetadataElement(const char* key) {
+  return StringBeginsWith(nsDependentCString(key),
+                          nsLiteralCString(META_DATA_PREFIX)) &&
+         !nsLiteralCString(SEEN_META_DATA).Equals(key) &&
+         !nsLiteralCString(RESOURCE_META_DATA).Equals(key);
+}
+
+nsresult Predictor::OnMetaDataElement(const char* asciiKey,
+                                      const char* asciiValue) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsURIMetadataElement(asciiKey)) {
+    // This isn't a bit of metadata we care about
+    return NS_OK;
+  }
+
+  nsCString key, value;
+  key.AssignASCII(asciiKey);
+  value.AssignASCII(asciiValue);
+  mKeysToOperateOn.AppendElement(key);
+  mValuesToOperateOn.AppendElement(value);
+
+  return NS_OK;
+}
+
+// Predictor::nsINetworkPredictor
+
+nsresult Predictor::Init() {
+  MOZ_DIAGNOSTIC_ASSERT(!IsNeckoChild());
+
+  if (!NS_IsMainThread()) {
+    MOZ_ASSERT(false, "Predictor::Init called off the main thread!");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsresult rv = NS_OK;
+
+  rv = InstallObserver();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mLastStartupTime = mStartupTime = NOW_IN_SECONDS();
+
+  if (!mDNSListener) {
+    mDNSListener = new DNSListener();
+  }
+
+  mCacheStorageService =
+      do_GetService("@mozilla.org/netwerk/cache-storage-service;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mSpeculativeService = do_GetService("@mozilla.org/network/io-service;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = NS_NewURI(getter_AddRefs(mStartupURI), "predictor://startup");
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mDnsService = do_GetService("@mozilla.org/network/dns-service;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mInitialized = true;
+
+  return rv;
+}
+
+namespace {
+class PredictorLearnRunnable final : public Runnable {
+ public:
+  PredictorLearnRunnable(nsIURI* targetURI, nsIURI* sourceURI,
+                         PredictorLearnReason reason,
+                         const OriginAttributes& oa)
+      : Runnable("PredictorLearnRunnable"),
+        mTargetURI(targetURI),
+        mSourceURI(sourceURI),
+        mReason(reason),
+        mOA(oa) {
+    MOZ_DIAGNOSTIC_ASSERT(targetURI, "Must have a target URI");
+  }
+
+  ~PredictorLearnRunnable() = default;
+
+  NS_IMETHOD Run() override {
+    if (!gNeckoChild) {
+      // This may have gone away between when this runnable was dispatched and
+      // when it actually runs, so let's be safe here, even though we asserted
+      // earlier.
+      PREDICTOR_LOG(("predictor::learn (async) gNeckoChild went away"));
+      return NS_OK;
+    }
+
+    PREDICTOR_LOG(("predictor::learn (async) forwarding to parent"));
+    gNeckoChild->SendPredLearn(mTargetURI, mSourceURI, mReason, mOA);
+
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIURI> mTargetURI;
+  nsCOMPtr<nsIURI> mSourceURI;
+  PredictorLearnReason mReason;
+  const OriginAttributes mOA;
+};
+
+}  // namespace
+
+void Predictor::Shutdown() {
+  if (!NS_IsMainThread()) {
+    MOZ_ASSERT(false, "Predictor::Shutdown called off the main thread!");
+    return;
+  }
+
+  RemoveObserver();
+
+  mInitialized = false;
+}
+
+nsresult Predictor::Create(const nsIID& aIID, void** aResult) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsresult rv;
+
+  RefPtr<Predictor> svc = new Predictor();
+  if (IsNeckoChild()) {
+    NeckoChild::InitNeckoChild();
+
+    // Child threads only need to be call into the public interface methods
+    // so we don't bother with initialization
+    return svc->QueryInterface(aIID, aResult);
+  }
+
+  rv = svc->Init();
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(("Failed to initialize predictor, predictor will be a noop"));
+  }
+
+  // We treat init failure the same as the service being disabled, since this
+  // is all an optimization anyway. No need to freak people out. That's why we
+  // gladly continue on QI'ing here.
+  rv = svc->QueryInterface(aIID, aResult);
+
+  return rv;
+}
+
+NS_IMETHODIMP
+Predictor::Predict(nsIURI* targetURI, nsIURI* sourceURI,
+                   PredictorPredictReason reason,
+                   JS::Handle<JS::Value> originAttributes,
+                   nsINetworkPredictorVerifier* verifier, JSContext* aCx) {
+  OriginAttributes attrs;
+
+  if (!originAttributes.isObject() || !attrs.Init(aCx, originAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return PredictNative(targetURI, sourceURI, reason, attrs, verifier);
+}
+
+// Called from the main thread to initiate predictive actions
+NS_IMETHODIMP
+Predictor::PredictNative(nsIURI* targetURI, nsIURI* sourceURI,
+                         PredictorPredictReason reason,
+                         const OriginAttributes& originAttributes,
+                         nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Predictor interface methods must be called on the main thread");
+
+  PREDICTOR_LOG(("Predictor::Predict"));
+
+  if (IsNeckoChild()) {
+    MOZ_DIAGNOSTIC_ASSERT(gNeckoChild);
+
+    PREDICTOR_LOG(("    called on child process"));
+    // If two different threads are predicting concurently, this will be
+    // overwritten. Thankfully, we only use this in tests, which will
+    // overwrite mVerifier perhaps multiple times for each individual test;
+    // however, within each test, the multiple predict calls should have the
+    // same verifier.
+    if (verifier) {
+      PREDICTOR_LOG(("    was given a verifier"));
+      mChildVerifier = verifier;
+    }
+    PREDICTOR_LOG(("    forwarding to parent process"));
+    gNeckoChild->SendPredPredict(targetURI, sourceURI, reason, originAttributes,
+                                 verifier);
+    return NS_OK;
+  }
+
+  PREDICTOR_LOG(("    called on parent process"));
+
+  if (!mInitialized) {
+    PREDICTOR_LOG(("    not initialized"));
+    return NS_OK;
+  }
+
+  if (!StaticPrefs::network_predictor_enabled()) {
+    PREDICTOR_LOG(("    not enabled"));
+    return NS_OK;
+  }
+
+  if (originAttributes.mPrivateBrowsingId > 0) {
+    // Don't want to do anything in PB mode
+    PREDICTOR_LOG(("    in PB mode"));
+    return NS_OK;
+  }
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    // Nothing we can do for non-HTTP[S] schemes
+    PREDICTOR_LOG(("    got non-http[s] URI"));
+    return NS_OK;
+  }
+
+  // Ensure we've been given the appropriate arguments for the kind of
+  // prediction we're being asked to do
+  nsCOMPtr<nsIURI> uriKey = targetURI;
+  nsCOMPtr<nsIURI> originKey;
+  switch (reason) {
+    case nsINetworkPredictor::PREDICT_LINK:
+      if (!targetURI || !sourceURI) {
+        PREDICTOR_LOG(("    link invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      // Link hover is a special case where we can predict without hitting the
+      // db, so let's go ahead and fire off that prediction here.
+      PredictForLink(targetURI, sourceURI, originAttributes, verifier);
+      return NS_OK;
+    case nsINetworkPredictor::PREDICT_LOAD:
+      if (!targetURI || sourceURI) {
+        PREDICTOR_LOG(("    load invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      break;
+    case nsINetworkPredictor::PREDICT_STARTUP:
+      if (targetURI || sourceURI) {
+        PREDICTOR_LOG(("    startup invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      uriKey = mStartupURI;
+      originKey = mStartupURI;
+      break;
+    default:
+      PREDICTOR_LOG(("    invalid reason"));
+      return NS_ERROR_INVALID_ARG;
+  }
+
+  Predictor::Reason argReason{};
+  argReason.mPredict = reason;
+
+  // First we open the regular cache entry, to ensure we don't gum up the works
+  // waiting on the less-important predictor-only cache entry
+  RefPtr<Predictor::Action> uriAction = new Predictor::Action(
+      Predictor::Action::IS_FULL_URI, Predictor::Action::DO_PREDICT, argReason,
+      targetURI, nullptr, verifier, this);
+  nsAutoCString uriKeyStr;
+  uriKey->GetAsciiSpec(uriKeyStr);
+  PREDICTOR_LOG(("    Predict uri=%s reason=%d action=%p", uriKeyStr.get(),
+                 reason, uriAction.get()));
+
+  nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+  RefPtr<LoadContextInfo> lci = new LoadContextInfo(false, originAttributes);
+
+  nsresult rv = mCacheStorageService->DiskCacheStorage(
+      lci, getter_AddRefs(cacheDiskStorage));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t openFlags =
+      nsICacheStorage::OPEN_READONLY | nsICacheStorage::OPEN_SECRETLY |
+      nsICacheStorage::OPEN_PRIORITY | nsICacheStorage::CHECK_MULTITHREADED;
+  cacheDiskStorage->AsyncOpenURI(uriKey, ""_ns, openFlags, uriAction);
+
+  // Now we do the origin-only (and therefore predictor-only) entry
+  nsCOMPtr<nsIURI> targetOrigin;
+  rv = ExtractOrigin(uriKey, getter_AddRefs(targetOrigin));
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (!originKey) {
+    originKey = targetOrigin;
+  }
+
+  RefPtr<Predictor::Action> originAction = new Predictor::Action(
+      Predictor::Action::IS_ORIGIN, Predictor::Action::DO_PREDICT, argReason,
+      targetOrigin, nullptr, verifier, this);
+  nsAutoCString originKeyStr;
+  originKey->GetAsciiSpec(originKeyStr);
+  PREDICTOR_LOG(("    Predict origin=%s reason=%d action=%p",
+                 originKeyStr.get(), reason, originAction.get()));
+  openFlags = nsICacheStorage::OPEN_READONLY | nsICacheStorage::OPEN_SECRETLY |
+              nsICacheStorage::CHECK_MULTITHREADED;
+  cacheDiskStorage->AsyncOpenURI(originKey,
+                                 nsLiteralCString(PREDICTOR_ORIGIN_EXTENSION),
+                                 openFlags, originAction);
+
+  PREDICTOR_LOG(("    predict returning"));
+  return NS_OK;
+}
+
+bool Predictor::PredictInternal(PredictorPredictReason reason,
+                                nsICacheEntry* entry, bool isNew, bool fullUri,
+                                nsIURI* targetURI,
+                                nsINetworkPredictorVerifier* verifier,
+                                uint8_t stackCount) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::PredictInternal"));
+  bool rv = false;
+
+  nsCOMPtr<nsILoadContextInfo> lci;
+  entry->GetLoadContextInfo(getter_AddRefs(lci));
+
+  if (!lci) {
+    return rv;
+  }
+
+  if (reason == nsINetworkPredictor::PREDICT_LOAD) {
+    MaybeLearnForStartup(targetURI, fullUri, *lci->OriginAttributesPtr());
+  }
+
+  if (isNew) {
+    // nothing else we can do here
+    PREDICTOR_LOG(("    new entry"));
+    return rv;
+  }
+
+  switch (reason) {
+    case nsINetworkPredictor::PREDICT_LOAD:
+      rv = PredictForPageload(entry, targetURI, stackCount, fullUri, verifier);
+      break;
+    case nsINetworkPredictor::PREDICT_STARTUP:
+      rv = PredictForStartup(entry, fullUri, verifier);
+      break;
+    default:
+      PREDICTOR_LOG(("    invalid reason"));
+      MOZ_ASSERT(false, "Got unexpected value for prediction reason");
+  }
+
+  return rv;
+}
+
+void Predictor::PredictForLink(nsIURI* targetURI, nsIURI* sourceURI,
+                               const OriginAttributes& originAttributes,
+                               nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::PredictForLink"));
+  if (!mSpeculativeService) {
+    PREDICTOR_LOG(("    missing speculative service"));
+    return;
+  }
+
+  if (!StaticPrefs::network_predictor_enable_hover_on_ssl()) {
+    if (sourceURI->SchemeIs("https")) {
+      // We don't want to predict from an HTTPS page, to avoid info leakage
+      PREDICTOR_LOG(("    Not predicting for link hover - on an SSL page"));
+      return;
+    }
+  }
+
+  nsCOMPtr<nsIPrincipal> principal =
+      BasePrincipal::CreateContentPrincipal(targetURI, originAttributes);
+
+  mSpeculativeService->SpeculativeConnect(targetURI, principal, nullptr, false);
+  if (verifier) {
+    PREDICTOR_LOG(("    sending verification"));
+    verifier->OnPredictPreconnect(targetURI);
+  }
+}
+
+// This is the driver for prediction based on a new pageload.
+static const uint8_t MAX_PAGELOAD_DEPTH = 10;
+bool Predictor::PredictForPageload(nsICacheEntry* entry, nsIURI* targetURI,
+                                   uint8_t stackCount, bool fullUri,
+                                   nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::PredictForPageload"));
+
+  if (stackCount > MAX_PAGELOAD_DEPTH) {
+    PREDICTOR_LOG(("    exceeded recursion depth!"));
+    return false;
+  }
+
+  uint32_t lastLoad;
+  nsresult rv = entry->GetLastFetched(&lastLoad);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  int32_t globalDegradation = CalculateGlobalDegradation(lastLoad);
+  PREDICTOR_LOG(("    globalDegradation = %d", globalDegradation));
+
+  uint32_t loadCount;
+  rv = entry->GetFetchCount(&loadCount);
+  NS_ENSURE_SUCCESS(rv, false);
+
+  nsCOMPtr<nsILoadContextInfo> lci;
+
+  rv = entry->GetLoadContextInfo(getter_AddRefs(lci));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  nsCOMPtr<nsIURI> redirectURI;
+  if (WouldRedirect(entry, loadCount, lastLoad, globalDegradation,
+                    getter_AddRefs(redirectURI))) {
+    mPreconnects.AppendElement(redirectURI);
+    Predictor::Reason reason{};
+    reason.mPredict = nsINetworkPredictor::PREDICT_LOAD;
+    RefPtr<Predictor::Action> redirectAction = new Predictor::Action(
+        Predictor::Action::IS_FULL_URI, Predictor::Action::DO_PREDICT, reason,
+        redirectURI, nullptr, verifier, this, stackCount + 1);
+    nsAutoCString redirectUriString;
+    redirectURI->GetAsciiSpec(redirectUriString);
+
+    nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+    rv = mCacheStorageService->DiskCacheStorage(
+        lci, getter_AddRefs(cacheDiskStorage));
+    NS_ENSURE_SUCCESS(rv, false);
+
+    PREDICTOR_LOG(("    Predict redirect uri=%s action=%p",
+                   redirectUriString.get(), redirectAction.get()));
+    uint32_t openFlags =
+        nsICacheStorage::OPEN_READONLY | nsICacheStorage::OPEN_SECRETLY |
+        nsICacheStorage::OPEN_PRIORITY | nsICacheStorage::CHECK_MULTITHREADED;
+    cacheDiskStorage->AsyncOpenURI(redirectURI, ""_ns, openFlags,
+                                   redirectAction);
+    return RunPredictions(nullptr, *lci->OriginAttributesPtr(), verifier);
+  }
+
+  CalculatePredictions(entry, targetURI, lastLoad, loadCount, globalDegradation,
+                       fullUri);
+
+  return RunPredictions(targetURI, *lci->OriginAttributesPtr(), verifier);
+}
+
+// This is the driver for predicting at browser startup time based on pages that
+// have previously been loaded close to startup.
+bool Predictor::PredictForStartup(nsICacheEntry* entry, bool fullUri,
+                                  nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::PredictForStartup"));
+
+  nsCOMPtr<nsILoadContextInfo> lci;
+
+  nsresult rv = entry->GetLoadContextInfo(getter_AddRefs(lci));
+  NS_ENSURE_SUCCESS(rv, false);
+
+  int32_t globalDegradation = CalculateGlobalDegradation(mLastStartupTime);
+  CalculatePredictions(entry, nullptr, mLastStartupTime, mStartupCount,
+                       globalDegradation, fullUri);
+  return RunPredictions(nullptr, *lci->OriginAttributesPtr(), verifier);
+}
+
+// This calculates how much to degrade our confidence in our data based on
+// the last time this top-level resource was loaded. This "global degradation"
+// applies to *all* subresources we have associated with the top-level
+// resource. This will be in addition to any reduction in confidence we have
+// associated with a particular subresource.
+int32_t Predictor::CalculateGlobalDegradation(uint32_t lastLoad) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  int32_t globalDegradation;
+  uint32_t delta = NOW_IN_SECONDS() - lastLoad;
+  if (delta < ONE_DAY) {
+    globalDegradation = StaticPrefs::network_predictor_page_degradation_day();
+  } else if (delta < ONE_WEEK) {
+    globalDegradation = StaticPrefs::network_predictor_page_degradation_week();
+  } else if (delta < ONE_MONTH) {
+    globalDegradation = StaticPrefs::network_predictor_page_degradation_month();
+  } else if (delta < ONE_YEAR) {
+    globalDegradation = StaticPrefs::network_predictor_page_degradation_year();
+  } else {
+    globalDegradation = StaticPrefs::network_predictor_page_degradation_max();
+  }
+
+  Telemetry::Accumulate(Telemetry::PREDICTOR_GLOBAL_DEGRADATION,
+                        globalDegradation);
+  return globalDegradation;
+}
+
+// This calculates our overall confidence that a particular subresource will be
+// loaded as part of a top-level load.
+// @param hitCount - the number of times we have loaded this subresource as part
+//                   of this top-level load
+// @param hitsPossible - the number of times we have performed this top-level
+//                       load
+// @param lastHit - the timestamp of the last time we loaded this subresource as
+//                  part of this top-level load
+// @param lastPossible - the timestamp of the last time we performed this
+//                       top-level load
+// @param globalDegradation - the degradation for this top-level load as
+//                            determined by CalculateGlobalDegradation
+int32_t Predictor::CalculateConfidence(uint32_t hitCount, uint32_t hitsPossible,
+                                       uint32_t lastHit, uint32_t lastPossible,
+                                       int32_t globalDegradation) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_PREDICTIONS_CALCULATED>
+      predictionsCalculated;
+  ++predictionsCalculated;
+
+  if (!hitsPossible) {
+    return 0;
+  }
+
+  int32_t baseConfidence = (hitCount * 100) / hitsPossible;
+  int32_t maxConfidence = 100;
+  int32_t confidenceDegradation = 0;
+
+  if (lastHit < lastPossible) {
+    // We didn't load this subresource the last time this top-level load was
+    // performed, so let's not bother preconnecting (at the very least).
+    maxConfidence =
+        StaticPrefs::network_predictor_preconnect_min_confidence() - 1;
+
+    // Now calculate how much we want to degrade our confidence based on how
+    // long it's been between the last time we did this top-level load and the
+    // last time this top-level load included this subresource.
+    PRTime delta = lastPossible - lastHit;
+    if (delta == 0) {
+      confidenceDegradation = 0;
+    } else if (delta < ONE_DAY) {
+      confidenceDegradation =
+          StaticPrefs::network_predictor_subresource_degradation_day();
+    } else if (delta < ONE_WEEK) {
+      confidenceDegradation =
+          StaticPrefs::network_predictor_subresource_degradation_week();
+    } else if (delta < ONE_MONTH) {
+      confidenceDegradation =
+          StaticPrefs::network_predictor_subresource_degradation_month();
+    } else if (delta < ONE_YEAR) {
+      confidenceDegradation =
+          StaticPrefs::network_predictor_subresource_degradation_year();
+    } else {
+      confidenceDegradation =
+          StaticPrefs::network_predictor_subresource_degradation_max();
+      maxConfidence = 0;
+    }
+  }
+
+  // Calculate our confidence and clamp it to between 0 and maxConfidence
+  // (<= 100)
+  int32_t confidence =
+      baseConfidence - confidenceDegradation - globalDegradation;
+  confidence = std::max(confidence, 0);
+  confidence = std::min(confidence, maxConfidence);
+
+  Telemetry::Accumulate(Telemetry::PREDICTOR_BASE_CONFIDENCE, baseConfidence);
+  Telemetry::Accumulate(Telemetry::PREDICTOR_SUBRESOURCE_DEGRADATION,
+                        confidenceDegradation);
+  Telemetry::Accumulate(Telemetry::PREDICTOR_CONFIDENCE, confidence);
+  return confidence;
+}
+
+static void MakeMetadataEntry(const uint32_t hitCount, const uint32_t lastHit,
+                              const uint32_t flags, nsCString& newValue) {
+  newValue.Truncate();
+  newValue.AppendInt(METADATA_VERSION);
+  newValue.Append(',');
+  newValue.AppendInt(hitCount);
+  newValue.Append(',');
+  newValue.AppendInt(lastHit);
+  newValue.Append(',');
+  newValue.AppendInt(flags);
+}
+
+// On every page load, the rolling window gets shifted by one bit, leaving the
+// lowest bit at 0, to indicate that the subresource in question has not been
+// seen on the most recent page load. If, at some point later during the page
+// load, the subresource is seen again, we will then set the lowest bit to 1.
+// This is how we keep track of how many of the last n pageloads (for n <= 20) a
+// particular subresource has been seen. The rolling window is kept in the upper
+// 20 bits of the flags element of the metadata. This saves 12 bits for regular
+// old flags.
+void Predictor::UpdateRollingLoadCount(nsICacheEntry* entry,
+                                       const uint32_t flags, const char* key,
+                                       const uint32_t hitCount,
+                                       const uint32_t lastHit) {
+  // Extract just the rolling load count from the flags, shift it to clear the
+  // lowest bit, and put the new value with the existing flags.
+  uint32_t rollingLoadCount = flags & ~kFlagsMask;
+  rollingLoadCount <<= 1;
+  uint32_t newFlags = (flags & kFlagsMask) | rollingLoadCount;
+
+  // Finally, update the metadata on the cache entry.
+  nsAutoCString newValue;
+  MakeMetadataEntry(hitCount, lastHit, newFlags, newValue);
+  entry->SetMetaDataElement(key, newValue.BeginReading());
+}
+
+uint32_t Predictor::ClampedPrefetchRollingLoadCount() {
+  int32_t n = StaticPrefs::network_predictor_prefetch_rolling_load_count();
+  if (n < 0) {
+    return 0;
+  }
+  if (n > kMaxPrefetchRollingLoadCount) {
+    return kMaxPrefetchRollingLoadCount;
+  }
+  return n;
+}
+
+void Predictor::CalculatePredictions(nsICacheEntry* entry, nsIURI* referrer,
+                                     uint32_t lastLoad, uint32_t loadCount,
+                                     int32_t globalDegradation, bool fullUri) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // Since the visitor gets called under a cache lock, all we do there is get
+  // copies of the keys/values we care about, and then do the real work here
+  entry->VisitMetaData(this);
+  nsTArray<nsCString> keysToOperateOn = std::move(mKeysToOperateOn),
+                      valuesToOperateOn = std::move(mValuesToOperateOn);
+
+  MOZ_ASSERT(keysToOperateOn.Length() == valuesToOperateOn.Length());
+  for (size_t i = 0; i < keysToOperateOn.Length(); ++i) {
+    const char* key = keysToOperateOn[i].BeginReading();
+    const char* value = valuesToOperateOn[i].BeginReading();
+
+    nsCString uri;
+    uint32_t hitCount, lastHit, flags;
+    if (!ParseMetaDataEntry(key, value, uri, hitCount, lastHit, flags)) {
+      // This failed, get rid of it so we don't waste space
+      entry->SetMetaDataElement(key, nullptr);
+      continue;
+    }
+
+    int32_t confidence = CalculateConfidence(hitCount, loadCount, lastHit,
+                                             lastLoad, globalDegradation);
+    if (fullUri) {
+      UpdateRollingLoadCount(entry, flags, key, hitCount, lastHit);
+    }
+    PREDICTOR_LOG(("CalculatePredictions key=%s value=%s confidence=%d", key,
+                   value, confidence));
+    PrefetchIgnoreReason reason = PREFETCH_OK;
+    if (!fullUri) {
+      // Not full URI - don't prefetch! No sense in it!
+      PREDICTOR_LOG(("    forcing non-cacheability - not full URI"));
+      if (flags & FLAG_PREFETCHABLE) {
+        // This only applies if we had somehow otherwise marked this
+        // prefetchable.
+        reason = NOT_FULL_URI;
+      }
+      flags &= ~FLAG_PREFETCHABLE;
+    } else if (!referrer) {
+      // No referrer means we can't prefetch, so pretend it's non-cacheable,
+      // no matter what.
+      PREDICTOR_LOG(("    forcing non-cacheability - no referrer"));
+      if (flags & FLAG_PREFETCHABLE) {
+        // This only applies if we had somehow otherwise marked this
+        // prefetchable.
+        reason = NO_REFERRER;
+      }
+      flags &= ~FLAG_PREFETCHABLE;
+    } else {
+      uint32_t expectedRollingLoadCount =
+          (1 << ClampedPrefetchRollingLoadCount()) - 1;
+      expectedRollingLoadCount <<= kRollingLoadOffset;
+      if ((flags & expectedRollingLoadCount) != expectedRollingLoadCount) {
+        PREDICTOR_LOG(("    forcing non-cacheability - missed a load"));
+        if (flags & FLAG_PREFETCHABLE) {
+          // This only applies if we had somehow otherwise marked this
+          // prefetchable.
+          reason = MISSED_A_LOAD;
+        }
+        flags &= ~FLAG_PREFETCHABLE;
+      }
+    }
+
+    PREDICTOR_LOG(("    setting up prediction"));
+    SetupPrediction(confidence, flags, uri, reason);
+  }
+}
+
+// (Maybe) adds a predictive action to the prediction runner, based on our
+// calculated confidence for the subresource in question.
+void Predictor::SetupPrediction(int32_t confidence, uint32_t flags,
+                                const nsCString& uri,
+                                PrefetchIgnoreReason earlyReason) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsresult rv = NS_OK;
+  PREDICTOR_LOG(
+      ("SetupPrediction enable-prefetch=%d prefetch-min-confidence=%d "
+       "preconnect-min-confidence=%d preresolve-min-confidence=%d "
+       "flags=%d confidence=%d uri=%s",
+       StaticPrefs::network_predictor_enable_prefetch(),
+       StaticPrefs::network_predictor_prefetch_min_confidence(),
+       StaticPrefs::network_predictor_preconnect_min_confidence(),
+       StaticPrefs::network_predictor_preresolve_min_confidence(), flags,
+       confidence, uri.get()));
+
+  bool prefetchOk = !!(flags & FLAG_PREFETCHABLE);
+  PrefetchIgnoreReason reason = earlyReason;
+  if (prefetchOk && !StaticPrefs::network_predictor_enable_prefetch()) {
+    prefetchOk = false;
+    reason = PREFETCH_DISABLED;
+  } else if (prefetchOk && !ClampedPrefetchRollingLoadCount() &&
+             confidence <
+                 StaticPrefs::network_predictor_prefetch_min_confidence()) {
+    prefetchOk = false;
+    if (!ClampedPrefetchRollingLoadCount()) {
+      reason = PREFETCH_DISABLED_VIA_COUNT;
+    } else {
+      reason = CONFIDENCE_TOO_LOW;
+    }
+  }
+
+  // prefetchOk == false and reason == PREFETCH_OK indicates that the reason
+  // we aren't prefetching this item is because it was marked un-prefetchable in
+  // our metadata. We already have separate telemetry on that decision, so we
+  // aren't going to accumulate more here. Right now we only care about why
+  // something we had marked prefetchable isn't being prefetched.
+  if (!prefetchOk && reason != PREFETCH_OK) {
+    Telemetry::Accumulate(Telemetry::PREDICTOR_PREFETCH_IGNORE_REASON, reason);
+  }
+
+  if (prefetchOk) {
+    nsCOMPtr<nsIURI> prefetchURI;
+    rv = NS_NewURI(getter_AddRefs(prefetchURI), uri);
+    if (NS_SUCCEEDED(rv)) {
+      mPrefetches.AppendElement(prefetchURI);
+    }
+  } else if (confidence >=
+             StaticPrefs::network_predictor_preconnect_min_confidence()) {
+    nsCOMPtr<nsIURI> preconnectURI;
+    rv = NS_NewURI(getter_AddRefs(preconnectURI), uri);
+    if (NS_SUCCEEDED(rv)) {
+      mPreconnects.AppendElement(preconnectURI);
+    }
+  } else if (confidence >=
+             StaticPrefs::network_predictor_preresolve_min_confidence()) {
+    nsCOMPtr<nsIURI> preresolveURI;
+    rv = NS_NewURI(getter_AddRefs(preresolveURI), uri);
+    if (NS_SUCCEEDED(rv)) {
+      mPreresolves.AppendElement(preresolveURI);
+    }
+  }
+
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    NS_NewURI returned 0x%" PRIx32, static_cast<uint32_t>(rv)));
+  }
+}
+
+nsresult Predictor::Prefetch(nsIURI* uri, nsIURI* referrer,
+                             const OriginAttributes& originAttributes,
+                             nsINetworkPredictorVerifier* verifier) {
+  nsAutoCString strUri, strReferrer;
+  uri->GetAsciiSpec(strUri);
+  referrer->GetAsciiSpec(strReferrer);
+  PREDICTOR_LOG(("Predictor::Prefetch uri=%s referrer=%s verifier=%p",
+                 strUri.get(), strReferrer.get(), verifier));
+  nsCOMPtr<nsIChannel> channel;
+  nsresult rv = NS_NewChannel(
+      getter_AddRefs(channel), uri, nsContentUtils::GetSystemPrincipal(),
+      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+      nsIContentPolicy::TYPE_OTHER, nullptr, /* nsICookieJarSettings */
+      nullptr,                               /* aPerformanceStorage */
+      nullptr,                               /* aLoadGroup */
+      nullptr,                               /* aCallbacks */
+      nsIRequest::LOAD_BACKGROUND);
+
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    NS_NewChannel failed rv=0x%" PRIX32, static_cast<uint32_t>(rv)));
+    return rv;
+  }
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  rv = loadInfo->SetOriginAttributes(originAttributes);
+
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    Set originAttributes into loadInfo failed rv=0x%" PRIX32,
+         static_cast<uint32_t>(rv)));
+    return rv;
+  }
+
+  nsCOMPtr<nsIHttpChannel> httpChannel;
+  httpChannel = do_QueryInterface(channel);
+  if (!httpChannel) {
+    PREDICTOR_LOG(("    Could not get HTTP Channel from new channel!"));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIReferrerInfo> referrerInfo = new dom::ReferrerInfo(referrer);
+  rv = httpChannel->SetReferrerInfoWithoutClone(referrerInfo);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // XXX - set a header here to indicate this is a prefetch?
+
+  nsCOMPtr<nsIStreamListener> listener =
+      new PrefetchListener(verifier, uri, this);
+  PREDICTOR_LOG(("    calling AsyncOpen listener=%p channel=%p", listener.get(),
+                 channel.get()));
+  rv = channel->AsyncOpen(listener);
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    AsyncOpen failed rv=0x%" PRIX32, static_cast<uint32_t>(rv)));
+  }
+
+  return rv;
+}
+
+// Runs predictions that have been set up.
+bool Predictor::RunPredictions(nsIURI* referrer,
+                               const OriginAttributes& originAttributes,
+                               nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread(), "Running prediction off main thread");
+
+  PREDICTOR_LOG(("Predictor::RunPredictions"));
+
+  bool predicted = false;
+  uint32_t len, i;
+
+  nsTArray<nsCOMPtr<nsIURI>> prefetches = std::move(mPrefetches),
+                             preconnects = std::move(mPreconnects),
+                             preresolves = std::move(mPreresolves);
+
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_TOTAL_PREDICTIONS>
+      totalPredictions;
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_TOTAL_PREFETCHES> totalPrefetches;
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_TOTAL_PRECONNECTS>
+      totalPreconnects;
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_TOTAL_PRERESOLVES>
+      totalPreresolves;
+
+  len = prefetches.Length();
+  for (i = 0; i < len; ++i) {
+    PREDICTOR_LOG(("    doing prefetch"));
+    nsCOMPtr<nsIURI> uri = prefetches[i];
+    if (NS_SUCCEEDED(Prefetch(uri, referrer, originAttributes, verifier))) {
+      ++totalPredictions;
+      ++totalPrefetches;
+      predicted = true;
+    }
+  }
+
+  len = preconnects.Length();
+  for (i = 0; i < len; ++i) {
+    PREDICTOR_LOG(("    doing preconnect"));
+    nsCOMPtr<nsIURI> uri = preconnects[i];
+    ++totalPredictions;
+    ++totalPreconnects;
+    nsCOMPtr<nsIPrincipal> principal =
+        BasePrincipal::CreateContentPrincipal(uri, originAttributes);
+    mSpeculativeService->SpeculativeConnect(uri, principal, this, false);
+    predicted = true;
+    if (verifier) {
+      PREDICTOR_LOG(("    sending preconnect verification"));
+      verifier->OnPredictPreconnect(uri);
+    }
+  }
+
+  len = preresolves.Length();
+  for (i = 0; i < len; ++i) {
+    nsCOMPtr<nsIURI> uri = preresolves[i];
+    ++totalPredictions;
+    ++totalPreresolves;
+    nsAutoCString hostname;
+    uri->GetAsciiHost(hostname);
+    PREDICTOR_LOG(("    doing preresolve %s", hostname.get()));
+    nsCOMPtr<nsICancelable> tmpCancelable;
+    mDnsService->AsyncResolveNative(
+        hostname, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+        (nsIDNSService::RESOLVE_PRIORITY_MEDIUM |
+         nsIDNSService::RESOLVE_SPECULATE),
+        nullptr, mDNSListener, nullptr, originAttributes,
+        getter_AddRefs(tmpCancelable));
+
+    // Fetch HTTPS RR if needed.
+    if (StaticPrefs::network_dns_upgrade_with_https_rr() ||
+        StaticPrefs::network_dns_use_https_rr_as_altsvc()) {
+      mDnsService->AsyncResolveNative(
+          hostname, nsIDNSService::RESOLVE_TYPE_HTTPSSVC,
+          (nsIDNSService::RESOLVE_PRIORITY_MEDIUM |
+           nsIDNSService::RESOLVE_SPECULATE),
+          nullptr, mDNSListener, nullptr, originAttributes,
+          getter_AddRefs(tmpCancelable));
+    }
+
+    predicted = true;
+    if (verifier) {
+      PREDICTOR_LOG(("    sending preresolve verification"));
+      verifier->OnPredictDNS(uri);
+    }
+  }
+
+  return predicted;
+}
+
+// Find out if a top-level page is likely to redirect.
+bool Predictor::WouldRedirect(nsICacheEntry* entry, uint32_t loadCount,
+                              uint32_t lastLoad, int32_t globalDegradation,
+                              nsIURI** redirectURI) {
+  // TODO - not doing redirects for first go around
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return false;
+}
+
+NS_IMETHODIMP
+Predictor::Learn(nsIURI* targetURI, nsIURI* sourceURI,
+                 PredictorLearnReason reason,
+                 JS::Handle<JS::Value> originAttributes, JSContext* aCx) {
+  OriginAttributes attrs;
+
+  if (!originAttributes.isObject() || !attrs.Init(aCx, originAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return LearnNative(targetURI, sourceURI, reason, attrs);
+}
+
+// Called from the main thread to update the database
+NS_IMETHODIMP
+Predictor::LearnNative(nsIURI* targetURI, nsIURI* sourceURI,
+                       PredictorLearnReason reason,
+                       const OriginAttributes& originAttributes) {
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Predictor interface methods must be called on the main thread");
+
+  PREDICTOR_LOG(("Predictor::Learn"));
+
+  if (IsNeckoChild()) {
+    MOZ_DIAGNOSTIC_ASSERT(gNeckoChild);
+
+    PREDICTOR_LOG(("    called on child process"));
+
+    RefPtr<PredictorLearnRunnable> runnable = new PredictorLearnRunnable(
+        targetURI, sourceURI, reason, originAttributes);
+    SchedulerGroup::Dispatch(TaskCategory::Other, runnable.forget());
+
+    return NS_OK;
+  }
+
+  PREDICTOR_LOG(("    called on parent process"));
+
+  if (!mInitialized) {
+    PREDICTOR_LOG(("    not initialized"));
+    return NS_OK;
+  }
+
+  if (!StaticPrefs::network_predictor_enabled()) {
+    PREDICTOR_LOG(("    not enabled"));
+    return NS_OK;
+  }
+
+  if (originAttributes.mPrivateBrowsingId > 0) {
+    // Don't want to do anything in PB mode
+    PREDICTOR_LOG(("    in PB mode"));
+    return NS_OK;
+  }
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    PREDICTOR_LOG(("    got non-HTTP[S] URI"));
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<nsIURI> targetOrigin;
+  nsCOMPtr<nsIURI> sourceOrigin;
+  nsCOMPtr<nsIURI> uriKey;
+  nsCOMPtr<nsIURI> originKey;
+  nsresult rv;
+
+  switch (reason) {
+    case nsINetworkPredictor::LEARN_LOAD_TOPLEVEL:
+      if (!targetURI || sourceURI) {
+        PREDICTOR_LOG(("    load toplevel invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      rv = ExtractOrigin(targetURI, getter_AddRefs(targetOrigin));
+      NS_ENSURE_SUCCESS(rv, rv);
+      uriKey = targetURI;
+      originKey = targetOrigin;
+      break;
+    case nsINetworkPredictor::LEARN_STARTUP:
+      if (!targetURI || sourceURI) {
+        PREDICTOR_LOG(("    startup invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      rv = ExtractOrigin(targetURI, getter_AddRefs(targetOrigin));
+      NS_ENSURE_SUCCESS(rv, rv);
+      uriKey = mStartupURI;
+      originKey = mStartupURI;
+      break;
+    case nsINetworkPredictor::LEARN_LOAD_REDIRECT:
+    case nsINetworkPredictor::LEARN_LOAD_SUBRESOURCE:
+      if (!targetURI || !sourceURI) {
+        PREDICTOR_LOG(("    redirect/subresource invalid URI state"));
+        return NS_ERROR_INVALID_ARG;
+      }
+      rv = ExtractOrigin(targetURI, getter_AddRefs(targetOrigin));
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = ExtractOrigin(sourceURI, getter_AddRefs(sourceOrigin));
+      NS_ENSURE_SUCCESS(rv, rv);
+      uriKey = sourceURI;
+      originKey = sourceOrigin;
+      break;
+    default:
+      PREDICTOR_LOG(("    invalid reason"));
+      return NS_ERROR_INVALID_ARG;
+  }
+
+  Telemetry::AutoCounter<Telemetry::PREDICTOR_LEARN_ATTEMPTS> learnAttempts;
+  ++learnAttempts;
+
+  Predictor::Reason argReason{};
+  argReason.mLearn = reason;
+
+  // We always open the full uri (general cache) entry first, so we don't gum up
+  // the works waiting on predictor-only entries to open
+  RefPtr<Predictor::Action> uriAction = new Predictor::Action(
+      Predictor::Action::IS_FULL_URI, Predictor::Action::DO_LEARN, argReason,
+      targetURI, sourceURI, nullptr, this);
+  nsAutoCString uriKeyStr, targetUriStr, sourceUriStr;
+  uriKey->GetAsciiSpec(uriKeyStr);
+  targetURI->GetAsciiSpec(targetUriStr);
+  if (sourceURI) {
+    sourceURI->GetAsciiSpec(sourceUriStr);
+  }
+  PREDICTOR_LOG(
+      ("    Learn uriKey=%s targetURI=%s sourceURI=%s reason=%d "
+       "action=%p",
+       uriKeyStr.get(), targetUriStr.get(), sourceUriStr.get(), reason,
+       uriAction.get()));
+
+  nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+  RefPtr<LoadContextInfo> lci = new LoadContextInfo(false, originAttributes);
+
+  rv = mCacheStorageService->DiskCacheStorage(lci,
+                                              getter_AddRefs(cacheDiskStorage));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // For learning full URI things, we *always* open readonly and secretly, as we
+  // rely on actual pageloads to update the entry's metadata for us.
+  uint32_t uriOpenFlags = nsICacheStorage::OPEN_READONLY |
+                          nsICacheStorage::OPEN_SECRETLY |
+                          nsICacheStorage::CHECK_MULTITHREADED;
+  if (reason == nsINetworkPredictor::LEARN_LOAD_TOPLEVEL) {
+    // Learning for toplevel we want to open the full uri entry priority, since
+    // it's likely this entry will be used soon anyway, and we want this to be
+    // opened ASAP.
+    uriOpenFlags |= nsICacheStorage::OPEN_PRIORITY;
+  }
+  cacheDiskStorage->AsyncOpenURI(uriKey, ""_ns, uriOpenFlags, uriAction);
+
+  // Now we open the origin-only (and therefore predictor-only) entry
+  RefPtr<Predictor::Action> originAction = new Predictor::Action(
+      Predictor::Action::IS_ORIGIN, Predictor::Action::DO_LEARN, argReason,
+      targetOrigin, sourceOrigin, nullptr, this);
+  nsAutoCString originKeyStr, targetOriginStr, sourceOriginStr;
+  originKey->GetAsciiSpec(originKeyStr);
+  targetOrigin->GetAsciiSpec(targetOriginStr);
+  if (sourceOrigin) {
+    sourceOrigin->GetAsciiSpec(sourceOriginStr);
+  }
+  PREDICTOR_LOG(
+      ("    Learn originKey=%s targetOrigin=%s sourceOrigin=%s reason=%d "
+       "action=%p",
+       originKeyStr.get(), targetOriginStr.get(), sourceOriginStr.get(), reason,
+       originAction.get()));
+  uint32_t originOpenFlags;
+  if (reason == nsINetworkPredictor::LEARN_LOAD_TOPLEVEL) {
+    // This is the only case when we want to update the 'last used' metadata on
+    // the cache entry we're getting. This only applies to predictor-specific
+    // entries.
+    originOpenFlags =
+        nsICacheStorage::OPEN_NORMALLY | nsICacheStorage::CHECK_MULTITHREADED;
+  } else {
+    originOpenFlags = nsICacheStorage::OPEN_READONLY |
+                      nsICacheStorage::OPEN_SECRETLY |
+                      nsICacheStorage::CHECK_MULTITHREADED;
+  }
+  cacheDiskStorage->AsyncOpenURI(originKey,
+                                 nsLiteralCString(PREDICTOR_ORIGIN_EXTENSION),
+                                 originOpenFlags, originAction);
+
+  PREDICTOR_LOG(("Predictor::Learn returning"));
+  return NS_OK;
+}
+
+void Predictor::LearnInternal(PredictorLearnReason reason, nsICacheEntry* entry,
+                              bool isNew, bool fullUri, nsIURI* targetURI,
+                              nsIURI* sourceURI) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::LearnInternal"));
+
+  nsCString junk;
+  if (!fullUri && reason == nsINetworkPredictor::LEARN_LOAD_TOPLEVEL &&
+      NS_FAILED(
+          entry->GetMetaDataElement(SEEN_META_DATA, getter_Copies(junk)))) {
+    // This is an origin-only entry that we haven't seen before. Let's mark it
+    // as seen.
+    PREDICTOR_LOG(("    marking new origin entry as seen"));
+    nsresult rv = entry->SetMetaDataElement(SEEN_META_DATA, "1");
+    if (NS_FAILED(rv)) {
+      PREDICTOR_LOG(("    failed to mark origin entry seen"));
+      return;
+    }
+
+    // Need to ensure someone else can get to the entry if necessary
+    entry->MetaDataReady();
+    return;
+  }
+
+  switch (reason) {
+    case nsINetworkPredictor::LEARN_LOAD_TOPLEVEL:
+      // This case only exists to be used during tests - code outside the
+      // predictor tests should NEVER call Learn with LEARN_LOAD_TOPLEVEL.
+      // The predictor xpcshell test needs this branch, however, because we
+      // have no real page loads in xpcshell, and this is how we fake it up
+      // so that all the work that normally happens behind the scenes in a
+      // page load can be done for testing purposes.
+      if (fullUri && StaticPrefs::network_predictor_doing_tests()) {
+        PREDICTOR_LOG(
+            ("    WARNING - updating rolling load count. "
+             "If you see this outside tests, you did it wrong"));
+
+        // Since the visitor gets called under a cache lock, all we do there is
+        // get copies of the keys/values we care about, and then do the real
+        // work here
+        entry->VisitMetaData(this);
+        nsTArray<nsCString> keysToOperateOn = std::move(mKeysToOperateOn),
+                            valuesToOperateOn = std::move(mValuesToOperateOn);
+
+        MOZ_ASSERT(keysToOperateOn.Length() == valuesToOperateOn.Length());
+        for (size_t i = 0; i < keysToOperateOn.Length(); ++i) {
+          const char* key = keysToOperateOn[i].BeginReading();
+          const char* value = valuesToOperateOn[i].BeginReading();
+
+          nsCString uri;
+          uint32_t hitCount, lastHit, flags;
+          if (!ParseMetaDataEntry(key, value, uri, hitCount, lastHit, flags)) {
+            // This failed, get rid of it so we don't waste space
+            entry->SetMetaDataElement(key, nullptr);
+            continue;
+          }
+          UpdateRollingLoadCount(entry, flags, key, hitCount, lastHit);
+        }
+      } else {
+        PREDICTOR_LOG(("    nothing to do for toplevel"));
+      }
+      break;
+    case nsINetworkPredictor::LEARN_LOAD_REDIRECT:
+      if (fullUri) {
+        LearnForRedirect(entry, targetURI);
+      }
+      break;
+    case nsINetworkPredictor::LEARN_LOAD_SUBRESOURCE:
+      LearnForSubresource(entry, targetURI);
+      break;
+    case nsINetworkPredictor::LEARN_STARTUP:
+      LearnForStartup(entry, targetURI);
+      break;
+    default:
+      PREDICTOR_LOG(("    unexpected reason value"));
+      MOZ_ASSERT(false, "Got unexpected value for learn reason!");
+  }
+}
+
+NS_IMPL_ISUPPORTS(Predictor::SpaceCleaner, nsICacheEntryMetaDataVisitor)
+
+NS_IMETHODIMP
+Predictor::SpaceCleaner::OnMetaDataElement(const char* key, const char* value) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsURIMetadataElement(key)) {
+    // This isn't a bit of metadata we care about
+    return NS_OK;
+  }
+
+  nsCString uri;
+  uint32_t hitCount, lastHit, flags;
+  bool ok =
+      mPredictor->ParseMetaDataEntry(key, value, uri, hitCount, lastHit, flags);
+
+  if (!ok) {
+    // Couldn't parse this one, just get rid of it
+    nsCString nsKey;
+    nsKey.AssignASCII(key);
+    mLongKeysToDelete.AppendElement(nsKey);
+    return NS_OK;
+  }
+
+  uint32_t uriLength = uri.Length();
+  if (uriLength > StaticPrefs::network_predictor_max_uri_length()) {
+    // Default to getting rid of URIs that are too long and were put in before
+    // we had our limit on URI length, in order to free up some space.
+    nsCString nsKey;
+    nsKey.AssignASCII(key);
+    mLongKeysToDelete.AppendElement(nsKey);
+    return NS_OK;
+  }
+
+  if (!mLRUKeyToDelete || lastHit < mLRUStamp) {
+    mLRUKeyToDelete = key;
+    mLRUStamp = lastHit;
+  }
+
+  return NS_OK;
+}
+
+void Predictor::SpaceCleaner::Finalize(nsICacheEntry* entry) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (mLRUKeyToDelete) {
+    entry->SetMetaDataElement(mLRUKeyToDelete, nullptr);
+  }
+
+  for (size_t i = 0; i < mLongKeysToDelete.Length(); ++i) {
+    entry->SetMetaDataElement(mLongKeysToDelete[i].BeginReading(), nullptr);
+  }
+}
+
+// Called when a subresource has been hit from a top-level load. Uses the two
+// helper functions above to update the database appropriately.
+void Predictor::LearnForSubresource(nsICacheEntry* entry, nsIURI* targetURI) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(("Predictor::LearnForSubresource"));
+
+  uint32_t lastLoad;
+  nsresult rv = entry->GetLastFetched(&lastLoad);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  uint32_t loadCount;
+  rv = entry->GetFetchCount(&loadCount);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCString key;
+  key.AssignLiteral(META_DATA_PREFIX);
+  nsCString uri;
+  targetURI->GetAsciiSpec(uri);
+  key.Append(uri);
+  if (uri.Length() > StaticPrefs::network_predictor_max_uri_length()) {
+    // We do this to conserve space/prevent OOMs
+    PREDICTOR_LOG(("    uri too long!"));
+    entry->SetMetaDataElement(key.BeginReading(), nullptr);
+    return;
+  }
+
+  nsCString value;
+  rv = entry->GetMetaDataElement(key.BeginReading(), getter_Copies(value));
+
+  uint32_t hitCount, lastHit, flags;
+  bool isNewResource =
+      (NS_FAILED(rv) ||
+       !ParseMetaDataEntry(key.BeginReading(), value.BeginReading(), uri,
+                           hitCount, lastHit, flags));
+
+  int32_t resourceCount = 0;
+  if (isNewResource) {
+    // This is a new addition
+    PREDICTOR_LOG(("    new resource"));
+    nsCString s;
+    rv = entry->GetMetaDataElement(RESOURCE_META_DATA, getter_Copies(s));
+    if (NS_SUCCEEDED(rv)) {
+      resourceCount = atoi(s.BeginReading());
+    }
+    if (resourceCount >=
+        StaticPrefs::network_predictor_max_resources_per_entry()) {
+      RefPtr<Predictor::SpaceCleaner> cleaner =
+          new Predictor::SpaceCleaner(this);
+      entry->VisitMetaData(cleaner);
+      cleaner->Finalize(entry);
+    } else {
+      ++resourceCount;
+    }
+    nsAutoCString count;
+    count.AppendInt(resourceCount);
+    rv = entry->SetMetaDataElement(RESOURCE_META_DATA, count.BeginReading());
+    if (NS_FAILED(rv)) {
+      PREDICTOR_LOG(("    failed to update resource count"));
+      return;
+    }
+    hitCount = 1;
+    flags = 0;
+  } else {
+    PREDICTOR_LOG(("    existing resource"));
+    hitCount = std::min(hitCount + 1, loadCount);
+  }
+
+  // Update the rolling load count to mark this sub-resource as seen on the
+  // most-recent pageload so it can be eligible for prefetch (assuming all
+  // the other stars align).
+  flags |= (1 << kRollingLoadOffset);
+
+  nsCString newValue;
+  MakeMetadataEntry(hitCount, lastLoad, flags, newValue);
+  rv = entry->SetMetaDataElement(key.BeginReading(), newValue.BeginReading());
+  PREDICTOR_LOG(
+      ("    SetMetaDataElement -> 0x%08" PRIX32, static_cast<uint32_t>(rv)));
+  if (NS_FAILED(rv) && isNewResource) {
+    // Roll back the increment to the resource count we made above.
+    PREDICTOR_LOG(("    rolling back resource count update"));
+    --resourceCount;
+    if (resourceCount == 0) {
+      entry->SetMetaDataElement(RESOURCE_META_DATA, nullptr);
+    } else {
+      nsAutoCString count;
+      count.AppendInt(resourceCount);
+      entry->SetMetaDataElement(RESOURCE_META_DATA, count.BeginReading());
+    }
+  }
+}
+
+// This is called when a top-level loaded ended up redirecting to a different
+// URI so we can keep track of that fact.
+void Predictor::LearnForRedirect(nsICacheEntry* entry, nsIURI* targetURI) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // TODO - not doing redirects for first go around
+  PREDICTOR_LOG(("Predictor::LearnForRedirect"));
+}
+
+// This will add a page to our list of startup pages if it's being loaded
+// before our startup window has expired.
+void Predictor::MaybeLearnForStartup(nsIURI* uri, bool fullUri,
+                                     const OriginAttributes& originAttributes) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // TODO - not doing startup for first go around
+  PREDICTOR_LOG(("Predictor::MaybeLearnForStartup"));
+}
+
+// Add information about a top-level load to our list of startup pages
+void Predictor::LearnForStartup(nsICacheEntry* entry, nsIURI* targetURI) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // These actually do the same set of work, just on different entries, so we
+  // can pass through to get the real work done here
+  PREDICTOR_LOG(("Predictor::LearnForStartup"));
+  LearnForSubresource(entry, targetURI);
+}
+
+bool Predictor::ParseMetaDataEntry(const char* key, const char* value,
+                                   nsCString& uri, uint32_t& hitCount,
+                                   uint32_t& lastHit, uint32_t& flags) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PREDICTOR_LOG(
+      ("Predictor::ParseMetaDataEntry key=%s value=%s", key ? key : "", value));
+
+  const char* comma = strchr(value, ',');
+  if (!comma) {
+    PREDICTOR_LOG(("    could not find first comma"));
+    return false;
+  }
+
+  uint32_t version = static_cast<uint32_t>(atoi(value));
+  PREDICTOR_LOG(("    version -> %u", version));
+
+  if (version != METADATA_VERSION) {
+    PREDICTOR_LOG(
+        ("    metadata version mismatch %u != %u", version, METADATA_VERSION));
+    return false;
+  }
+
+  value = comma + 1;
+  comma = strchr(value, ',');
+  if (!comma) {
+    PREDICTOR_LOG(("    could not find second comma"));
+    return false;
+  }
+
+  hitCount = static_cast<uint32_t>(atoi(value));
+  PREDICTOR_LOG(("    hitCount -> %u", hitCount));
+
+  value = comma + 1;
+  comma = strchr(value, ',');
+  if (!comma) {
+    PREDICTOR_LOG(("    could not find third comma"));
+    return false;
+  }
+
+  lastHit = static_cast<uint32_t>(atoi(value));
+  PREDICTOR_LOG(("    lastHit -> %u", lastHit));
+
+  value = comma + 1;
+  flags = static_cast<uint32_t>(atoi(value));
+  PREDICTOR_LOG(("    flags -> %u", flags));
+
+  if (key) {
+    const char* uriStart = key + (sizeof(META_DATA_PREFIX) - 1);
+    uri.AssignASCII(uriStart);
+    PREDICTOR_LOG(("    uri -> %s", uriStart));
+  } else {
+    uri.Truncate();
+  }
+
+  return true;
+}
+
+NS_IMETHODIMP
+Predictor::Reset() {
+  MOZ_ASSERT(NS_IsMainThread(),
+             "Predictor interface methods must be called on the main thread");
+
+  PREDICTOR_LOG(("Predictor::Reset"));
+
+  if (IsNeckoChild()) {
+    MOZ_DIAGNOSTIC_ASSERT(gNeckoChild);
+
+    PREDICTOR_LOG(("    forwarding to parent process"));
+    gNeckoChild->SendPredReset();
+    return NS_OK;
+  }
+
+  PREDICTOR_LOG(("    called on parent process"));
+
+  if (!mInitialized) {
+    PREDICTOR_LOG(("    not initialized"));
+    return NS_OK;
+  }
+
+  if (!StaticPrefs::network_predictor_enabled()) {
+    PREDICTOR_LOG(("    not enabled"));
+    return NS_OK;
+  }
+
+  RefPtr<Predictor::Resetter> reset = new Predictor::Resetter(this);
+  PREDICTOR_LOG(("    created a resetter"));
+  mCacheStorageService->AsyncVisitAllStorages(reset, true);
+  PREDICTOR_LOG(("    Cache async launched, returning now"));
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(Predictor::Resetter, nsICacheEntryOpenCallback,
+                  nsICacheEntryMetaDataVisitor, nsICacheStorageVisitor);
+
+Predictor::Resetter::Resetter(Predictor* predictor)
+    : mEntriesToVisit(0), mPredictor(predictor) {}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnCacheEntryCheck(nsICacheEntry* entry, uint32_t* result) {
+  *result = nsICacheEntryOpenCallback::ENTRY_WANTED;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnCacheEntryAvailable(nsICacheEntry* entry, bool isNew,
+                                           nsresult result) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (NS_FAILED(result)) {
+    // This can happen when we've tried to open an entry that doesn't exist for
+    // some non-reset operation, and then get reset shortly thereafter (as
+    // happens in some of our tests).
+    --mEntriesToVisit;
+    if (!mEntriesToVisit) {
+      Complete();
+    }
+    return NS_OK;
+  }
+
+  entry->VisitMetaData(this);
+  nsTArray<nsCString> keysToDelete = std::move(mKeysToDelete);
+
+  for (size_t i = 0; i < keysToDelete.Length(); ++i) {
+    const char* key = keysToDelete[i].BeginReading();
+    entry->SetMetaDataElement(key, nullptr);
+  }
+
+  --mEntriesToVisit;
+  if (!mEntriesToVisit) {
+    Complete();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnMetaDataElement(const char* asciiKey,
+                                       const char* asciiValue) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!StringBeginsWith(nsDependentCString(asciiKey),
+                        nsLiteralCString(META_DATA_PREFIX))) {
+    // Not a metadata entry we care about, carry on
+    return NS_OK;
+  }
+
+  nsCString key;
+  key.AssignASCII(asciiKey);
+  mKeysToDelete.AppendElement(key);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnCacheStorageInfo(uint32_t entryCount,
+                                        uint64_t consumption, uint64_t capacity,
+                                        nsIFile* diskDirectory) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnCacheEntryInfo(nsIURI* uri, const nsACString& idEnhance,
+                                      int64_t dataSize, int64_t altDataSize,
+                                      uint32_t fetchCount,
+                                      uint32_t lastModifiedTime,
+                                      uint32_t expirationTime, bool aPinned,
+                                      nsILoadContextInfo* aInfo) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsresult rv;
+
+  // The predictor will only ever touch entries with no idEnhance ("") or an
+  // idEnhance of PREDICTOR_ORIGIN_EXTENSION, so we filter out any entries that
+  // don't match that to avoid doing extra work.
+  if (idEnhance.EqualsLiteral(PREDICTOR_ORIGIN_EXTENSION)) {
+    // This is an entry we own, so we can just doom it entirely
+    nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+    rv = mPredictor->mCacheStorageService->DiskCacheStorage(
+        aInfo, getter_AddRefs(cacheDiskStorage));
+
+    NS_ENSURE_SUCCESS(rv, rv);
+    cacheDiskStorage->AsyncDoomURI(uri, idEnhance, nullptr);
+  } else if (idEnhance.IsEmpty()) {
+    // This is an entry we don't own, so we have to be a little more careful and
+    // just get rid of our own metadata entries. Append it to an array of things
+    // to operate on and then do the operations later so we don't end up calling
+    // Complete() multiple times/too soon.
+    ++mEntriesToVisit;
+    mURIsToVisit.AppendElement(uri);
+    mInfosToVisit.AppendElement(aInfo);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::Resetter::OnCacheEntryVisitCompleted() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsresult rv;
+
+  nsTArray<nsCOMPtr<nsIURI>> urisToVisit = std::move(mURIsToVisit);
+
+  MOZ_ASSERT(mEntriesToVisit == urisToVisit.Length());
+
+  nsTArray<nsCOMPtr<nsILoadContextInfo>> infosToVisit =
+      std::move(mInfosToVisit);
+
+  MOZ_ASSERT(mEntriesToVisit == infosToVisit.Length());
+
+  if (!mEntriesToVisit) {
+    Complete();
+    return NS_OK;
+  }
+
+  uint32_t entriesToVisit = urisToVisit.Length();
+  for (uint32_t i = 0; i < entriesToVisit; ++i) {
+    nsCString u;
+    nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+    rv = mPredictor->mCacheStorageService->DiskCacheStorage(
+        infosToVisit[i], getter_AddRefs(cacheDiskStorage));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    urisToVisit[i]->GetAsciiSpec(u);
+    rv = cacheDiskStorage->AsyncOpenURI(
+        urisToVisit[i], ""_ns,
+        nsICacheStorage::OPEN_READONLY | nsICacheStorage::OPEN_SECRETLY |
+            nsICacheStorage::CHECK_MULTITHREADED,
+        this);
+    if (NS_FAILED(rv)) {
+      mEntriesToVisit--;
+      if (!mEntriesToVisit) {
+        Complete();
+        return NS_OK;
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+void Predictor::Resetter::Complete() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (!obs) {
+    PREDICTOR_LOG(("COULD NOT GET OBSERVER SERVICE!"));
+    return;
+  }
+
+  obs->NotifyObservers(nullptr, "predictor-reset-complete", nullptr);
+}
+
+// Helper functions to make using the predictor easier from native code
+
+static StaticRefPtr<nsINetworkPredictor> sPredictor;
+
+static nsresult EnsureGlobalPredictor(nsINetworkPredictor** aPredictor) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!sPredictor) {
+    nsresult rv;
+    nsCOMPtr<nsINetworkPredictor> predictor =
+        do_GetService("@mozilla.org/network/predictor;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    sPredictor = predictor;
+    ClearOnShutdown(&sPredictor);
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor = sPredictor.get();
+  predictor.forget(aPredictor);
+  return NS_OK;
+}
+
+nsresult PredictorPredict(nsIURI* targetURI, nsIURI* sourceURI,
+                          PredictorPredictReason reason,
+                          const OriginAttributes& originAttributes,
+                          nsINetworkPredictorVerifier* verifier) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor;
+  nsresult rv = EnsureGlobalPredictor(getter_AddRefs(predictor));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return predictor->PredictNative(targetURI, sourceURI, reason,
+                                  originAttributes, verifier);
+}
+
+nsresult PredictorLearn(nsIURI* targetURI, nsIURI* sourceURI,
+                        PredictorLearnReason reason,
+                        const OriginAttributes& originAttributes) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor;
+  nsresult rv = EnsureGlobalPredictor(getter_AddRefs(predictor));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return predictor->LearnNative(targetURI, sourceURI, reason, originAttributes);
+}
+
+nsresult PredictorLearn(nsIURI* targetURI, nsIURI* sourceURI,
+                        PredictorLearnReason reason, nsILoadGroup* loadGroup) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor;
+  nsresult rv = EnsureGlobalPredictor(getter_AddRefs(predictor));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsILoadContext> loadContext;
+  OriginAttributes originAttributes;
+
+  if (loadGroup) {
+    nsCOMPtr<nsIInterfaceRequestor> callbacks;
+    loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+    if (callbacks) {
+      loadContext = do_GetInterface(callbacks);
+
+      if (loadContext) {
+        loadContext->GetOriginAttributes(originAttributes);
+      }
+    }
+  }
+
+  return predictor->LearnNative(targetURI, sourceURI, reason, originAttributes);
+}
+
+nsresult PredictorLearn(nsIURI* targetURI, nsIURI* sourceURI,
+                        PredictorLearnReason reason, dom::Document* document) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor;
+  nsresult rv = EnsureGlobalPredictor(getter_AddRefs(predictor));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  OriginAttributes originAttributes;
+
+  if (document) {
+    nsCOMPtr<nsIPrincipal> docPrincipal = document->NodePrincipal();
+
+    if (docPrincipal) {
+      originAttributes = docPrincipal->OriginAttributesRef();
+    }
+  }
+
+  return predictor->LearnNative(targetURI, sourceURI, reason, originAttributes);
+}
+
+nsresult PredictorLearnRedirect(nsIURI* targetURI, nsIChannel* channel,
+                                const OriginAttributes& originAttributes) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIURI> sourceURI;
+  nsresult rv = channel->GetOriginalURI(getter_AddRefs(sourceURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool sameUri;
+  rv = targetURI->Equals(sourceURI, &sameUri);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (sameUri) {
+    return NS_OK;
+  }
+
+  if (!IsNullOrHttp(targetURI) || !IsNullOrHttp(sourceURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINetworkPredictor> predictor;
+  rv = EnsureGlobalPredictor(getter_AddRefs(predictor));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return predictor->LearnNative(targetURI, sourceURI,
+                                nsINetworkPredictor::LEARN_LOAD_REDIRECT,
+                                originAttributes);
+}
+
+// nsINetworkPredictorVerifier
+
+/**
+ * Call through to the child's verifier (only during tests)
+ */
+NS_IMETHODIMP
+Predictor::OnPredictPrefetch(nsIURI* aURI, uint32_t httpStatus) {
+  if (IsNeckoChild()) {
+    if (mChildVerifier) {
+      // Ideally, we'd assert here. But since we're slowly moving towards a
+      // world where we have multiple child processes, and only one child
+      // process will be likely to have a verifier, we have to play it safer.
+      return mChildVerifier->OnPredictPrefetch(aURI, httpStatus);
+    }
+    return NS_OK;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aURI, "aURI must not be null");
+
+  for (auto* cp : dom::ContentParent::AllProcesses(dom::ContentParent::eLive)) {
+    PNeckoParent* neckoParent = SingleManagedOrNull(cp->ManagedPNeckoParent());
+    if (!neckoParent) {
+      continue;
+    }
+    if (!neckoParent->SendPredOnPredictPrefetch(aURI, httpStatus)) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::OnPredictPreconnect(nsIURI* aURI) {
+  if (IsNeckoChild()) {
+    if (mChildVerifier) {
+      // Ideally, we'd assert here. But since we're slowly moving towards a
+      // world where we have multiple child processes, and only one child
+      // process will be likely to have a verifier, we have to play it safer.
+      return mChildVerifier->OnPredictPreconnect(aURI);
+    }
+    return NS_OK;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aURI, "aURI must not be null");
+
+  for (auto* cp : dom::ContentParent::AllProcesses(dom::ContentParent::eLive)) {
+    PNeckoParent* neckoParent = SingleManagedOrNull(cp->ManagedPNeckoParent());
+    if (!neckoParent) {
+      continue;
+    }
+    if (!neckoParent->SendPredOnPredictPreconnect(aURI)) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::OnPredictDNS(nsIURI* aURI) {
+  if (IsNeckoChild()) {
+    if (mChildVerifier) {
+      // Ideally, we'd assert here. But since we're slowly moving towards a
+      // world where we have multiple child processes, and only one child
+      // process will be likely to have a verifier, we have to play it safer.
+      return mChildVerifier->OnPredictDNS(aURI);
+    }
+    return NS_OK;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aURI, "aURI must not be null");
+
+  for (auto* cp : dom::ContentParent::AllProcesses(dom::ContentParent::eLive)) {
+    PNeckoParent* neckoParent = SingleManagedOrNull(cp->ManagedPNeckoParent());
+    if (!neckoParent) {
+      continue;
+    }
+    if (!neckoParent->SendPredOnPredictDNS(aURI)) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  return NS_OK;
+}
+
+// Predictor::PrefetchListener
+// nsISupports
+NS_IMPL_ISUPPORTS(Predictor::PrefetchListener, nsIStreamListener,
+                  nsIRequestObserver)
+
+// nsIRequestObserver
+NS_IMETHODIMP
+Predictor::PrefetchListener::OnStartRequest(nsIRequest* aRequest) {
+  mStartTime = TimeStamp::Now();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::PrefetchListener::OnStopRequest(nsIRequest* aRequest,
+                                           nsresult aStatusCode) {
+  PREDICTOR_LOG(("OnStopRequest this=%p aStatusCode=0x%" PRIX32, this,
+                 static_cast<uint32_t>(aStatusCode)));
+  NS_ENSURE_ARG(aRequest);
+  if (NS_FAILED(aStatusCode)) {
+    return aStatusCode;
+  }
+  Telemetry::AccumulateTimeDelta(Telemetry::PREDICTOR_PREFETCH_TIME,
+                                 mStartTime);
+
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aRequest);
+  if (!httpChannel) {
+    PREDICTOR_LOG(("    Could not get HTTP Channel!"));
+    return NS_ERROR_UNEXPECTED;
+  }
+  nsCOMPtr<nsICachingChannel> cachingChannel = do_QueryInterface(httpChannel);
+  if (!cachingChannel) {
+    PREDICTOR_LOG(("    Could not get caching channel!"));
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsresult rv = NS_OK;
+  uint32_t httpStatus;
+  rv = httpChannel->GetResponseStatus(&httpStatus);
+  if (NS_SUCCEEDED(rv) && httpStatus == 200) {
+    rv = cachingChannel->ForceCacheEntryValidFor(
+        StaticPrefs::network_predictor_prefetch_force_valid_for());
+    PREDICTOR_LOG(("    forcing entry valid for %d seconds rv=%" PRIX32,
+                   StaticPrefs::network_predictor_prefetch_force_valid_for(),
+                   static_cast<uint32_t>(rv)));
+  } else {
+    rv = cachingChannel->ForceCacheEntryValidFor(0);
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_PREDICTOR_PREFETCH_USE_STATUS::Not200);
+    PREDICTOR_LOG(("    removing any forced validity rv=%" PRIX32,
+                   static_cast<uint32_t>(rv)));
+  }
+
+  nsAutoCString reqName;
+  rv = aRequest->GetName(reqName);
+  if (NS_FAILED(rv)) {
+    reqName.AssignLiteral("<unknown>");
+  }
+
+  PREDICTOR_LOG(("    request %s status %u", reqName.get(), httpStatus));
+
+  if (mVerifier) {
+    mVerifier->OnPredictPrefetch(mURI, httpStatus);
+  }
+
+  return rv;
+}
+
+// nsIStreamListener
+NS_IMETHODIMP
+Predictor::PrefetchListener::OnDataAvailable(nsIRequest* aRequest,
+                                             nsIInputStream* aInputStream,
+                                             uint64_t aOffset,
+                                             const uint32_t aCount) {
+  uint32_t result;
+  return aInputStream->ReadSegments(NS_DiscardSegment, nullptr, aCount,
+                                    &result);
+}
+
+// Miscellaneous Predictor
+
+void Predictor::UpdateCacheability(nsIURI* sourceURI, nsIURI* targetURI,
+                                   uint32_t httpStatus,
+                                   nsHttpRequestHead& requestHead,
+                                   nsHttpResponseHead* responseHead,
+                                   nsILoadContextInfo* lci, bool isTracking) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (lci && lci->IsPrivate()) {
+    PREDICTOR_LOG(("Predictor::UpdateCacheability in PB mode - ignoring"));
+    return;
+  }
+
+  if (!sourceURI || !targetURI) {
+    PREDICTOR_LOG(
+        ("Predictor::UpdateCacheability missing source or target uri"));
+    return;
+  }
+
+  if (!IsNullOrHttp(sourceURI) || !IsNullOrHttp(targetURI)) {
+    PREDICTOR_LOG(("Predictor::UpdateCacheability non-http(s) uri"));
+    return;
+  }
+
+  RefPtr<Predictor> self = sSelf;
+  if (self) {
+    nsAutoCString method;
+    requestHead.Method(method);
+
+    nsAutoCString vary;
+    Unused << responseHead->GetHeader(nsHttp::Vary, vary);
+
+    nsAutoCString cacheControlHeader;
+    Unused << responseHead->GetHeader(nsHttp::Cache_Control,
+                                      cacheControlHeader);
+    CacheControlParser cacheControl(cacheControlHeader);
+
+    self->UpdateCacheabilityInternal(sourceURI, targetURI, httpStatus, method,
+                                     *lci->OriginAttributesPtr(), isTracking,
+                                     !vary.IsEmpty(), cacheControl.NoStore());
+  }
+}
+
+void Predictor::UpdateCacheabilityInternal(
+    nsIURI* sourceURI, nsIURI* targetURI, uint32_t httpStatus,
+    const nsCString& method, const OriginAttributes& originAttributes,
+    bool isTracking, bool couldVary, bool isNoStore) {
+  PREDICTOR_LOG(("Predictor::UpdateCacheability httpStatus=%u", httpStatus));
+
+  nsresult rv;
+
+  if (!mInitialized) {
+    PREDICTOR_LOG(("    not initialized"));
+    return;
+  }
+
+  if (!StaticPrefs::network_predictor_enabled()) {
+    PREDICTOR_LOG(("    not enabled"));
+    return;
+  }
+
+  nsCOMPtr<nsICacheStorage> cacheDiskStorage;
+
+  RefPtr<LoadContextInfo> lci = new LoadContextInfo(false, originAttributes);
+
+  rv = mCacheStorageService->DiskCacheStorage(lci,
+                                              getter_AddRefs(cacheDiskStorage));
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(("    cannot get disk cache storage"));
+    return;
+  }
+
+  uint32_t openFlags = nsICacheStorage::OPEN_READONLY |
+                       nsICacheStorage::OPEN_SECRETLY |
+                       nsICacheStorage::CHECK_MULTITHREADED;
+  RefPtr<Predictor::CacheabilityAction> action =
+      new Predictor::CacheabilityAction(targetURI, httpStatus, method,
+                                        isTracking, couldVary, isNoStore, this);
+  nsAutoCString uri;
+  targetURI->GetAsciiSpec(uri);
+  PREDICTOR_LOG(("    uri=%s action=%p", uri.get(), action.get()));
+  cacheDiskStorage->AsyncOpenURI(sourceURI, ""_ns, openFlags, action);
+}
+
+NS_IMPL_ISUPPORTS(Predictor::CacheabilityAction, nsICacheEntryOpenCallback,
+                  nsICacheEntryMetaDataVisitor);
+
+NS_IMETHODIMP
+Predictor::CacheabilityAction::OnCacheEntryCheck(nsICacheEntry* entry,
+                                                 uint32_t* result) {
+  *result = nsICacheEntryOpenCallback::ENTRY_WANTED;
+  return NS_OK;
+}
+
+namespace {
+enum PrefetchDecisionReason {
+  PREFETCHABLE,
+  STATUS_NOT_200,
+  METHOD_NOT_GET,
+  URL_HAS_QUERY_STRING,
+  RESOURCE_IS_TRACKING,
+  RESOURCE_COULD_VARY,
+  RESOURCE_IS_NO_STORE
+};
+}
+
+NS_IMETHODIMP
+Predictor::CacheabilityAction::OnCacheEntryAvailable(nsICacheEntry* entry,
+                                                     bool isNew,
+                                                     nsresult result) {
+  MOZ_ASSERT(NS_IsMainThread());
+  // This is being opened read-only, so isNew should always be false
+  MOZ_ASSERT(!isNew);
+
+  PREDICTOR_LOG(("CacheabilityAction::OnCacheEntryAvailable this=%p", this));
+  if (NS_FAILED(result)) {
+    // Nothing to do
+    PREDICTOR_LOG(("    nothing to do result=%" PRIX32 " isNew=%d",
+                   static_cast<uint32_t>(result), isNew));
+    return NS_OK;
+  }
+
+  nsCString strTargetURI;
+  nsresult rv = mTargetURI->GetAsciiSpec(strTargetURI);
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    GetAsciiSpec returned %" PRIx32, static_cast<uint32_t>(rv)));
+    return NS_OK;
+  }
+
+  rv = entry->VisitMetaData(this);
+  if (NS_FAILED(rv)) {
+    PREDICTOR_LOG(
+        ("    VisitMetaData returned %" PRIx32, static_cast<uint32_t>(rv)));
+    return NS_OK;
+  }
+
+  nsTArray<nsCString> keysToCheck = std::move(mKeysToCheck),
+                      valuesToCheck = std::move(mValuesToCheck);
+
+  bool hasQueryString = false;
+  nsAutoCString query;
+  if (NS_SUCCEEDED(mTargetURI->GetQuery(query)) && !query.IsEmpty()) {
+    hasQueryString = true;
+  }
+
+  MOZ_ASSERT(keysToCheck.Length() == valuesToCheck.Length());
+  for (size_t i = 0; i < keysToCheck.Length(); ++i) {
+    const char* key = keysToCheck[i].BeginReading();
+    const char* value = valuesToCheck[i].BeginReading();
+    nsCString uri;
+    uint32_t hitCount, lastHit, flags;
+
+    if (!mPredictor->ParseMetaDataEntry(key, value, uri, hitCount, lastHit,
+                                        flags)) {
+      PREDICTOR_LOG(("    failed to parse key=%s value=%s", key, value));
+      continue;
+    }
+
+    if (strTargetURI.Equals(uri)) {
+      bool prefetchable = true;
+      PrefetchDecisionReason reason = PREFETCHABLE;
+
+      if (mHttpStatus != 200) {
+        prefetchable = false;
+        reason = STATUS_NOT_200;
+      } else if (!mMethod.EqualsLiteral("GET")) {
+        prefetchable = false;
+        reason = METHOD_NOT_GET;
+      } else if (hasQueryString) {
+        prefetchable = false;
+        reason = URL_HAS_QUERY_STRING;
+      } else if (mIsTracking) {
+        prefetchable = false;
+        reason = RESOURCE_IS_TRACKING;
+      } else if (mCouldVary) {
+        prefetchable = false;
+        reason = RESOURCE_COULD_VARY;
+      } else if (mIsNoStore) {
+        // We don't set prefetchable = false yet, because we just want to know
+        // what kind of effect this would have on prefetching.
+        reason = RESOURCE_IS_NO_STORE;
+      }
+
+      Telemetry::Accumulate(Telemetry::PREDICTOR_PREFETCH_DECISION_REASON,
+                            reason);
+
+      if (prefetchable) {
+        PREDICTOR_LOG(("    marking %s cacheable", key));
+        flags |= FLAG_PREFETCHABLE;
+      } else {
+        PREDICTOR_LOG(("    marking %s uncacheable", key));
+        flags &= ~FLAG_PREFETCHABLE;
+      }
+      nsCString newValue;
+      MakeMetadataEntry(hitCount, lastHit, flags, newValue);
+      entry->SetMetaDataElement(key, newValue.BeginReading());
+      break;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+Predictor::CacheabilityAction::OnMetaDataElement(const char* asciiKey,
+                                                 const char* asciiValue) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!IsURIMetadataElement(asciiKey)) {
+    return NS_OK;
+  }
+
+  nsCString key, value;
+  key.AssignASCII(asciiKey);
+  value.AssignASCII(asciiValue);
+  mKeysToCheck.AppendElement(key);
+  mValuesToCheck.AppendElement(value);
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/Predictor.h b/netwerk/base/Predictor.h
new file mode 100644
index 0000000000..a16e09adad
--- /dev/null
+++ b/netwerk/base/Predictor.h
@@ -0,0 +1,458 @@
+/* vim: set ts=2 sts=2 et sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_Predictor_h
+#define mozilla_net_Predictor_h
+
+#include "nsINetworkPredictor.h"
+#include "nsINetworkPredictorVerifier.h"
+
+#include "nsCOMPtr.h"
+#include "nsICacheEntry.h"
+#include "nsICacheEntryOpenCallback.h"
+#include "nsICacheStorageService.h"
+#include "nsICacheStorageVisitor.h"
+#include "nsIDNSListener.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIObserver.h"
+#include "nsISpeculativeConnect.h"
+#include "nsIStreamListener.h"
+#include "mozilla/RefPtr.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+#include "mozilla/TimeStamp.h"
+
+class nsICacheStorage;
+class nsIDNSService;
+class nsIIOService;
+class nsILoadContextInfo;
+class nsITimer;
+
+namespace mozilla {
+namespace net {
+
+class nsHttpRequestHead;
+class nsHttpResponseHead;
+
+class Predictor final : public nsINetworkPredictor,
+                        public nsIObserver,
+                        public nsISpeculativeConnectionOverrider,
+                        public nsIInterfaceRequestor,
+                        public nsICacheEntryMetaDataVisitor,
+                        public nsINetworkPredictorVerifier {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSINETWORKPREDICTOR
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSISPECULATIVECONNECTIONOVERRIDER
+  NS_DECL_NSIINTERFACEREQUESTOR
+  NS_DECL_NSICACHEENTRYMETADATAVISITOR
+  NS_DECL_NSINETWORKPREDICTORVERIFIER
+
+  Predictor();
+
+  nsresult Init();
+  void Shutdown();
+  static nsresult Create(const nsIID& iid, void** result);
+
+  // Used to update whether a particular URI was cacheable or not.
+  // sourceURI and targetURI are the same as the arguments to Learn
+  // and httpStatus is the status code we got while loading targetURI.
+  static void UpdateCacheability(nsIURI* sourceURI, nsIURI* targetURI,
+                                 uint32_t httpStatus,
+                                 nsHttpRequestHead& requestHead,
+                                 nsHttpResponseHead* responseHead,
+                                 nsILoadContextInfo* lci, bool isTracking);
+
+ private:
+  virtual ~Predictor();
+
+  // Stores callbacks for a child process predictor (for test purposes)
+  nsCOMPtr<nsINetworkPredictorVerifier> mChildVerifier;
+
+  union Reason {
+    PredictorLearnReason mLearn;
+    PredictorPredictReason mPredict;
+  };
+
+  class DNSListener : public nsIDNSListener {
+   public:
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSIDNSLISTENER
+
+    DNSListener() = default;
+
+   private:
+    virtual ~DNSListener() = default;
+  };
+
+  class Action : public nsICacheEntryOpenCallback {
+   public:
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSICACHEENTRYOPENCALLBACK
+
+    Action(bool fullUri, bool predict, Reason reason, nsIURI* targetURI,
+           nsIURI* sourceURI, nsINetworkPredictorVerifier* verifier,
+           Predictor* predictor);
+    Action(bool fullUri, bool predict, Reason reason, nsIURI* targetURI,
+           nsIURI* sourceURI, nsINetworkPredictorVerifier* verifier,
+           Predictor* predictor, uint8_t stackCount);
+
+    static const bool IS_FULL_URI = true;
+    static const bool IS_ORIGIN = false;
+
+    static const bool DO_PREDICT = true;
+    static const bool DO_LEARN = false;
+
+   private:
+    virtual ~Action() = default;
+
+    bool mFullUri : 1;
+    bool mPredict : 1;
+    union {
+      PredictorPredictReason mPredictReason;
+      PredictorLearnReason mLearnReason;
+    };
+    nsCOMPtr<nsIURI> mTargetURI;
+    nsCOMPtr<nsIURI> mSourceURI;
+    nsCOMPtr<nsINetworkPredictorVerifier> mVerifier;
+    TimeStamp mStartTime;
+    uint8_t mStackCount;
+    RefPtr<Predictor> mPredictor;
+  };
+
+  class CacheabilityAction : public nsICacheEntryOpenCallback,
+                             public nsICacheEntryMetaDataVisitor {
+   public:
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSICACHEENTRYOPENCALLBACK
+    NS_DECL_NSICACHEENTRYMETADATAVISITOR
+
+    CacheabilityAction(nsIURI* targetURI, uint32_t httpStatus,
+                       const nsCString& method, bool isTracking, bool couldVary,
+                       bool isNoStore, Predictor* predictor)
+        : mTargetURI(targetURI),
+          mHttpStatus(httpStatus),
+          mMethod(method),
+          mIsTracking(isTracking),
+          mCouldVary(couldVary),
+          mIsNoStore(isNoStore),
+          mPredictor(predictor) {}
+
+   private:
+    virtual ~CacheabilityAction() = default;
+
+    nsCOMPtr<nsIURI> mTargetURI;
+    uint32_t mHttpStatus;
+    nsCString mMethod;
+    bool mIsTracking;
+    bool mCouldVary;
+    bool mIsNoStore;
+    RefPtr<Predictor> mPredictor;
+    nsTArray<nsCString> mKeysToCheck;
+    nsTArray<nsCString> mValuesToCheck;
+  };
+
+  class Resetter : public nsICacheEntryOpenCallback,
+                   public nsICacheEntryMetaDataVisitor,
+                   public nsICacheStorageVisitor {
+   public:
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSICACHEENTRYOPENCALLBACK
+    NS_DECL_NSICACHEENTRYMETADATAVISITOR
+    NS_DECL_NSICACHESTORAGEVISITOR
+
+    explicit Resetter(Predictor* predictor);
+
+   private:
+    virtual ~Resetter() = default;
+
+    void Complete();
+
+    uint32_t mEntriesToVisit;
+    nsTArray<nsCString> mKeysToDelete;
+    RefPtr<Predictor> mPredictor;
+    nsTArray<nsCOMPtr<nsIURI>> mURIsToVisit;
+    nsTArray<nsCOMPtr<nsILoadContextInfo>> mInfosToVisit;
+  };
+
+  class SpaceCleaner : public nsICacheEntryMetaDataVisitor {
+   public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSICACHEENTRYMETADATAVISITOR
+
+    explicit SpaceCleaner(Predictor* predictor)
+        : mLRUStamp(0), mLRUKeyToDelete(nullptr), mPredictor(predictor) {}
+
+    void Finalize(nsICacheEntry* entry);
+
+   private:
+    virtual ~SpaceCleaner() = default;
+    uint32_t mLRUStamp;
+    const char* mLRUKeyToDelete;
+    nsTArray<nsCString> mLongKeysToDelete;
+    RefPtr<Predictor> mPredictor;
+  };
+
+  class PrefetchListener : public nsIStreamListener {
+   public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSISTREAMLISTENER
+
+    PrefetchListener(nsINetworkPredictorVerifier* verifier, nsIURI* uri,
+                     Predictor* predictor)
+        : mVerifier(verifier), mURI(uri), mPredictor(predictor) {}
+
+   private:
+    virtual ~PrefetchListener() = default;
+
+    nsCOMPtr<nsINetworkPredictorVerifier> mVerifier;
+    nsCOMPtr<nsIURI> mURI;
+    RefPtr<Predictor> mPredictor;
+    TimeStamp mStartTime;
+  };
+
+  // Observer-related stuff
+  nsresult InstallObserver();
+  void RemoveObserver();
+
+  // Service startup utilities
+  void MaybeCleanupOldDBFiles();
+
+  // The guts of prediction
+
+  // This is the top-level driver for doing any prediction that needs
+  // information from the cache. Returns true if any predictions were queued up
+  //   * reason - What kind of prediction this is/why this prediction is
+  //              happening (pageload, startup)
+  //   * entry - the cache entry with the information we need
+  //   * isNew - whether or not the cache entry is brand new and empty
+  //   * fullUri - whether we are doing predictions based on a full page URI, or
+  //               just the origin of the page
+  //   * targetURI - the URI that we are predicting based upon - IOW, the URI
+  //                 that is being loaded or being redirected to
+  //   * verifier - used for testing to verify the expected predictions happen
+  //   * stackCount - used to ensure we don't recurse too far trying to find the
+  //                  final redirection in a redirect chain
+  bool PredictInternal(PredictorPredictReason reason, nsICacheEntry* entry,
+                       bool isNew, bool fullUri, nsIURI* targetURI,
+                       nsINetworkPredictorVerifier* verifier,
+                       uint8_t stackCount);
+
+  // Used when predicting because the user's mouse hovered over a link
+  //   * targetURI - the URI target of the link
+  //   * sourceURI - the URI of the page on which the link appears
+  //   * originAttributes - the originAttributes for this prediction
+  //   * verifier - used for testing to verify the expected predictions happen
+  void PredictForLink(nsIURI* targetURI, nsIURI* sourceURI,
+                      const OriginAttributes& originAttributes,
+                      nsINetworkPredictorVerifier* verifier);
+
+  // Used when predicting because a page is being loaded (which may include
+  // being the target of a redirect). All arguments are the same as for
+  // PredictInternal. Returns true if any predictions were queued up.
+  bool PredictForPageload(nsICacheEntry* entry, nsIURI* targetURI,
+                          uint8_t stackCount, bool fullUri,
+                          nsINetworkPredictorVerifier* verifier);
+
+  // Used when predicting pages that will be used near browser startup. All
+  // arguments are the same as for PredictInternal. Returns true if any
+  // predictions were queued up.
+  bool PredictForStartup(nsICacheEntry* entry, bool fullUri,
+                         nsINetworkPredictorVerifier* verifier);
+
+  // Utilities related to prediction
+
+  // Used to update our rolling load count (how many of the last n loads was a
+  // partular resource loaded on?)
+  //   * entry - cache entry of page we're loading
+  //   * flags - value that contains our rolling count as the top 20 bits (but
+  //             we may use fewer than those 20 bits for calculations)
+  //   * key - metadata key that we will update on entry
+  //   * hitCount - part of the metadata we need to preserve
+  //   * lastHit - part of the metadata we need to preserve
+  void UpdateRollingLoadCount(nsICacheEntry* entry, const uint32_t flags,
+                              const char* key, const uint32_t hitCount,
+                              const uint32_t lastHit);
+
+  // Used to calculate how much to degrade our confidence for all resources
+  // on a particular page, because of how long ago the most recent load of that
+  // page was. Returns a value between 0 (very recent most recent load) and 100
+  // (very distant most recent load)
+  //   * lastLoad - time stamp of most recent load of a page
+  int32_t CalculateGlobalDegradation(uint32_t lastLoad);
+
+  // Used to calculate how confident we are that a particular resource will be
+  // used. Returns a value between 0 (no confidence) and 100 (very confident)
+  //   * hitCount - number of times this resource has been seen when loading
+  //                this page
+  //   * hitsPossible - number of times this page has been loaded
+  //   * lastHit - timestamp of the last time this resource was seen when
+  //               loading this page
+  //   * lastPossible - timestamp of the last time this page was loaded
+  //   * globalDegradation - value calculated by CalculateGlobalDegradation for
+  //                         this page
+  int32_t CalculateConfidence(uint32_t hitCount, uint32_t hitsPossible,
+                              uint32_t lastHit, uint32_t lastPossible,
+                              int32_t globalDegradation);
+
+  // Used to calculate all confidence values for all resources associated with a
+  // page.
+  //   * entry - the cache entry with all necessary information about this page
+  //   * referrer - the URI that we are loading (may be null)
+  //   * lastLoad - timestamp of the last time this page was loaded
+  //   * loadCount - number of times this page has been loaded
+  //   * gloablDegradation - value calculated by CalculateGlobalDegradation for
+  //                         this page
+  //   * fullUri - whether we're predicting for a full URI or origin-only
+  void CalculatePredictions(nsICacheEntry* entry, nsIURI* referrer,
+                            uint32_t lastLoad, uint32_t loadCount,
+                            int32_t globalDegradation, bool fullUri);
+
+  enum PrefetchIgnoreReason {
+    PREFETCH_OK,
+    NOT_FULL_URI,
+    NO_REFERRER,
+    MISSED_A_LOAD,
+    PREFETCH_DISABLED,
+    PREFETCH_DISABLED_VIA_COUNT,
+    CONFIDENCE_TOO_LOW
+  };
+
+  // Used to prepare any necessary prediction for a resource on a page
+  //   * confidence - value calculated by CalculateConfidence for this resource
+  //   * flags - the flags taken from the resource
+  //   * uri - the ascii spec of the URI of the resource
+  void SetupPrediction(int32_t confidence, uint32_t flags, const nsCString& uri,
+                       PrefetchIgnoreReason reason);
+
+  // Used to kick off a prefetch from RunPredictions if necessary
+  //   * uri - the URI to prefetch
+  //   * referrer - the URI of the referring page
+  //   * originAttributes - the originAttributes of this prefetch
+  //   * verifier - used for testing to ensure the expected prefetch happens
+  nsresult Prefetch(nsIURI* uri, nsIURI* referrer,
+                    const OriginAttributes& originAttributes,
+                    nsINetworkPredictorVerifier* verifier);
+
+  // Used to actually perform any predictions set up via SetupPrediction.
+  // Returns true if any predictions were performed.
+  //   * referrer - the URI we are predicting from
+  //   * originAttributs - the originAttributes we are predicting from
+  //   * verifier - used for testing to ensure the expected predictions happen
+  bool RunPredictions(nsIURI* referrer,
+                      const OriginAttributes& originAttributes,
+                      nsINetworkPredictorVerifier* verifier);
+
+  // Used to guess whether a page will redirect to another page or not. Returns
+  // true if a redirection is likely.
+  //   * entry - cache entry with all necessary information about this page
+  //   * loadCount - number of times this page has been loaded
+  //   * lastLoad - timestamp of the last time this page was loaded
+  //   * globalDegradation - value calculated by CalculateGlobalDegradation for
+  //                         this page
+  //   * redirectURI - if this returns true, the URI that is likely to be
+  //                   redirected to, otherwise null
+  bool WouldRedirect(nsICacheEntry* entry, uint32_t loadCount,
+                     uint32_t lastLoad, int32_t globalDegradation,
+                     nsIURI** redirectURI);
+
+  // The guts of learning information
+
+  // This is the top-level driver for doing any updating of our information in
+  // the cache
+  //   * reason - why this learn is happening (pageload, startup, redirect)
+  //   * entry - the cache entry with the information we need
+  //   * isNew - whether or not the cache entry is brand new and empty
+  //   * fullUri - whether we are doing predictions based on a full page URI, or
+  //               just the origin of the page
+  //   * targetURI - the URI that we are adding to our data - most often a
+  //                 resource loaded by a page the user navigated to
+  //   * sourceURI - the URI that caused targetURI to be loaded, usually the
+  //                 page the user navigated to
+  void LearnInternal(PredictorLearnReason reason, nsICacheEntry* entry,
+                     bool isNew, bool fullUri, nsIURI* targetURI,
+                     nsIURI* sourceURI);
+
+  // Used when learning about a resource loaded by a page
+  //   * entry - the cache entry with information that needs updating
+  //   * targetURI - the URI of the resource that was loaded by the page
+  void LearnForSubresource(nsICacheEntry* entry, nsIURI* targetURI);
+
+  // Used when learning about a redirect from one page to another
+  //   * entry - the cache entry of the page that was redirected from
+  //   * targetURI - the URI of the redirect target
+  void LearnForRedirect(nsICacheEntry* entry, nsIURI* targetURI);
+
+  // Used to learn about pages loaded close to browser startup. This results in
+  // LearnForStartup being called if we are, in fact, near browser startup
+  //   * uri - the URI of a page that has been loaded (may not have been near
+  //           browser startup)
+  //   * fullUri - true if this is a full page uri, false if it's an origin
+  //   * originAttributes - the originAttributes for this learning.
+  void MaybeLearnForStartup(nsIURI* uri, bool fullUri,
+                            const OriginAttributes& originAttributes);
+
+  // Used in conjunction with MaybeLearnForStartup to learn about pages loaded
+  // close to browser startup
+  //   * entry - the cache entry that stores the startup page list
+  //   * targetURI - the URI of a page that was loaded near browser startup
+  void LearnForStartup(nsICacheEntry* entry, nsIURI* targetURI);
+
+  // Used to parse the data we store in cache metadata
+  //   * key - the cache metadata key
+  //   * value - the cache metadata value
+  //   * uri - (out) the ascii spec of the URI this metadata entry was about
+  //   * hitCount - (out) the number of times this URI has been seen
+  //   * lastHit - (out) timestamp of the last time this URI was seen
+  //   * flags - (out) flags for this metadata entry
+  bool ParseMetaDataEntry(const char* key, const char* value, nsCString& uri,
+                          uint32_t& hitCount, uint32_t& lastHit,
+                          uint32_t& flags);
+
+  // Used to update whether a particular URI was cacheable or not.
+  // sourceURI and targetURI are the same as the arguments to Learn
+  // and httpStatus is the status code we got while loading targetURI.
+  void UpdateCacheabilityInternal(nsIURI* sourceURI, nsIURI* targetURI,
+                                  uint32_t httpStatus, const nsCString& method,
+                                  const OriginAttributes& originAttributes,
+                                  bool isTracking, bool couldVary,
+                                  bool isNoStore);
+
+  // Gets the pref value and clamps it within the acceptable range.
+  uint32_t ClampedPrefetchRollingLoadCount();
+
+  // Our state
+  bool mInitialized{false};
+
+  nsTArray<nsCString> mKeysToOperateOn;
+  nsTArray<nsCString> mValuesToOperateOn;
+
+  nsCOMPtr<nsICacheStorageService> mCacheStorageService;
+
+  nsCOMPtr<nsISpeculativeConnect> mSpeculativeService;
+
+  nsCOMPtr<nsIURI> mStartupURI;
+  uint32_t mStartupTime{0};
+  uint32_t mLastStartupTime{0};
+  int32_t mStartupCount{1};
+
+  nsCOMPtr<nsIDNSService> mDnsService;
+
+  RefPtr<DNSListener> mDNSListener;
+
+  nsTArray<nsCOMPtr<nsIURI>> mPrefetches;
+  nsTArray<nsCOMPtr<nsIURI>> mPreconnects;
+  nsTArray<nsCOMPtr<nsIURI>> mPreresolves;
+
+  static Predictor* sSelf;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_Predictor_h
diff --git a/netwerk/base/PrivateBrowsingChannel.h b/netwerk/base/PrivateBrowsingChannel.h
new file mode 100644
index 0000000000..a2e224f092
--- /dev/null
+++ b/netwerk/base/PrivateBrowsingChannel.h
@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sts=2 sw=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_PrivateBrowsingChannel_h__
+#define mozilla_net_PrivateBrowsingChannel_h__
+
+#include "nsIPrivateBrowsingChannel.h"
+#include "nsCOMPtr.h"
+#include "nsILoadGroup.h"
+#include "nsILoadContext.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsNetUtil.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla {
+namespace net {
+
+template <class Channel>
+class PrivateBrowsingChannel : public nsIPrivateBrowsingChannel {
+ public:
+  PrivateBrowsingChannel()
+      : mPrivateBrowsingOverriden(false), mPrivateBrowsing(false) {}
+
+  NS_IMETHOD SetPrivate(bool aPrivate) override {
+    // Make sure that we don't have a load context
+    // This is a fatal error in debug builds, and a runtime error in release
+    // builds.
+    nsCOMPtr<nsILoadContext> loadContext;
+    NS_QueryNotificationCallbacks(static_cast<Channel*>(this), loadContext);
+    MOZ_ASSERT(!loadContext);
+    if (loadContext) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mPrivateBrowsingOverriden = true;
+    mPrivateBrowsing = aPrivate;
+    return NS_OK;
+  }
+
+  NS_IMETHOD GetIsChannelPrivate(bool* aResult) override {
+    NS_ENSURE_ARG_POINTER(aResult);
+    *aResult = mPrivateBrowsing;
+    return NS_OK;
+  }
+
+  NS_IMETHOD IsPrivateModeOverriden(bool* aValue, bool* aResult) override {
+    NS_ENSURE_ARG_POINTER(aValue);
+    NS_ENSURE_ARG_POINTER(aResult);
+    *aResult = mPrivateBrowsingOverriden;
+    if (mPrivateBrowsingOverriden) {
+      *aValue = mPrivateBrowsing;
+    }
+    return NS_OK;
+  }
+
+  // Must be called every time the channel's callbacks or loadGroup is updated
+  void UpdatePrivateBrowsing() {
+    // once marked as private we never go un-private
+    if (mPrivateBrowsing) {
+      return;
+    }
+
+    auto channel = static_cast<Channel*>(this);
+
+    nsCOMPtr<nsILoadContext> loadContext;
+    NS_QueryNotificationCallbacks(channel, loadContext);
+    if (loadContext) {
+      mPrivateBrowsing = loadContext->UsePrivateBrowsing();
+      return;
+    }
+
+    nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+    OriginAttributes attrs = loadInfo->GetOriginAttributes();
+    mPrivateBrowsing = attrs.mPrivateBrowsingId > 0;
+  }
+
+  bool CanSetCallbacks(nsIInterfaceRequestor* aCallbacks) const {
+    // Make sure that the private bit override flag is not set.
+    // This is a fatal error in debug builds, and a runtime error in release
+    // builds.
+    if (!aCallbacks) {
+      return true;
+    }
+    nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(aCallbacks);
+    if (!loadContext) {
+      return true;
+    }
+    MOZ_ASSERT(!mPrivateBrowsingOverriden);
+    return !mPrivateBrowsingOverriden;
+  }
+
+  bool CanSetLoadGroup(nsILoadGroup* aLoadGroup) const {
+    // Make sure that the private bit override flag is not set.
+    // This is a fatal error in debug builds, and a runtime error in release
+    // builds.
+    if (!aLoadGroup) {
+      return true;
+    }
+    nsCOMPtr<nsIInterfaceRequestor> callbacks;
+    aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+    // From this point on, we just hand off the work to CanSetCallbacks,
+    // because the logic is exactly the same.
+    return CanSetCallbacks(callbacks);
+  }
+
+ protected:
+  bool mPrivateBrowsingOverriden;
+  bool mPrivateBrowsing;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/ProtocolHandlerInfo.cpp b/netwerk/base/ProtocolHandlerInfo.cpp
new file mode 100644
index 0000000000..432ff965ce
--- /dev/null
+++ b/netwerk/base/ProtocolHandlerInfo.cpp
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ProtocolHandlerInfo.h"
+#include "StaticComponents.h"
+#include "nsIProtocolHandler.h"
+
+namespace mozilla::net {
+
+uint32_t ProtocolHandlerInfo::StaticProtocolFlags() const {
+  uint32_t flags = mInner.match(
+      [&](const xpcom::StaticProtocolHandler* handler) {
+        return handler->mProtocolFlags;
+      },
+      [&](const RuntimeProtocolHandler& handler) {
+        return handler.mProtocolFlags;
+      });
+#if !IS_ORIGIN_IS_FULL_SPEC_DEFINED
+  MOZ_RELEASE_ASSERT(!(flags & nsIProtocolHandler::ORIGIN_IS_FULL_SPEC),
+                     "ORIGIN_IS_FULL_SPEC is unsupported but used");
+#endif
+  return flags;
+}
+
+int32_t ProtocolHandlerInfo::DefaultPort() const {
+  return mInner.match(
+      [&](const xpcom::StaticProtocolHandler* handler) {
+        return handler->mDefaultPort;
+      },
+      [&](const RuntimeProtocolHandler& handler) {
+        return handler.mDefaultPort;
+      });
+}
+
+nsresult ProtocolHandlerInfo::DynamicProtocolFlags(nsIURI* aURI,
+                                                   uint32_t* aFlags) const {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+
+  // If we're querying dynamic flags, we'll need to fetch the actual xpcom
+  // component in order to check them.
+  if (HasDynamicFlags()) {
+    nsCOMPtr<nsIProtocolHandler> handler = Handler();
+    if (nsCOMPtr<nsIProtocolHandlerWithDynamicFlags> dynamic =
+            do_QueryInterface(handler)) {
+      nsresult rv = dynamic->GetFlagsForURI(aURI, aFlags);
+      NS_ENSURE_SUCCESS(rv, rv);
+      MOZ_DIAGNOSTIC_ASSERT(
+          (StaticProtocolFlags() & ~nsIProtocolHandler::DYNAMIC_URI_FLAGS) ==
+              (*aFlags & ~nsIProtocolHandler::DYNAMIC_URI_FLAGS),
+          "only DYNAMIC_URI_FLAGS may be changed by a "
+          "nsIProtocolHandlerWithDynamicFlags implementation");
+      return NS_OK;
+    }
+  }
+
+  // Otherwise, just check against static flags.
+  *aFlags = StaticProtocolFlags();
+  return NS_OK;
+}
+
+bool ProtocolHandlerInfo::HasDynamicFlags() const {
+  return mInner.match(
+      [&](const xpcom::StaticProtocolHandler* handler) {
+        return handler->mHasDynamicFlags;
+      },
+      [&](const RuntimeProtocolHandler&) { return false; });
+}
+
+already_AddRefed<nsIProtocolHandler> ProtocolHandlerInfo::Handler() const {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIProtocolHandler> retval;
+  mInner.match(
+      [&](const xpcom::StaticProtocolHandler* handler) {
+        retval = handler->Module().GetService();
+      },
+      [&](const RuntimeProtocolHandler& handler) {
+        retval = handler.mHandler.get();
+      });
+  return retval.forget();
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/ProtocolHandlerInfo.h b/netwerk/base/ProtocolHandlerInfo.h
new file mode 100644
index 0000000000..337dbddcfc
--- /dev/null
+++ b/netwerk/base/ProtocolHandlerInfo.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_ProtocolHandlerInfo_h
+#define mozilla_net_ProtocolHandlerInfo_h
+
+#include "mozilla/Variant.h"
+#include "nsProxyRelease.h"
+#include "nsIProtocolHandler.h"
+
+namespace mozilla {
+namespace xpcom {
+struct StaticProtocolHandler;
+}
+
+namespace net {
+
+struct RuntimeProtocolHandler {
+  nsMainThreadPtrHandle<nsIProtocolHandler> mHandler;
+  uint32_t mProtocolFlags;
+  int32_t mDefaultPort;
+};
+
+// Information about a specific protocol handler.
+class ProtocolHandlerInfo {
+ public:
+  explicit ProtocolHandlerInfo(const xpcom::StaticProtocolHandler& aStatic)
+      : mInner(AsVariant(&aStatic)) {}
+  explicit ProtocolHandlerInfo(RuntimeProtocolHandler aDynamic)
+      : mInner(AsVariant(std::move(aDynamic))) {}
+
+  // Returns the statically known protocol-specific flags.
+  // See `nsIProtocolHandler` for valid values.
+  uint32_t StaticProtocolFlags() const;
+
+  // The port that this protocol normally uses.
+  // If a port does not make sense for the protocol (e.g., "about:") then -1
+  // will be returned.
+  int32_t DefaultPort() const;
+
+  // If true, `DynamicProtocolFlags()` may return a different value than
+  // `StaticProtocolFlags()` for flags in `DYNAMIC_URI_FLAGS`, due to a
+  // `nsIProtocolHandlerWithDynamicFlags` implementation.
+  bool HasDynamicFlags() const;
+
+  // Like `StaticProtocolFlags()` but also checks
+  // `nsIProtocolHandlerWithDynamicFlags` for uri-specific flags.
+  //
+  // NOTE: Only safe to call from the main thread.
+  nsresult DynamicProtocolFlags(nsIURI* aURI, uint32_t* aFlags) const
+      MOZ_REQUIRES(sMainThreadCapability);
+
+  // Get the main-thread-only nsIProtocolHandler instance.
+  already_AddRefed<nsIProtocolHandler> Handler() const
+      MOZ_REQUIRES(sMainThreadCapability);
+
+ private:
+  Variant<const xpcom::StaticProtocolHandler*, RuntimeProtocolHandler> mInner;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_ProtocolHandlerInfo_h
diff --git a/netwerk/base/ProxyAutoConfig.cpp b/netwerk/base/ProxyAutoConfig.cpp
new file mode 100644
index 0000000000..e5c585ec1a
--- /dev/null
+++ b/netwerk/base/ProxyAutoConfig.cpp
@@ -0,0 +1,940 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ProxyAutoConfig.h"
+#include "nsICancelable.h"
+#include "nsIDNSListener.h"
+#include "nsIDNSRecord.h"
+#include "nsIDNSService.h"
+#include "nsINamed.h"
+#include "nsThreadUtils.h"
+#include "nsIConsoleService.h"
+#include "nsIURLParser.h"
+#include "nsJSUtils.h"
+#include "jsfriendapi.h"
+#include "js/CallAndConstruct.h"          // JS_CallFunctionName
+#include "js/CompilationAndEvaluation.h"  // JS::Compile
+#include "js/ContextOptions.h"
+#include "js/Initialization.h"
+#include "js/PropertyAndElement.h"  // JS_DefineFunctions, JS_GetProperty
+#include "js/PropertySpec.h"
+#include "js/SourceText.h"  // JS::Source{Ownership,Text}
+#include "js/Utility.h"
+#include "js/Warnings.h"  // JS::SetWarningReporter
+#include "prnetdb.h"
+#include "nsITimer.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/SpinEventLoopUntil.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/net/SocketProcessChild.h"
+#include "mozilla/net/SocketProcessParent.h"
+#include "mozilla/net/ProxyAutoConfigChild.h"
+#include "mozilla/net/ProxyAutoConfigParent.h"
+#include "mozilla/Utf8.h"  // mozilla::Utf8Unit
+#include "nsServiceManagerUtils.h"
+#include "nsNetCID.h"
+
+#if defined(XP_MACOSX)
+#  include "nsMacUtilsImpl.h"
+#endif
+
+#include "XPCSelfHostedShmem.h"
+
+namespace mozilla {
+namespace net {
+
+// These are some global helper symbols the PAC format requires that we provide
+// that are initialized as part of the global javascript context used for PAC
+// evaluations. Additionally dnsResolve(host) and myIpAddress() are supplied in
+// the same context but are implemented as c++ helpers. alert(msg) is similarly
+// defined.
+//
+// Per ProxyAutoConfig::Init, this data must be ASCII.
+
+static const char sAsciiPacUtils[] =
+#include "ascii_pac_utils.inc"
+    ;
+
+// sRunning is defined for the helper functions only while the
+// Javascript engine is running and the PAC object cannot be deleted
+// or reset.
+static Atomic<uint32_t, Relaxed>& RunningIndex() {
+  static Atomic<uint32_t, Relaxed> sRunningIndex(0xdeadbeef);
+  return sRunningIndex;
+}
+static ProxyAutoConfig* GetRunning() {
+  MOZ_ASSERT(RunningIndex() != 0xdeadbeef);
+  return static_cast<ProxyAutoConfig*>(PR_GetThreadPrivate(RunningIndex()));
+}
+
+static void SetRunning(ProxyAutoConfig* arg) {
+  MOZ_ASSERT(RunningIndex() != 0xdeadbeef);
+  MOZ_DIAGNOSTIC_ASSERT_IF(!arg, GetRunning() != nullptr);
+  MOZ_DIAGNOSTIC_ASSERT_IF(arg, GetRunning() == nullptr);
+  PR_SetThreadPrivate(RunningIndex(), arg);
+}
+
+// The PACResolver is used for dnsResolve()
+class PACResolver final : public nsIDNSListener,
+                          public nsITimerCallback,
+                          public nsINamed {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  explicit PACResolver(nsIEventTarget* aTarget)
+      : mStatus(NS_ERROR_FAILURE),
+        mMainThreadEventTarget(aTarget),
+        mMutex("PACResolver::Mutex") {}
+
+  // nsIDNSListener
+  NS_IMETHOD OnLookupComplete(nsICancelable* request, nsIDNSRecord* record,
+                              nsresult status) override {
+    nsCOMPtr<nsITimer> timer;
+    {
+      MutexAutoLock lock(mMutex);
+      timer.swap(mTimer);
+      mRequest = nullptr;
+    }
+
+    if (timer) {
+      timer->Cancel();
+    }
+
+    mStatus = status;
+    mResponse = record;
+    return NS_OK;
+  }
+
+  // nsITimerCallback
+  NS_IMETHOD Notify(nsITimer* timer) override {
+    nsCOMPtr<nsICancelable> request;
+    {
+      MutexAutoLock lock(mMutex);
+      request.swap(mRequest);
+      mTimer = nullptr;
+    }
+    if (request) {
+      request->Cancel(NS_ERROR_NET_TIMEOUT);
+    }
+    return NS_OK;
+  }
+
+  // nsINamed
+  NS_IMETHOD GetName(nsACString& aName) override {
+    aName.AssignLiteral("PACResolver");
+    return NS_OK;
+  }
+
+  nsresult mStatus;
+  nsCOMPtr<nsICancelable> mRequest;
+  nsCOMPtr<nsIDNSRecord> mResponse;
+  nsCOMPtr<nsITimer> mTimer;
+  nsCOMPtr<nsIEventTarget> mMainThreadEventTarget;
+  Mutex mMutex MOZ_UNANNOTATED;
+
+ private:
+  ~PACResolver() = default;
+};
+NS_IMPL_ISUPPORTS(PACResolver, nsIDNSListener, nsITimerCallback, nsINamed)
+
+static void PACLogToConsole(nsString& aMessage) {
+  if (XRE_IsSocketProcess()) {
+    auto task = [message(aMessage)]() {
+      SocketProcessChild* child = SocketProcessChild::GetSingleton();
+      if (child) {
+        Unused << child->SendOnConsoleMessage(message);
+      }
+    };
+    if (NS_IsMainThread()) {
+      task();
+    } else {
+      NS_DispatchToMainThread(NS_NewRunnableFunction("PACLogToConsole", task));
+    }
+    return;
+  }
+
+  nsCOMPtr<nsIConsoleService> consoleService =
+      do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+  if (!consoleService) return;
+
+  consoleService->LogStringMessage(aMessage.get());
+}
+
+// Javascript errors and warnings are logged to the main error console
+static void PACLogErrorOrWarning(const nsAString& aKind,
+                                 JSErrorReport* aReport) {
+  nsString formattedMessage(u"PAC Execution "_ns);
+  formattedMessage += aKind;
+  formattedMessage += u": "_ns;
+  if (aReport->message()) {
+    formattedMessage.Append(NS_ConvertUTF8toUTF16(aReport->message().c_str()));
+  }
+  formattedMessage += u" ["_ns;
+  formattedMessage.Append(aReport->linebuf(), aReport->linebufLength());
+  formattedMessage += u"]"_ns;
+  PACLogToConsole(formattedMessage);
+}
+
+static void PACWarningReporter(JSContext* aCx, JSErrorReport* aReport) {
+  MOZ_ASSERT(aReport);
+  MOZ_ASSERT(aReport->isWarning());
+
+  PACLogErrorOrWarning(u"Warning"_ns, aReport);
+}
+
+class MOZ_STACK_CLASS AutoPACErrorReporter {
+  JSContext* mCx;
+
+ public:
+  explicit AutoPACErrorReporter(JSContext* aCx) : mCx(aCx) {}
+  ~AutoPACErrorReporter() {
+    if (!JS_IsExceptionPending(mCx)) {
+      return;
+    }
+    JS::ExceptionStack exnStack(mCx);
+    if (!JS::StealPendingExceptionStack(mCx, &exnStack)) {
+      return;
+    }
+
+    JS::ErrorReportBuilder report(mCx);
+    if (!report.init(mCx, exnStack, JS::ErrorReportBuilder::WithSideEffects)) {
+      JS_ClearPendingException(mCx);
+      return;
+    }
+
+    PACLogErrorOrWarning(u"Error"_ns, report.report());
+  }
+};
+
+// timeout of 0 means the normal necko timeout strategy, otherwise the dns
+// request will be canceled after aTimeout milliseconds
+static bool PACResolve(const nsACString& aHostName, NetAddr* aNetAddr,
+                       unsigned int aTimeout) {
+  if (!GetRunning()) {
+    NS_WARNING("PACResolve without a running ProxyAutoConfig object");
+    return false;
+  }
+
+  return GetRunning()->ResolveAddress(aHostName, aNetAddr, aTimeout);
+}
+
+ProxyAutoConfig::ProxyAutoConfig()
+
+{
+  MOZ_COUNT_CTOR(ProxyAutoConfig);
+}
+
+bool ProxyAutoConfig::ResolveAddress(const nsACString& aHostName,
+                                     NetAddr* aNetAddr, unsigned int aTimeout) {
+  nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
+  if (!dns) return false;
+
+  RefPtr<PACResolver> helper = new PACResolver(mMainThreadEventTarget);
+  OriginAttributes attrs;
+
+  // When the PAC script attempts to resolve a domain, we must make sure we
+  // don't use TRR, otherwise the TRR channel might also attempt to resolve
+  // a name and we'll have a deadlock.
+  nsIDNSService::DNSFlags flags =
+      nsIDNSService::RESOLVE_PRIORITY_MEDIUM |
+      nsIDNSService::GetFlagsFromTRRMode(nsIRequest::TRR_DISABLED_MODE);
+
+  if (NS_FAILED(dns->AsyncResolveNative(
+          aHostName, nsIDNSService::RESOLVE_TYPE_DEFAULT, flags, nullptr,
+          helper, GetCurrentSerialEventTarget(), attrs,
+          getter_AddRefs(helper->mRequest)))) {
+    return false;
+  }
+
+  if (aTimeout && helper->mRequest) {
+    if (!mTimer) mTimer = NS_NewTimer();
+    if (mTimer) {
+      mTimer->SetTarget(mMainThreadEventTarget);
+      mTimer->InitWithCallback(helper, aTimeout, nsITimer::TYPE_ONE_SHOT);
+      helper->mTimer = mTimer;
+    }
+  }
+
+  // Spin the event loop of the pac thread until lookup is complete.
+  // nsPACman is responsible for keeping a queue and only allowing
+  // one PAC execution at a time even when it is called re-entrantly.
+  SpinEventLoopUntil("ProxyAutoConfig::ResolveAddress"_ns, [&, helper, this]() {
+    if (!helper->mRequest) {
+      return true;
+    }
+    if (this->mShutdown) {
+      NS_WARNING("mShutdown set with PAC request not cancelled");
+      MOZ_ASSERT(NS_FAILED(helper->mStatus));
+      return true;
+    }
+    return false;
+  });
+
+  if (NS_FAILED(helper->mStatus)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDNSAddrRecord> rec = do_QueryInterface(helper->mResponse);
+  return !(!rec || NS_FAILED(rec->GetNextAddr(0, aNetAddr)));
+}
+
+static bool PACResolveToString(const nsACString& aHostName,
+                               nsCString& aDottedDecimal,
+                               unsigned int aTimeout) {
+  NetAddr netAddr;
+  if (!PACResolve(aHostName, &netAddr, aTimeout)) return false;
+
+  char dottedDecimal[128];
+  if (!netAddr.ToStringBuffer(dottedDecimal, sizeof(dottedDecimal))) {
+    return false;
+  }
+
+  aDottedDecimal.Assign(dottedDecimal);
+  return true;
+}
+
+// dnsResolve(host) javascript implementation
+static bool PACDnsResolve(JSContext* cx, unsigned int argc, JS::Value* vp) {
+  JS::CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (NS_IsMainThread()) {
+    NS_WARNING("DNS Resolution From PAC on Main Thread. How did that happen?");
+    return false;
+  }
+
+  if (!args.requireAtLeast(cx, "dnsResolve", 1)) return false;
+
+  // Previously we didn't check the type of the argument, so just converted it
+  // to string. A badly written PAC file oculd pass null or undefined here
+  // which could lead to odd results if there are any hosts called "null"
+  // on the network. See bug 1724345 comment 6.
+  if (!args[0].isString()) {
+    args.rval().setNull();
+    return true;
+  }
+
+  JS::Rooted<JSString*> arg1(cx);
+  arg1 = args[0].toString();
+
+  nsAutoJSString hostName;
+  nsAutoCString dottedDecimal;
+
+  if (!hostName.init(cx, arg1)) return false;
+  if (PACResolveToString(NS_ConvertUTF16toUTF8(hostName), dottedDecimal, 0)) {
+    JSString* dottedDecimalString = JS_NewStringCopyZ(cx, dottedDecimal.get());
+    if (!dottedDecimalString) {
+      return false;
+    }
+
+    args.rval().setString(dottedDecimalString);
+  } else {
+    args.rval().setNull();
+  }
+
+  return true;
+}
+
+// myIpAddress() javascript implementation
+static bool PACMyIpAddress(JSContext* cx, unsigned int argc, JS::Value* vp) {
+  JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
+
+  if (NS_IsMainThread()) {
+    NS_WARNING("DNS Resolution From PAC on Main Thread. How did that happen?");
+    return false;
+  }
+
+  if (!GetRunning()) {
+    NS_WARNING("PAC myIPAddress without a running ProxyAutoConfig object");
+    return false;
+  }
+
+  return GetRunning()->MyIPAddress(args);
+}
+
+// proxyAlert(msg) javascript implementation
+static bool PACProxyAlert(JSContext* cx, unsigned int argc, JS::Value* vp) {
+  JS::CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (!args.requireAtLeast(cx, "alert", 1)) return false;
+
+  JS::Rooted<JSString*> arg1(cx, JS::ToString(cx, args[0]));
+  if (!arg1) return false;
+
+  nsAutoJSString message;
+  if (!message.init(cx, arg1)) return false;
+
+  nsAutoString alertMessage;
+  alertMessage.AssignLiteral(u"PAC-alert: ");
+  alertMessage.Append(message);
+  PACLogToConsole(alertMessage);
+
+  args.rval().setUndefined(); /* return undefined */
+  return true;
+}
+
+static const JSFunctionSpec PACGlobalFunctions[] = {
+    JS_FN("dnsResolve", PACDnsResolve, 1, 0),
+
+    // a global "var pacUseMultihomedDNS = true;" will change behavior
+    // of myIpAddress to actively use DNS
+    JS_FN("myIpAddress", PACMyIpAddress, 0, 0),
+    JS_FN("alert", PACProxyAlert, 1, 0), JS_FS_END};
+
+// JSContextWrapper is a c++ object that manages the context for the JS engine
+// used on the PAC thread. It is initialized and destroyed on the PAC thread.
+class JSContextWrapper {
+ public:
+  static JSContextWrapper* Create(uint32_t aExtraHeapSize) {
+    JSContext* cx = JS_NewContext(JS::DefaultHeapMaxBytes + aExtraHeapSize);
+    if (NS_WARN_IF(!cx)) return nullptr;
+
+    JS::ContextOptionsRef(cx).setDisableIon().setDisableEvalSecurityChecks();
+
+    JSContextWrapper* entry = new JSContextWrapper(cx);
+    if (NS_FAILED(entry->Init())) {
+      delete entry;
+      return nullptr;
+    }
+
+    return entry;
+  }
+
+  JSContext* Context() const { return mContext; }
+
+  JSObject* Global() const { return mGlobal; }
+
+  ~JSContextWrapper() {
+    mGlobal = nullptr;
+
+    MOZ_COUNT_DTOR(JSContextWrapper);
+
+    if (mContext) {
+      JS_DestroyContext(mContext);
+    }
+  }
+
+  void SetOK() { mOK = true; }
+
+  bool IsOK() { return mOK; }
+
+ private:
+  JSContext* mContext;
+  JS::PersistentRooted<JSObject*> mGlobal;
+  bool mOK;
+
+  static const JSClass sGlobalClass;
+
+  explicit JSContextWrapper(JSContext* cx)
+      : mContext(cx), mGlobal(cx, nullptr), mOK(false) {
+    MOZ_COUNT_CTOR(JSContextWrapper);
+  }
+
+  nsresult Init() {
+    /*
+     * Not setting this will cause JS_CHECK_RECURSION to report false
+     * positives
+     */
+    JS_SetNativeStackQuota(mContext, 128 * sizeof(size_t) * 1024);
+
+    JS::SetWarningReporter(mContext, PACWarningReporter);
+
+    // When available, set the self-hosted shared memory to be read, so that
+    // we can decode the self-hosted content instead of parsing it.
+    {
+      auto& shm = xpc::SelfHostedShmem::GetSingleton();
+      JS::SelfHostedCache selfHostedContent = shm.Content();
+
+      if (!JS::InitSelfHostedCode(mContext, selfHostedContent)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+
+    JS::RealmOptions options;
+    options.creationOptions().setNewCompartmentInSystemZone();
+    options.behaviors().setClampAndJitterTime(false);
+    mGlobal = JS_NewGlobalObject(mContext, &sGlobalClass, nullptr,
+                                 JS::DontFireOnNewGlobalHook, options);
+    if (!mGlobal) {
+      JS_ClearPendingException(mContext);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    JS::Rooted<JSObject*> global(mContext, mGlobal);
+
+    JSAutoRealm ar(mContext, global);
+    AutoPACErrorReporter aper(mContext);
+    if (!JS_DefineFunctions(mContext, global, PACGlobalFunctions)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    JS_FireOnNewGlobalObject(mContext, global);
+
+    return NS_OK;
+  }
+};
+
+const JSClass JSContextWrapper::sGlobalClass = {"PACResolutionThreadGlobal",
+                                                JSCLASS_GLOBAL_FLAGS,
+                                                &JS::DefaultGlobalClassOps};
+
+void ProxyAutoConfig::SetThreadLocalIndex(uint32_t index) {
+  RunningIndex() = index;
+}
+
+nsresult ProxyAutoConfig::ConfigurePAC(const nsACString& aPACURI,
+                                       const nsACString& aPACScriptData,
+                                       bool aIncludePath,
+                                       uint32_t aExtraHeapSize,
+                                       nsISerialEventTarget* aEventTarget) {
+  mShutdown = false;  // Shutdown needs to be called prior to destruction
+
+  mPACURI = aPACURI;
+
+  // The full PAC script data is the concatenation of 1) the various functions
+  // exposed to PAC scripts in |sAsciiPacUtils| and 2) the user-provided PAC
+  // script data.  Historically this was single-byte Latin-1 text (usually just
+  // ASCII, but bug 296163 has a real-world Latin-1 example).  We now support
+  // UTF-8 if the full data validates as UTF-8, before falling back to Latin-1.
+  // (Technically this is a breaking change: intentional Latin-1 scripts that
+  // happen to be valid UTF-8 may have different behavior.  We assume such cases
+  // are vanishingly rare.)
+  //
+  // Supporting both UTF-8 and Latin-1 requires that the functions exposed to
+  // PAC scripts be both UTF-8- and Latin-1-compatible: that is, they must be
+  // ASCII.
+  mConcatenatedPACData = sAsciiPacUtils;
+  if (!mConcatenatedPACData.Append(aPACScriptData, mozilla::fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mIncludePath = aIncludePath;
+  mExtraHeapSize = aExtraHeapSize;
+  mMainThreadEventTarget = aEventTarget;
+
+  if (!GetRunning()) return SetupJS();
+
+  mJSNeedsSetup = true;
+  return NS_OK;
+}
+
+nsresult ProxyAutoConfig::SetupJS() {
+  mJSNeedsSetup = false;
+  MOZ_DIAGNOSTIC_ASSERT(!GetRunning(), "JIT is running");
+  if (GetRunning()) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+#if defined(XP_MACOSX)
+  nsMacUtilsImpl::EnableTCSMIfAvailable();
+#endif
+
+  delete mJSContext;
+  mJSContext = nullptr;
+
+  if (mConcatenatedPACData.IsEmpty()) return NS_ERROR_FAILURE;
+
+  NS_GetCurrentThread()->SetCanInvokeJS(true);
+
+  mJSContext = JSContextWrapper::Create(mExtraHeapSize);
+  if (!mJSContext) return NS_ERROR_FAILURE;
+
+  JSContext* cx = mJSContext->Context();
+  JSAutoRealm ar(cx, mJSContext->Global());
+  AutoPACErrorReporter aper(cx);
+
+  // check if this is a data: uri so that we don't spam the js console with
+  // huge meaningless strings. this is not on the main thread, so it can't
+  // use nsIURI scheme methods
+  bool isDataURI =
+      nsDependentCSubstring(mPACURI, 0, 5).LowerCaseEqualsASCII("data:", 5);
+
+  SetRunning(this);
+
+  JS::Rooted<JSObject*> global(cx, mJSContext->Global());
+
+  auto CompilePACScript = [this](JSContext* cx) -> JSScript* {
+    JS::CompileOptions options(cx);
+    options.setSkipFilenameValidation(true);
+    options.setFileAndLine(this->mPACURI.get(), 1);
+
+    // Per ProxyAutoConfig::Init, compile as UTF-8 if the full data is UTF-8,
+    // and otherwise inflate Latin-1 to UTF-16 and compile that.
+    const char* scriptData = this->mConcatenatedPACData.get();
+    size_t scriptLength = this->mConcatenatedPACData.Length();
+    if (mozilla::IsUtf8(mozilla::Span(scriptData, scriptLength))) {
+      JS::SourceText<Utf8Unit> srcBuf;
+      if (!srcBuf.init(cx, scriptData, scriptLength,
+                       JS::SourceOwnership::Borrowed)) {
+        return nullptr;
+      }
+
+      return JS::Compile(cx, options, srcBuf);
+    }
+
+    // nsReadableUtils.h says that "ASCII" is a misnomer "for legacy reasons",
+    // and this handles not just ASCII but Latin-1 too.
+    NS_ConvertASCIItoUTF16 inflated(this->mConcatenatedPACData);
+
+    JS::SourceText<char16_t> source;
+    if (!source.init(cx, inflated.get(), inflated.Length(),
+                     JS::SourceOwnership::Borrowed)) {
+      return nullptr;
+    }
+
+    return JS::Compile(cx, options, source);
+  };
+
+  JS::Rooted<JSScript*> script(cx, CompilePACScript(cx));
+  if (!script || !JS_ExecuteScript(cx, script)) {
+    nsString alertMessage(u"PAC file failed to install from "_ns);
+    if (isDataURI) {
+      alertMessage += u"data: URI"_ns;
+    } else {
+      alertMessage += NS_ConvertUTF8toUTF16(mPACURI);
+    }
+    PACLogToConsole(alertMessage);
+    SetRunning(nullptr);
+    return NS_ERROR_FAILURE;
+  }
+  SetRunning(nullptr);
+
+  mJSContext->SetOK();
+  nsString alertMessage(u"PAC file installed from "_ns);
+  if (isDataURI) {
+    alertMessage += u"data: URI"_ns;
+  } else {
+    alertMessage += NS_ConvertUTF8toUTF16(mPACURI);
+  }
+  PACLogToConsole(alertMessage);
+
+  // we don't need these now
+  mConcatenatedPACData.Truncate();
+  mPACURI.Truncate();
+
+  return NS_OK;
+}
+
+void ProxyAutoConfig::GetProxyForURIWithCallback(
+    const nsACString& aTestURI, const nsACString& aTestHost,
+    std::function<void(nsresult aStatus, const nsACString& aResult)>&&
+        aCallback) {
+  nsAutoCString result;
+  nsresult status = GetProxyForURI(aTestURI, aTestHost, result);
+  aCallback(status, result);
+}
+
+nsresult ProxyAutoConfig::GetProxyForURI(const nsACString& aTestURI,
+                                         const nsACString& aTestHost,
+                                         nsACString& result) {
+  if (mJSNeedsSetup) SetupJS();
+
+  if (!mJSContext || !mJSContext->IsOK()) return NS_ERROR_NOT_AVAILABLE;
+
+  JSContext* cx = mJSContext->Context();
+  JSAutoRealm ar(cx, mJSContext->Global());
+  AutoPACErrorReporter aper(cx);
+
+  // the sRunning flag keeps a new PAC file from being installed
+  // while the event loop is spinning on a DNS function. Don't early return.
+  SetRunning(this);
+  mRunningHost = aTestHost;
+
+  nsresult rv = NS_ERROR_FAILURE;
+  nsCString clensedURI(aTestURI);
+
+  if (!mIncludePath) {
+    nsCOMPtr<nsIURLParser> urlParser =
+        do_GetService(NS_STDURLPARSER_CONTRACTID);
+    int32_t pathLen = 0;
+    if (urlParser) {
+      uint32_t schemePos;
+      int32_t schemeLen;
+      uint32_t authorityPos;
+      int32_t authorityLen;
+      uint32_t pathPos;
+      rv = urlParser->ParseURL(aTestURI.BeginReading(), aTestURI.Length(),
+                               &schemePos, &schemeLen, &authorityPos,
+                               &authorityLen, &pathPos, &pathLen);
+    }
+    if (NS_SUCCEEDED(rv)) {
+      if (pathLen) {
+        // cut off the path but leave the initial slash
+        pathLen--;
+      }
+      aTestURI.Left(clensedURI, aTestURI.Length() - pathLen);
+    }
+  }
+
+  JS::Rooted<JSString*> uriString(
+      cx,
+      JS_NewStringCopyN(cx, clensedURI.BeginReading(), clensedURI.Length()));
+  JS::Rooted<JSString*> hostString(
+      cx, JS_NewStringCopyN(cx, aTestHost.BeginReading(), aTestHost.Length()));
+
+  if (uriString && hostString) {
+    JS::RootedValueArray<2> args(cx);
+    args[0].setString(uriString);
+    args[1].setString(hostString);
+
+    JS::Rooted<JS::Value> rval(cx);
+    JS::Rooted<JSObject*> global(cx, mJSContext->Global());
+    bool ok = JS_CallFunctionName(cx, global, "FindProxyForURL", args, &rval);
+
+    if (ok && rval.isString()) {
+      nsAutoJSString pacString;
+      if (pacString.init(cx, rval.toString())) {
+        CopyUTF16toUTF8(pacString, result);
+        rv = NS_OK;
+      }
+    }
+  }
+
+  mRunningHost.Truncate();
+  SetRunning(nullptr);
+  return rv;
+}
+
+void ProxyAutoConfig::GC() {
+  if (!mJSContext || !mJSContext->IsOK()) return;
+
+  JSAutoRealm ar(mJSContext->Context(), mJSContext->Global());
+  JS_MaybeGC(mJSContext->Context());
+}
+
+ProxyAutoConfig::~ProxyAutoConfig() {
+  MOZ_COUNT_DTOR(ProxyAutoConfig);
+  MOZ_ASSERT(mShutdown, "Shutdown must be called before dtor.");
+  NS_ASSERTION(!mJSContext,
+               "~ProxyAutoConfig leaking JS context that "
+               "should have been deleted on pac thread");
+}
+
+void ProxyAutoConfig::Shutdown() {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread for shutdown");
+
+  if (NS_WARN_IF(GetRunning()) || mShutdown) {
+    return;
+  }
+
+  mShutdown = true;
+  delete mJSContext;
+  mJSContext = nullptr;
+}
+
+bool ProxyAutoConfig::SrcAddress(const NetAddr* remoteAddress,
+                                 nsCString& localAddress) {
+  PRFileDesc* fd;
+  fd = PR_OpenUDPSocket(remoteAddress->raw.family);
+  if (!fd) return false;
+
+  PRNetAddr prRemoteAddress;
+  NetAddrToPRNetAddr(remoteAddress, &prRemoteAddress);
+  if (PR_Connect(fd, &prRemoteAddress, 0) != PR_SUCCESS) {
+    PR_Close(fd);
+    return false;
+  }
+
+  PRNetAddr localName;
+  if (PR_GetSockName(fd, &localName) != PR_SUCCESS) {
+    PR_Close(fd);
+    return false;
+  }
+
+  PR_Close(fd);
+
+  char dottedDecimal[128];
+  if (PR_NetAddrToString(&localName, dottedDecimal, sizeof(dottedDecimal)) !=
+      PR_SUCCESS) {
+    return false;
+  }
+
+  localAddress.Assign(dottedDecimal);
+
+  return true;
+}
+
+// hostName is run through a dns lookup and then a udp socket is connected
+// to the result. If that all works, the local IP address of the socket is
+// returned to the javascript caller and |*aResult| is set to true. Otherwise
+// |*aResult| is set to false.
+bool ProxyAutoConfig::MyIPAddressTryHost(const nsACString& hostName,
+                                         unsigned int timeout,
+                                         const JS::CallArgs& aArgs,
+                                         bool* aResult) {
+  *aResult = false;
+
+  NetAddr remoteAddress;
+  nsAutoCString localDottedDecimal;
+  JSContext* cx = mJSContext->Context();
+
+  if (PACResolve(hostName, &remoteAddress, timeout) &&
+      SrcAddress(&remoteAddress, localDottedDecimal)) {
+    JSString* dottedDecimalString =
+        JS_NewStringCopyZ(cx, localDottedDecimal.get());
+    if (!dottedDecimalString) {
+      return false;
+    }
+
+    *aResult = true;
+    aArgs.rval().setString(dottedDecimalString);
+  }
+  return true;
+}
+
+bool ProxyAutoConfig::MyIPAddress(const JS::CallArgs& aArgs) {
+  nsAutoCString remoteDottedDecimal;
+  nsAutoCString localDottedDecimal;
+  JSContext* cx = mJSContext->Context();
+  JS::Rooted<JS::Value> v(cx);
+  JS::Rooted<JSObject*> global(cx, mJSContext->Global());
+
+  bool useMultihomedDNS =
+      JS_GetProperty(cx, global, "pacUseMultihomedDNS", &v) &&
+      !v.isUndefined() && ToBoolean(v);
+
+  // first, lookup the local address of a socket connected
+  // to the host of uri being resolved by the pac file. This is
+  // v6 safe.. but is the last step like that
+  bool rvalAssigned = false;
+  if (useMultihomedDNS) {
+    if (!MyIPAddressTryHost(mRunningHost, kTimeout, aArgs, &rvalAssigned) ||
+        rvalAssigned) {
+      return rvalAssigned;
+    }
+  } else {
+    // we can still do the fancy multi homing thing if the host is a literal
+    if (HostIsIPLiteral(mRunningHost) &&
+        (!MyIPAddressTryHost(mRunningHost, kTimeout, aArgs, &rvalAssigned) ||
+         rvalAssigned)) {
+      return rvalAssigned;
+    }
+  }
+
+  // next, look for a route to a public internet address that doesn't need DNS.
+  // This is the google anycast dns address, but it doesn't matter if it
+  // remains operable (as we don't contact it) as long as the address stays
+  // in commonly routed IP address space.
+  remoteDottedDecimal.AssignLiteral("8.8.8.8");
+  if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
+      rvalAssigned) {
+    return rvalAssigned;
+  }
+
+  // finally, use the old algorithm based on the local hostname
+  nsAutoCString hostName;
+  nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
+  // without multihomedDNS use such a short timeout that we are basically
+  // just looking at the cache for raw dotted decimals
+  uint32_t timeout = useMultihomedDNS ? kTimeout : 1;
+  if (dns && NS_SUCCEEDED(dns->GetMyHostName(hostName)) &&
+      PACResolveToString(hostName, localDottedDecimal, timeout)) {
+    JSString* dottedDecimalString =
+        JS_NewStringCopyZ(cx, localDottedDecimal.get());
+    if (!dottedDecimalString) {
+      return false;
+    }
+
+    aArgs.rval().setString(dottedDecimalString);
+    return true;
+  }
+
+  // next try a couple RFC 1918 variants.. maybe there is a
+  // local route
+  remoteDottedDecimal.AssignLiteral("192.168.0.1");
+  if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
+      rvalAssigned) {
+    return rvalAssigned;
+  }
+
+  // more RFC 1918
+  remoteDottedDecimal.AssignLiteral("10.0.0.1");
+  if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
+      rvalAssigned) {
+    return rvalAssigned;
+  }
+
+  // who knows? let's fallback to localhost
+  localDottedDecimal.AssignLiteral("127.0.0.1");
+  JSString* dottedDecimalString =
+      JS_NewStringCopyZ(cx, localDottedDecimal.get());
+  if (!dottedDecimalString) {
+    return false;
+  }
+
+  aArgs.rval().setString(dottedDecimalString);
+  return true;
+}
+
+RemoteProxyAutoConfig::RemoteProxyAutoConfig() = default;
+
+RemoteProxyAutoConfig::~RemoteProxyAutoConfig() = default;
+
+nsresult RemoteProxyAutoConfig::Init(nsIThread* aPACThread) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  SocketProcessParent* socketProcessParent =
+      SocketProcessParent::GetSingleton();
+  if (!socketProcessParent) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  ipc::Endpoint<PProxyAutoConfigParent> parent;
+  ipc::Endpoint<PProxyAutoConfigChild> child;
+  nsresult rv = PProxyAutoConfig::CreateEndpoints(
+      base::GetCurrentProcId(), socketProcessParent->OtherPid(), &parent,
+      &child);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  Unused << socketProcessParent->SendInitProxyAutoConfigChild(std::move(child));
+  mProxyAutoConfigParent = new ProxyAutoConfigParent();
+  return aPACThread->Dispatch(
+      NS_NewRunnableFunction("ProxyAutoConfigParent::ProxyAutoConfigParent",
+                             [proxyAutoConfigParent(mProxyAutoConfigParent),
+                              endpoint{std::move(parent)}]() mutable {
+                               proxyAutoConfigParent->Init(std::move(endpoint));
+                             }));
+}
+
+nsresult RemoteProxyAutoConfig::ConfigurePAC(const nsACString& aPACURI,
+                                             const nsACString& aPACScriptData,
+                                             bool aIncludePath,
+                                             uint32_t aExtraHeapSize,
+                                             nsISerialEventTarget*) {
+  Unused << mProxyAutoConfigParent->SendConfigurePAC(
+      aPACURI, aPACScriptData, aIncludePath, aExtraHeapSize);
+  return NS_OK;
+}
+
+void RemoteProxyAutoConfig::Shutdown() { mProxyAutoConfigParent->Close(); }
+
+void RemoteProxyAutoConfig::GC() {
+  // Do nothing. GC would be performed when there is not pending query in socket
+  // process.
+}
+
+void RemoteProxyAutoConfig::GetProxyForURIWithCallback(
+    const nsACString& aTestURI, const nsACString& aTestHost,
+    std::function<void(nsresult aStatus, const nsACString& aResult)>&&
+        aCallback) {
+  if (!mProxyAutoConfigParent->CanSend()) {
+    return;
+  }
+
+  mProxyAutoConfigParent->SendGetProxyForURI(
+      aTestURI, aTestHost,
+      [aCallback](std::tuple<nsresult, nsCString>&& aResult) {
+        auto [status, result] = aResult;
+        aCallback(status, result);
+      },
+      [aCallback](mozilla::ipc::ResponseRejectReason&& aReason) {
+        aCallback(NS_ERROR_FAILURE, ""_ns);
+      });
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/ProxyAutoConfig.h b/netwerk/base/ProxyAutoConfig.h
new file mode 100644
index 0000000000..e01450eadd
--- /dev/null
+++ b/netwerk/base/ProxyAutoConfig.h
@@ -0,0 +1,155 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProxyAutoConfig_h__
+#define ProxyAutoConfig_h__
+
+#include <functional>
+#include "nsString.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+class nsIEventTarget;
+class nsITimer;
+class nsIThread;
+namespace JS {
+class CallArgs;
+}  // namespace JS
+
+namespace mozilla {
+namespace net {
+
+class JSContextWrapper;
+class ProxyAutoConfigParent;
+union NetAddr;
+
+class ProxyAutoConfigBase {
+ public:
+  virtual ~ProxyAutoConfigBase() = default;
+  virtual nsresult Init(nsIThread* aPACThread) { return NS_OK; }
+  virtual nsresult ConfigurePAC(const nsACString& aPACURI,
+                                const nsACString& aPACScriptData,
+                                bool aIncludePath, uint32_t aExtraHeapSize,
+                                nsISerialEventTarget* aEventTarget) = 0;
+  virtual void SetThreadLocalIndex(uint32_t index) {}
+  virtual void Shutdown() = 0;
+  virtual void GC() = 0;
+  virtual void GetProxyForURIWithCallback(
+      const nsACString& aTestURI, const nsACString& aTestHost,
+      std::function<void(nsresult aStatus, const nsACString& aResult)>&&
+          aCallback) = 0;
+};
+
+// The ProxyAutoConfig class is meant to be created and run on a
+// non main thread. It synchronously resolves PAC files by blocking that
+// thread and running nested event loops. GetProxyForURI is not re-entrant.
+
+class ProxyAutoConfig : public ProxyAutoConfigBase {
+ public:
+  ProxyAutoConfig();
+  virtual ~ProxyAutoConfig();
+
+  nsresult ConfigurePAC(const nsACString& aPACURI,
+                        const nsACString& aPACScriptData, bool aIncludePath,
+                        uint32_t aExtraHeapSize,
+                        nsISerialEventTarget* aEventTarget) override;
+  void SetThreadLocalIndex(uint32_t index) override;
+  void Shutdown() override;
+  void GC() override;
+  bool MyIPAddress(const JS::CallArgs& aArgs);
+  bool ResolveAddress(const nsACString& aHostName, NetAddr* aNetAddr,
+                      unsigned int aTimeout);
+
+  /**
+   * Get the proxy string for the specified URI.  The proxy string is
+   * given by the following:
+   *
+   *   result      = proxy-spec *( proxy-sep proxy-spec )
+   *   proxy-spec  = direct-type | proxy-type LWS proxy-host [":" proxy-port]
+   *   direct-type = "DIRECT"
+   *   proxy-type  = "PROXY" | "HTTP" | "HTTPS" | "SOCKS" | "SOCKS4" | "SOCKS5"
+   *   proxy-sep   = ";" LWS
+   *   proxy-host  = hostname | ipv4-address-literal
+   *   proxy-port  = <any 16-bit unsigned integer>
+   *   LWS         = *( SP | HT )
+   *   SP          = <US-ASCII SP, space (32)>
+   *   HT          = <US-ASCII HT, horizontal-tab (9)>
+   *
+   * NOTE: direct-type and proxy-type are case insensitive
+   * NOTE: SOCKS implies SOCKS4
+   *
+   * Examples:
+   *   "PROXY proxy1.foo.com:8080; PROXY proxy2.foo.com:8080; DIRECT"
+   *   "SOCKS socksproxy"
+   *   "DIRECT"
+   *
+   * XXX add support for IPv6 address literals.
+   * XXX quote whatever the official standard is for PAC.
+   *
+   * @param aTestURI
+   *        The URI as an ASCII string to test.
+   * @param aTestHost
+   *        The ASCII hostname to test.
+   *
+   * @param result
+   *        result string as defined above.
+   */
+  nsresult GetProxyForURI(const nsACString& aTestURI,
+                          const nsACString& aTestHost, nsACString& result);
+
+  void GetProxyForURIWithCallback(
+      const nsACString& aTestURI, const nsACString& aTestHost,
+      std::function<void(nsresult aStatus, const nsACString& aResult)>&&
+          aCallback) override;
+
+ private:
+  // allow 665ms for myipaddress dns queries. That's 95th percentile.
+  const static unsigned int kTimeout = 665;
+
+  // used to compile the PAC file and setup the execution context
+  nsresult SetupJS();
+
+  bool SrcAddress(const NetAddr* remoteAddress, nsCString& localAddress);
+  bool MyIPAddressTryHost(const nsACString& hostName, unsigned int timeout,
+                          const JS::CallArgs& aArgs, bool* aResult);
+
+  JSContextWrapper* mJSContext{nullptr};
+  bool mJSNeedsSetup{false};
+  bool mShutdown{true};
+  nsCString mConcatenatedPACData;
+  nsCString mPACURI;
+  bool mIncludePath{false};
+  uint32_t mExtraHeapSize{0};
+  nsCString mRunningHost;
+  nsCOMPtr<nsITimer> mTimer;
+  nsCOMPtr<nsISerialEventTarget> mMainThreadEventTarget;
+};
+
+class RemoteProxyAutoConfig : public ProxyAutoConfigBase {
+ public:
+  RemoteProxyAutoConfig();
+  virtual ~RemoteProxyAutoConfig();
+
+  nsresult Init(nsIThread* aPACThread) override;
+  nsresult ConfigurePAC(const nsACString& aPACURI,
+                        const nsACString& aPACScriptData, bool aIncludePath,
+                        uint32_t aExtraHeapSize,
+                        nsISerialEventTarget* aEventTarget) override;
+  void Shutdown() override;
+  void GC() override;
+  void GetProxyForURIWithCallback(
+      const nsACString& aTestURI, const nsACString& aTestHost,
+      std::function<void(nsresult aStatus, const nsACString& aResult)>&&
+          aCallback) override;
+
+ private:
+  RefPtr<ProxyAutoConfigParent> mProxyAutoConfigParent;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // ProxyAutoConfig_h__
diff --git a/netwerk/base/ProxyConfig.h b/netwerk/base/ProxyConfig.h
new file mode 100644
index 0000000000..2deb1dd2a1
--- /dev/null
+++ b/netwerk/base/ProxyConfig.h
@@ -0,0 +1,199 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_netwerk_base_proxy_config_h
+#define mozilla_netwerk_base_proxy_config_h
+
+#include <map>
+
+#include "nsCRT.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+// NOTE: This file is inspired by Chromium's code.
+// https://source.chromium.org/chromium/chromium/src/+/main:net/proxy_resolution/proxy_config.h.
+
+namespace mozilla {
+namespace net {
+
+// ProxyServer stores the {type, host, port} of a proxy server.
+// ProxyServer is immutable.
+class ProxyServer final {
+ public:
+  enum class ProxyType {
+    DIRECT = 0,
+    HTTP,
+    HTTPS,
+    SOCKS,
+    SOCKS4,
+    SOCKS5,
+    FTP,
+    // DEFAULT is a special type used on windows only.
+    DEFAULT
+  };
+
+  ProxyServer() = default;
+
+  ProxyServer(ProxyType aType, const nsACString& aHost, int32_t aPort)
+      : mType(aType), mHost(aHost), mPort(aPort) {}
+
+  const nsCString& Host() const { return mHost; }
+
+  int32_t Port() const { return mPort; }
+
+  ProxyType Type() const { return mType; }
+
+  void ToHostAndPortStr(nsACString& aOutput) {
+    aOutput.Truncate();
+    if (mType == ProxyType::DIRECT) {
+      return;
+    }
+
+    aOutput.Assign(mHost);
+    if (mPort != -1) {
+      aOutput.Append(':');
+      aOutput.AppendInt(mPort);
+    }
+  }
+
+  bool operator==(const ProxyServer& aOther) const {
+    return mType == aOther.mType && mHost == aOther.mHost &&
+           mPort == aOther.mPort;
+  }
+
+  bool operator!=(const ProxyServer& aOther) const {
+    return !(*this == aOther);
+  }
+
+ private:
+  ProxyType mType{ProxyType::DIRECT};
+  nsCString mHost;
+  int32_t mPort{-1};
+};
+
+// This class includes the information about proxy configuration.
+// It contains enabled proxy servers, exception list, and the url of PAC
+// script.
+class ProxyConfig {
+ public:
+  struct ProxyRules {
+    ProxyRules() = default;
+    ~ProxyRules() = default;
+
+    std::map<ProxyServer::ProxyType, ProxyServer> mProxyServers;
+  };
+
+  struct ProxyBypassRules {
+    ProxyBypassRules() = default;
+    ~ProxyBypassRules() = default;
+
+    CopyableTArray<nsCString> mExceptions;
+  };
+
+  ProxyConfig() = default;
+  ProxyConfig(const ProxyConfig& config);
+  ~ProxyConfig() = default;
+
+  ProxyRules& Rules() { return mRules; }
+
+  const ProxyRules& Rules() const { return mRules; }
+
+  ProxyBypassRules& ByPassRules() { return mBypassRules; }
+
+  const ProxyBypassRules& ByPassRules() const { return mBypassRules; }
+
+  void SetPACUrl(const nsACString& aUrl) { mPACUrl = aUrl; }
+
+  const nsCString& PACUrl() const { return mPACUrl; }
+
+  static ProxyServer::ProxyType ToProxyType(const char* aType) {
+    if (!aType) {
+      return ProxyServer::ProxyType::DIRECT;
+    }
+
+    if (nsCRT::strcasecmp(aType, "http") == 0) {
+      return ProxyServer::ProxyType::HTTP;
+    }
+    if (nsCRT::strcasecmp(aType, "https") == 0) {
+      return ProxyServer::ProxyType::HTTPS;
+    }
+    if (nsCRT::strcasecmp(aType, "socks") == 0) {
+      return ProxyServer::ProxyType::SOCKS;
+    }
+    if (nsCRT::strcasecmp(aType, "socks4") == 0) {
+      return ProxyServer::ProxyType::SOCKS4;
+    }
+    if (nsCRT::strcasecmp(aType, "socks5") == 0) {
+      return ProxyServer::ProxyType::SOCKS5;
+    }
+    if (nsCRT::strcasecmp(aType, "ftp") == 0) {
+      return ProxyServer::ProxyType::FTP;
+    }
+
+    return ProxyServer::ProxyType::DIRECT;
+  }
+
+  static void SetProxyResult(const char* aType, const nsACString& aHostPort,
+                             nsACString& aResult) {
+    aResult.AssignASCII(aType);
+    aResult.Append(' ');
+    aResult.Append(aHostPort);
+  }
+
+  static void SetProxyResultDirect(nsACString& aResult) {
+    // For whatever reason, a proxy is not to be used.
+    aResult.AssignLiteral("DIRECT");
+  }
+
+  static void ProxyStrToResult(const nsACString& aSpecificProxy,
+                               const nsACString& aDefaultProxy,
+                               const nsACString& aSocksProxy,
+                               nsACString& aResult) {
+    if (!aSpecificProxy.IsEmpty()) {
+      SetProxyResult("PROXY", aSpecificProxy,
+                     aResult);  // Protocol-specific proxy.
+    } else if (!aDefaultProxy.IsEmpty()) {
+      SetProxyResult("PROXY", aDefaultProxy, aResult);  // Default proxy.
+    } else if (!aSocksProxy.IsEmpty()) {
+      SetProxyResult("SOCKS", aSocksProxy, aResult);  // SOCKS proxy.
+    } else {
+      SetProxyResultDirect(aResult);  // Direct connection.
+    }
+  }
+
+  void GetProxyString(const nsACString& aScheme, nsACString& aResult) {
+    SetProxyResultDirect(aResult);
+
+    nsAutoCString specificProxy;
+    nsAutoCString defaultProxy;
+    nsAutoCString socksProxy;
+    nsAutoCString prefix;
+    ToLowerCase(aScheme, prefix);
+    ProxyServer::ProxyType type = ProxyConfig::ToProxyType(prefix.get());
+    for (auto& [key, value] : mRules.mProxyServers) {
+      // Break the loop if we found a specific proxy.
+      if (key == type) {
+        value.ToHostAndPortStr(specificProxy);
+        break;
+      } else if (key == ProxyServer::ProxyType::DEFAULT) {
+        value.ToHostAndPortStr(defaultProxy);
+      } else if (key == ProxyServer::ProxyType::SOCKS) {
+        value.ToHostAndPortStr(socksProxy);
+      }
+    }
+
+    ProxyStrToResult(specificProxy, defaultProxy, socksProxy, aResult);
+  }
+
+ private:
+  nsCString mPACUrl;
+  ProxyRules mRules;
+  ProxyBypassRules mBypassRules;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_netwerk_base_proxy_config_h
diff --git a/netwerk/base/RedirectChannelRegistrar.cpp b/netwerk/base/RedirectChannelRegistrar.cpp
new file mode 100644
index 0000000000..9aa687ed88
--- /dev/null
+++ b/netwerk/base/RedirectChannelRegistrar.cpp
@@ -0,0 +1,86 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "RedirectChannelRegistrar.h"
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace net {
+
+StaticRefPtr<RedirectChannelRegistrar> RedirectChannelRegistrar::gSingleton;
+
+NS_IMPL_ISUPPORTS(RedirectChannelRegistrar, nsIRedirectChannelRegistrar)
+
+RedirectChannelRegistrar::RedirectChannelRegistrar()
+    : mRealChannels(32),
+      mParentChannels(32),
+      mLock("RedirectChannelRegistrar") {
+  MOZ_ASSERT(!gSingleton);
+}
+
+// static
+already_AddRefed<nsIRedirectChannelRegistrar>
+RedirectChannelRegistrar::GetOrCreate() {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!gSingleton) {
+    gSingleton = new RedirectChannelRegistrar();
+    ClearOnShutdown(&gSingleton);
+  }
+  return do_AddRef(gSingleton);
+}
+
+NS_IMETHODIMP
+RedirectChannelRegistrar::RegisterChannel(nsIChannel* channel, uint64_t id) {
+  MutexAutoLock lock(mLock);
+
+  mRealChannels.InsertOrUpdate(id, channel);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RedirectChannelRegistrar::GetRegisteredChannel(uint64_t id,
+                                               nsIChannel** _retval) {
+  MutexAutoLock lock(mLock);
+
+  if (!mRealChannels.Get(id, _retval)) return NS_ERROR_NOT_AVAILABLE;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RedirectChannelRegistrar::LinkChannels(uint64_t id, nsIParentChannel* channel,
+                                       nsIChannel** _retval) {
+  MutexAutoLock lock(mLock);
+
+  if (!mRealChannels.Get(id, _retval)) return NS_ERROR_NOT_AVAILABLE;
+
+  mParentChannels.InsertOrUpdate(id, channel);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RedirectChannelRegistrar::GetParentChannel(uint64_t id,
+                                           nsIParentChannel** _retval) {
+  MutexAutoLock lock(mLock);
+
+  if (!mParentChannels.Get(id, _retval)) return NS_ERROR_NOT_AVAILABLE;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RedirectChannelRegistrar::DeregisterChannels(uint64_t id) {
+  MutexAutoLock lock(mLock);
+
+  mRealChannels.Remove(id);
+  mParentChannels.Remove(id);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/RedirectChannelRegistrar.h b/netwerk/base/RedirectChannelRegistrar.h
new file mode 100644
index 0000000000..5041726043
--- /dev/null
+++ b/netwerk/base/RedirectChannelRegistrar.h
@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef RedirectChannelRegistrar_h__
+#define RedirectChannelRegistrar_h__
+
+#include "nsIRedirectChannelRegistrar.h"
+
+#include "nsIChannel.h"
+#include "nsIParentChannel.h"
+#include "nsInterfaceHashtable.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+class RedirectChannelRegistrar final : public nsIRedirectChannelRegistrar {
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREDIRECTCHANNELREGISTRAR
+
+  RedirectChannelRegistrar();
+
+ private:
+  ~RedirectChannelRegistrar() = default;
+
+ public:
+  // Singleton accessor
+  static already_AddRefed<nsIRedirectChannelRegistrar> GetOrCreate();
+
+ protected:
+  using ChannelHashtable = nsInterfaceHashtable<nsUint64HashKey, nsIChannel>;
+  using ParentChannelHashtable =
+      nsInterfaceHashtable<nsUint64HashKey, nsIParentChannel>;
+
+  ChannelHashtable mRealChannels;
+  ParentChannelHashtable mParentChannels;
+  Mutex mLock MOZ_UNANNOTATED;
+
+  static StaticRefPtr<RedirectChannelRegistrar> gSingleton;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/RequestContextService.cpp b/netwerk/base/RequestContextService.cpp
new file mode 100644
index 0000000000..72331bdc1e
--- /dev/null
+++ b/netwerk/base/RequestContextService.cpp
@@ -0,0 +1,622 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 ;*; */
+/* vim: set sw=2 ts=8 et tw=80 : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIDocShell.h"
+#include "mozilla/dom/Document.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIDocumentLoader.h"
+#include "nsIObserverService.h"
+#include "nsITimer.h"
+#include "nsIXULRuntime.h"
+#include "nsServiceManagerUtils.h"
+#include "nsThreadUtils.h"
+#include "RequestContextService.h"
+
+#include "mozilla/Atomics.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/TimeStamp.h"
+
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/net/PSpdyPush.h"
+
+#include "../protocol/http/nsHttpHandler.h"
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gRequestContextLog("RequestContext");
+#undef LOG
+#define LOG(args) MOZ_LOG(gRequestContextLog, LogLevel::Info, args)
+
+static StaticRefPtr<RequestContextService> gSingleton;
+
+// This is used to prevent adding tail pending requests after shutdown
+static bool sShutdown = false;
+
+// nsIRequestContext
+class RequestContext final : public nsIRequestContext,
+                             public nsITimerCallback,
+                             public nsINamed {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUESTCONTEXT
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSINAMED
+
+  explicit RequestContext(const uint64_t id);
+
+ private:
+  virtual ~RequestContext();
+
+  void ProcessTailQueue(nsresult aResult);
+  // Reschedules the timer if needed
+  void ScheduleUnblock();
+  // Hard-reschedules the timer
+  void RescheduleUntailTimer(TimeStamp const& now);
+
+  uint64_t mID;
+  Atomic<uint32_t> mBlockingTransactionCount;
+  UniquePtr<SpdyPushCache> mSpdyCache;
+
+  using PendingTailRequest = nsCOMPtr<nsIRequestTailUnblockCallback>;
+  // Number of known opened non-tailed requets
+  uint32_t mNonTailRequests;
+  // Queue of requests that have been tailed, when conditions are met
+  // we call each of them to unblock and drop the reference
+  nsTArray<PendingTailRequest> mTailQueue;
+  // Loosly scheduled timer, never scheduled further to the future than
+  // mUntailAt time
+  nsCOMPtr<nsITimer> mUntailTimer;
+  // Timestamp when the timer is expected to fire,
+  // always less than or equal to mUntailAt
+  TimeStamp mTimerScheduledAt;
+  // Timestamp when we want to actually untail queued requets based on
+  // the number of request count change in the past; iff this timestamp
+  // is set, we tail requests
+  TimeStamp mUntailAt;
+
+  // Timestamp of the navigation start time, set to Now() in BeginLoad().
+  // This is used to progressively lower the maximum delay time so that
+  // we can't get to a situation when a number of repetitive requests
+  // on the page causes forever tailing.
+  TimeStamp mBeginLoadTime;
+
+  // This member is true only between DOMContentLoaded notification and
+  // next document load beginning for this request context.
+  // Top level request contexts are recycled.
+  bool mAfterDOMContentLoaded;
+};
+
+NS_IMPL_ISUPPORTS(RequestContext, nsIRequestContext, nsITimerCallback, nsINamed)
+
+RequestContext::RequestContext(const uint64_t aID)
+    : mID(aID),
+      mBlockingTransactionCount(0),
+      mNonTailRequests(0),
+      mAfterDOMContentLoaded(false) {
+  LOG(("RequestContext::RequestContext this=%p id=%" PRIx64, this, mID));
+}
+
+RequestContext::~RequestContext() {
+  MOZ_ASSERT(mTailQueue.Length() == 0);
+
+  LOG(("RequestContext::~RequestContext this=%p blockers=%u", this,
+       static_cast<uint32_t>(mBlockingTransactionCount)));
+}
+
+NS_IMETHODIMP
+RequestContext::BeginLoad() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  LOG(("RequestContext::BeginLoad %p", this));
+
+  if (IsNeckoChild()) {
+    // Tailing is not supported on the child process
+    if (gNeckoChild) {
+      gNeckoChild->SendRequestContextLoadBegin(mID);
+    }
+    return NS_OK;
+  }
+
+  mAfterDOMContentLoaded = false;
+  mBeginLoadTime = TimeStamp::NowLoRes();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::DOMContentLoaded() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  LOG(("RequestContext::DOMContentLoaded %p", this));
+
+  if (IsNeckoChild()) {
+    // Tailing is not supported on the child process
+    if (gNeckoChild) {
+      gNeckoChild->SendRequestContextAfterDOMContentLoaded(mID);
+    }
+    return NS_OK;
+  }
+
+  if (mAfterDOMContentLoaded) {
+    // There is a possibility of a duplicate notification
+    return NS_OK;
+  }
+
+  mAfterDOMContentLoaded = true;
+
+  // Conditions for the delay calculation has changed.
+  ScheduleUnblock();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::GetBlockingTransactionCount(
+    uint32_t* aBlockingTransactionCount) {
+  NS_ENSURE_ARG_POINTER(aBlockingTransactionCount);
+  *aBlockingTransactionCount = mBlockingTransactionCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::AddBlockingTransaction() {
+  mBlockingTransactionCount++;
+  LOG(("RequestContext::AddBlockingTransaction this=%p blockers=%u", this,
+       static_cast<uint32_t>(mBlockingTransactionCount)));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::RemoveBlockingTransaction(uint32_t* outval) {
+  NS_ENSURE_ARG_POINTER(outval);
+  mBlockingTransactionCount--;
+  LOG(("RequestContext::RemoveBlockingTransaction this=%p blockers=%u", this,
+       static_cast<uint32_t>(mBlockingTransactionCount)));
+  *outval = mBlockingTransactionCount;
+  return NS_OK;
+}
+
+SpdyPushCache* RequestContext::GetSpdyPushCache() { return mSpdyCache.get(); }
+
+void RequestContext::SetSpdyPushCache(SpdyPushCache* aSpdyPushCache) {
+  mSpdyCache = WrapUnique(aSpdyPushCache);
+}
+
+uint64_t RequestContext::GetID() { return mID; }
+
+NS_IMETHODIMP
+RequestContext::AddNonTailRequest() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  ++mNonTailRequests;
+  LOG(("RequestContext::AddNonTailRequest this=%p, cnt=%u", this,
+       mNonTailRequests));
+
+  ScheduleUnblock();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::RemoveNonTailRequest() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mNonTailRequests > 0);
+
+  LOG(("RequestContext::RemoveNonTailRequest this=%p, cnt=%u", this,
+       mNonTailRequests - 1));
+
+  --mNonTailRequests;
+
+  ScheduleUnblock();
+  return NS_OK;
+}
+
+void RequestContext::ScheduleUnblock() {
+  MOZ_ASSERT(!IsNeckoChild());
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!gHttpHandler) {
+    return;
+  }
+
+  uint32_t quantum =
+      gHttpHandler->TailBlockingDelayQuantum(mAfterDOMContentLoaded);
+  uint32_t delayMax = gHttpHandler->TailBlockingDelayMax();
+  uint32_t totalMax = gHttpHandler->TailBlockingTotalMax();
+
+  if (!mBeginLoadTime.IsNull()) {
+    // We decrease the maximum delay progressively with the time since the page
+    // load begin.  This seems like a reasonable and clear heuristic allowing us
+    // to start loading tailed requests in a deterministic time after the load
+    // has started.
+
+    uint32_t sinceBeginLoad = static_cast<uint32_t>(
+        (TimeStamp::NowLoRes() - mBeginLoadTime).ToMilliseconds());
+    uint32_t tillTotal = totalMax - std::min(sinceBeginLoad, totalMax);
+    uint32_t proportion = totalMax  // values clamped between 0 and 60'000
+                              ? (delayMax * tillTotal) / totalMax
+                              : 0;
+    delayMax = std::min(delayMax, proportion);
+  }
+
+  CheckedInt<uint32_t> delay = quantum * mNonTailRequests;
+
+  if (!mAfterDOMContentLoaded) {
+    // Before DOMContentLoaded notification we want to make sure that tailed
+    // requests don't start when there is a short delay during which we may
+    // not have any active requests on the page happening.
+    delay += quantum;
+  }
+
+  if (!delay.isValid() || delay.value() > delayMax) {
+    delay = delayMax;
+  }
+
+  LOG(
+      ("RequestContext::ScheduleUnblock this=%p non-tails=%u tail-queue=%zu "
+       "delay=%u after-DCL=%d",
+       this, mNonTailRequests, mTailQueue.Length(), delay.value(),
+       mAfterDOMContentLoaded));
+
+  TimeStamp now = TimeStamp::NowLoRes();
+  mUntailAt = now + TimeDuration::FromMilliseconds(delay.value());
+
+  if (mTimerScheduledAt.IsNull() || mUntailAt < mTimerScheduledAt) {
+    LOG(("RequestContext %p timer would fire too late, rescheduling", this));
+    RescheduleUntailTimer(now);
+  }
+}
+
+void RequestContext::RescheduleUntailTimer(TimeStamp const& now) {
+  MOZ_ASSERT(mUntailAt >= now);
+
+  if (mUntailTimer) {
+    mUntailTimer->Cancel();
+  }
+
+  if (!mTailQueue.Length()) {
+    mUntailTimer = nullptr;
+    mTimerScheduledAt = TimeStamp();
+    return;
+  }
+
+  TimeDuration interval = mUntailAt - now;
+  if (!mTimerScheduledAt.IsNull() && mUntailAt < mTimerScheduledAt) {
+    // When the number of untailed requests goes down,
+    // let's half the interval, since it's likely we would
+    // reschedule for a shorter time again very soon.
+    // This will likely save rescheduling this timer.
+    interval = interval / int64_t(2);
+    mTimerScheduledAt = mUntailAt - interval;
+  } else {
+    mTimerScheduledAt = mUntailAt;
+  }
+
+  uint32_t delay = interval.ToMilliseconds();
+  nsresult rv =
+      NS_NewTimerWithCallback(getter_AddRefs(mUntailTimer), this, delay,
+                              nsITimer::TYPE_ONE_SHOT, nullptr);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Could not reschedule untail timer");
+  }
+
+  LOG(("RequestContext::RescheduleUntailTimer %p in %d", this, delay));
+}
+
+NS_IMETHODIMP
+RequestContext::Notify(nsITimer* timer) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(timer == mUntailTimer);
+  MOZ_ASSERT(!mTimerScheduledAt.IsNull());
+  MOZ_ASSERT(mTailQueue.Length());
+
+  mUntailTimer = nullptr;
+
+  TimeStamp now = TimeStamp::NowLoRes();
+  if (mUntailAt > mTimerScheduledAt && mUntailAt > now) {
+    LOG(("RequestContext %p timer fired too soon, rescheduling", this));
+    RescheduleUntailTimer(now);
+    return NS_OK;
+  }
+
+  // Must drop to allow re-engage of the timer
+  mTimerScheduledAt = TimeStamp();
+
+  ProcessTailQueue(NS_OK);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::GetName(nsACString& aName) {
+  aName.AssignLiteral("RequestContext");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::IsContextTailBlocked(nsIRequestTailUnblockCallback* aRequest,
+                                     bool* aBlocked) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  LOG(("RequestContext::IsContextTailBlocked this=%p, request=%p, queued=%zu",
+       this, aRequest, mTailQueue.Length()));
+
+  *aBlocked = false;
+
+  if (sShutdown) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  if (mUntailAt.IsNull()) {
+    LOG(("  untail time passed"));
+    return NS_OK;
+  }
+
+  if (mAfterDOMContentLoaded && !mNonTailRequests) {
+    LOG(("  after DOMContentLoaded and no untailed requests"));
+    return NS_OK;
+  }
+
+  if (!gHttpHandler) {
+    // Xpcshell tests may not have http handler
+    LOG(("  missing gHttpHandler?"));
+    return NS_OK;
+  }
+
+  *aBlocked = true;
+  mTailQueue.AppendElement(aRequest);
+
+  LOG(("  request queued"));
+
+  if (!mUntailTimer) {
+    ScheduleUnblock();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContext::CancelTailedRequest(nsIRequestTailUnblockCallback* aRequest) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  bool removed = mTailQueue.RemoveElement(aRequest);
+
+  LOG(("RequestContext::CancelTailedRequest %p req=%p removed=%d", this,
+       aRequest, removed));
+
+  // Stop untail timer if all tail requests are canceled.
+  if (removed && mTailQueue.IsEmpty()) {
+    if (mUntailTimer) {
+      mUntailTimer->Cancel();
+      mUntailTimer = nullptr;
+    }
+
+    // Must drop to allow re-engage of the timer
+    mTimerScheduledAt = TimeStamp();
+  }
+
+  return NS_OK;
+}
+
+void RequestContext::ProcessTailQueue(nsresult aResult) {
+  LOG(("RequestContext::ProcessTailQueue this=%p, queued=%zu, rv=%" PRIx32,
+       this, mTailQueue.Length(), static_cast<uint32_t>(aResult)));
+
+  if (mUntailTimer) {
+    mUntailTimer->Cancel();
+    mUntailTimer = nullptr;
+  }
+
+  // Must drop to stop tailing requests
+  mUntailAt = TimeStamp();
+
+  nsTArray<PendingTailRequest> queue = std::move(mTailQueue);
+
+  for (const auto& request : queue) {
+    LOG(("  untailing %p", request.get()));
+    request->OnTailUnblock(aResult);
+  }
+}
+
+NS_IMETHODIMP
+RequestContext::CancelTailPendingRequests(nsresult aResult) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(NS_FAILED(aResult));
+
+  ProcessTailQueue(aResult);
+  return NS_OK;
+}
+
+// nsIRequestContextService
+RequestContextService* RequestContextService::sSelf = nullptr;
+
+NS_IMPL_ISUPPORTS(RequestContextService, nsIRequestContextService, nsIObserver)
+
+RequestContextService::RequestContextService() {
+  MOZ_ASSERT(!sSelf, "multiple rcs instances!");
+  MOZ_ASSERT(NS_IsMainThread());
+  sSelf = this;
+
+  nsCOMPtr<nsIXULRuntime> runtime = do_GetService("@mozilla.org/xre/runtime;1");
+  runtime->GetProcessID(&mRCIDNamespace);
+}
+
+RequestContextService::~RequestContextService() {
+  MOZ_ASSERT(NS_IsMainThread());
+  Shutdown();
+  sSelf = nullptr;
+}
+
+nsresult RequestContextService::Init() {
+  nsresult rv;
+
+  MOZ_ASSERT(NS_IsMainThread());
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (!obs) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  rv = obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  obs->AddObserver(this, "content-document-interactive", false);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+void RequestContextService::Shutdown() {
+  MOZ_ASSERT(NS_IsMainThread());
+  // We need to do this to prevent the requests from being scheduled after
+  // shutdown.
+  for (const auto& data : mTable.Values()) {
+    data->CancelTailPendingRequests(NS_ERROR_ABORT);
+  }
+  mTable.Clear();
+  sShutdown = true;
+}
+
+/* static */
+already_AddRefed<nsIRequestContextService>
+RequestContextService::GetOrCreate() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (sShutdown) {
+    return nullptr;
+  }
+
+  RefPtr<RequestContextService> svc;
+  if (gSingleton) {
+    svc = gSingleton;
+  } else {
+    svc = new RequestContextService();
+    nsresult rv = svc->Init();
+    NS_ENSURE_SUCCESS(rv, nullptr);
+    gSingleton = svc;
+    ClearOnShutdown(&gSingleton);
+  }
+
+  return svc.forget();
+}
+
+NS_IMETHODIMP
+RequestContextService::GetRequestContext(const uint64_t rcID,
+                                         nsIRequestContext** rc) {
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_ENSURE_ARG_POINTER(rc);
+  *rc = nullptr;
+
+  if (sShutdown) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  if (!rcID) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *rc = do_AddRef(mTable.LookupOrInsertWith(rcID, [&] {
+          nsCOMPtr<nsIRequestContext> newSC = new RequestContext(rcID);
+          return newSC;
+        })).take();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContextService::GetRequestContextFromLoadGroup(nsILoadGroup* aLoadGroup,
+                                                      nsIRequestContext** rc) {
+  nsresult rv;
+
+  uint64_t rcID;
+  rv = aLoadGroup->GetRequestContextID(&rcID);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return GetRequestContext(rcID, rc);
+}
+
+NS_IMETHODIMP
+RequestContextService::NewRequestContext(nsIRequestContext** rc) {
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_ENSURE_ARG_POINTER(rc);
+  *rc = nullptr;
+
+  if (sShutdown) {
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  uint64_t rcID =
+      ((static_cast<uint64_t>(mRCIDNamespace) << 32) & 0xFFFFFFFF00000000LL) |
+      mNextRCID++;
+
+  nsCOMPtr<nsIRequestContext> newSC = new RequestContext(rcID);
+  mTable.InsertOrUpdate(rcID, newSC);
+  newSC.swap(*rc);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContextService::RemoveRequestContext(const uint64_t rcID) {
+  MOZ_ASSERT(NS_IsMainThread());
+  mTable.Remove(rcID);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+RequestContextService::Observe(nsISupports* subject, const char* topic,
+                               const char16_t* data_unicode) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!strcmp(NS_XPCOM_SHUTDOWN_OBSERVER_ID, topic)) {
+    Shutdown();
+    return NS_OK;
+  }
+
+  if (!strcmp("content-document-interactive", topic)) {
+    nsCOMPtr<dom::Document> document(do_QueryInterface(subject));
+    MOZ_ASSERT(document);
+    // We want this be triggered also for iframes, since those track their
+    // own request context ids.
+    if (!document) {
+      return NS_OK;
+    }
+    nsIDocShell* ds = document->GetDocShell();
+    // XML documents don't always have a docshell assigned
+    if (!ds) {
+      return NS_OK;
+    }
+    nsCOMPtr<nsIDocumentLoader> dl(do_QueryInterface(ds));
+    if (!dl) {
+      return NS_OK;
+    }
+    nsCOMPtr<nsILoadGroup> lg;
+    dl->GetLoadGroup(getter_AddRefs(lg));
+    if (!lg) {
+      return NS_OK;
+    }
+    nsCOMPtr<nsIRequestContext> rc;
+    GetRequestContextFromLoadGroup(lg, getter_AddRefs(rc));
+    if (rc) {
+      rc->DOMContentLoaded();
+    }
+
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(false, "Unexpected observer topic");
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
+
+#undef LOG
diff --git a/netwerk/base/RequestContextService.h b/netwerk/base/RequestContextService.h
new file mode 100644
index 0000000000..4aafdb8ed6
--- /dev/null
+++ b/netwerk/base/RequestContextService.h
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 ;*; */
+/* vim: set sw=2 ts=8 et tw=80 : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla__net__RequestContextService_h
+#define mozilla__net__RequestContextService_h
+
+#include "nsCOMPtr.h"
+#include "nsInterfaceHashtable.h"
+#include "nsIObserver.h"
+#include "nsIRequestContext.h"
+
+namespace mozilla {
+namespace net {
+
+class RequestContextService final : public nsIRequestContextService,
+                                    public nsIObserver {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUESTCONTEXTSERVICE
+  NS_DECL_NSIOBSERVER
+
+  static already_AddRefed<nsIRequestContextService> GetOrCreate();
+
+ private:
+  RequestContextService();
+  virtual ~RequestContextService();
+
+  nsresult Init();
+  void Shutdown();
+
+  static RequestContextService* sSelf;
+
+  nsInterfaceHashtable<nsUint64HashKey, nsIRequestContext> mTable;
+  uint32_t mRCIDNamespace{0};
+  uint32_t mNextRCID{1};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla__net__RequestContextService_h
diff --git a/netwerk/base/SSLTokensCache.cpp b/netwerk/base/SSLTokensCache.cpp
new file mode 100644
index 0000000000..34ca2d82c9
--- /dev/null
+++ b/netwerk/base/SSLTokensCache.cpp
@@ -0,0 +1,570 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SSLTokensCache.h"
+
+#include "CertVerifier.h"
+#include "CommonSocketControl.h"
+#include "TransportSecurityInfo.h"
+#include "mozilla/ArrayAlgorithm.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Preferences.h"
+#include "nsIOService.h"
+#include "ssl.h"
+#include "sslexp.h"
+
+namespace mozilla {
+namespace net {
+
+static LazyLogModule gSSLTokensCacheLog("SSLTokensCache");
+#undef LOG
+#define LOG(args) MOZ_LOG(gSSLTokensCacheLog, mozilla::LogLevel::Debug, args)
+#undef LOG5_ENABLED
+#define LOG5_ENABLED() \
+  MOZ_LOG_TEST(mozilla::net::gSSLTokensCacheLog, mozilla::LogLevel::Verbose)
+
+class ExpirationComparator {
+ public:
+  bool Equals(SSLTokensCache::TokenCacheRecord* a,
+              SSLTokensCache::TokenCacheRecord* b) const {
+    return a->mExpirationTime == b->mExpirationTime;
+  }
+  bool LessThan(SSLTokensCache::TokenCacheRecord* a,
+                SSLTokensCache::TokenCacheRecord* b) const {
+    return a->mExpirationTime < b->mExpirationTime;
+  }
+};
+
+SessionCacheInfo SessionCacheInfo::Clone() const {
+  SessionCacheInfo result;
+  result.mEVStatus = mEVStatus;
+  result.mCertificateTransparencyStatus = mCertificateTransparencyStatus;
+  result.mServerCertBytes = mServerCertBytes.Clone();
+  result.mSucceededCertChainBytes =
+      mSucceededCertChainBytes
+          ? Some(TransformIntoNewArray(
+                *mSucceededCertChainBytes,
+                [](const auto& element) { return element.Clone(); }))
+          : Nothing();
+  result.mIsBuiltCertChainRootBuiltInRoot = mIsBuiltCertChainRootBuiltInRoot;
+  result.mOverridableErrorCategory = mOverridableErrorCategory;
+  result.mFailedCertChainBytes =
+      mFailedCertChainBytes
+          ? Some(TransformIntoNewArray(
+                *mFailedCertChainBytes,
+                [](const auto& element) { return element.Clone(); }))
+          : Nothing();
+  return result;
+}
+
+StaticRefPtr<SSLTokensCache> SSLTokensCache::gInstance;
+StaticMutex SSLTokensCache::sLock;
+uint64_t SSLTokensCache::sRecordId = 0;
+
+SSLTokensCache::TokenCacheRecord::~TokenCacheRecord() {
+  if (!gInstance) {
+    return;
+  }
+
+  gInstance->OnRecordDestroyed(this);
+}
+
+uint32_t SSLTokensCache::TokenCacheRecord::Size() const {
+  uint32_t size = mToken.Length() + sizeof(mSessionCacheInfo.mEVStatus) +
+                  sizeof(mSessionCacheInfo.mCertificateTransparencyStatus) +
+                  mSessionCacheInfo.mServerCertBytes.Length() +
+                  sizeof(mSessionCacheInfo.mIsBuiltCertChainRootBuiltInRoot) +
+                  sizeof(mSessionCacheInfo.mOverridableErrorCategory);
+  if (mSessionCacheInfo.mSucceededCertChainBytes) {
+    for (const auto& cert : mSessionCacheInfo.mSucceededCertChainBytes.ref()) {
+      size += cert.Length();
+    }
+  }
+  if (mSessionCacheInfo.mFailedCertChainBytes) {
+    for (const auto& cert : mSessionCacheInfo.mFailedCertChainBytes.ref()) {
+      size += cert.Length();
+    }
+  }
+  return size;
+}
+
+void SSLTokensCache::TokenCacheRecord::Reset() {
+  mToken.Clear();
+  mExpirationTime = 0;
+  mSessionCacheInfo.mEVStatus = psm::EVStatus::NotEV;
+  mSessionCacheInfo.mCertificateTransparencyStatus =
+      nsITransportSecurityInfo::CERTIFICATE_TRANSPARENCY_NOT_APPLICABLE;
+  mSessionCacheInfo.mServerCertBytes.Clear();
+  mSessionCacheInfo.mSucceededCertChainBytes.reset();
+  mSessionCacheInfo.mIsBuiltCertChainRootBuiltInRoot.reset();
+  mSessionCacheInfo.mOverridableErrorCategory =
+      nsITransportSecurityInfo::OverridableErrorCategory::ERROR_UNSET;
+  mSessionCacheInfo.mFailedCertChainBytes.reset();
+}
+
+uint32_t SSLTokensCache::TokenCacheEntry::Size() const {
+  uint32_t size = 0;
+  for (const auto& rec : mRecords) {
+    size += rec->Size();
+  }
+  return size;
+}
+
+void SSLTokensCache::TokenCacheEntry::AddRecord(
+    UniquePtr<SSLTokensCache::TokenCacheRecord>&& aRecord,
+    nsTArray<TokenCacheRecord*>& aExpirationArray) {
+  if (mRecords.Length() ==
+      StaticPrefs::network_ssl_tokens_cache_records_per_entry()) {
+    aExpirationArray.RemoveElement(mRecords[0].get());
+    mRecords.RemoveElementAt(0);
+  }
+
+  aExpirationArray.AppendElement(aRecord.get());
+  for (int32_t i = mRecords.Length() - 1; i >= 0; --i) {
+    if (aRecord->mExpirationTime > mRecords[i]->mExpirationTime) {
+      mRecords.InsertElementAt(i + 1, std::move(aRecord));
+      return;
+    }
+  }
+  mRecords.InsertElementAt(0, std::move(aRecord));
+}
+
+UniquePtr<SSLTokensCache::TokenCacheRecord>
+SSLTokensCache::TokenCacheEntry::RemoveWithId(uint64_t aId) {
+  for (int32_t i = mRecords.Length() - 1; i >= 0; --i) {
+    if (mRecords[i]->mId == aId) {
+      UniquePtr<TokenCacheRecord> record = std::move(mRecords[i]);
+      mRecords.RemoveElementAt(i);
+      return record;
+    }
+  }
+  return nullptr;
+}
+
+const UniquePtr<SSLTokensCache::TokenCacheRecord>&
+SSLTokensCache::TokenCacheEntry::Get() {
+  return mRecords[0];
+}
+
+NS_IMPL_ISUPPORTS(SSLTokensCache, nsIMemoryReporter)
+
+// static
+nsresult SSLTokensCache::Init() {
+  StaticMutexAutoLock lock(sLock);
+
+  // SSLTokensCache should be only used in parent process and socket process.
+  // Ideally, parent process should not use this when socket process is enabled.
+  // However, some xpcsehll tests may need to create and use sockets directly,
+  // so we still allow to use this in parent process no matter socket process is
+  // enabled or not.
+  if (!(XRE_IsSocketProcess() || XRE_IsParentProcess())) {
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(!gInstance);
+
+  gInstance = new SSLTokensCache();
+
+  RegisterWeakMemoryReporter(gInstance);
+
+  return NS_OK;
+}
+
+// static
+nsresult SSLTokensCache::Shutdown() {
+  StaticMutexAutoLock lock(sLock);
+
+  if (!gInstance) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  UnregisterWeakMemoryReporter(gInstance);
+
+  gInstance = nullptr;
+
+  return NS_OK;
+}
+
+SSLTokensCache::SSLTokensCache() { LOG(("SSLTokensCache::SSLTokensCache")); }
+
+SSLTokensCache::~SSLTokensCache() { LOG(("SSLTokensCache::~SSLTokensCache")); }
+
+// static
+nsresult SSLTokensCache::Put(const nsACString& aKey, const uint8_t* aToken,
+                             uint32_t aTokenLen,
+                             CommonSocketControl* aSocketControl) {
+  PRUint32 expirationTime;
+  SSLResumptionTokenInfo tokenInfo;
+  if (SSL_GetResumptionTokenInfo(aToken, aTokenLen, &tokenInfo,
+                                 sizeof(tokenInfo)) != SECSuccess) {
+    LOG(("  cannot get expiration time from the token, NSS error %d",
+         PORT_GetError()));
+    return NS_ERROR_FAILURE;
+  }
+
+  expirationTime = tokenInfo.expirationTime;
+  SSL_DestroyResumptionTokenInfo(&tokenInfo);
+
+  return Put(aKey, aToken, aTokenLen, aSocketControl, expirationTime);
+}
+
+// static
+nsresult SSLTokensCache::Put(const nsACString& aKey, const uint8_t* aToken,
+                             uint32_t aTokenLen,
+                             CommonSocketControl* aSocketControl,
+                             PRUint32 aExpirationTime) {
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("SSLTokensCache::Put [key=%s, tokenLen=%u]",
+       PromiseFlatCString(aKey).get(), aTokenLen));
+
+  if (!gInstance) {
+    LOG(("  service not initialized"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!aSocketControl) {
+    return NS_ERROR_FAILURE;
+  }
+  nsCOMPtr<nsITransportSecurityInfo> securityInfo;
+  nsresult rv = aSocketControl->GetSecurityInfo(getter_AddRefs(securityInfo));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIX509Cert> cert;
+  securityInfo->GetServerCert(getter_AddRefs(cert));
+  if (!cert) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsTArray<uint8_t> certBytes;
+  rv = cert->GetRawDER(certBytes);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  Maybe<nsTArray<nsTArray<uint8_t>>> succeededCertChainBytes;
+  nsTArray<RefPtr<nsIX509Cert>> succeededCertArray;
+  rv = securityInfo->GetSucceededCertChain(succeededCertArray);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  Maybe<bool> isBuiltCertChainRootBuiltInRoot;
+  if (!succeededCertArray.IsEmpty()) {
+    succeededCertChainBytes.emplace();
+    for (const auto& cert : succeededCertArray) {
+      nsTArray<uint8_t> rawCert;
+      nsresult rv = cert->GetRawDER(rawCert);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      succeededCertChainBytes->AppendElement(std::move(rawCert));
+    }
+
+    bool builtInRoot = false;
+    rv = securityInfo->GetIsBuiltCertChainRootBuiltInRoot(&builtInRoot);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    isBuiltCertChainRootBuiltInRoot.emplace(builtInRoot);
+  }
+
+  bool isEV;
+  rv = securityInfo->GetIsExtendedValidation(&isEV);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  uint16_t certificateTransparencyStatus;
+  rv = securityInfo->GetCertificateTransparencyStatus(
+      &certificateTransparencyStatus);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsITransportSecurityInfo::OverridableErrorCategory overridableErrorCategory;
+  rv = securityInfo->GetOverridableErrorCategory(&overridableErrorCategory);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  Maybe<nsTArray<nsTArray<uint8_t>>> failedCertChainBytes;
+  nsTArray<RefPtr<nsIX509Cert>> failedCertArray;
+  rv = securityInfo->GetFailedCertChain(failedCertArray);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (!failedCertArray.IsEmpty()) {
+    failedCertChainBytes.emplace();
+    for (const auto& cert : failedCertArray) {
+      nsTArray<uint8_t> rawCert;
+      nsresult rv = cert->GetRawDER(rawCert);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      failedCertChainBytes->AppendElement(std::move(rawCert));
+    }
+  }
+
+  auto makeUniqueRecord = [&]() {
+    auto rec = MakeUnique<TokenCacheRecord>();
+    rec->mKey = aKey;
+    rec->mExpirationTime = aExpirationTime;
+    MOZ_ASSERT(rec->mToken.IsEmpty());
+    rec->mToken.AppendElements(aToken, aTokenLen);
+    rec->mId = ++sRecordId;
+    rec->mSessionCacheInfo.mServerCertBytes = std::move(certBytes);
+    rec->mSessionCacheInfo.mSucceededCertChainBytes =
+        std::move(succeededCertChainBytes);
+    if (isEV) {
+      rec->mSessionCacheInfo.mEVStatus = psm::EVStatus::EV;
+    }
+    rec->mSessionCacheInfo.mCertificateTransparencyStatus =
+        certificateTransparencyStatus;
+    rec->mSessionCacheInfo.mIsBuiltCertChainRootBuiltInRoot =
+        std::move(isBuiltCertChainRootBuiltInRoot);
+    rec->mSessionCacheInfo.mOverridableErrorCategory = overridableErrorCategory;
+    rec->mSessionCacheInfo.mFailedCertChainBytes =
+        std::move(failedCertChainBytes);
+    return rec;
+  };
+
+  TokenCacheEntry* const cacheEntry =
+      gInstance->mTokenCacheRecords.WithEntryHandle(aKey, [&](auto&& entry) {
+        if (!entry) {
+          auto rec = makeUniqueRecord();
+          auto cacheEntry = MakeUnique<TokenCacheEntry>();
+          cacheEntry->AddRecord(std::move(rec), gInstance->mExpirationArray);
+          entry.Insert(std::move(cacheEntry));
+        } else {
+          // To make sure the cache size is synced, we take away the size of
+          // whole entry and add it back later.
+          gInstance->mCacheSize -= entry.Data()->Size();
+          entry.Data()->AddRecord(makeUniqueRecord(),
+                                  gInstance->mExpirationArray);
+        }
+
+        return entry->get();
+      });
+
+  gInstance->mCacheSize += cacheEntry->Size();
+
+  gInstance->LogStats();
+
+  gInstance->EvictIfNecessary();
+
+  return NS_OK;
+}
+
+// static
+nsresult SSLTokensCache::Get(const nsACString& aKey, nsTArray<uint8_t>& aToken,
+                             SessionCacheInfo& aResult, uint64_t* aTokenId) {
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("SSLTokensCache::Get [key=%s]", PromiseFlatCString(aKey).get()));
+
+  if (!gInstance) {
+    LOG(("  service not initialized"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  return gInstance->GetLocked(aKey, aToken, aResult, aTokenId);
+}
+
+nsresult SSLTokensCache::GetLocked(const nsACString& aKey,
+                                   nsTArray<uint8_t>& aToken,
+                                   SessionCacheInfo& aResult,
+                                   uint64_t* aTokenId) {
+  sLock.AssertCurrentThreadOwns();
+
+  TokenCacheEntry* cacheEntry = nullptr;
+
+  if (mTokenCacheRecords.Get(aKey, &cacheEntry)) {
+    if (cacheEntry->RecordCount() == 0) {
+      MOZ_ASSERT(false, "Found a cacheEntry with no records");
+      mTokenCacheRecords.Remove(aKey);
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    const UniquePtr<TokenCacheRecord>& rec = cacheEntry->Get();
+    aToken = rec->mToken.Clone();
+    aResult = rec->mSessionCacheInfo.Clone();
+    if (aTokenId) {
+      *aTokenId = rec->mId;
+    }
+    if (StaticPrefs::network_ssl_tokens_cache_use_only_once()) {
+      mCacheSize -= rec->Size();
+      cacheEntry->RemoveWithId(rec->mId);
+      if (cacheEntry->RecordCount() == 0) {
+        mTokenCacheRecords.Remove(aKey);
+      }
+    }
+    return NS_OK;
+  }
+
+  LOG(("  token not found"));
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+// static
+nsresult SSLTokensCache::Remove(const nsACString& aKey, uint64_t aId) {
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("SSLTokensCache::Remove [key=%s]", PromiseFlatCString(aKey).get()));
+
+  if (!gInstance) {
+    LOG(("  service not initialized"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  return gInstance->RemoveLocked(aKey, aId);
+}
+
+nsresult SSLTokensCache::RemoveLocked(const nsACString& aKey, uint64_t aId) {
+  sLock.AssertCurrentThreadOwns();
+
+  LOG(("SSLTokensCache::RemoveLocked [key=%s, id=%" PRIu64 "]",
+       PromiseFlatCString(aKey).get(), aId));
+
+  TokenCacheEntry* cacheEntry;
+  if (!mTokenCacheRecords.Get(aKey, &cacheEntry)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  UniquePtr<TokenCacheRecord> rec = cacheEntry->RemoveWithId(aId);
+  if (!rec) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  mCacheSize -= rec->Size();
+  if (cacheEntry->RecordCount() == 0) {
+    mTokenCacheRecords.Remove(aKey);
+  }
+
+  // Release the record immediately, so mExpirationArray can be also updated.
+  rec = nullptr;
+
+  LogStats();
+
+  return NS_OK;
+}
+
+// static
+nsresult SSLTokensCache::RemoveAll(const nsACString& aKey) {
+  StaticMutexAutoLock lock(sLock);
+
+  LOG(("SSLTokensCache::RemoveAll [key=%s]", PromiseFlatCString(aKey).get()));
+
+  if (!gInstance) {
+    LOG(("  service not initialized"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  return gInstance->RemovAllLocked(aKey);
+}
+
+nsresult SSLTokensCache::RemovAllLocked(const nsACString& aKey) {
+  sLock.AssertCurrentThreadOwns();
+
+  LOG(("SSLTokensCache::RemovAllLocked [key=%s]",
+       PromiseFlatCString(aKey).get()));
+
+  UniquePtr<TokenCacheEntry> cacheEntry;
+  if (!mTokenCacheRecords.Remove(aKey, &cacheEntry)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  mCacheSize -= cacheEntry->Size();
+  cacheEntry = nullptr;
+
+  LogStats();
+
+  return NS_OK;
+}
+
+void SSLTokensCache::OnRecordDestroyed(TokenCacheRecord* aRec) {
+  mExpirationArray.RemoveElement(aRec);
+}
+
+void SSLTokensCache::EvictIfNecessary() {
+  // kilobytes to bytes
+  uint32_t capacity = StaticPrefs::network_ssl_tokens_cache_capacity() << 10;
+  if (mCacheSize <= capacity) {
+    return;
+  }
+
+  LOG(("SSLTokensCache::EvictIfNecessary - evicting"));
+
+  mExpirationArray.Sort(ExpirationComparator());
+
+  while (mCacheSize > capacity && mExpirationArray.Length() > 0) {
+    DebugOnly<nsresult> rv =
+        RemoveLocked(mExpirationArray[0]->mKey, mExpirationArray[0]->mId);
+    MOZ_ASSERT(NS_SUCCEEDED(rv),
+               "mExpirationArray and mTokenCacheRecords are out of sync!");
+  }
+}
+
+void SSLTokensCache::LogStats() {
+  if (!LOG5_ENABLED()) {
+    return;
+  }
+  LOG(("SSLTokensCache::LogStats [count=%zu, cacheSize=%u]",
+       mExpirationArray.Length(), mCacheSize));
+  for (const auto& ent : mTokenCacheRecords.Values()) {
+    const UniquePtr<TokenCacheRecord>& rec = ent->Get();
+    LOG(("key=%s count=%d", rec->mKey.get(), ent->RecordCount()));
+  }
+}
+
+size_t SSLTokensCache::SizeOfIncludingThis(
+    mozilla::MallocSizeOf mallocSizeOf) const {
+  size_t n = mallocSizeOf(this);
+
+  n += mTokenCacheRecords.ShallowSizeOfExcludingThis(mallocSizeOf);
+  n += mExpirationArray.ShallowSizeOfExcludingThis(mallocSizeOf);
+
+  for (uint32_t i = 0; i < mExpirationArray.Length(); ++i) {
+    n += mallocSizeOf(mExpirationArray[i]);
+    n += mExpirationArray[i]->mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+    n += mExpirationArray[i]->mToken.ShallowSizeOfExcludingThis(mallocSizeOf);
+  }
+
+  return n;
+}
+
+MOZ_DEFINE_MALLOC_SIZE_OF(SSLTokensCacheMallocSizeOf)
+
+NS_IMETHODIMP
+SSLTokensCache::CollectReports(nsIHandleReportCallback* aHandleReport,
+                               nsISupports* aData, bool aAnonymize) {
+  StaticMutexAutoLock lock(sLock);
+
+  MOZ_COLLECT_REPORT("explicit/network/ssl-tokens-cache", KIND_HEAP,
+                     UNITS_BYTES,
+                     SizeOfIncludingThis(SSLTokensCacheMallocSizeOf),
+                     "Memory used for the SSL tokens cache.");
+
+  return NS_OK;
+}
+
+// static
+void SSLTokensCache::Clear() {
+  LOG(("SSLTokensCache::Clear"));
+
+  StaticMutexAutoLock lock(sLock);
+  if (!gInstance) {
+    LOG(("  service not initialized"));
+    return;
+  }
+
+  gInstance->mExpirationArray.Clear();
+  gInstance->mTokenCacheRecords.Clear();
+  gInstance->mCacheSize = 0;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/SSLTokensCache.h b/netwerk/base/SSLTokensCache.h
new file mode 100644
index 0000000000..b335457526
--- /dev/null
+++ b/netwerk/base/SSLTokensCache.h
@@ -0,0 +1,123 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SSLTokensCache_h_
+#define SSLTokensCache_h_
+
+#include "CertVerifier.h"  // For EVStatus
+#include "mozilla/Maybe.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StaticPtr.h"
+#include "nsClassHashtable.h"
+#include "nsIMemoryReporter.h"
+#include "nsITransportSecurityInfo.h"
+#include "nsTArray.h"
+#include "nsTHashMap.h"
+#include "nsXULAppAPI.h"
+
+class CommonSocketControl;
+
+namespace mozilla {
+namespace net {
+
+struct SessionCacheInfo {
+  SessionCacheInfo Clone() const;
+
+  psm::EVStatus mEVStatus = psm::EVStatus::NotEV;
+  uint16_t mCertificateTransparencyStatus =
+      nsITransportSecurityInfo::CERTIFICATE_TRANSPARENCY_NOT_APPLICABLE;
+  nsTArray<uint8_t> mServerCertBytes;
+  Maybe<nsTArray<nsTArray<uint8_t>>> mSucceededCertChainBytes;
+  Maybe<bool> mIsBuiltCertChainRootBuiltInRoot;
+  nsITransportSecurityInfo::OverridableErrorCategory mOverridableErrorCategory;
+  Maybe<nsTArray<nsTArray<uint8_t>>> mFailedCertChainBytes;
+};
+
+class SSLTokensCache : public nsIMemoryReporter {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIMEMORYREPORTER
+
+  friend class ExpirationComparator;
+
+  static nsresult Init();
+  static nsresult Shutdown();
+
+  static nsresult Put(const nsACString& aKey, const uint8_t* aToken,
+                      uint32_t aTokenLen, CommonSocketControl* aSocketControl);
+  static nsresult Put(const nsACString& aKey, const uint8_t* aToken,
+                      uint32_t aTokenLen, CommonSocketControl* aSocketControl,
+                      PRUint32 aExpirationTime);
+  static nsresult Get(const nsACString& aKey, nsTArray<uint8_t>& aToken,
+                      SessionCacheInfo& aResult, uint64_t* aTokenId = nullptr);
+  static nsresult Remove(const nsACString& aKey, uint64_t aId);
+  static nsresult RemoveAll(const nsACString& aKey);
+  static void Clear();
+
+ private:
+  SSLTokensCache();
+  virtual ~SSLTokensCache();
+
+  nsresult RemoveLocked(const nsACString& aKey, uint64_t aId);
+  nsresult RemovAllLocked(const nsACString& aKey);
+  nsresult GetLocked(const nsACString& aKey, nsTArray<uint8_t>& aToken,
+                     SessionCacheInfo& aResult, uint64_t* aTokenId);
+
+  void EvictIfNecessary();
+  void LogStats();
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  static mozilla::StaticRefPtr<SSLTokensCache> gInstance;
+  static StaticMutex sLock MOZ_UNANNOTATED;
+  static uint64_t sRecordId;
+
+  uint32_t mCacheSize{0};  // Actual cache size in bytes
+
+  class TokenCacheRecord {
+   public:
+    ~TokenCacheRecord();
+
+    uint32_t Size() const;
+    void Reset();
+
+    nsCString mKey;
+    PRUint32 mExpirationTime = 0;
+    nsTArray<uint8_t> mToken;
+    SessionCacheInfo mSessionCacheInfo;
+    // An unique id to identify the record. Mostly used when we want to remove a
+    // record from TokenCacheEntry.
+    uint64_t mId = 0;
+  };
+
+  class TokenCacheEntry {
+   public:
+    uint32_t Size() const;
+    // Add a record into |mRecords|. To make sure |mRecords| is sorted, we
+    // iterate |mRecords| everytime to find a right place to insert the new
+    // record.
+    void AddRecord(UniquePtr<TokenCacheRecord>&& aRecord,
+                   nsTArray<TokenCacheRecord*>& aExpirationArray);
+    // This function returns the first record in |mRecords|.
+    const UniquePtr<TokenCacheRecord>& Get();
+    UniquePtr<TokenCacheRecord> RemoveWithId(uint64_t aId);
+    uint32_t RecordCount() const { return mRecords.Length(); }
+    const nsTArray<UniquePtr<TokenCacheRecord>>& Records() { return mRecords; }
+
+   private:
+    // The records in this array are ordered by the expiration time.
+    nsTArray<UniquePtr<TokenCacheRecord>> mRecords;
+  };
+
+  void OnRecordDestroyed(TokenCacheRecord* aRec);
+
+  nsClassHashtable<nsCStringHashKey, TokenCacheEntry> mTokenCacheRecords;
+  nsTArray<TokenCacheRecord*> mExpirationArray;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // SSLTokensCache_h_
diff --git a/netwerk/base/ShutdownLayer.cpp b/netwerk/base/ShutdownLayer.cpp
new file mode 100644
index 0000000000..db62ea691d
--- /dev/null
+++ b/netwerk/base/ShutdownLayer.cpp
@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Assertions.h"
+#include "ShutdownLayer.h"
+#include "prerror.h"
+#include "private/pprio.h"
+#include "prmem.h"
+#include <winsock2.h>
+
+static PRDescIdentity sWinSockShutdownLayerIdentity;
+static PRIOMethods sWinSockShutdownLayerMethods;
+static PRIOMethods* sWinSockShutdownLayerMethodsPtr = nullptr;
+
+namespace mozilla {
+namespace net {
+
+extern PRDescIdentity nsNamedPipeLayerIdentity;
+
+}  // namespace net
+}  // namespace mozilla
+
+PRStatus WinSockClose(PRFileDesc* aFd) {
+  MOZ_RELEASE_ASSERT(aFd->identity == sWinSockShutdownLayerIdentity,
+                     "Windows shutdown layer not on the top of the stack");
+
+  PROsfd osfd = PR_FileDesc2NativeHandle(aFd);
+  if (osfd != -1) {
+    shutdown(osfd, SD_BOTH);
+  }
+
+  aFd->identity = PR_INVALID_IO_LAYER;
+
+  if (aFd->lower) {
+    return aFd->lower->methods->close(aFd->lower);
+  } else {
+    return PR_SUCCESS;
+  }
+}
+
+nsresult mozilla::net::AttachShutdownLayer(PRFileDesc* aFd) {
+  if (!sWinSockShutdownLayerMethodsPtr) {
+    sWinSockShutdownLayerIdentity =
+        PR_GetUniqueIdentity("windows shutdown call layer");
+    sWinSockShutdownLayerMethods = *PR_GetDefaultIOMethods();
+    sWinSockShutdownLayerMethods.close = WinSockClose;
+    sWinSockShutdownLayerMethodsPtr = &sWinSockShutdownLayerMethods;
+  }
+
+  if (mozilla::net::nsNamedPipeLayerIdentity &&
+      PR_GetIdentitiesLayer(aFd, mozilla::net::nsNamedPipeLayerIdentity)) {
+    // Do not attach shutdown layer on named pipe layer,
+    // it is for PR_NSPR_IO_LAYER only.
+    return NS_OK;
+  }
+
+  PRFileDesc* layer;
+  PRStatus status;
+
+  layer = PR_CreateIOLayerStub(sWinSockShutdownLayerIdentity,
+                               sWinSockShutdownLayerMethodsPtr);
+  if (!layer) {
+    return NS_OK;
+  }
+
+  status = PR_PushIOLayer(aFd, PR_NSPR_IO_LAYER, layer);
+
+  if (status == PR_FAILURE) {
+    PR_Free(layer);  // PR_CreateIOLayerStub() uses PR_Malloc().
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
diff --git a/netwerk/base/ShutdownLayer.h b/netwerk/base/ShutdownLayer.h
new file mode 100644
index 0000000000..2bf68fdcdc
--- /dev/null
+++ b/netwerk/base/ShutdownLayer.h
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SHUTDOWNLAYER_H___
+#define SHUTDOWNLAYER_H___
+
+#include "nscore.h"
+#include "prio.h"
+
+namespace mozilla {
+namespace net {
+
+// This is only for windows. This layer will be attached jus before PR_CLose
+// is call and it will only call shutdown(sock).
+extern nsresult AttachShutdownLayer(PRFileDesc* fd);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif /* SHUTDOWN_H___ */
diff --git a/netwerk/base/SimpleBuffer.cpp b/netwerk/base/SimpleBuffer.cpp
new file mode 100644
index 0000000000..46b8654efa
--- /dev/null
+++ b/netwerk/base/SimpleBuffer.cpp
@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SimpleBuffer.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+nsresult SimpleBuffer::Write(char* src, size_t len) {
+  NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  while (len > 0) {
+    SimpleBufferPage* p = mBufferList.getLast();
+    if (p && (p->mWriteOffset == SimpleBufferPage::kSimpleBufferPageSize)) {
+      // no room.. make a new page
+      p = nullptr;
+    }
+    if (!p) {
+      p = new (fallible) SimpleBufferPage();
+      if (!p) {
+        mStatus = NS_ERROR_OUT_OF_MEMORY;
+        return mStatus;
+      }
+      mBufferList.insertBack(p);
+    }
+    size_t roomOnPage =
+        SimpleBufferPage::kSimpleBufferPageSize - p->mWriteOffset;
+    size_t toWrite = std::min(roomOnPage, len);
+    memcpy(p->mBuffer + p->mWriteOffset, src, toWrite);
+    src += toWrite;
+    len -= toWrite;
+    p->mWriteOffset += toWrite;
+    mAvailable += toWrite;
+  }
+  return NS_OK;
+}
+
+size_t SimpleBuffer::Read(char* dest, size_t maxLen) {
+  NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
+  if (NS_FAILED(mStatus)) {
+    return 0;
+  }
+
+  size_t rv = 0;
+  for (SimpleBufferPage* p = mBufferList.getFirst(); p && (rv < maxLen);
+       p = mBufferList.getFirst()) {
+    size_t avail = p->mWriteOffset - p->mReadOffset;
+    size_t toRead = std::min(avail, (maxLen - rv));
+    memcpy(dest + rv, p->mBuffer + p->mReadOffset, toRead);
+    rv += toRead;
+    p->mReadOffset += toRead;
+    if (p->mReadOffset == p->mWriteOffset) {
+      p->remove();
+      delete p;
+    }
+  }
+
+  MOZ_ASSERT(mAvailable >= rv);
+  mAvailable -= rv;
+  return rv;
+}
+
+size_t SimpleBuffer::Available() {
+  NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
+  return NS_SUCCEEDED(mStatus) ? mAvailable : 0;
+}
+
+void SimpleBuffer::Clear() {
+  NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
+  SimpleBufferPage* p;
+  while ((p = mBufferList.popFirst())) {
+    delete p;
+  }
+  mAvailable = 0;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/SimpleBuffer.h b/netwerk/base/SimpleBuffer.h
new file mode 100644
index 0000000000..031f59afe5
--- /dev/null
+++ b/netwerk/base/SimpleBuffer.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SimpleBuffer_h__
+#define SimpleBuffer_h__
+
+/*
+  This class is similar to a nsPipe except it does not have any locking, stores
+  an unbounded amount of data, can only be used on one thread, and has much
+  simpler result code semantics to deal with.
+*/
+
+#include "prtypes.h"
+#include "ErrorList.h"
+#include "mozilla/LinkedList.h"
+#include "nsISupportsImpl.h"
+
+namespace mozilla {
+namespace net {
+
+class SimpleBufferPage : public LinkedListElement<SimpleBufferPage> {
+ public:
+  SimpleBufferPage() = default;
+  static const size_t kSimpleBufferPageSize = 32000;
+
+ private:
+  friend class SimpleBuffer;
+  char mBuffer[kSimpleBufferPageSize]{0};
+  size_t mReadOffset{0};
+  size_t mWriteOffset{0};
+};
+
+class SimpleBuffer {
+ public:
+  SimpleBuffer() = default;
+  ~SimpleBuffer() = default;
+
+  nsresult Write(char* src, size_t len);   // return OK or OUT_OF_MEMORY
+  size_t Read(char* dest, size_t maxLen);  // return bytes read
+  size_t Available();
+  void Clear();
+
+ private:
+  NS_DECL_OWNINGTHREAD
+
+  nsresult mStatus{NS_OK};
+  AutoCleanLinkedList<SimpleBufferPage> mBufferList;
+  size_t mAvailable{0};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/SimpleChannel.cpp b/netwerk/base/SimpleChannel.cpp
new file mode 100644
index 0000000000..07d54c5f4e
--- /dev/null
+++ b/netwerk/base/SimpleChannel.cpp
@@ -0,0 +1,136 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SimpleChannel.h"
+
+#include "nsBaseChannel.h"
+#include "nsIChannel.h"
+#include "nsIChildChannel.h"
+#include "nsICancelable.h"
+#include "nsIInputStream.h"
+#include "nsIRequest.h"
+#include "nsISupportsImpl.h"
+#include "nsNetUtil.h"
+
+#include "mozilla/Unused.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/net/PSimpleChannelChild.h"
+
+namespace mozilla {
+namespace net {
+
+SimpleChannel::SimpleChannel(UniquePtr<SimpleChannelCallbacks>&& aCallbacks)
+    : mCallbacks(std::move(aCallbacks)) {
+  EnableSynthesizedProgressEvents(true);
+}
+
+nsresult SimpleChannel::OpenContentStream(bool async,
+                                          nsIInputStream** streamOut,
+                                          nsIChannel** channel) {
+  NS_ENSURE_TRUE(mCallbacks, NS_ERROR_UNEXPECTED);
+
+  nsCOMPtr<nsIInputStream> stream;
+  MOZ_TRY_VAR(stream, mCallbacks->OpenContentStream(async, this));
+  MOZ_ASSERT(stream);
+
+  mCallbacks = nullptr;
+
+  *channel = nullptr;
+  stream.forget(streamOut);
+  return NS_OK;
+}
+
+nsresult SimpleChannel::BeginAsyncRead(nsIStreamListener* listener,
+                                       nsIRequest** request,
+                                       nsICancelable** cancelableRequest) {
+  NS_ENSURE_TRUE(mCallbacks, NS_ERROR_UNEXPECTED);
+
+  RequestOrReason res = mCallbacks->StartAsyncRead(listener, this);
+
+  if (res.isErr()) {
+    return res.propagateErr();
+  }
+
+  mCallbacks = nullptr;
+
+  RequestOrCancelable value = res.unwrap();
+
+  if (value.is<NotNullRequest>()) {
+    nsCOMPtr<nsIRequest> req = value.as<NotNullRequest>().get();
+    req.forget(request);
+  } else if (value.is<NotNullCancelable>()) {
+    nsCOMPtr<nsICancelable> cancelable = value.as<NotNullCancelable>().get();
+    cancelable.forget(cancelableRequest);
+  } else {
+    MOZ_ASSERT_UNREACHABLE(
+        "StartAsyncRead didn't return a NotNull nsIRequest or nsICancelable.");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(SimpleChannelChild, SimpleChannel, nsIChildChannel)
+
+SimpleChannelChild::SimpleChannelChild(
+    UniquePtr<SimpleChannelCallbacks>&& aCallbacks)
+    : SimpleChannel(std::move(aCallbacks)) {}
+
+NS_IMETHODIMP
+SimpleChannelChild::ConnectParent(uint32_t aId) {
+  MOZ_ASSERT(NS_IsMainThread());
+  mozilla::dom::ContentChild* cc =
+      static_cast<mozilla::dom::ContentChild*>(gNeckoChild->Manager());
+  if (cc->IsShuttingDown()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Reference freed in DeallocPSimpleChannelChild.
+  if (!gNeckoChild->SendPSimpleChannelConstructor(do_AddRef(this).take(),
+                                                  aId)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelChild::CompleteRedirectSetup(nsIStreamListener* aListener) {
+  if (CanSend()) {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  nsresult rv;
+  rv = AsyncOpen(aListener);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (CanSend()) {
+    Unused << Send__delete__(this);
+  }
+  return NS_OK;
+}
+
+already_AddRefed<nsIChannel> NS_NewSimpleChannelInternal(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo,
+    UniquePtr<SimpleChannelCallbacks>&& aCallbacks) {
+  RefPtr<SimpleChannel> chan;
+  if (IsNeckoChild()) {
+    chan = new SimpleChannelChild(std::move(aCallbacks));
+  } else {
+    chan = new SimpleChannel(std::move(aCallbacks));
+  }
+
+  chan->SetURI(aURI);
+
+  MOZ_ALWAYS_SUCCEEDS(chan->SetLoadInfo(aLoadInfo));
+
+  return chan.forget();
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/SimpleChannel.h b/netwerk/base/SimpleChannel.h
new file mode 100644
index 0000000000..d469adf65d
--- /dev/null
+++ b/netwerk/base/SimpleChannel.h
@@ -0,0 +1,152 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SimpleChannel_h
+#define SimpleChannel_h
+
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/UniquePtr.h"
+#include "nsBaseChannel.h"
+#include "nsIChildChannel.h"
+#include "mozilla/net/PSimpleChannelChild.h"
+#include "nsCOMPtr.h"
+
+class nsIChannel;
+class nsIInputStream;
+class nsILoadInfo;
+class nsIRequest;
+class nsIStreamListener;
+class nsIURI;
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+
+using InputStreamOrReason = Result<nsCOMPtr<nsIInputStream>, nsresult>;
+using NotNullRequest = NotNull<nsCOMPtr<nsIRequest>>;
+using NotNullCancelable = NotNull<nsCOMPtr<nsICancelable>>;
+using RequestOrCancelable = Variant<NotNullRequest, NotNullCancelable>;
+using RequestOrReason = Result<RequestOrCancelable, nsresult>;
+
+namespace net {
+
+class SimpleChannelCallbacks {
+ public:
+  virtual InputStreamOrReason OpenContentStream(bool async,
+                                                nsIChannel* channel) = 0;
+
+  virtual RequestOrReason StartAsyncRead(nsIStreamListener* stream,
+                                         nsIChannel* channel) = 0;
+
+  virtual ~SimpleChannelCallbacks() = default;
+};
+
+template <typename F1, typename F2, typename T>
+class SimpleChannelCallbacksImpl final : public SimpleChannelCallbacks {
+ public:
+  SimpleChannelCallbacksImpl(F1&& aStartAsyncRead, F2&& aOpenContentStream,
+                             T* context)
+      : mStartAsyncRead(aStartAsyncRead),
+        mOpenContentStream(aOpenContentStream),
+        mContext(context) {}
+
+  virtual ~SimpleChannelCallbacksImpl() = default;
+
+  virtual InputStreamOrReason OpenContentStream(bool async,
+                                                nsIChannel* channel) override {
+    return mOpenContentStream(async, channel, mContext);
+  }
+
+  virtual RequestOrReason StartAsyncRead(nsIStreamListener* listener,
+                                         nsIChannel* channel) override {
+    return mStartAsyncRead(listener, channel, mContext);
+  }
+
+ private:
+  F1 mStartAsyncRead;
+  F2 mOpenContentStream;
+  RefPtr<T> mContext;
+};
+
+class SimpleChannel : public nsBaseChannel {
+ public:
+  explicit SimpleChannel(UniquePtr<SimpleChannelCallbacks>&& aCallbacks);
+
+ protected:
+  virtual ~SimpleChannel() = default;
+
+  virtual nsresult OpenContentStream(bool async, nsIInputStream** streamOut,
+                                     nsIChannel** channel) override;
+
+  virtual nsresult BeginAsyncRead(nsIStreamListener* listener,
+                                  nsIRequest** request,
+                                  nsICancelable** cancelableRequest) override;
+
+ private:
+  UniquePtr<SimpleChannelCallbacks> mCallbacks;
+};
+
+class SimpleChannelChild final : public SimpleChannel,
+                                 public nsIChildChannel,
+                                 public PSimpleChannelChild {
+ public:
+  explicit SimpleChannelChild(UniquePtr<SimpleChannelCallbacks>&& aCallbacks);
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSICHILDCHANNEL
+
+ private:
+  virtual ~SimpleChannelChild() = default;
+};
+
+already_AddRefed<nsIChannel> NS_NewSimpleChannelInternal(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo,
+    UniquePtr<SimpleChannelCallbacks>&& aCallbacks);
+
+}  // namespace net
+}  // namespace mozilla
+
+/**
+ * Creates a simple channel which wraps an input stream created by the given
+ * callbacks. The callbacks are not called until the underlying AsyncOpen or
+ * Open methods are called, and correspond to the nsBaseChannel::StartAsyncRead
+ * and nsBaseChannel::OpenContentStream methods of the same names.
+ *
+ * The last two arguments of each callback are the created channel instance,
+ * and the ref-counted context object passed to NS_NewSimpleChannel. A strong
+ * reference to that object is guaranteed to be kept alive until after a
+ * callback successfully completes.
+ */
+template <typename T, typename F1, typename F2>
+inline already_AddRefed<nsIChannel> NS_NewSimpleChannel(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo, T* context, F1&& aStartAsyncRead,
+    F2&& aOpenContentStream) {
+  using namespace mozilla;
+
+  auto callbacks = MakeUnique<net::SimpleChannelCallbacksImpl<F1, F2, T>>(
+      std::forward<F1>(aStartAsyncRead), std::forward<F2>(aOpenContentStream),
+      context);
+
+  return net::NS_NewSimpleChannelInternal(aURI, aLoadInfo,
+                                          std::move(callbacks));
+}
+
+template <typename T, typename F1>
+inline already_AddRefed<nsIChannel> NS_NewSimpleChannel(nsIURI* aURI,
+                                                        nsILoadInfo* aLoadInfo,
+                                                        T* context,
+                                                        F1&& aStartAsyncRead) {
+  using namespace mozilla;
+
+  auto openContentStream = [](bool async, nsIChannel* channel, T* context) {
+    return Err(NS_ERROR_NOT_IMPLEMENTED);
+  };
+
+  return NS_NewSimpleChannel(aURI, aLoadInfo, context,
+                             std::forward<F1>(aStartAsyncRead),
+                             std::move(openContentStream));
+}
+
+#endif  // SimpleChannel_h
diff --git a/netwerk/base/SimpleChannelParent.cpp b/netwerk/base/SimpleChannelParent.cpp
new file mode 100644
index 0000000000..3a58e14843
--- /dev/null
+++ b/netwerk/base/SimpleChannelParent.cpp
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=4 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SimpleChannelParent.h"
+#include "mozilla/Assertions.h"
+#include "nsNetUtil.h"
+#include "nsIChannel.h"
+
+#ifdef FUZZING_SNAPSHOT
+#  define MOZ_ALWAYS_SUCCEEDS_FUZZING(...) (void)__VA_ARGS__
+#else
+#  define MOZ_ALWAYS_SUCCEEDS_FUZZING(...) MOZ_ALWAYS_SUCCEEDS(__VA_ARGS__)
+#endif
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(SimpleChannelParent, nsIParentChannel, nsIStreamListener)
+
+bool SimpleChannelParent::Init(const uint64_t& aChannelId) {
+  nsCOMPtr<nsIChannel> channel;
+
+  MOZ_ALWAYS_SUCCEEDS_FUZZING(
+      NS_LinkRedirectChannels(aChannelId, this, getter_AddRefs(channel)));
+
+  return true;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::SetParentListener(ParentChannelListener* aListener) {
+  // Nothing to do.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::NotifyClassificationFlags(uint32_t aClassificationFlags,
+                                               bool aIsThirdParty) {
+  // Nothing to do.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::SetClassifierMatchedInfo(const nsACString& aList,
+                                              const nsACString& aProvider,
+                                              const nsACString& aPrefix) {
+  // nothing to do
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::SetClassifierMatchedTrackingInfo(
+    const nsACString& aLists, const nsACString& aFullHashes) {
+  // nothing to do
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::Delete() {
+  // Nothing to do.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::GetRemoteType(nsACString& aRemoteType) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+void SimpleChannelParent::ActorDestroy(ActorDestroyReason aWhy) {}
+
+NS_IMETHODIMP
+SimpleChannelParent::OnStartRequest(nsIRequest* aRequest) {
+  // We don't have a way to prevent nsBaseChannel from calling AsyncOpen on
+  // the created nsSimpleChannel. We don't have anywhere to send the data in the
+  // parent, so abort the binding.
+  return NS_BINDING_ABORTED;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
+  // See above.
+  MOZ_ASSERT(NS_FAILED(aStatusCode));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SimpleChannelParent::OnDataAvailable(nsIRequest* aRequest,
+                                     nsIInputStream* aInputStream,
+                                     uint64_t aOffset, uint32_t aCount) {
+  // See above.
+  MOZ_CRASH("Should never be called");
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/SimpleChannelParent.h b/netwerk/base/SimpleChannelParent.h
new file mode 100644
index 0000000000..6a8f2c867b
--- /dev/null
+++ b/netwerk/base/SimpleChannelParent.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=4 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NS_SIMPLECHANNELPARENT_H
+#define NS_SIMPLECHANNELPARENT_H
+
+#include "nsIParentChannel.h"
+#include "nsISupportsImpl.h"
+
+#include "mozilla/net/PSimpleChannelParent.h"
+
+namespace mozilla {
+namespace net {
+
+// In order to support HTTP redirects, we need to implement the HTTP
+// redirection API, which requires a class that implements nsIParentChannel
+// and which calls NS_LinkRedirectChannels.
+class SimpleChannelParent : public nsIParentChannel,
+                            public PSimpleChannelParent {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIPARENTCHANNEL
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER;  // semicolon for clang-format bug 1629756
+
+  [[nodiscard]] bool Init(const uint64_t& aChannelId);
+
+ private:
+  ~SimpleChannelParent() = default;
+
+  virtual void ActorDestroy(ActorDestroyReason why) override;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif /* NS_SIMPLECHANNELPARENT_H */
diff --git a/netwerk/base/TLSServerSocket.cpp b/netwerk/base/TLSServerSocket.cpp
new file mode 100644
index 0000000000..131ea50573
--- /dev/null
+++ b/netwerk/base/TLSServerSocket.cpp
@@ -0,0 +1,446 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TLSServerSocket.h"
+
+#include "mozilla/net/DNS.h"
+#include "nsComponentManagerUtils.h"
+#include "nsDependentSubstring.h"
+#include "nsIServerSocket.h"
+#include "nsIX509Cert.h"
+#include "nsIX509CertDB.h"
+#include "nsNetCID.h"
+#include "nsProxyRelease.h"
+#include "nsServiceManagerUtils.h"
+#include "nsSocketTransport2.h"
+#include "nsThreadUtils.h"
+#include "ScopedNSSTypes.h"
+#include "ssl.h"
+
+namespace mozilla {
+namespace net {
+
+//-----------------------------------------------------------------------------
+// TLSServerSocket
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS_INHERITED(TLSServerSocket, nsServerSocket, nsITLSServerSocket)
+
+nsresult TLSServerSocket::SetSocketDefaults() {
+  // Set TLS options on the listening socket
+  mFD = SSL_ImportFD(nullptr, mFD);
+  if (NS_WARN_IF(!mFD)) {
+    return mozilla::psm::GetXPCOMFromNSSError(PR_GetError());
+  }
+
+  SSL_OptionSet(mFD, SSL_SECURITY, true);
+  SSL_OptionSet(mFD, SSL_HANDSHAKE_AS_CLIENT, false);
+  SSL_OptionSet(mFD, SSL_HANDSHAKE_AS_SERVER, true);
+  SSL_OptionSet(mFD, SSL_NO_CACHE, true);
+
+  // We don't currently notify the server API consumer of renegotiation events
+  // (to revalidate peer certs, etc.), so disable it for now.
+  SSL_OptionSet(mFD, SSL_ENABLE_RENEGOTIATION, SSL_RENEGOTIATE_NEVER);
+
+  SetSessionTickets(true);
+  SetRequestClientCertificate(REQUEST_NEVER);
+
+  return NS_OK;
+}
+
+void TLSServerSocket::CreateClientTransport(PRFileDesc* aClientFD,
+                                            const NetAddr& aClientAddr) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  nsresult rv;
+
+  RefPtr<nsSocketTransport> trans = new nsSocketTransport;
+  if (NS_WARN_IF(!trans)) {
+    mCondition = NS_ERROR_OUT_OF_MEMORY;
+    return;
+  }
+
+  RefPtr<TLSServerConnectionInfo> info = new TLSServerConnectionInfo();
+  info->mServerSocket = this;
+  info->mTransport = trans;
+  nsCOMPtr<nsIInterfaceRequestor> infoInterfaceRequestor(info);
+  rv = trans->InitWithConnectedSocket(aClientFD, &aClientAddr,
+                                      infoInterfaceRequestor);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    mCondition = rv;
+    return;
+  }
+
+  // Override the default peer certificate validation, so that server consumers
+  // can make their own choice after the handshake completes.
+  SSL_AuthCertificateHook(aClientFD, AuthCertificateHook, nullptr);
+  // Once the TLS handshake has completed, the server consumer is notified and
+  // has access to various TLS state details.
+  // It's safe to pass info here because the socket transport holds it as
+  // |mSecInfo| which keeps it alive for the lifetime of the socket.
+  SSL_HandshakeCallback(aClientFD, TLSServerConnectionInfo::HandshakeCallback,
+                        info);
+
+  // Notify the consumer of the new client so it can manage the streams.
+  // Security details aren't known yet.  The security observer will be notified
+  // later when they are ready.
+  nsCOMPtr<nsIServerSocket> serverSocket =
+      do_QueryInterface(NS_ISUPPORTS_CAST(nsITLSServerSocket*, this));
+  mListener->OnSocketAccepted(serverSocket, trans);
+}
+
+nsresult TLSServerSocket::OnSocketListen() {
+  if (NS_WARN_IF(!mServerCert)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  UniqueCERTCertificate cert(mServerCert->GetCert());
+  if (NS_WARN_IF(!cert)) {
+    return mozilla::psm::GetXPCOMFromNSSError(PR_GetError());
+  }
+
+  UniqueSECKEYPrivateKey key(PK11_FindKeyByAnyCert(cert.get(), nullptr));
+  if (NS_WARN_IF(!key)) {
+    return mozilla::psm::GetXPCOMFromNSSError(PR_GetError());
+  }
+
+  SSLKEAType certKEA = NSS_FindCertKEAType(cert.get());
+
+  nsresult rv =
+      MapSECStatus(SSL_ConfigSecureServer(mFD, cert.get(), key.get(), certKEA));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+// static
+SECStatus TLSServerSocket::AuthCertificateHook(void* arg, PRFileDesc* fd,
+                                               PRBool checksig,
+                                               PRBool isServer) {
+  // Allow any client cert here, server consumer code can decide whether it's
+  // okay after being notified of the new client socket.
+  return SECSuccess;
+}
+
+//-----------------------------------------------------------------------------
+// TLSServerSocket::nsITLSServerSocket
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+TLSServerSocket::GetServerCert(nsIX509Cert** aCert) {
+  if (NS_WARN_IF(!aCert)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aCert = do_AddRef(mServerCert).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerSocket::SetServerCert(nsIX509Cert* aCert) {
+  // If AsyncListen was already called (and set mListener), it's too late to set
+  // this.
+  if (NS_WARN_IF(mListener)) {
+    return NS_ERROR_IN_PROGRESS;
+  }
+  mServerCert = aCert;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerSocket::SetSessionTickets(bool aEnabled) {
+  // If AsyncListen was already called (and set mListener), it's too late to set
+  // this.
+  if (NS_WARN_IF(mListener)) {
+    return NS_ERROR_IN_PROGRESS;
+  }
+  SSL_OptionSet(mFD, SSL_ENABLE_SESSION_TICKETS, aEnabled);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerSocket::SetRequestClientCertificate(uint32_t aMode) {
+  // If AsyncListen was already called (and set mListener), it's too late to set
+  // this.
+  if (NS_WARN_IF(mListener)) {
+    return NS_ERROR_IN_PROGRESS;
+  }
+  SSL_OptionSet(mFD, SSL_REQUEST_CERTIFICATE, aMode != REQUEST_NEVER);
+
+  switch (aMode) {
+    case REQUEST_ALWAYS:
+      SSL_OptionSet(mFD, SSL_REQUIRE_CERTIFICATE, SSL_REQUIRE_NO_ERROR);
+      break;
+    case REQUIRE_FIRST_HANDSHAKE:
+      SSL_OptionSet(mFD, SSL_REQUIRE_CERTIFICATE, SSL_REQUIRE_FIRST_HANDSHAKE);
+      break;
+    case REQUIRE_ALWAYS:
+      SSL_OptionSet(mFD, SSL_REQUIRE_CERTIFICATE, SSL_REQUIRE_ALWAYS);
+      break;
+    default:
+      SSL_OptionSet(mFD, SSL_REQUIRE_CERTIFICATE, SSL_REQUIRE_NEVER);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerSocket::SetVersionRange(uint16_t aMinVersion, uint16_t aMaxVersion) {
+  // If AsyncListen was already called (and set mListener), it's too late to set
+  // this.
+  if (NS_WARN_IF(mListener)) {
+    return NS_ERROR_IN_PROGRESS;
+  }
+
+  SSLVersionRange range = {aMinVersion, aMaxVersion};
+  if (SSL_VersionRangeSet(mFD, &range) != SECSuccess) {
+    return mozilla::psm::GetXPCOMFromNSSError(PR_GetError());
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// TLSServerConnectionInfo
+//-----------------------------------------------------------------------------
+
+namespace {
+
+class TLSServerSecurityObserverProxy final
+    : public nsITLSServerSecurityObserver {
+  ~TLSServerSecurityObserverProxy() = default;
+
+ public:
+  explicit TLSServerSecurityObserverProxy(
+      nsITLSServerSecurityObserver* aListener)
+      : mListener(new nsMainThreadPtrHolder<nsITLSServerSecurityObserver>(
+            "TLSServerSecurityObserverProxy::mListener", aListener)) {}
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITLSSERVERSECURITYOBSERVER
+
+  class OnHandshakeDoneRunnable : public Runnable {
+   public:
+    OnHandshakeDoneRunnable(
+        const nsMainThreadPtrHandle<nsITLSServerSecurityObserver>& aListener,
+        nsITLSServerSocket* aServer, nsITLSClientStatus* aStatus)
+        : Runnable(
+              "net::TLSServerSecurityObserverProxy::OnHandshakeDoneRunnable"),
+          mListener(aListener),
+          mServer(aServer),
+          mStatus(aStatus) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsMainThreadPtrHandle<nsITLSServerSecurityObserver> mListener;
+    nsCOMPtr<nsITLSServerSocket> mServer;
+    nsCOMPtr<nsITLSClientStatus> mStatus;
+  };
+
+ private:
+  nsMainThreadPtrHandle<nsITLSServerSecurityObserver> mListener;
+};
+
+NS_IMPL_ISUPPORTS(TLSServerSecurityObserverProxy, nsITLSServerSecurityObserver)
+
+NS_IMETHODIMP
+TLSServerSecurityObserverProxy::OnHandshakeDone(nsITLSServerSocket* aServer,
+                                                nsITLSClientStatus* aStatus) {
+  RefPtr<OnHandshakeDoneRunnable> r =
+      new OnHandshakeDoneRunnable(mListener, aServer, aStatus);
+  return NS_DispatchToMainThread(r);
+}
+
+NS_IMETHODIMP
+TLSServerSecurityObserverProxy::OnHandshakeDoneRunnable::Run() {
+  mListener->OnHandshakeDone(mServer, mStatus);
+  return NS_OK;
+}
+
+}  // namespace
+
+NS_IMPL_ISUPPORTS(TLSServerConnectionInfo, nsITLSServerConnectionInfo,
+                  nsITLSClientStatus, nsIInterfaceRequestor)
+
+TLSServerConnectionInfo::~TLSServerConnectionInfo() {
+  RefPtr<nsITLSServerSecurityObserver> observer;
+  {
+    MutexAutoLock lock(mLock);
+    observer = ToRefPtr(std::move(mSecurityObserver));
+  }
+
+  if (observer) {
+    NS_ReleaseOnMainThread("TLSServerConnectionInfo::mSecurityObserver",
+                           observer.forget());
+  }
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::SetSecurityObserver(
+    nsITLSServerSecurityObserver* aObserver) {
+  {
+    MutexAutoLock lock(mLock);
+    if (!aObserver) {
+      mSecurityObserver = nullptr;
+      return NS_OK;
+    }
+
+    mSecurityObserver = new TLSServerSecurityObserverProxy(aObserver);
+    // Call `OnHandshakeDone` if TLS handshake is already completed.
+    if (mTlsVersionUsed != TLS_VERSION_UNKNOWN) {
+      nsCOMPtr<nsITLSServerSocket> serverSocket;
+      GetServerSocket(getter_AddRefs(serverSocket));
+      mSecurityObserver->OnHandshakeDone(serverSocket, this);
+      mSecurityObserver = nullptr;
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetServerSocket(nsITLSServerSocket** aSocket) {
+  if (NS_WARN_IF(!aSocket)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aSocket = do_AddRef(mServerSocket).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetStatus(nsITLSClientStatus** aStatus) {
+  if (NS_WARN_IF(!aStatus)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aStatus = do_AddRef(this).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetPeerCert(nsIX509Cert** aCert) {
+  if (NS_WARN_IF(!aCert)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aCert = do_AddRef(mPeerCert).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetTlsVersionUsed(int16_t* aTlsVersionUsed) {
+  if (NS_WARN_IF(!aTlsVersionUsed)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aTlsVersionUsed = mTlsVersionUsed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetCipherName(nsACString& aCipherName) {
+  aCipherName.Assign(mCipherName);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetKeyLength(uint32_t* aKeyLength) {
+  if (NS_WARN_IF(!aKeyLength)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aKeyLength = mKeyLength;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetMacLength(uint32_t* aMacLength) {
+  if (NS_WARN_IF(!aMacLength)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  *aMacLength = mMacLength;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TLSServerConnectionInfo::GetInterface(const nsIID& aIID, void** aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = nullptr;
+
+  if (aIID.Equals(NS_GET_IID(nsITLSServerConnectionInfo))) {
+    *aResult = static_cast<nsITLSServerConnectionInfo*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+
+  return NS_NOINTERFACE;
+}
+
+// static
+void TLSServerConnectionInfo::HandshakeCallback(PRFileDesc* aFD, void* aArg) {
+  RefPtr<TLSServerConnectionInfo> info =
+      static_cast<TLSServerConnectionInfo*>(aArg);
+  nsISocketTransport* transport = info->mTransport;
+  // No longer needed outside this function, so clear the weak ref
+  info->mTransport = nullptr;
+  nsresult rv = info->HandshakeCallback(aFD);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    transport->Close(rv);
+  }
+}
+
+nsresult TLSServerConnectionInfo::HandshakeCallback(PRFileDesc* aFD) {
+  nsresult rv;
+
+  UniqueCERTCertificate clientCert(SSL_PeerCertificate(aFD));
+  if (clientCert) {
+    nsCOMPtr<nsIX509CertDB> certDB =
+        do_GetService(NS_X509CERTDB_CONTRACTID, &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    nsCOMPtr<nsIX509Cert> clientCertPSM;
+    nsTArray<uint8_t> clientCertBytes;
+    clientCertBytes.AppendElements(clientCert->derCert.data,
+                                   clientCert->derCert.len);
+    rv = certDB->ConstructX509(clientCertBytes, getter_AddRefs(clientCertPSM));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    mPeerCert = clientCertPSM;
+  }
+
+  SSLChannelInfo channelInfo;
+  rv = MapSECStatus(SSL_GetChannelInfo(aFD, &channelInfo, sizeof(channelInfo)));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  SSLCipherSuiteInfo cipherInfo;
+  rv = MapSECStatus(SSL_GetCipherSuiteInfo(channelInfo.cipherSuite, &cipherInfo,
+                                           sizeof(cipherInfo)));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mCipherName.Assign(cipherInfo.cipherSuiteName);
+  mKeyLength = cipherInfo.effectiveKeyBits;
+  mMacLength = cipherInfo.macBits;
+
+  // Notify consumer code that handshake is complete
+  nsCOMPtr<nsITLSServerSecurityObserver> observer;
+  {
+    MutexAutoLock lock(mLock);
+    mTlsVersionUsed = channelInfo.protocolVersion;
+    if (!mSecurityObserver) {
+      return NS_OK;
+    }
+    mSecurityObserver.swap(observer);
+  }
+  nsCOMPtr<nsITLSServerSocket> serverSocket;
+  GetServerSocket(getter_AddRefs(serverSocket));
+  observer->OnHandshakeDone(serverSocket, this);
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/TLSServerSocket.h b/netwerk/base/TLSServerSocket.h
new file mode 100644
index 0000000000..c8f4380d46
--- /dev/null
+++ b/netwerk/base/TLSServerSocket.h
@@ -0,0 +1,81 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_TLSServerSocket_h
+#define mozilla_net_TLSServerSocket_h
+
+#include "nsIInterfaceRequestor.h"
+#include "nsITLSServerSocket.h"
+#include "nsServerSocket.h"
+#include "nsString.h"
+#include "mozilla/Mutex.h"
+#include "seccomon.h"
+
+namespace mozilla {
+namespace net {
+
+class TLSServerSocket final : public nsServerSocket, public nsITLSServerSocket {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_FORWARD_NSISERVERSOCKET(nsServerSocket::)
+  NS_DECL_NSITLSSERVERSOCKET
+
+  // Override methods from nsServerSocket
+  virtual void CreateClientTransport(PRFileDesc* clientFD,
+                                     const NetAddr& clientAddr) override;
+  virtual nsresult SetSocketDefaults() override;
+  virtual nsresult OnSocketListen() override;
+
+  TLSServerSocket() = default;
+
+ private:
+  virtual ~TLSServerSocket() = default;
+
+  static SECStatus AuthCertificateHook(void* arg, PRFileDesc* fd,
+                                       PRBool checksig, PRBool isServer);
+
+  nsCOMPtr<nsIX509Cert> mServerCert;
+};
+
+class TLSServerConnectionInfo : public nsITLSServerConnectionInfo,
+                                public nsITLSClientStatus,
+                                public nsIInterfaceRequestor {
+  friend class TLSServerSocket;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITLSSERVERCONNECTIONINFO
+  NS_DECL_NSITLSCLIENTSTATUS
+  NS_DECL_NSIINTERFACEREQUESTOR
+
+  TLSServerConnectionInfo() = default;
+
+ private:
+  virtual ~TLSServerConnectionInfo();
+
+  static void HandshakeCallback(PRFileDesc* aFD, void* aArg);
+  nsresult HandshakeCallback(PRFileDesc* aFD);
+
+  RefPtr<TLSServerSocket> mServerSocket;
+  // Weak ref to the transport, to avoid cycles since the transport holds a
+  // reference to the TLSServerConnectionInfo object.  This is not handed out to
+  // anyone, and is only used in HandshakeCallback to close the transport in
+  // case of an error.  After this, it's set to nullptr.
+  nsISocketTransport* mTransport{nullptr};
+  nsCOMPtr<nsIX509Cert> mPeerCert;
+  int16_t mTlsVersionUsed{TLS_VERSION_UNKNOWN};
+  nsCString mCipherName;
+  uint32_t mKeyLength{0};
+  uint32_t mMacLength{0};
+  // lock protects access to mSecurityObserver
+  mozilla::Mutex mLock{"TLSServerConnectionInfo.mLock"};
+  nsCOMPtr<nsITLSServerSecurityObserver> mSecurityObserver
+      MOZ_GUARDED_BY(mLock);
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_TLSServerSocket_h
diff --git a/netwerk/base/TRRLoadInfo.cpp b/netwerk/base/TRRLoadInfo.cpp
new file mode 100644
index 0000000000..e5cbe5e213
--- /dev/null
+++ b/netwerk/base/TRRLoadInfo.cpp
@@ -0,0 +1,821 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TRRLoadInfo.h"
+#include "mozilla/dom/ClientSource.h"
+#include "nsContentUtils.h"
+#include "nsIRedirectHistoryEntry.h"
+
+using namespace mozilla::dom;
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(TRRLoadInfo, nsILoadInfo)
+
+TRRLoadInfo::TRRLoadInfo(nsIURI* aResultPrincipalURI,
+                         nsContentPolicyType aContentPolicyType)
+    : mResultPrincipalURI(aResultPrincipalURI),
+      mInternalContentPolicyType(aContentPolicyType) {}
+
+already_AddRefed<nsILoadInfo> TRRLoadInfo::Clone() const {
+  nsCOMPtr<nsILoadInfo> loadInfo =
+      new TRRLoadInfo(mResultPrincipalURI, mInternalContentPolicyType);
+
+  return loadInfo.forget();
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadingPrincipal(nsIPrincipal** aLoadingPrincipal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsIPrincipal* TRRLoadInfo::VirtualGetLoadingPrincipal() { return nullptr; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetTriggeringPrincipal(nsIPrincipal** aTriggeringPrincipal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsIPrincipal* TRRLoadInfo::TriggeringPrincipal() { return nullptr; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetPrincipalToInherit(nsIPrincipal** aPrincipalToInherit) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetPrincipalToInherit(nsIPrincipal* aPrincipalToInherit) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsIPrincipal* TRRLoadInfo::PrincipalToInherit() { return nullptr; }
+
+nsIPrincipal* TRRLoadInfo::FindPrincipalToInherit(nsIChannel* aChannel) {
+  return nullptr;
+}
+
+const nsID& TRRLoadInfo::GetSandboxedNullPrincipalID() {
+  return mSandboxedNullPrincipalID;
+}
+
+void TRRLoadInfo::ResetSandboxedNullPrincipalID() {}
+
+nsIPrincipal* TRRLoadInfo::GetTopLevelPrincipal() { return nullptr; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetTriggeringRemoteType(nsACString& aTriggeringRemoteType) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetTriggeringRemoteType(const nsACString& aTriggeringRemoteType) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadingDocument(Document** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsINode* TRRLoadInfo::LoadingNode() { return nullptr; }
+
+already_AddRefed<nsISupports> TRRLoadInfo::ContextForTopLevelLoad() {
+  return nullptr;
+}
+
+already_AddRefed<nsISupports> TRRLoadInfo::GetLoadingContext() {
+  return nullptr;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadingContextXPCOM(nsISupports** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSecurityFlags(nsSecurityFlags* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSandboxFlags(uint32_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+NS_IMETHODIMP
+TRRLoadInfo::GetTriggeringSandboxFlags(uint32_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+NS_IMETHODIMP
+TRRLoadInfo::SetTriggeringSandboxFlags(uint32_t aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSecurityMode(uint32_t* aFlags) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsInThirdPartyContext(bool* aIsInThirdPartyContext) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsInThirdPartyContext(bool aIsInThirdPartyContext) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsThirdPartyContextToTopWindow(
+    bool* aIsThirdPartyContextToTopWindow) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsThirdPartyContextToTopWindow(
+    bool aIsThirdPartyContextToTopWindow) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetCookiePolicy(uint32_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetCookieJarSettings(nsICookieJarSettings** aCookieJarSettings) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetCookieJarSettings(nsICookieJarSettings* aCookieJarSettings) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetStoragePermission(
+    nsILoadInfo::StoragePermissionState* aHasStoragePermission) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetStoragePermission(
+    nsILoadInfo::StoragePermissionState aHasStoragePermission) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsMetaRefresh(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsMetaRefresh(bool aResult) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetForceInheritPrincipal(bool* aInheritPrincipal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetForceInheritPrincipalOverruleOwner(bool* aInheritPrincipal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadingSandboxed(bool* aLoadingSandboxed) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetAboutBlankInherits(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetAllowChrome(bool* aResult) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetDisallowScript(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetDontFollowRedirects(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadErrorPage(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsFormSubmission(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsFormSubmission(bool aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSendCSPViolationEvents(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetSendCSPViolationEvents(bool aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetExternalContentPolicyType(nsContentPolicyType* aResult) {
+  // We have to use nsContentPolicyType because ExtContentPolicyType is not
+  // visible from xpidl.
+  *aResult = static_cast<nsContentPolicyType>(
+      nsContentUtils::InternalContentPolicyTypeToExternal(
+          mInternalContentPolicyType));
+  return NS_OK;
+}
+
+nsContentPolicyType TRRLoadInfo::InternalContentPolicyType() {
+  return mInternalContentPolicyType;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBlockAllMixedContent(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetUpgradeInsecureRequests(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBrowserUpgradeInsecureRequests(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBrowserDidUpgradeInsecureRequests(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetBrowserDidUpgradeInsecureRequests(
+    bool aBrowserDidUpgradeInsecureRequests) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBrowserWouldUpgradeInsecureRequests(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetForceAllowDataURI(bool aForceAllowDataURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetForceAllowDataURI(bool* aForceAllowDataURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetAllowInsecureRedirectToDataURI(
+    bool aAllowInsecureRedirectToDataURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetAllowInsecureRedirectToDataURI(
+    bool* aAllowInsecureRedirectToDataURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetSkipContentPolicyCheckForWebRequest(bool aSkip) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSkipContentPolicyCheckForWebRequest(bool* aSkip) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetOriginalFrameSrcLoad(bool aOriginalFrameSrcLoad) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetOriginalFrameSrcLoad(bool* aOriginalFrameSrcLoad) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetForceInheritPrincipalDropped(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetInnerWindowID(uint64_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBrowsingContextID(uint64_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetWorkerAssociatedBrowsingContextID(uint64_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetWorkerAssociatedBrowsingContextID(uint64_t aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetFrameBrowsingContextID(uint64_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetTargetBrowsingContextID(uint64_t* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetBrowsingContext(dom::BrowsingContext** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetWorkerAssociatedBrowsingContext(
+    dom::BrowsingContext** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetFrameBrowsingContext(dom::BrowsingContext** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetTargetBrowsingContext(dom::BrowsingContext** aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetScriptableOriginAttributes(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aOriginAttributes) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::ResetPrincipalToInheritToNullPrincipal() {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetScriptableOriginAttributes(
+    JSContext* aCx, JS::Handle<JS::Value> aOriginAttributes) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult TRRLoadInfo::GetOriginAttributes(
+    mozilla::OriginAttributes* aOriginAttributes) {
+  NS_ENSURE_ARG(aOriginAttributes);
+  *aOriginAttributes = mOriginAttributes;
+  return NS_OK;
+}
+
+nsresult TRRLoadInfo::SetOriginAttributes(
+    const mozilla::OriginAttributes& aOriginAttributes) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetInitialSecurityCheckDone(bool aInitialSecurityCheckDone) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetInitialSecurityCheckDone(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::AppendRedirectHistoryEntry(nsIChannel* aChannelToDeriveFrom,
+                                        bool aIsInternalRedirect) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetRedirectChainIncludingInternalRedirects(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aChain) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+const nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>&
+TRRLoadInfo::RedirectChainIncludingInternalRedirects() {
+  return mEmptyRedirectChain;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetRedirectChain(JSContext* aCx,
+                              JS::MutableHandle<JS::Value> aChain) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+const nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>&
+TRRLoadInfo::RedirectChain() {
+  return mEmptyRedirectChain;
+}
+
+const nsTArray<nsCOMPtr<nsIPrincipal>>& TRRLoadInfo::AncestorPrincipals() {
+  return mEmptyPrincipals;
+}
+
+const nsTArray<uint64_t>& TRRLoadInfo::AncestorBrowsingContextIDs() {
+  return mEmptyBrowsingContextIDs;
+}
+
+void TRRLoadInfo::SetCorsPreflightInfo(const nsTArray<nsCString>& aHeaders,
+                                       bool aForcePreflight) {}
+
+const nsTArray<nsCString>& TRRLoadInfo::CorsUnsafeHeaders() {
+  return mCorsUnsafeHeaders;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetForcePreflight(bool* aForcePreflight) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsPreflight(bool* aIsPreflight) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetLoadTriggeredFromExternal(bool aLoadTriggeredFromExternal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadTriggeredFromExternal(bool* aLoadTriggeredFromExternal) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetServiceWorkerTaintingSynthesized(
+    bool* aServiceWorkerTaintingSynthesized) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetTainting(uint32_t* aTaintingOut) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::MaybeIncreaseTainting(uint32_t aTainting) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+void TRRLoadInfo::SynthesizeServiceWorkerTainting(LoadTainting aTainting) {}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetDocumentHasUserInteracted(bool* aDocumentHasUserInteracted) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetDocumentHasUserInteracted(bool aDocumentHasUserInteracted) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetAllowListFutureDocumentsCreatedFromThisRedirectChain(
+    bool* aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetAllowListFutureDocumentsCreatedFromThisRedirectChain(
+    bool aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetNeedForCheckingAntiTrackingHeuristic(bool* aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetNeedForCheckingAntiTrackingHeuristic(bool aValue) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetCspNonce(nsAString& aCspNonce) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetCspNonce(const nsAString& aCspNonce) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetSkipContentSniffing(bool* aSkipContentSniffing) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetSkipContentSniffing(bool aSkipContentSniffing) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsTopLevelLoad(bool* aResult) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsFromProcessingFrameAttributes(
+    bool* aIsFromProcessingFrameAttributes) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsMediaRequest(bool aIsMediaRequest) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsMediaRequest(bool* aIsMediaRequest) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsMediaInitialRequest(bool aIsMediaInitialRequest) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsMediaInitialRequest(bool* aIsMediaInitialRequest) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsFromObjectOrEmbed(bool aIsFromObjectOrEmbed) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsFromObjectOrEmbed(bool* aIsFromObjectOrEmbed) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetShouldSkipCheckForBrokenURLOrZeroSized(
+    bool* aShouldSkipCheckForBrokenURLOrZeroSized) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetResultPrincipalURI(nsIURI** aURI) {
+  nsCOMPtr<nsIURI> uri = mResultPrincipalURI;
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetResultPrincipalURI(nsIURI* aURI) {
+  mResultPrincipalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetChannelCreationOriginalURI(nsIURI** aURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetChannelCreationOriginalURI(nsIURI* aURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetRequestBlockingReason(uint32_t aReason) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+NS_IMETHODIMP
+TRRLoadInfo::GetRequestBlockingReason(uint32_t* aReason) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+void TRRLoadInfo::SetClientInfo(const ClientInfo& aClientInfo) {}
+
+const Maybe<ClientInfo>& TRRLoadInfo::GetClientInfo() { return mClientInfo; }
+
+void TRRLoadInfo::GiveReservedClientSource(
+    UniquePtr<ClientSource>&& aClientSource) {}
+
+UniquePtr<ClientSource> TRRLoadInfo::TakeReservedClientSource() {
+  return nullptr;
+}
+
+void TRRLoadInfo::SetReservedClientInfo(const ClientInfo& aClientInfo) {}
+
+void TRRLoadInfo::OverrideReservedClientInfoInParent(
+    const ClientInfo& aClientInfo) {}
+
+const Maybe<ClientInfo>& TRRLoadInfo::GetReservedClientInfo() {
+  return mReservedClientInfo;
+}
+
+void TRRLoadInfo::SetInitialClientInfo(const ClientInfo& aClientInfo) {}
+
+const Maybe<ClientInfo>& TRRLoadInfo::GetInitialClientInfo() {
+  return mInitialClientInfo;
+}
+
+void TRRLoadInfo::SetController(const ServiceWorkerDescriptor& aServiceWorker) {
+}
+
+void TRRLoadInfo::ClearController() {}
+
+const Maybe<ServiceWorkerDescriptor>& TRRLoadInfo::GetController() {
+  return mController;
+}
+
+void TRRLoadInfo::SetPerformanceStorage(
+    PerformanceStorage* aPerformanceStorage) {}
+
+PerformanceStorage* TRRLoadInfo::GetPerformanceStorage() { return nullptr; }
+
+NS_IMETHODIMP
+TRRLoadInfo::GetCspEventListener(nsICSPEventListener** aCSPEventListener) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetCspEventListener(nsICSPEventListener* aCSPEventListener) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+already_AddRefed<nsIContentSecurityPolicy> TRRLoadInfo::GetCsp() {
+  return nullptr;
+}
+
+already_AddRefed<nsIContentSecurityPolicy> TRRLoadInfo::GetPreloadCsp() {
+  return nullptr;
+}
+
+already_AddRefed<nsIContentSecurityPolicy> TRRLoadInfo::GetCspToInherit() {
+  return nullptr;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetHttpsOnlyStatus(uint32_t* aHttpsOnlyStatus) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetHttpsOnlyStatus(uint32_t aHttpsOnlyStatus) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetHstsStatus(bool* aHstsStatus) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetHstsStatus(bool aHstsStatus) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetHasValidUserGestureActivation(
+    bool* aHasValidUserGestureActivation) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetHasValidUserGestureActivation(
+    bool aHasValidUserGestureActivation) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetInternalContentPolicyType(nsContentPolicyType* aResult) {
+  *aResult = mInternalContentPolicyType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetAllowDeprecatedSystemRequests(
+    bool* aAllowDeprecatedSystemRequests) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetAllowDeprecatedSystemRequests(
+    bool aAllowDeprecatedSystemRequests) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsUserTriggeredSave(bool* aIsUserTriggeredSave) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsUserTriggeredSave(bool aIsUserTriggeredSave) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsInDevToolsContext(bool* aIsInDevToolsContext) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsInDevToolsContext(bool aIsInDevToolsContext) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetParserCreatedScript(bool* aParserCreatedScript) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetParserCreatedScript(bool aParserCreatedScript) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetLoadingEmbedderPolicy(
+    nsILoadInfo::CrossOriginEmbedderPolicy* aOutPolicy) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetLoadingEmbedderPolicy(
+    nsILoadInfo::CrossOriginEmbedderPolicy aPolicy) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+    bool* aIsOriginTrialCoepCredentiallessEnabledForTopLevel) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetIsOriginTrialCoepCredentiallessEnabledForTopLevel(
+    bool aIsOriginTrialCoepCredentiallessEnabledForTopLevel) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetUnstrippedURI(nsIURI** aURI) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetUnstrippedURI(nsIURI* aURI) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+nsIInterceptionInfo* TRRLoadInfo::InterceptionInfo() { return nullptr; }
+void TRRLoadInfo::SetInterceptionInfo(nsIInterceptionInfo* aPrincipla) {}
+
+NS_IMETHODIMP
+TRRLoadInfo::GetHasInjectedCookieForCookieBannerHandling(
+    bool* aHasInjectedCookieForCookieBannerHandling) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+TRRLoadInfo::SetHasInjectedCookieForCookieBannerHandling(
+    bool aHasInjectedCookieForCookieBannerHandling) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/TRRLoadInfo.h b/netwerk/base/TRRLoadInfo.h
new file mode 100644
index 0000000000..a19c86601e
--- /dev/null
+++ b/netwerk/base/TRRLoadInfo.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_TRRLoadInfo_h
+#define mozilla_TRRLoadInfo_h
+
+#include "nsILoadInfo.h"
+#include "nsIURI.h"
+#include "nsTArray.h"
+#include "mozilla/dom/ClientInfo.h"
+#include "mozilla/dom/ServiceWorkerDescriptor.h"
+#include "mozilla/OriginAttributes.h"
+
+namespace mozilla {
+namespace net {
+
+// TRRLoadInfo is designed to be used by TRRServiceChannel only. Most of
+// nsILoadInfo functions are not implemented since TRRLoadInfo needs to
+// support off main thread.
+class TRRLoadInfo final : public nsILoadInfo {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSILOADINFO
+
+  TRRLoadInfo(nsIURI* aResultPrincipalURI,
+              nsContentPolicyType aContentPolicyType);
+
+  already_AddRefed<nsILoadInfo> Clone() const;
+
+ private:
+  virtual ~TRRLoadInfo() = default;
+
+  nsCOMPtr<nsIURI> mResultPrincipalURI;
+  nsContentPolicyType mInternalContentPolicyType;
+  OriginAttributes mOriginAttributes;
+  nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>> mEmptyRedirectChain;
+  nsTArray<nsCOMPtr<nsIPrincipal>> mEmptyPrincipals;
+  nsTArray<uint64_t> mEmptyBrowsingContextIDs;
+  nsTArray<nsCString> mCorsUnsafeHeaders;
+  nsID mSandboxedNullPrincipalID;
+  Maybe<mozilla::dom::ClientInfo> mClientInfo;
+  Maybe<mozilla::dom::ClientInfo> mReservedClientInfo;
+  Maybe<mozilla::dom::ClientInfo> mInitialClientInfo;
+  Maybe<mozilla::dom::ServiceWorkerDescriptor> mController;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_TRRLoadInfo_h
diff --git a/netwerk/base/ThrottleQueue.cpp b/netwerk/base/ThrottleQueue.cpp
new file mode 100644
index 0000000000..4313a6ecb3
--- /dev/null
+++ b/netwerk/base/ThrottleQueue.cpp
@@ -0,0 +1,410 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ThrottleQueue.h"
+#include "mozilla/net/InputChannelThrottleQueueParent.h"
+#include "nsISeekableStream.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIOService.h"
+#include "nsSocketTransportService2.h"
+#include "nsStreamUtils.h"
+#include "nsNetUtil.h"
+
+namespace mozilla {
+namespace net {
+
+//-----------------------------------------------------------------------------
+
+class ThrottleInputStream final : public nsIAsyncInputStream,
+                                  public nsISeekableStream {
+ public:
+  ThrottleInputStream(nsIInputStream* aStream, ThrottleQueue* aQueue);
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+
+  void AllowInput();
+
+ private:
+  ~ThrottleInputStream();
+
+  nsCOMPtr<nsIInputStream> mStream;
+  RefPtr<ThrottleQueue> mQueue;
+  nsresult mClosedStatus;
+
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  nsCOMPtr<nsIEventTarget> mEventTarget;
+};
+
+NS_IMPL_ISUPPORTS(ThrottleInputStream, nsIAsyncInputStream, nsIInputStream,
+                  nsITellableStream, nsISeekableStream)
+
+ThrottleInputStream::ThrottleInputStream(nsIInputStream* aStream,
+                                         ThrottleQueue* aQueue)
+    : mStream(aStream), mQueue(aQueue), mClosedStatus(NS_OK) {
+  MOZ_ASSERT(aQueue != nullptr);
+}
+
+ThrottleInputStream::~ThrottleInputStream() { Close(); }
+
+NS_IMETHODIMP
+ThrottleInputStream::Close() {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  if (mQueue) {
+    mQueue->DequeueStream(this);
+    mQueue = nullptr;
+    mClosedStatus = NS_BASE_STREAM_CLOSED;
+  }
+  return mStream->Close();
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::Available(uint64_t* aResult) {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  return mStream->Available(aResult);
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::StreamStatus() {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  return mStream->StreamStatus();
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::Read(char* aBuf, uint32_t aCount, uint32_t* aResult) {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  uint32_t realCount;
+  nsresult rv = mQueue->Available(aCount, &realCount);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (realCount == 0) {
+    return NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  rv = mStream->Read(aBuf, realCount, aResult);
+  if (NS_SUCCEEDED(rv) && *aResult > 0) {
+    mQueue->RecordRead(*aResult);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                                  uint32_t aCount, uint32_t* aResult) {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  uint32_t realCount;
+  nsresult rv = mQueue->Available(aCount, &realCount);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  MOZ_ASSERT(realCount <= aCount);
+
+  if (realCount == 0) {
+    return NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  rv = mStream->ReadSegments(aWriter, aClosure, realCount, aResult);
+  if (NS_SUCCEEDED(rv) && *aResult > 0) {
+    mQueue->RecordRead(*aResult);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::Seek(int32_t aWhence, int64_t aOffset) {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  nsCOMPtr<nsISeekableStream> sstream = do_QueryInterface(mStream);
+  if (!sstream) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return sstream->Seek(aWhence, aOffset);
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::Tell(int64_t* aResult) {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  nsCOMPtr<nsITellableStream> sstream = do_QueryInterface(mStream);
+  if (!sstream) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return sstream->Tell(aResult);
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::SetEOF() {
+  if (NS_FAILED(mClosedStatus)) {
+    return mClosedStatus;
+  }
+
+  nsCOMPtr<nsISeekableStream> sstream = do_QueryInterface(mStream);
+  if (!sstream) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return sstream->SetEOF();
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::CloseWithStatus(nsresult aStatus) {
+  if (NS_FAILED(mClosedStatus)) {
+    // Already closed, ignore.
+    return NS_OK;
+  }
+  if (NS_SUCCEEDED(aStatus)) {
+    aStatus = NS_BASE_STREAM_CLOSED;
+  }
+
+  mClosedStatus = Close();
+  if (NS_SUCCEEDED(mClosedStatus)) {
+    mClosedStatus = aStatus;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleInputStream::AsyncWait(nsIInputStreamCallback* aCallback,
+                               uint32_t aFlags, uint32_t aRequestedCount,
+                               nsIEventTarget* aEventTarget) {
+  if (aFlags != 0) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+
+  mCallback = aCallback;
+  mEventTarget = aEventTarget;
+  if (mCallback) {
+    mQueue->QueueStream(this);
+  } else {
+    mQueue->DequeueStream(this);
+  }
+  return NS_OK;
+}
+
+void ThrottleInputStream::AllowInput() {
+  MOZ_ASSERT(mCallback);
+  nsCOMPtr<nsIInputStreamCallback> callbackEvent = NS_NewInputStreamReadyEvent(
+      "ThrottleInputStream::AllowInput", mCallback, mEventTarget);
+  mCallback = nullptr;
+  mEventTarget = nullptr;
+  callbackEvent->OnInputStreamReady(this);
+}
+
+//-----------------------------------------------------------------------------
+
+// static
+already_AddRefed<nsIInputChannelThrottleQueue> ThrottleQueue::Create() {
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  nsCOMPtr<nsIInputChannelThrottleQueue> tq;
+  if (nsIOService::UseSocketProcess()) {
+    tq = new InputChannelThrottleQueueParent();
+  } else {
+    tq = new ThrottleQueue();
+  }
+
+  return tq.forget();
+}
+
+NS_IMPL_ISUPPORTS(ThrottleQueue, nsIInputChannelThrottleQueue, nsITimerCallback,
+                  nsINamed)
+
+ThrottleQueue::ThrottleQueue()
+
+{
+  nsresult rv;
+  nsCOMPtr<nsIEventTarget> sts;
+  nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
+  if (NS_SUCCEEDED(rv)) {
+    sts = do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
+  }
+  if (NS_SUCCEEDED(rv)) mTimer = NS_NewTimer(sts);
+}
+
+ThrottleQueue::~ThrottleQueue() {
+  if (mTimer && mTimerArmed) {
+    mTimer->Cancel();
+  }
+  mTimer = nullptr;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::RecordRead(uint32_t aBytesRead) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  ThrottleEntry entry;
+  entry.mTime = TimeStamp::Now();
+  entry.mBytesRead = aBytesRead;
+  mReadEvents.AppendElement(entry);
+  mBytesProcessed += aBytesRead;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::Available(uint32_t aRemaining, uint32_t* aAvailable) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  TimeStamp now = TimeStamp::Now();
+  TimeStamp oneSecondAgo = now - TimeDuration::FromSeconds(1);
+  size_t i;
+
+  // Remove all stale events.
+  for (i = 0; i < mReadEvents.Length(); ++i) {
+    if (mReadEvents[i].mTime >= oneSecondAgo) {
+      break;
+    }
+  }
+  mReadEvents.RemoveElementsAt(0, i);
+
+  uint32_t totalBytes = 0;
+  for (i = 0; i < mReadEvents.Length(); ++i) {
+    totalBytes += mReadEvents[i].mBytesRead;
+  }
+
+  uint32_t spread = mMaxBytesPerSecond - mMeanBytesPerSecond;
+  double prob = static_cast<double>(rand()) / RAND_MAX;
+  uint32_t thisSliceBytes =
+      mMeanBytesPerSecond - spread + static_cast<uint32_t>(2 * spread * prob);
+
+  if (totalBytes >= thisSliceBytes) {
+    *aAvailable = 0;
+  } else {
+    *aAvailable = std::min(thisSliceBytes, aRemaining);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::Init(uint32_t aMeanBytesPerSecond, uint32_t aMaxBytesPerSecond) {
+  // Can be called on any thread.
+  if (aMeanBytesPerSecond == 0 || aMaxBytesPerSecond == 0 ||
+      aMaxBytesPerSecond < aMeanBytesPerSecond) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+
+  mMeanBytesPerSecond = aMeanBytesPerSecond;
+  mMaxBytesPerSecond = aMaxBytesPerSecond;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::BytesProcessed(uint64_t* aResult) {
+  *aResult = mBytesProcessed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::WrapStream(nsIInputStream* aInputStream,
+                          nsIAsyncInputStream** aResult) {
+  nsCOMPtr<nsIAsyncInputStream> result =
+      new ThrottleInputStream(aInputStream, this);
+  result.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::Notify(nsITimer* aTimer) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  // A notified reader may need to push itself back on the queue.
+  // Swap out the list of readers so that this works properly.
+  nsTArray<RefPtr<ThrottleInputStream>> events = std::move(mAsyncEvents);
+
+  // Optimistically notify all the waiting readers, and then let them
+  // requeue if there isn't enough bandwidth.
+  for (size_t i = 0; i < events.Length(); ++i) {
+    events[i]->AllowInput();
+  }
+
+  mTimerArmed = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::GetName(nsACString& aName) {
+  aName.AssignLiteral("net::ThrottleQueue");
+  return NS_OK;
+}
+
+void ThrottleQueue::QueueStream(ThrottleInputStream* aStream) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (mAsyncEvents.IndexOf(aStream) ==
+      nsTArray<RefPtr<mozilla::net::ThrottleInputStream>>::NoIndex) {
+    mAsyncEvents.AppendElement(aStream);
+
+    if (!mTimerArmed) {
+      uint32_t ms = 1000;
+      if (mReadEvents.Length() > 0) {
+        TimeStamp t = mReadEvents[0].mTime + TimeDuration::FromSeconds(1);
+        TimeStamp now = TimeStamp::Now();
+
+        if (t > now) {
+          ms = static_cast<uint32_t>((t - now).ToMilliseconds());
+        } else {
+          ms = 1;
+        }
+      }
+
+      if (NS_SUCCEEDED(
+              mTimer->InitWithCallback(this, ms, nsITimer::TYPE_ONE_SHOT))) {
+        mTimerArmed = true;
+      }
+    }
+  }
+}
+
+void ThrottleQueue::DequeueStream(ThrottleInputStream* aStream) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  mAsyncEvents.RemoveElement(aStream);
+}
+
+NS_IMETHODIMP
+ThrottleQueue::GetMeanBytesPerSecond(uint32_t* aMeanBytesPerSecond) {
+  NS_ENSURE_ARG(aMeanBytesPerSecond);
+
+  *aMeanBytesPerSecond = mMeanBytesPerSecond;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ThrottleQueue::GetMaxBytesPerSecond(uint32_t* aMaxBytesPerSecond) {
+  NS_ENSURE_ARG(aMaxBytesPerSecond);
+
+  *aMaxBytesPerSecond = mMaxBytesPerSecond;
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/ThrottleQueue.h b/netwerk/base/ThrottleQueue.h
new file mode 100644
index 0000000000..4d06af8e64
--- /dev/null
+++ b/netwerk/base/ThrottleQueue.h
@@ -0,0 +1,66 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_ThrottleQueue_h
+#define mozilla_net_ThrottleQueue_h
+
+#include "mozilla/TimeStamp.h"
+#include "nsINamed.h"
+#include "nsIThrottledInputChannel.h"
+#include "nsITimer.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace net {
+
+class ThrottleInputStream;
+
+/**
+ * An implementation of nsIInputChannelThrottleQueue that can be used
+ * to throttle uploads.  This class is not thread-safe.
+ * Initialization and calls to WrapStream may be done on any thread;
+ * but otherwise, after creation, it can only be used on the socket
+ * thread.  It currently throttles with a one second granularity, so
+ * may be a bit choppy.
+ */
+
+class ThrottleQueue : public nsIInputChannelThrottleQueue,
+                      public nsITimerCallback,
+                      public nsINamed {
+ public:
+  static already_AddRefed<nsIInputChannelThrottleQueue> Create();
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTCHANNELTHROTTLEQUEUE
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSINAMED
+
+  void QueueStream(ThrottleInputStream* aStream);
+  void DequeueStream(ThrottleInputStream* aStream);
+
+ protected:
+  ThrottleQueue();
+  virtual ~ThrottleQueue();
+
+  struct ThrottleEntry {
+    TimeStamp mTime;
+    uint32_t mBytesRead = 0;
+  };
+
+  nsTArray<ThrottleEntry> mReadEvents;
+  uint32_t mMeanBytesPerSecond{0};
+  uint32_t mMaxBytesPerSecond{0};
+  uint64_t mBytesProcessed{0};
+
+  nsTArray<RefPtr<ThrottleInputStream>> mAsyncEvents;
+  nsCOMPtr<nsITimer> mTimer;
+  bool mTimerArmed{false};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  //  mozilla_net_ThrottleQueue_h
diff --git a/netwerk/base/Tickler.cpp b/netwerk/base/Tickler.cpp
new file mode 100644
index 0000000000..3030b24653
--- /dev/null
+++ b/netwerk/base/Tickler.cpp
@@ -0,0 +1,249 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Tickler.h"
+
+#ifdef MOZ_USE_WIFI_TICKLER
+#  include "nsComponentManagerUtils.h"
+#  include "nsINamed.h"
+#  include "nsServiceManagerUtils.h"
+#  include "nsThreadUtils.h"
+#  include "prnetdb.h"
+
+#  include "mozilla/java/GeckoAppShellWrappers.h"
+#  include "mozilla/jni/Utils.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(Tickler, nsISupportsWeakReference, Tickler)
+
+Tickler::Tickler()
+    : mLock("Tickler::mLock"),
+      mActive(false),
+      mCanceled(false),
+      mEnabled(false),
+      mDelay(16),
+      mDuration(TimeDuration::FromMilliseconds(400)),
+      mFD(nullptr) {
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+Tickler::~Tickler() {
+  // non main thread uses of the tickler should hold weak
+  // references to it if they must hold a reference at all
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (mThread) {
+    mThread->AsyncShutdown();
+    mThread = nullptr;
+  }
+
+  if (mTimer) mTimer->Cancel();
+  if (mFD) PR_Close(mFD);
+}
+
+nsresult Tickler::Init() {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mTimer);
+  MOZ_ASSERT(!mActive);
+  MOZ_ASSERT(!mThread);
+  MOZ_ASSERT(!mFD);
+
+  if (jni::IsAvailable()) {
+    java::GeckoAppShell::EnableNetworkNotifications();
+  }
+
+  mFD = PR_OpenUDPSocket(PR_AF_INET);
+  if (!mFD) return NS_ERROR_FAILURE;
+
+  // make sure new socket has a ttl of 1
+  // failure is not fatal.
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_IpTimeToLive;
+  opt.value.ip_ttl = 1;
+  PR_SetSocketOption(mFD, &opt);
+
+  nsresult rv = NS_NewNamedThread("wifi tickler", getter_AddRefs(mThread));
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsITimer> tmpTimer = NS_NewTimer(mThread);
+  if (!tmpTimer) return NS_ERROR_OUT_OF_MEMORY;
+
+  mTimer.swap(tmpTimer);
+
+  mAddr.inet.family = PR_AF_INET;
+  mAddr.inet.port = PR_htons(4886);
+  mAddr.inet.ip = 0;
+
+  return NS_OK;
+}
+
+void Tickler::Tickle() {
+  MutexAutoLock lock(mLock);
+  MOZ_ASSERT(mThread);
+  mLastTickle = TimeStamp::Now();
+  if (!mActive) MaybeStartTickler();
+}
+
+void Tickler::PostCheckTickler() {
+  mLock.AssertCurrentThreadOwns();
+  mThread->Dispatch(NewRunnableMethod("net::Tickler::CheckTickler", this,
+                                      &Tickler::CheckTickler),
+                    NS_DISPATCH_NORMAL);
+  return;
+}
+
+void Tickler::MaybeStartTicklerUnlocked() {
+  MutexAutoLock lock(mLock);
+  MaybeStartTickler();
+}
+
+void Tickler::MaybeStartTickler() {
+  mLock.AssertCurrentThreadOwns();
+  if (!NS_IsMainThread()) {
+    NS_DispatchToMainThread(
+        NewRunnableMethod("net::Tickler::MaybeStartTicklerUnlocked", this,
+                          &Tickler::MaybeStartTicklerUnlocked));
+    return;
+  }
+
+  if (!mPrefs) mPrefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (mPrefs) {
+    int32_t val;
+    bool boolVal;
+
+    if (NS_SUCCEEDED(
+            mPrefs->GetBoolPref("network.tickle-wifi.enabled", &boolVal)))
+      mEnabled = boolVal;
+
+    if (NS_SUCCEEDED(
+            mPrefs->GetIntPref("network.tickle-wifi.duration", &val))) {
+      if (val < 1) val = 1;
+      if (val > 100000) val = 100000;
+      mDuration = TimeDuration::FromMilliseconds(val);
+    }
+
+    if (NS_SUCCEEDED(mPrefs->GetIntPref("network.tickle-wifi.delay", &val))) {
+      if (val < 1) val = 1;
+      if (val > 1000) val = 1000;
+      mDelay = static_cast<uint32_t>(val);
+    }
+  }
+
+  PostCheckTickler();
+}
+
+void Tickler::CheckTickler() {
+  MutexAutoLock lock(mLock);
+  MOZ_ASSERT(mThread == NS_GetCurrentThread());
+
+  bool shouldRun =
+      (!mCanceled) && ((TimeStamp::Now() - mLastTickle) <= mDuration);
+
+  if ((shouldRun && mActive) || (!shouldRun && !mActive))
+    return;  // no change in state
+
+  if (mActive)
+    StopTickler();
+  else
+    StartTickler();
+}
+
+void Tickler::Cancel() {
+  MutexAutoLock lock(mLock);
+  MOZ_ASSERT(NS_IsMainThread());
+  mCanceled = true;
+  if (mThread) PostCheckTickler();
+}
+
+void Tickler::StopTickler() {
+  mLock.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mThread == NS_GetCurrentThread());
+  MOZ_ASSERT(mTimer);
+  MOZ_ASSERT(mActive);
+
+  mTimer->Cancel();
+  mActive = false;
+}
+
+class TicklerTimer final : public nsITimerCallback, public nsINamed {
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITIMERCALLBACK
+
+  explicit TicklerTimer(Tickler* aTickler) {
+    mTickler = do_GetWeakReference(aTickler);
+  }
+
+  // nsINamed
+  NS_IMETHOD GetName(nsACString& aName) override {
+    aName.AssignLiteral("TicklerTimer");
+    return NS_OK;
+  }
+
+ private:
+  ~TicklerTimer() {}
+
+  nsWeakPtr mTickler;
+};
+
+void Tickler::StartTickler() {
+  mLock.AssertCurrentThreadOwns();
+  MOZ_ASSERT(mThread == NS_GetCurrentThread());
+  MOZ_ASSERT(!mActive);
+  MOZ_ASSERT(mTimer);
+
+  if (NS_SUCCEEDED(mTimer->InitWithCallback(new TicklerTimer(this),
+                                            mEnabled ? mDelay : 1000,
+                                            nsITimer::TYPE_REPEATING_SLACK)))
+    mActive = true;
+}
+
+// argument should be in network byte order
+void Tickler::SetIPV4Address(uint32_t address) { mAddr.inet.ip = address; }
+
+// argument should be in network byte order
+void Tickler::SetIPV4Port(uint16_t port) { mAddr.inet.port = port; }
+
+NS_IMPL_ISUPPORTS(TicklerTimer, nsITimerCallback, nsINamed)
+
+NS_IMETHODIMP TicklerTimer::Notify(nsITimer* timer) {
+  RefPtr<Tickler> tickler = do_QueryReferent(mTickler);
+  if (!tickler) return NS_ERROR_FAILURE;
+  MutexAutoLock lock(tickler->mLock);
+
+  if (!tickler->mFD) {
+    tickler->StopTickler();
+    return NS_ERROR_FAILURE;
+  }
+
+  if (tickler->mCanceled ||
+      ((TimeStamp::Now() - tickler->mLastTickle) > tickler->mDuration)) {
+    tickler->StopTickler();
+    return NS_OK;
+  }
+
+  if (!tickler->mEnabled) return NS_OK;
+
+  PR_SendTo(tickler->mFD, "", 0, 0, &tickler->mAddr, 0);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
+
+#else  // not defined MOZ_USE_WIFI_TICKLER
+
+namespace mozilla {
+namespace net {
+NS_IMPL_ISUPPORTS0(Tickler)
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // defined MOZ_USE_WIFI_TICKLER
diff --git a/netwerk/base/Tickler.h b/netwerk/base/Tickler.h
new file mode 100644
index 0000000000..264ecefebb
--- /dev/null
+++ b/netwerk/base/Tickler.h
@@ -0,0 +1,132 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_Tickler_h
+#define mozilla_net_Tickler_h
+
+// The tickler sends a regular 0 byte UDP heartbeat out to a
+// particular address for a short time after it has been touched. This
+// is used on some mobile wifi chipsets to mitigate Power Save Polling
+// (PSP) Mode when we are anticipating a response packet
+// soon. Typically PSP adds 100ms of latency to a read event because
+// the packet delivery is not triggered until the 802.11 beacon is
+// delivered to the host (100ms is the standard Access Point
+// configuration for the beacon interval.) Requesting a frequent
+// transmission and getting a CTS frame from the AP at least that
+// frequently allows for low latency receives when we have reason to
+// expect them (e.g a SYN-ACK).
+//
+// The tickler is used to allow RTT based phases of web transport to
+// complete quickly when on wifi - ARP, DNS, TCP handshake, SSL
+// handshake, HTTP headers, and the TCP slow start phase. The
+// transaction is given up to 400 miliseconds by default to get
+// through those phases before the tickler is disabled.
+//
+// The tickler only applies to wifi on mobile right now. Hopefully it
+// can also be restricted to particular handset models in the future.
+
+#if defined(ANDROID) && !defined(MOZ_PROXY_BYPASS_PROTECTION)
+#  define MOZ_USE_WIFI_TICKLER
+#endif
+
+#include "mozilla/Attributes.h"
+#include "nsISupports.h"
+#include <stdint.h>
+
+#ifdef MOZ_USE_WIFI_TICKLER
+#  include "mozilla/Mutex.h"
+#  include "mozilla/TimeStamp.h"
+#  include "nsISupports.h"
+#  include "nsIThread.h"
+#  include "nsITimer.h"
+#  include "nsWeakReference.h"
+#  include "prio.h"
+
+class nsIPrefBranch;
+#endif
+
+namespace mozilla {
+namespace net {
+
+#ifdef MOZ_USE_WIFI_TICKLER
+
+// 8f769ed6-207c-4af9-9f7e-9e832da3754e
+#  define NS_TICKLER_IID                               \
+    {                                                  \
+      0x8f769ed6, 0x207c, 0x4af9, {                    \
+        0x9f, 0x7e, 0x9e, 0x83, 0x2d, 0xa3, 0x75, 0x4e \
+      }                                                \
+    }
+
+class Tickler final : public nsSupportsWeakReference {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_TICKLER_IID)
+
+  // These methods are main thread only
+  Tickler();
+  void Cancel();
+  nsresult Init();
+  void SetIPV4Address(uint32_t address);
+  void SetIPV4Port(uint16_t port);
+
+  // Tickle the tickler to (re-)start the activity.
+  // May call from any thread
+  void Tickle();
+
+ private:
+  ~Tickler();
+
+  friend class TicklerTimer;
+  Mutex mLock MOZ_UNANNOTATED;
+  nsCOMPtr<nsIThread> mThread;
+  nsCOMPtr<nsITimer> mTimer;
+  nsCOMPtr<nsIPrefBranch> mPrefs;
+
+  bool mActive;
+  bool mCanceled;
+  bool mEnabled;
+  uint32_t mDelay;
+  TimeDuration mDuration;
+  PRFileDesc* mFD;
+
+  TimeStamp mLastTickle;
+  PRNetAddr mAddr;
+
+  // These functions may be called from any thread
+  void PostCheckTickler();
+  void MaybeStartTickler();
+  void MaybeStartTicklerUnlocked();
+
+  // Tickler thread only
+  void CheckTickler();
+  void StartTickler();
+  void StopTickler();
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Tickler, NS_TICKLER_IID)
+
+#else  // not defined MOZ_USE_WIFI_TICKLER
+
+class Tickler final : public nsISupports {
+  ~Tickler() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  Tickler() = default;
+  nsresult Init() { return NS_ERROR_NOT_IMPLEMENTED; }
+  void Cancel() {}
+  void SetIPV4Address(uint32_t){};
+  void SetIPV4Port(uint16_t) {}
+  void Tickle() {}
+};
+
+#endif  // defined MOZ_USE_WIFI_TICKLER
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_net_Tickler_h
diff --git a/netwerk/base/ascii_pac_utils.js b/netwerk/base/ascii_pac_utils.js
new file mode 100644
index 0000000000..cedb1a0f21
--- /dev/null
+++ b/netwerk/base/ascii_pac_utils.js
@@ -0,0 +1,256 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* global dnsResolve */
+
+function dnsDomainIs(host, domain) {
+  return (
+    host.length >= domain.length &&
+    host.substring(host.length - domain.length) == domain
+  );
+}
+
+function dnsDomainLevels(host) {
+  return host.split(".").length - 1;
+}
+
+function isValidIpAddress(ipchars) {
+  var matches = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/.exec(ipchars);
+  if (matches == null) {
+    return false;
+  } else if (
+    matches[1] > 255 ||
+    matches[2] > 255 ||
+    matches[3] > 255 ||
+    matches[4] > 255
+  ) {
+    return false;
+  }
+  return true;
+}
+
+function convert_addr(ipchars) {
+  var bytes = ipchars.split(".");
+  var result =
+    ((bytes[0] & 0xff) << 24) |
+    ((bytes[1] & 0xff) << 16) |
+    ((bytes[2] & 0xff) << 8) |
+    (bytes[3] & 0xff);
+  return result;
+}
+
+function isInNet(ipaddr, pattern, maskstr) {
+  if (!isValidIpAddress(pattern) || !isValidIpAddress(maskstr)) {
+    return false;
+  }
+  if (!isValidIpAddress(ipaddr)) {
+    ipaddr = dnsResolve(ipaddr);
+    if (ipaddr == null) {
+      return false;
+    }
+  }
+  var host = convert_addr(ipaddr);
+  var pat = convert_addr(pattern);
+  var mask = convert_addr(maskstr);
+  return (host & mask) == (pat & mask);
+}
+
+function isPlainHostName(host) {
+  return host.search("(\\.)|:") == -1;
+}
+
+function isResolvable(host) {
+  var ip = dnsResolve(host);
+  return ip != null;
+}
+
+function localHostOrDomainIs(host, hostdom) {
+  return host == hostdom || hostdom.lastIndexOf(host + ".", 0) == 0;
+}
+
+function shExpMatch(url, pattern) {
+  pattern = pattern.replace(/\./g, "\\.");
+  pattern = pattern.replace(/\*/g, ".*");
+  pattern = pattern.replace(/\?/g, ".");
+  var newRe = new RegExp("^" + pattern + "$");
+  return newRe.test(url);
+}
+
+var wdays = { SUN: 0, MON: 1, TUE: 2, WED: 3, THU: 4, FRI: 5, SAT: 6 };
+var months = {
+  JAN: 0,
+  FEB: 1,
+  MAR: 2,
+  APR: 3,
+  MAY: 4,
+  JUN: 5,
+  JUL: 6,
+  AUG: 7,
+  SEP: 8,
+  OCT: 9,
+  NOV: 10,
+  DEC: 11,
+};
+
+function weekdayRange() {
+  function getDay(weekday) {
+    if (weekday in wdays) {
+      return wdays[weekday];
+    }
+    return -1;
+  }
+  var date = new Date();
+  var argc = arguments.length;
+  var wday;
+  if (argc < 1) {
+    return false;
+  }
+  if (arguments[argc - 1] == "GMT") {
+    argc--;
+    wday = date.getUTCDay();
+  } else {
+    wday = date.getDay();
+  }
+  var wd1 = getDay(arguments[0]);
+  var wd2 = argc == 2 ? getDay(arguments[1]) : wd1;
+  if (wd1 == -1 || wd2 == -1) {
+    return false;
+  }
+
+  if (wd1 <= wd2) {
+    return wd1 <= wday && wday <= wd2;
+  }
+
+  return wd2 >= wday || wday >= wd1;
+}
+
+function dateRange() {
+  function getMonth(name) {
+    if (name in months) {
+      return months[name];
+    }
+    return -1;
+  }
+  var date = new Date();
+  var argc = arguments.length;
+  if (argc < 1) {
+    return false;
+  }
+  var isGMT = arguments[argc - 1] == "GMT";
+
+  if (isGMT) {
+    argc--;
+  }
+  // function will work even without explict handling of this case
+  if (argc == 1) {
+    let tmp = parseInt(arguments[0]);
+    if (isNaN(tmp)) {
+      return (
+        (isGMT ? date.getUTCMonth() : date.getMonth()) == getMonth(arguments[0])
+      );
+    } else if (tmp < 32) {
+      return (isGMT ? date.getUTCDate() : date.getDate()) == tmp;
+    }
+    return (isGMT ? date.getUTCFullYear() : date.getFullYear()) == tmp;
+  }
+  var year = date.getFullYear();
+  var date1, date2;
+  date1 = new Date(year, 0, 1, 0, 0, 0);
+  date2 = new Date(year, 11, 31, 23, 59, 59);
+  var adjustMonth = false;
+  for (let i = 0; i < argc >> 1; i++) {
+    let tmp = parseInt(arguments[i]);
+    if (isNaN(tmp)) {
+      let mon = getMonth(arguments[i]);
+      date1.setMonth(mon);
+    } else if (tmp < 32) {
+      adjustMonth = argc <= 2;
+      date1.setDate(tmp);
+    } else {
+      date1.setFullYear(tmp);
+    }
+  }
+  for (let i = argc >> 1; i < argc; i++) {
+    let tmp = parseInt(arguments[i]);
+    if (isNaN(tmp)) {
+      let mon = getMonth(arguments[i]);
+      date2.setMonth(mon);
+    } else if (tmp < 32) {
+      date2.setDate(tmp);
+    } else {
+      date2.setFullYear(tmp);
+    }
+  }
+  if (adjustMonth) {
+    date1.setMonth(date.getMonth());
+    date2.setMonth(date.getMonth());
+  }
+  if (isGMT) {
+    let tmp = date;
+    tmp.setFullYear(date.getUTCFullYear());
+    tmp.setMonth(date.getUTCMonth());
+    tmp.setDate(date.getUTCDate());
+    tmp.setHours(date.getUTCHours());
+    tmp.setMinutes(date.getUTCMinutes());
+    tmp.setSeconds(date.getUTCSeconds());
+    date = tmp;
+  }
+  return date1 <= date2
+    ? date1 <= date && date <= date2
+    : date2 >= date || date >= date1;
+}
+
+function timeRange() {
+  var argc = arguments.length;
+  var date = new Date();
+  var isGMT = false;
+  if (argc < 1) {
+    return false;
+  }
+  if (arguments[argc - 1] == "GMT") {
+    isGMT = true;
+    argc--;
+  }
+
+  var hour = isGMT ? date.getUTCHours() : date.getHours();
+  var date1, date2;
+  date1 = new Date();
+  date2 = new Date();
+
+  if (argc == 1) {
+    return hour == arguments[0];
+  } else if (argc == 2) {
+    return arguments[0] <= hour && hour <= arguments[1];
+  }
+  switch (argc) {
+    case 6:
+      date1.setSeconds(arguments[2]);
+      date2.setSeconds(arguments[5]);
+    // falls through
+    case 4:
+      var middle = argc >> 1;
+      date1.setHours(arguments[0]);
+      date1.setMinutes(arguments[1]);
+      date2.setHours(arguments[middle]);
+      date2.setMinutes(arguments[middle + 1]);
+      if (middle == 2) {
+        date2.setSeconds(59);
+      }
+      break;
+    default:
+      throw new Error("timeRange: bad number of arguments");
+  }
+
+  if (isGMT) {
+    date.setFullYear(date.getUTCFullYear());
+    date.setMonth(date.getUTCMonth());
+    date.setDate(date.getUTCDate());
+    date.setHours(date.getUTCHours());
+    date.setMinutes(date.getUTCMinutes());
+    date.setSeconds(date.getUTCSeconds());
+  }
+  return date1 <= date2
+    ? date1 <= date && date <= date2
+    : date2 >= date || date >= date1;
+}
diff --git a/netwerk/base/http-sfv/Cargo.toml b/netwerk/base/http-sfv/Cargo.toml
new file mode 100644
index 0000000000..4625cdf974
--- /dev/null
+++ b/netwerk/base/http-sfv/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "http_sfv"
+version = "0.1.0"
+authors = ["barabass <yalyna.ts@gmail.com>"]
+edition = "2018"
+license = "MPL-2.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nserror = { path = "../../../xpcom/rust/nserror" }
+nsstring = { path = "../../../xpcom/rust/nsstring" }
+sfv = "0.9.1"
+xpcom = { path = "../../../xpcom/rust/xpcom" }
+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }
diff --git a/netwerk/base/http-sfv/SFVService.cpp b/netwerk/base/http-sfv/SFVService.cpp
new file mode 100644
index 0000000000..9759993e7f
--- /dev/null
+++ b/netwerk/base/http-sfv/SFVService.cpp
@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+#include "nsCOMPtr.h"
+#include "SFVService.h"
+
+// This anonymous namespace prevents outside C++ code from improperly accessing
+// these implementation details.
+namespace {
+extern "C" {
+// Implemented in Rust.
+void new_sfv_service(nsISFVService** result);
+}
+
+static mozilla::StaticRefPtr<nsISFVService> sService;
+}  // namespace
+
+namespace mozilla::net {
+
+already_AddRefed<nsISFVService> GetSFVService() {
+  nsCOMPtr<nsISFVService> service;
+
+  if (sService) {
+    service = sService;
+  } else {
+    new_sfv_service(getter_AddRefs(service));
+    sService = service;
+    mozilla::ClearOnShutdown(&sService);
+  }
+
+  return service.forget();
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/http-sfv/SFVService.h b/netwerk/base/http-sfv/SFVService.h
new file mode 100644
index 0000000000..4016951609
--- /dev/null
+++ b/netwerk/base/http-sfv/SFVService.h
@@ -0,0 +1,14 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStructuredFieldValues.h"
+namespace mozilla {
+namespace net {
+
+already_AddRefed<nsISFVService> GetSFVService();
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/http-sfv/moz.build b/netwerk/base/http-sfv/moz.build
new file mode 100644
index 0000000000..ed857c91a8
--- /dev/null
+++ b/netwerk/base/http-sfv/moz.build
@@ -0,0 +1,17 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    "nsIStructuredFieldValues.idl",
+]
+
+XPIDL_MODULE = "http-sfv"
+
+EXPORTS.mozilla.net += ["SFVService.h"]
+
+SOURCES += ["SFVService.cpp"]
+
+FINAL_LIBRARY = "xul"
diff --git a/netwerk/base/http-sfv/nsIStructuredFieldValues.idl b/netwerk/base/http-sfv/nsIStructuredFieldValues.idl
new file mode 100644
index 0000000000..3f02b33953
--- /dev/null
+++ b/netwerk/base/http-sfv/nsIStructuredFieldValues.idl
@@ -0,0 +1,290 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * Conceptually, there are three types of structured field (header) values:
+ *
+ * Item - can be an Integer, Decimal, String, Token, Byte Sequence, or Boolean.
+ * It can have associated Parameters.
+ * List - array of zero or more members, each of which can be an Item or an InnerList,
+ * both of which can be Parameterized.
+ * Dictionary - ordered map of name-value pairs, where the names are short textual strings
+ * and the values are Items or arrays of Items (represented with InnerList),
+ * both of which can be Parameterized. There can be zero or more members,
+ * and their names are unique in the scope of the Dictionary they occur within.
+ *
+ *
+ * There's also a few primitive types used to construct structured field values:
+ * - BareItem used as Item's value or as a parameter value in Parameters.
+ * - Parameters are an ordered map of key-value pairs that are associated with an Item or InnerList.
+ * The keys are unique within the scope the Parameters they occur within, and the values are BareItem.
+ * - InnerList is an array of zero or more Items. Can have Parameters.
+ * - ListEntry represents either Item or InnerList as a member of List or as member-value in Dictionary.
+ */
+
+
+
+/**
+ * nsISFVBareItem is a building block for Item header value (nsISFVItem) and Parameters (nsISFVParams).
+ * It can be of type BOOL, STRING, DECIMAL, INTEGER, TOKEN, BYTE_SEQUENCE.
+ * Each type is represented by its own interface which is used to create
+ * a bare item of that type.
+ */
+[scriptable, builtinclass, uuid(7072853f-215b-4a8a-92e5-9732bccc377b)]
+interface nsISFVBareItem : nsISupports {
+    const long BOOL = 1;
+    const long STRING = 2;
+    const long DECIMAL = 3;
+    const long INTEGER = 4;
+    const long TOKEN = 5;
+    const long BYTE_SEQUENCE = 6;
+
+    /**
+     * Returns value associated with type of bare item.
+     * Used to identify type of bare item without querying for interface
+     * (like nsISFVString, etc).
+     */
+    readonly attribute long type;
+};
+
+[scriptable, builtinclass, uuid(843eea44-990a-422c-bbf2-2aa4ba9ee4d2)]
+interface nsISFVInteger : nsISFVBareItem {
+    attribute long long value;
+};
+
+[scriptable, builtinclass, uuid(df6a0787-7caa-4fef-b145-08c1104c2fde)]
+interface nsISFVString : nsISFVBareItem {
+    attribute ACString value;
+};
+
+[scriptable, builtinclass, uuid(d263c6d7-4123-4c39-a121-ccf874a19012)]
+interface nsISFVBool : nsISFVBareItem {
+    attribute boolean value;
+};
+
+[scriptable, builtinclass, uuid(1098da8b-b4df-4526-b985-53dbd4160ad2)]
+interface nsISFVDecimal : nsISFVBareItem {
+    attribute double value;
+};
+
+[scriptable, builtinclass, uuid(8ad33d52-b9b2-4a17-8aa8-991250fc1214)]
+interface nsISFVToken : nsISFVBareItem {
+    attribute ACString value;
+};
+
+[scriptable, builtinclass, uuid(887eaef0-19fe-42bc-9a42-9ff773aa8fea)]
+interface nsISFVByteSeq : nsISFVBareItem {
+    attribute ACString value;
+};
+
+
+/**
+ * nsISFVParams represents parameters, key-value pairs of ACString and nsISFVBareItem,
+ * which parametrize Item type header or InnerList type withing List type header.
+ */
+[scriptable, builtinclass, uuid(b1a397d7-3333-43e7-993a-fbe8ab90ee96)]
+interface nsISFVParams : nsISupports {
+    /**
+     * Return value (nsISFVBareItem) stored for key, if it is present
+     *
+     * @throws NS_ERROR_UNEXPECTED if the key does not exist in parameters.
+     */
+    nsISFVBareItem get(in ACString key);
+
+    /**
+     * Insert a new key-value pair.
+     * If an equivalent key already exists: the key remains and retains in its place in the order,
+     * its corresponding value is updated with the new value.
+     *
+     * @throws NS_ERROR_UNEXPECTED if supplied item does not implement nsISFVBareItem interface.
+     */
+    void set(in ACString key, in nsISFVBareItem item);
+
+    /**
+     * Remove the key-value pair equivalent to key.
+     *
+     * @throws NS_ERROR_UNEXPECTED upon attempt to delete  key that does not exist in parameters.
+     */
+    void delete(in ACString key);
+
+    /**
+     * Returns array of keys.
+     */
+    Array<ACString> keys();
+};
+
+/**
+ * nsISFVParametrizable is implemented for types that
+ * can be parametrized with nsISFVParams
+ */
+[scriptable, builtinclass, uuid(6c0399f8-01de-4b25-b339-68e35e8d2e49)]
+interface nsISFVParametrizable : nsISupports {
+    readonly attribute nsISFVParams params;
+};
+
+/**
+ * nsISFVItemOrInnerList represents member in nsISFVList
+ * or member-value in nsISFVDictionary.
+ * nsISFVItemOrInnerList is implemented for
+ * nsISFVItem or nsISFVInnerList, both of which are used
+ * to create nsISFVList and nsISFVDictionary.
+ */
+[scriptable, builtinclass, uuid(99ac1b56-b5b3-44e7-ad96-db7444aae4b2)]
+interface nsISFVItemOrInnerList : nsISFVParametrizable {
+};
+
+/**
+ * nsISFVSerialize indicates that object can be serialized into ACString.
+ */
+[scriptable, builtinclass, uuid(28b9215d-c131-413c-9482-0004a371a5ec)]
+interface nsISFVSerialize : nsISupports {
+    ACString serialize();
+};
+
+/**
+ * nsISFVItem represents Item structured header value.
+ */
+[scriptable, builtinclass, uuid(abe8826b-6af7-4e54-bd2c-46ab231700ce)]
+interface nsISFVItem : nsISFVItemOrInnerList {
+    readonly attribute nsISFVBareItem value;
+    ACString serialize();
+};
+
+/**
+ * nsISFVInnerList can be used as a member of nsISFVList
+ * or a member-value of nsISFVDictionary.
+ */
+[scriptable, builtinclass, uuid(b2e52be2-8488-41b2-9ee2-3c48d92d095c)]
+interface nsISFVInnerList : nsISFVItemOrInnerList {
+    attribute Array<nsISFVItem> items;
+};
+
+/**
+ * nsISFVList represents List structured header value.
+ */
+[scriptable, builtinclass, uuid(02bb92a6-d1de-449c-b54f-d137f30c613d)]
+interface nsISFVList : nsISFVSerialize {
+    /**
+     * Returns array of members.
+     * QueryInterface can be used on a member to get more specific type.
+     */
+    attribute Array<nsISFVItemOrInnerList> members;
+
+    /**
+     * In case when header value is split across lines, it's possible
+     * this method parses supplied line and merges it with members of existing object.
+     */
+    void parseMore(in ACString header);
+};
+
+/**
+ * nsISFVDictionary represents nsISFVDictionary structured header value.
+ */
+[scriptable, builtinclass, uuid(6642a7fe-7026-4eba-b730-05e230ee3437)]
+interface nsISFVDictionary : nsISFVSerialize {
+
+    /**
+     * Return value (nsISFVItemOrInnerList) stored for key, if it is present.
+     * QueryInterface can be used on a value to get more specific type.
+     *
+     * @throws NS_ERROR_UNEXPECTED if the key does not exist in parameters.
+     */
+    nsISFVItemOrInnerList get(in ACString key);
+
+    /**
+     * Insert a new key-value pair.
+     * If an equivalent key already exists: the key remains and retains in its place in the order,
+     * its corresponding value is updated with the new value.
+     *
+     * @throws NS_ERROR_UNEXPECTED if supplied item does not implement nsISFVItemOrInnerList interface.
+     */
+    void set(in ACString key, in nsISFVItemOrInnerList member_value);
+
+    /**
+     * Remove the key-value pair equivalent to key.
+     *
+     * @throws NS_ERROR_UNEXPECTED upon attempt to delete  key that does not exist in parameters.
+     */
+    void delete(in ACString key);
+
+    /**
+     * Returns array of keys.
+     */
+    Array<ACString> keys();
+
+    /**
+     * In case when header value is split across lines, it's possible
+     * this method parses supplied line and merges it with members of existing object.
+     */
+    void parseMore(in ACString header);
+};
+
+
+/**
+ * nsISFVService provides a set of functions for working with HTTP header value as an object.
+ * It exposes functions for creating object from string containing header value,
+ * as well as individual components for manual structured header object creation.
+ */
+[scriptable, builtinclass, uuid(049f4be1-2f22-4438-a8da-518552ed390c)]
+interface nsISFVService: nsISupports
+{
+    /**
+     * Parses provided string into Dictionary header value (nsISFVDictionary).
+     *
+     * @throws NS_ERROR_FAILURE if parsing fails.
+     */
+    nsISFVDictionary parseDictionary(in ACString header);
+
+    /**
+     * Parses provided string into List header value (nsISFVList).
+     *
+     * @throws NS_ERROR_FAILURE if parsing fails.
+     */
+    nsISFVList parseList(in ACString header);
+
+    /**
+     * Parses provided string into Item header value (nsISFVItem).
+     *
+     * @throws NS_ERROR_FAILURE if parsing fails.
+     */
+    nsISFVItem parseItem(in ACString header);
+
+    /**
+     * The following functions create bare item of specific type.
+     */
+    nsISFVInteger newInteger(in long long value);
+    nsISFVBool newBool(in bool value);
+    nsISFVDecimal newDecimal(in double value);
+    nsISFVString newString(in ACString value);
+    nsISFVByteSeq newByteSequence(in ACString value);
+    nsISFVToken newToken(in ACString value);
+
+    /**
+     * Creates nsISFVParams with no parameters. In other words, it's an empty map byt default.
+     */
+    nsISFVParams newParameters();
+
+    /**
+     * Creates nsISFVInnerList from nsISFVItem array and nsISFVParams.
+     */
+    nsISFVInnerList newInnerList(in Array<nsISFVItem> items, in nsISFVParams params);
+
+    /**
+     * Creates nsISFVItem, which represents Item header value, from nsISFVBareItem and associated nsISFVParams.
+     */
+    nsISFVItem newItem(in nsISFVBareItem value, in nsISFVParams params);
+
+    /**
+     * Creates nsISFVList, which represents List header value, from array of nsISFVItemOrInnerList.
+     * nsISFVItemOrInnerList represens either Item (nsISFVItem) or Inner List (nsISFVInnerList).
+     */
+    nsISFVList newList(in Array<nsISFVItemOrInnerList> members);
+
+    /**
+     * Creates nsISFVDictionary representing Dictionary header value. It is empty by default.
+     */
+    nsISFVDictionary newDictionary();
+};
diff --git a/netwerk/base/http-sfv/src/lib.rs b/netwerk/base/http-sfv/src/lib.rs
new file mode 100644
index 0000000000..fe669f5f3f
--- /dev/null
+++ b/netwerk/base/http-sfv/src/lib.rs
@@ -0,0 +1,873 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use nserror::{nsresult, NS_ERROR_FAILURE, NS_ERROR_NULL_POINTER, NS_ERROR_UNEXPECTED, NS_OK};
+use nsstring::{nsACString, nsCString};
+use sfv::Parser;
+use sfv::SerializeValue;
+use sfv::{
+    BareItem, Decimal, Dictionary, FromPrimitive, InnerList, Item, List, ListEntry, Parameters,
+    ParseMore,
+};
+use std::cell::RefCell;
+use std::ops::Deref;
+use thin_vec::ThinVec;
+use xpcom::interfaces::{
+    nsISFVBareItem, nsISFVBool, nsISFVByteSeq, nsISFVDecimal, nsISFVDictionary, nsISFVInnerList,
+    nsISFVInteger, nsISFVItem, nsISFVItemOrInnerList, nsISFVList, nsISFVParams, nsISFVService,
+    nsISFVString, nsISFVToken,
+};
+use xpcom::{xpcom, xpcom_method, RefPtr, XpCom};
+
+#[no_mangle]
+pub unsafe extern "C" fn new_sfv_service(result: *mut *const nsISFVService) {
+    let service: RefPtr<SFVService> = SFVService::new();
+    RefPtr::new(service.coerce::<nsISFVService>()).forget(&mut *result);
+}
+
+#[xpcom(implement(nsISFVService), atomic)]
+struct SFVService {}
+
+impl SFVService {
+    fn new() -> RefPtr<SFVService> {
+        SFVService::allocate(InitSFVService {})
+    }
+
+    xpcom_method!(parse_dictionary => ParseDictionary(header: *const nsACString) -> *const nsISFVDictionary);
+    fn parse_dictionary(&self, header: &nsACString) -> Result<RefPtr<nsISFVDictionary>, nsresult> {
+        let parsed_dict = Parser::parse_dictionary(&header).map_err(|_| NS_ERROR_FAILURE)?;
+        let sfv_dict = SFVDictionary::new();
+        sfv_dict.value.replace(parsed_dict);
+        Ok(RefPtr::new(sfv_dict.coerce::<nsISFVDictionary>()))
+    }
+
+    xpcom_method!(parse_list => ParseList(field_value: *const nsACString) -> *const nsISFVList);
+    fn parse_list(&self, header: &nsACString) -> Result<RefPtr<nsISFVList>, nsresult> {
+        let parsed_list = Parser::parse_list(&header).map_err(|_| NS_ERROR_FAILURE)?;
+
+        let mut nsi_members = Vec::new();
+        for item_or_inner_list in parsed_list.iter() {
+            nsi_members.push(interface_from_list_entry(item_or_inner_list)?)
+        }
+        let sfv_list = SFVList::allocate(InitSFVList {
+            members: RefCell::new(nsi_members),
+        });
+        Ok(RefPtr::new(sfv_list.coerce::<nsISFVList>()))
+    }
+
+    xpcom_method!(parse_item => ParseItem(header: *const nsACString) -> *const nsISFVItem);
+    fn parse_item(&self, header: &nsACString) -> Result<RefPtr<nsISFVItem>, nsresult> {
+        let parsed_item = Parser::parse_item(&header).map_err(|_| NS_ERROR_FAILURE)?;
+        interface_from_item(&parsed_item)
+    }
+
+    xpcom_method!(new_integer => NewInteger(value: i64) -> *const nsISFVInteger);
+    fn new_integer(&self, value: i64) -> Result<RefPtr<nsISFVInteger>, nsresult> {
+        Ok(RefPtr::new(
+            SFVInteger::new(value).coerce::<nsISFVInteger>(),
+        ))
+    }
+
+    xpcom_method!(new_decimal => NewDecimal(value: f64) -> *const nsISFVDecimal);
+    fn new_decimal(&self, value: f64) -> Result<RefPtr<nsISFVDecimal>, nsresult> {
+        Ok(RefPtr::new(
+            SFVDecimal::new(value).coerce::<nsISFVDecimal>(),
+        ))
+    }
+
+    xpcom_method!(new_bool => NewBool(value: bool) -> *const nsISFVBool);
+    fn new_bool(&self, value: bool) -> Result<RefPtr<nsISFVBool>, nsresult> {
+        Ok(RefPtr::new(SFVBool::new(value).coerce::<nsISFVBool>()))
+    }
+
+    xpcom_method!(new_string => NewString(value: *const nsACString) -> *const nsISFVString);
+    fn new_string(&self, value: &nsACString) -> Result<RefPtr<nsISFVString>, nsresult> {
+        Ok(RefPtr::new(SFVString::new(value).coerce::<nsISFVString>()))
+    }
+
+    xpcom_method!(new_token => NewToken(value: *const nsACString) -> *const nsISFVToken);
+    fn new_token(&self, value: &nsACString) -> Result<RefPtr<nsISFVToken>, nsresult> {
+        Ok(RefPtr::new(SFVToken::new(value).coerce::<nsISFVToken>()))
+    }
+
+    xpcom_method!(new_byte_sequence => NewByteSequence(value: *const nsACString) -> *const nsISFVByteSeq);
+    fn new_byte_sequence(&self, value: &nsACString) -> Result<RefPtr<nsISFVByteSeq>, nsresult> {
+        Ok(RefPtr::new(
+            SFVByteSeq::new(value).coerce::<nsISFVByteSeq>(),
+        ))
+    }
+
+    xpcom_method!(new_parameters => NewParameters() -> *const nsISFVParams);
+    fn new_parameters(&self) -> Result<RefPtr<nsISFVParams>, nsresult> {
+        Ok(RefPtr::new(SFVParams::new().coerce::<nsISFVParams>()))
+    }
+
+    xpcom_method!(new_item => NewItem(value: *const nsISFVBareItem, params:  *const nsISFVParams) -> *const nsISFVItem);
+    fn new_item(
+        &self,
+        value: &nsISFVBareItem,
+        params: &nsISFVParams,
+    ) -> Result<RefPtr<nsISFVItem>, nsresult> {
+        Ok(RefPtr::new(
+            SFVItem::new(value, params).coerce::<nsISFVItem>(),
+        ))
+    }
+
+    xpcom_method!(new_inner_list => NewInnerList(items: *const thin_vec::ThinVec<Option<RefPtr<nsISFVItem>>>, params:  *const nsISFVParams) -> *const nsISFVInnerList);
+    fn new_inner_list(
+        &self,
+        items: &thin_vec::ThinVec<Option<RefPtr<nsISFVItem>>>,
+        params: &nsISFVParams,
+    ) -> Result<RefPtr<nsISFVInnerList>, nsresult> {
+        let items = items
+            .iter()
+            .cloned()
+            .map(|item| item.ok_or(NS_ERROR_NULL_POINTER))
+            .collect::<Result<Vec<_>, nsresult>>()?;
+        Ok(RefPtr::new(
+            SFVInnerList::new(items, params).coerce::<nsISFVInnerList>(),
+        ))
+    }
+
+    xpcom_method!(new_list => NewList(members: *const thin_vec::ThinVec<Option<RefPtr<nsISFVItemOrInnerList>>>) -> *const nsISFVList);
+    fn new_list(
+        &self,
+        members: &thin_vec::ThinVec<Option<RefPtr<nsISFVItemOrInnerList>>>,
+    ) -> Result<RefPtr<nsISFVList>, nsresult> {
+        let members = members
+            .iter()
+            .cloned()
+            .map(|item| item.ok_or(NS_ERROR_NULL_POINTER))
+            .collect::<Result<Vec<_>, nsresult>>()?;
+        Ok(RefPtr::new(SFVList::new(members).coerce::<nsISFVList>()))
+    }
+
+    xpcom_method!(new_dictionary => NewDictionary() -> *const nsISFVDictionary);
+    fn new_dictionary(&self) -> Result<RefPtr<nsISFVDictionary>, nsresult> {
+        Ok(RefPtr::new(
+            SFVDictionary::new().coerce::<nsISFVDictionary>(),
+        ))
+    }
+}
+
+#[xpcom(implement(nsISFVInteger, nsISFVBareItem), nonatomic)]
+struct SFVInteger {
+    value: RefCell<i64>,
+}
+
+impl SFVInteger {
+    fn new(value: i64) -> RefPtr<SFVInteger> {
+        SFVInteger::allocate(InitSFVInteger {
+            value: RefCell::new(value),
+        })
+    }
+
+    xpcom_method!(get_value => GetValue() -> i64);
+    fn get_value(&self) -> Result<i64, nsresult> {
+        Ok(*self.value.borrow())
+    }
+
+    xpcom_method!(set_value => SetValue(value: i64));
+    fn set_value(&self, value: i64) -> Result<(), nsresult> {
+        self.value.replace(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::INTEGER)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVBool, nsISFVBareItem), nonatomic)]
+struct SFVBool {
+    value: RefCell<bool>,
+}
+
+impl SFVBool {
+    fn new(value: bool) -> RefPtr<SFVBool> {
+        SFVBool::allocate(InitSFVBool {
+            value: RefCell::new(value),
+        })
+    }
+
+    xpcom_method!(get_value => GetValue() -> bool);
+    fn get_value(&self) -> Result<bool, nsresult> {
+        Ok(*self.value.borrow())
+    }
+
+    xpcom_method!(set_value => SetValue(value: bool));
+    fn set_value(&self, value: bool) -> Result<(), nsresult> {
+        self.value.replace(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::BOOL)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVString, nsISFVBareItem), nonatomic)]
+struct SFVString {
+    value: RefCell<nsCString>,
+}
+
+impl SFVString {
+    fn new(value: &nsACString) -> RefPtr<SFVString> {
+        SFVString::allocate(InitSFVString {
+            value: RefCell::new(nsCString::from(value)),
+        })
+    }
+
+    xpcom_method!(
+        get_value => GetValue(
+        ) -> nsACString
+    );
+
+    fn get_value(&self) -> Result<nsCString, nsresult> {
+        Ok(self.value.borrow().clone())
+    }
+
+    xpcom_method!(
+        set_value => SetValue(value: *const nsACString)
+    );
+
+    fn set_value(&self, value: &nsACString) -> Result<(), nsresult> {
+        self.value.borrow_mut().assign(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::STRING)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVToken, nsISFVBareItem), nonatomic)]
+struct SFVToken {
+    value: RefCell<nsCString>,
+}
+
+impl SFVToken {
+    fn new(value: &nsACString) -> RefPtr<SFVToken> {
+        SFVToken::allocate(InitSFVToken {
+            value: RefCell::new(nsCString::from(value)),
+        })
+    }
+
+    xpcom_method!(
+        get_value => GetValue(
+        ) -> nsACString
+    );
+
+    fn get_value(&self) -> Result<nsCString, nsresult> {
+        Ok(self.value.borrow().clone())
+    }
+
+    xpcom_method!(
+        set_value => SetValue(value: *const nsACString)
+    );
+
+    fn set_value(&self, value: &nsACString) -> Result<(), nsresult> {
+        self.value.borrow_mut().assign(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::TOKEN)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVByteSeq, nsISFVBareItem), nonatomic)]
+struct SFVByteSeq {
+    value: RefCell<nsCString>,
+}
+
+impl SFVByteSeq {
+    fn new(value: &nsACString) -> RefPtr<SFVByteSeq> {
+        SFVByteSeq::allocate(InitSFVByteSeq {
+            value: RefCell::new(nsCString::from(value)),
+        })
+    }
+
+    xpcom_method!(
+        get_value => GetValue(
+        ) -> nsACString
+    );
+
+    fn get_value(&self) -> Result<nsCString, nsresult> {
+        Ok(self.value.borrow().clone())
+    }
+
+    xpcom_method!(
+        set_value => SetValue(value: *const nsACString)
+    );
+
+    fn set_value(&self, value: &nsACString) -> Result<(), nsresult> {
+        self.value.borrow_mut().assign(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::BYTE_SEQUENCE)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVDecimal, nsISFVBareItem), nonatomic)]
+struct SFVDecimal {
+    value: RefCell<f64>,
+}
+
+impl SFVDecimal {
+    fn new(value: f64) -> RefPtr<SFVDecimal> {
+        SFVDecimal::allocate(InitSFVDecimal {
+            value: RefCell::new(value),
+        })
+    }
+
+    xpcom_method!(
+        get_value => GetValue(
+        ) -> f64
+    );
+
+    fn get_value(&self) -> Result<f64, nsresult> {
+        Ok(*self.value.borrow())
+    }
+
+    xpcom_method!(
+        set_value => SetValue(value: f64)
+    );
+
+    fn set_value(&self, value: f64) -> Result<(), nsresult> {
+        self.value.replace(value);
+        Ok(())
+    }
+
+    xpcom_method!(get_type => GetType() -> i32);
+    fn get_type(&self) -> Result<i32, nsresult> {
+        Ok(nsISFVBareItem::DECIMAL)
+    }
+
+    fn from_bare_item_interface(obj: &nsISFVBareItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVParams), nonatomic)]
+struct SFVParams {
+    params: RefCell<Parameters>,
+}
+
+impl SFVParams {
+    fn new() -> RefPtr<SFVParams> {
+        SFVParams::allocate(InitSFVParams {
+            params: RefCell::new(Parameters::new()),
+        })
+    }
+
+    xpcom_method!(
+        get => Get(key: *const nsACString) -> *const nsISFVBareItem
+    );
+
+    fn get(&self, key: &nsACString) -> Result<RefPtr<nsISFVBareItem>, nsresult> {
+        let key = key.to_utf8();
+        let params = self.params.borrow();
+        let param_val = params.get(key.as_ref());
+
+        match param_val {
+            Some(val) => interface_from_bare_item(val),
+            None => return Err(NS_ERROR_UNEXPECTED),
+        }
+    }
+
+    xpcom_method!(
+        set => Set(key: *const nsACString, item: *const nsISFVBareItem)
+    );
+
+    fn set(&self, key: &nsACString, item: &nsISFVBareItem) -> Result<(), nsresult> {
+        let key = key.to_utf8().into_owned();
+        let bare_item = bare_item_from_interface(item)?;
+        self.params.borrow_mut().insert(key, bare_item);
+        Ok(())
+    }
+
+    xpcom_method!(
+        delete => Delete(key: *const nsACString)
+    );
+    fn delete(&self, key: &nsACString) -> Result<(), nsresult> {
+        let key = key.to_utf8();
+        let mut params = self.params.borrow_mut();
+
+        if !params.contains_key(key.as_ref()) {
+            return Err(NS_ERROR_UNEXPECTED);
+        }
+
+        // Keeps only entries that don't match key
+        params.retain(|k, _| k != key.as_ref());
+        Ok(())
+    }
+
+    xpcom_method!(
+        keys => Keys() -> thin_vec::ThinVec<nsCString>
+    );
+    fn keys(&self) -> Result<thin_vec::ThinVec<nsCString>, nsresult> {
+        let keys = self.params.borrow();
+        let keys = keys
+            .keys()
+            .map(nsCString::from)
+            .collect::<ThinVec<nsCString>>();
+        Ok(keys)
+    }
+
+    fn from_interface(obj: &nsISFVParams) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVItem, nsISFVItemOrInnerList), nonatomic)]
+struct SFVItem {
+    value: RefPtr<nsISFVBareItem>,
+    params: RefPtr<nsISFVParams>,
+}
+
+impl SFVItem {
+    fn new(value: &nsISFVBareItem, params: &nsISFVParams) -> RefPtr<SFVItem> {
+        SFVItem::allocate(InitSFVItem {
+            value: RefPtr::new(value),
+            params: RefPtr::new(params),
+        })
+    }
+
+    xpcom_method!(
+        get_value => GetValue(
+        ) -> *const nsISFVBareItem
+    );
+
+    fn get_value(&self) -> Result<RefPtr<nsISFVBareItem>, nsresult> {
+        Ok(self.value.clone())
+    }
+
+    xpcom_method!(
+        get_params => GetParams(
+        ) -> *const nsISFVParams
+    );
+    fn get_params(&self) -> Result<RefPtr<nsISFVParams>, nsresult> {
+        Ok(self.params.clone())
+    }
+
+    xpcom_method!(
+        serialize => Serialize() -> nsACString
+    );
+    fn serialize(&self) -> Result<nsCString, nsresult> {
+        let bare_item = bare_item_from_interface(self.value.deref())?;
+        let params = params_from_interface(self.params.deref())?;
+        let serialized = Item::with_params(bare_item, params)
+            .serialize_value()
+            .map_err(|_| NS_ERROR_FAILURE)?;
+        Ok(nsCString::from(serialized))
+    }
+
+    fn from_interface(obj: &nsISFVItem) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVInnerList, nsISFVItemOrInnerList), nonatomic)]
+struct SFVInnerList {
+    items: RefCell<Vec<RefPtr<nsISFVItem>>>,
+    params: RefPtr<nsISFVParams>,
+}
+
+impl SFVInnerList {
+    fn new(items: Vec<RefPtr<nsISFVItem>>, params: &nsISFVParams) -> RefPtr<SFVInnerList> {
+        SFVInnerList::allocate(InitSFVInnerList {
+            items: RefCell::new(items),
+            params: RefPtr::new(params),
+        })
+    }
+
+    xpcom_method!(
+        get_items => GetItems() -> thin_vec::ThinVec<Option<RefPtr<nsISFVItem>>>
+    );
+
+    fn get_items(&self) -> Result<thin_vec::ThinVec<Option<RefPtr<nsISFVItem>>>, nsresult> {
+        let items = self.items.borrow().iter().cloned().map(Some).collect();
+        Ok(items)
+    }
+
+    #[allow(non_snake_case)]
+    unsafe fn SetItems(
+        &self,
+        value: *const thin_vec::ThinVec<Option<RefPtr<nsISFVItem>>>,
+    ) -> nsresult {
+        if value.is_null() {
+            return NS_ERROR_NULL_POINTER;
+        }
+        match (*value)
+            .iter()
+            .map(|v| v.clone().ok_or(NS_ERROR_NULL_POINTER))
+            .collect::<Result<Vec<_>, nsresult>>()
+        {
+            Ok(value) => *self.items.borrow_mut() = value,
+            Err(rv) => return rv,
+        }
+        NS_OK
+    }
+
+    xpcom_method!(
+        get_params => GetParams(
+        ) -> *const nsISFVParams
+    );
+    fn get_params(&self) -> Result<RefPtr<nsISFVParams>, nsresult> {
+        Ok(self.params.clone())
+    }
+
+    fn from_interface(obj: &nsISFVInnerList) -> &Self {
+        unsafe { ::std::mem::transmute(obj) }
+    }
+}
+
+#[xpcom(implement(nsISFVList, nsISFVSerialize), nonatomic)]
+struct SFVList {
+    members: RefCell<Vec<RefPtr<nsISFVItemOrInnerList>>>,
+}
+
+impl SFVList {
+    fn new(members: Vec<RefPtr<nsISFVItemOrInnerList>>) -> RefPtr<SFVList> {
+        SFVList::allocate(InitSFVList {
+            members: RefCell::new(members),
+        })
+    }
+
+    xpcom_method!(
+        get_members => GetMembers() -> thin_vec::ThinVec<Option<RefPtr<nsISFVItemOrInnerList>>>
+    );
+
+    fn get_members(
+        &self,
+    ) -> Result<thin_vec::ThinVec<Option<RefPtr<nsISFVItemOrInnerList>>>, nsresult> {
+        Ok(self.members.borrow().iter().cloned().map(Some).collect())
+    }
+
+    #[allow(non_snake_case)]
+    unsafe fn SetMembers(
+        &self,
+        value: *const thin_vec::ThinVec<Option<RefPtr<nsISFVItemOrInnerList>>>,
+    ) -> nsresult {
+        if value.is_null() {
+            return NS_ERROR_NULL_POINTER;
+        }
+        match (*value)
+            .iter()
+            .map(|v| v.clone().ok_or(NS_ERROR_NULL_POINTER))
+            .collect::<Result<Vec<_>, nsresult>>()
+        {
+            Ok(value) => *self.members.borrow_mut() = value,
+            Err(rv) => return rv,
+        }
+        NS_OK
+    }
+
+    xpcom_method!(
+        parse_more => ParseMore(header: *const nsACString)
+    );
+    fn parse_more(&self, header: &nsACString) -> Result<(), nsresult> {
+        // create List from SFVList to call parse_more on it
+        let mut list = List::new();
+        let members = self.members.borrow().clone();
+        for interface_entry in members.iter() {
+            let item_or_inner_list = list_entry_from_interface(interface_entry)?;
+            list.push(item_or_inner_list);
+        }
+
+        let _ = list.parse_more(&header).map_err(|_| NS_ERROR_FAILURE)?;
+
+        // replace SFVList's members with new_members
+        let mut new_members = Vec::new();
+        for item_or_inner_list in list.iter() {
+            new_members.push(interface_from_list_entry(item_or_inner_list)?)
+        }
+        self.members.replace(new_members);
+        Ok(())
+    }
+
+    xpcom_method!(
+        serialize => Serialize() -> nsACString
+    );
+    fn serialize(&self) -> Result<nsCString, nsresult> {
+        let mut list = List::new();
+        let members = self.members.borrow().clone();
+        for interface_entry in members.iter() {
+            let item_or_inner_list = list_entry_from_interface(interface_entry)?;
+            list.push(item_or_inner_list);
+        }
+
+        let serialized = list.serialize_value().map_err(|_| NS_ERROR_FAILURE)?;
+        Ok(nsCString::from(serialized))
+    }
+}
+
+#[xpcom(implement(nsISFVDictionary, nsISFVSerialize), nonatomic)]
+struct SFVDictionary {
+    value: RefCell<Dictionary>,
+}
+
+impl SFVDictionary {
+    fn new() -> RefPtr<SFVDictionary> {
+        SFVDictionary::allocate(InitSFVDictionary {
+            value: RefCell::new(Dictionary::new()),
+        })
+    }
+
+    xpcom_method!(
+        get => Get(key: *const nsACString) -> *const nsISFVItemOrInnerList
+    );
+
+    fn get(&self, key: &nsACString) -> Result<RefPtr<nsISFVItemOrInnerList>, nsresult> {
+        let key = key.to_utf8();
+        let value = self.value.borrow();
+        let member_value = value.get(key.as_ref());
+
+        match member_value {
+            Some(member) => interface_from_list_entry(member),
+            None => return Err(NS_ERROR_UNEXPECTED),
+        }
+    }
+
+    xpcom_method!(
+        set => Set(key: *const nsACString, item: *const nsISFVItemOrInnerList)
+    );
+
+    fn set(&self, key: &nsACString, member_value: &nsISFVItemOrInnerList) -> Result<(), nsresult> {
+        let key = key.to_utf8().into_owned();
+        let value = list_entry_from_interface(member_value)?;
+        self.value.borrow_mut().insert(key, value);
+        Ok(())
+    }
+
+    xpcom_method!(
+        delete => Delete(key: *const nsACString)
+    );
+
+    fn delete(&self, key: &nsACString) -> Result<(), nsresult> {
+        let key = key.to_utf8();
+        let mut params = self.value.borrow_mut();
+
+        if !params.contains_key(key.as_ref()) {
+            return Err(NS_ERROR_UNEXPECTED);
+        }
+
+        // Keeps only entries that don't match key
+        params.retain(|k, _| k != key.as_ref());
+        Ok(())
+    }
+
+    xpcom_method!(
+        keys => Keys() -> thin_vec::ThinVec<nsCString>
+    );
+    fn keys(&self) -> Result<thin_vec::ThinVec<nsCString>, nsresult> {
+        let members = self.value.borrow();
+        let keys = members
+            .keys()
+            .map(nsCString::from)
+            .collect::<ThinVec<nsCString>>();
+        Ok(keys)
+    }
+
+    xpcom_method!(
+        parse_more => ParseMore(header: *const nsACString)
+    );
+    fn parse_more(&self, header: &nsACString) -> Result<(), nsresult> {
+        let _ = self
+            .value
+            .borrow_mut()
+            .parse_more(&header)
+            .map_err(|_| NS_ERROR_FAILURE)?;
+        Ok(())
+    }
+
+    xpcom_method!(
+        serialize => Serialize() -> nsACString
+    );
+    fn serialize(&self) -> Result<nsCString, nsresult> {
+        let serialized = self
+            .value
+            .borrow()
+            .serialize_value()
+            .map_err(|_| NS_ERROR_FAILURE)?;
+        Ok(nsCString::from(serialized))
+    }
+}
+
+fn bare_item_from_interface(obj: &nsISFVBareItem) -> Result<BareItem, nsresult> {
+    let obj = obj
+        .query_interface::<nsISFVBareItem>()
+        .ok_or(NS_ERROR_UNEXPECTED)?;
+    let mut obj_type: i32 = -1;
+    unsafe {
+        obj.deref().GetType(&mut obj_type);
+    }
+
+    match obj_type {
+        nsISFVBareItem::BOOL => {
+            let item_value = SFVBool::from_bare_item_interface(obj.deref()).get_value()?;
+            Ok(BareItem::Boolean(item_value))
+        }
+        nsISFVBareItem::STRING => {
+            let string_itm = SFVString::from_bare_item_interface(obj.deref()).get_value()?;
+            let item_value = (*string_itm.to_utf8()).to_string();
+            Ok(BareItem::String(item_value))
+        }
+        nsISFVBareItem::TOKEN => {
+            let token_itm = SFVToken::from_bare_item_interface(obj.deref()).get_value()?;
+            let item_value = (*token_itm.to_utf8()).to_string();
+            Ok(BareItem::Token(item_value))
+        }
+        nsISFVBareItem::INTEGER => {
+            let item_value = SFVInteger::from_bare_item_interface(obj.deref()).get_value()?;
+            Ok(BareItem::Integer(item_value))
+        }
+        nsISFVBareItem::DECIMAL => {
+            let item_value = SFVDecimal::from_bare_item_interface(obj.deref()).get_value()?;
+            let decimal: Decimal = Decimal::from_f64(item_value).ok_or(NS_ERROR_UNEXPECTED)?;
+            Ok(BareItem::Decimal(decimal))
+        }
+        nsISFVBareItem::BYTE_SEQUENCE => {
+            let token_itm = SFVByteSeq::from_bare_item_interface(obj.deref()).get_value()?;
+            let item_value: String = (*token_itm.to_utf8()).to_string();
+            Ok(BareItem::ByteSeq(item_value.into_bytes()))
+        }
+        _ => return Err(NS_ERROR_UNEXPECTED),
+    }
+}
+
+fn params_from_interface(obj: &nsISFVParams) -> Result<Parameters, nsresult> {
+    let params = SFVParams::from_interface(obj).params.borrow();
+    Ok(params.clone())
+}
+
+fn item_from_interface(obj: &nsISFVItem) -> Result<Item, nsresult> {
+    let sfv_item = SFVItem::from_interface(obj);
+    let bare_item = bare_item_from_interface(sfv_item.value.deref())?;
+    let parameters = params_from_interface(sfv_item.params.deref())?;
+    Ok(Item::with_params(bare_item, parameters))
+}
+
+fn inner_list_from_interface(obj: &nsISFVInnerList) -> Result<InnerList, nsresult> {
+    let sfv_inner_list = SFVInnerList::from_interface(obj);
+
+    let mut inner_list_items: Vec<Item> = vec![];
+    for item in sfv_inner_list.items.borrow().iter() {
+        let item = item_from_interface(item)?;
+        inner_list_items.push(item);
+    }
+    let inner_list_params = params_from_interface(sfv_inner_list.params.deref())?;
+    Ok(InnerList::with_params(inner_list_items, inner_list_params))
+}
+
+fn list_entry_from_interface(obj: &nsISFVItemOrInnerList) -> Result<ListEntry, nsresult> {
+    if let Some(nsi_item) = obj.query_interface::<nsISFVItem>() {
+        let item = item_from_interface(nsi_item.deref())?;
+        Ok(ListEntry::Item(item))
+    } else if let Some(nsi_inner_list) = obj.query_interface::<nsISFVInnerList>() {
+        let inner_list = inner_list_from_interface(nsi_inner_list.deref())?;
+        Ok(ListEntry::InnerList(inner_list))
+    } else {
+        return Err(NS_ERROR_UNEXPECTED);
+    }
+}
+
+fn interface_from_bare_item(bare_item: &BareItem) -> Result<RefPtr<nsISFVBareItem>, nsresult> {
+    let bare_item = match bare_item {
+        BareItem::Boolean(val) => RefPtr::new(SFVBool::new(*val).coerce::<nsISFVBareItem>()),
+        BareItem::String(val) => {
+            RefPtr::new(SFVString::new(&nsCString::from(val)).coerce::<nsISFVBareItem>())
+        }
+        BareItem::Token(val) => {
+            RefPtr::new(SFVToken::new(&nsCString::from(val)).coerce::<nsISFVBareItem>())
+        }
+        BareItem::ByteSeq(val) => RefPtr::new(
+            SFVByteSeq::new(&nsCString::from(String::from_utf8(val.to_vec()).unwrap()))
+                .coerce::<nsISFVBareItem>(),
+        ),
+        BareItem::Decimal(val) => {
+            let val = val
+                .to_string()
+                .parse::<f64>()
+                .map_err(|_| NS_ERROR_UNEXPECTED)?;
+            RefPtr::new(SFVDecimal::new(val).coerce::<nsISFVBareItem>())
+        }
+        BareItem::Integer(val) => RefPtr::new(SFVInteger::new(*val).coerce::<nsISFVBareItem>()),
+    };
+
+    Ok(bare_item)
+}
+
+fn interface_from_item(item: &Item) -> Result<RefPtr<nsISFVItem>, nsresult> {
+    let nsi_bare_item = interface_from_bare_item(&item.bare_item)?;
+    let nsi_params = interface_from_params(&item.params)?;
+    Ok(RefPtr::new(
+        SFVItem::new(&nsi_bare_item, &nsi_params).coerce::<nsISFVItem>(),
+    ))
+}
+
+fn interface_from_params(params: &Parameters) -> Result<RefPtr<nsISFVParams>, nsresult> {
+    let sfv_params = SFVParams::new();
+    for (key, value) in params.iter() {
+        sfv_params
+            .params
+            .borrow_mut()
+            .insert(key.clone(), value.clone());
+    }
+    Ok(RefPtr::new(sfv_params.coerce::<nsISFVParams>()))
+}
+
+fn interface_from_list_entry(
+    member: &ListEntry,
+) -> Result<RefPtr<nsISFVItemOrInnerList>, nsresult> {
+    match member {
+        ListEntry::Item(item) => {
+            let nsi_bare_item = interface_from_bare_item(&item.bare_item)?;
+            let nsi_params = interface_from_params(&item.params)?;
+            Ok(RefPtr::new(
+                SFVItem::new(&nsi_bare_item, &nsi_params).coerce::<nsISFVItemOrInnerList>(),
+            ))
+        }
+        ListEntry::InnerList(inner_list) => {
+            let mut nsi_inner_list = Vec::new();
+            for item in inner_list.items.iter() {
+                let nsi_item = interface_from_item(item)?;
+                nsi_inner_list.push(nsi_item);
+            }
+
+            let nsi_params = interface_from_params(&inner_list.params)?;
+            Ok(RefPtr::new(
+                SFVInnerList::new(nsi_inner_list, &nsi_params).coerce::<nsISFVItemOrInnerList>(),
+            ))
+        }
+    }
+}
diff --git a/netwerk/base/makecppstring.py b/netwerk/base/makecppstring.py
new file mode 100644
index 0000000000..330fcfb04c
--- /dev/null
+++ b/netwerk/base/makecppstring.py
@@ -0,0 +1,17 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import sys
+
+
+def main(output, filename):
+    file = open(filename, "r")
+    output.write('R"(')  # insert literal start
+    for line in file:
+        output.write(line)
+    output.write(')"')  # insert literal end
+
+
+if __name__ == "__main__":
+    main(sys.stdout, sys.argv[1])
diff --git a/netwerk/base/moz.build b/netwerk/base/moz.build
new file mode 100644
index 0000000000..d35714df21
--- /dev/null
+++ b/netwerk/base/moz.build
@@ -0,0 +1,336 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    "mozIThirdPartyUtil.idl",
+    "nsIArrayBufferInputStream.idl",
+    "nsIAsyncStreamCopier.idl",
+    "nsIAsyncStreamCopier2.idl",
+    "nsIAsyncVerifyRedirectCallback.idl",
+    "nsIAuthInformation.idl",
+    "nsIAuthModule.idl",
+    "nsIAuthPrompt.idl",
+    "nsIAuthPrompt2.idl",
+    "nsIAuthPromptAdapterFactory.idl",
+    "nsIAuthPromptCallback.idl",
+    "nsIAuthPromptProvider.idl",
+    "nsIBackgroundFileSaver.idl",
+    "nsIBufferedStreams.idl",
+    "nsIByteRangeRequest.idl",
+    "nsICacheInfoChannel.idl",
+    "nsICachingChannel.idl",
+    "nsICancelable.idl",
+    "nsICaptivePortalService.idl",
+    "nsIChannel.idl",
+    "nsIChannelEventSink.idl",
+    "nsIChildChannel.idl",
+    "nsIClassifiedChannel.idl",
+    "nsIClassOfService.idl",
+    "nsIContentSniffer.idl",
+    "nsIDashboard.idl",
+    "nsIDashboardEventNotifier.idl",
+    "nsIDHCPClient.idl",
+    "nsIDownloader.idl",
+    "nsIEncodedChannel.idl",
+    "nsIExternalProtocolHandler.idl",
+    "nsIFileStreams.idl",
+    "nsIFileURL.idl",
+    "nsIForcePendingChannel.idl",
+    "nsIFormPOSTActionChannel.idl",
+    "nsIHttpAuthenticatorCallback.idl",
+    "nsIHttpPushListener.idl",
+    "nsIIncrementalDownload.idl",
+    "nsIIncrementalStreamLoader.idl",
+    "nsIInputStreamChannel.idl",
+    "nsIInputStreamPump.idl",
+    "nsIInterceptionInfo.idl",
+    "nsIIOService.idl",
+    "nsILoadContextInfo.idl",
+    "nsILoadGroup.idl",
+    "nsILoadGroupChild.idl",
+    "nsILoadInfo.idl",
+    "nsIMIMEInputStream.idl",
+    "nsIMultiPartChannel.idl",
+    "nsINestedURI.idl",
+    "nsINetAddr.idl",
+    "nsINetUtil.idl",
+    "nsINetworkConnectivityService.idl",
+    "nsINetworkInfoService.idl",
+    "nsINetworkInterceptController.idl",
+    "nsINetworkLinkService.idl",
+    "nsINetworkPredictor.idl",
+    "nsINetworkPredictorVerifier.idl",
+    "nsINullChannel.idl",
+    "nsIParentChannel.idl",
+    "nsIParentRedirectingChannel.idl",
+    "nsIPermission.idl",
+    "nsIPermissionManager.idl",
+    "nsIPrivateBrowsingChannel.idl",
+    "nsIProgressEventSink.idl",
+    "nsIPrompt.idl",
+    "nsIProtocolHandler.idl",
+    "nsIProtocolProxyCallback.idl",
+    "nsIProtocolProxyFilter.idl",
+    "nsIProtocolProxyService.idl",
+    "nsIProtocolProxyService2.idl",
+    "nsIProxiedChannel.idl",
+    "nsIProxiedProtocolHandler.idl",
+    "nsIProxyInfo.idl",
+    "nsIRandomGenerator.idl",
+    "nsIRedirectChannelRegistrar.idl",
+    "nsIRedirectHistoryEntry.idl",
+    "nsIRedirectResultListener.idl",
+    "nsIRequest.idl",
+    "nsIRequestContext.idl",
+    "nsIRequestObserver.idl",
+    "nsIRequestObserverProxy.idl",
+    "nsIResumableChannel.idl",
+    "nsISecCheckWrapChannel.idl",
+    "nsISecureBrowserUI.idl",
+    "nsISensitiveInfoHiddenURI.idl",
+    "nsISerializationHelper.idl",
+    "nsIServerSocket.idl",
+    "nsISimpleStreamListener.idl",
+    "nsISimpleURIMutator.idl",
+    "nsISocketFilter.idl",
+    "nsISocketTransport.idl",
+    "nsISocketTransportService.idl",
+    "nsISpeculativeConnect.idl",
+    "nsIStandardURL.idl",
+    "nsIStreamListener.idl",
+    "nsIStreamListenerTee.idl",
+    "nsIStreamLoader.idl",
+    "nsIStreamTransportService.idl",
+    "nsISyncStreamListener.idl",
+    "nsISystemProxySettings.idl",
+    "nsIThreadRetargetableRequest.idl",
+    "nsIThreadRetargetableStreamListener.idl",
+    "nsIThrottledInputChannel.idl",
+    "nsITimedChannel.idl",
+    "nsITLSServerSocket.idl",
+    "nsITraceableChannel.idl",
+    "nsITransport.idl",
+    "nsIUDPSocket.idl",
+    "nsIUploadChannel.idl",
+    "nsIUploadChannel2.idl",
+    "nsIURI.idl",
+    "nsIURIMutator.idl",
+    "nsIURIWithSpecialOrigin.idl",
+    "nsIURL.idl",
+    "nsIURLParser.idl",
+    "nsPISocketTransportService.idl",
+]
+
+XPIDL_MODULE = "necko"
+
+EXPORTS += [
+    "netCore.h",
+    "nsASocketHandler.h",
+    "nsAsyncRedirectVerifyHelper.h",
+    "nsBaseChannel.h",
+    "nsFileStreams.h",
+    "nsInputStreamPump.h",
+    "nsMIMEInputStream.h",
+    "nsNetUtil.h",
+    "nsReadLine.h",
+    "nsSerializationHelper.h",
+    "nsSimpleNestedURI.h",
+    "nsSimpleURI.h",
+    "nsStandardURL.h",
+    "nsStreamListenerWrapper.h",
+    "nsURIHashKey.h",
+    "nsURLHelper.h",
+    "nsURLParsers.h",
+    "SimpleChannel.h",
+]
+
+EXPORTS.mozilla += [
+    "LoadContextInfo.h",
+    "LoadInfo.h",
+    "LoadTainting.h",
+    "nsRedirectHistoryEntry.h",
+]
+
+EXPORTS.mozilla.net += [
+    "CacheInfoIPCTypes.h",
+    "CaptivePortalService.h",
+    "Dashboard.h",
+    "DashboardTypes.h",
+    "DefaultURI.h",
+    "InterceptionInfo.h",
+    "IOActivityMonitor.h",
+    "MemoryDownloader.h",
+    "NetworkConnectivityService.h",
+    "Predictor.h",
+    "PrivateBrowsingChannel.h",
+    "ProtocolHandlerInfo.h",
+    "RedirectChannelRegistrar.h",
+    "RequestContextService.h",
+    "SimpleChannelParent.h",
+    "SSLTokensCache.h",
+    "ThrottleQueue.h",
+]
+
+UNIFIED_SOURCES += [
+    "ArrayBufferInputStream.cpp",
+    "BackgroundFileSaver.cpp",
+    "CaptivePortalService.cpp",
+    "Dashboard.cpp",
+    "DefaultURI.cpp",
+    "EventTokenBucket.cpp",
+    "InterceptionInfo.cpp",
+    "IOActivityMonitor.cpp",
+    "LoadContextInfo.cpp",
+    "LoadInfo.cpp",
+    "MemoryDownloader.cpp",
+    "NetworkConnectivityService.cpp",
+    "NetworkDataCountLayer.cpp",
+    "nsAsyncRedirectVerifyHelper.cpp",
+    "nsAsyncStreamCopier.cpp",
+    "nsAuthInformationHolder.cpp",
+    "nsBase64Encoder.cpp",
+    "nsBaseChannel.cpp",
+    "nsBaseContentStream.cpp",
+    "nsBufferedStreams.cpp",
+    "nsDirectoryIndexStream.cpp",
+    "nsDNSPrefetch.cpp",
+    "nsDownloader.cpp",
+    "nsFileStreams.cpp",
+    "nsIncrementalDownload.cpp",
+    "nsIncrementalStreamLoader.cpp",
+    "nsInputStreamChannel.cpp",
+    "nsInputStreamPump.cpp",
+    "nsIOService.cpp",
+    "nsIURIMutatorUtils.cpp",
+    "nsLoadGroup.cpp",
+    "nsMIMEInputStream.cpp",
+    "nsNetAddr.cpp",
+    "nsNetUtil.cpp",
+    "nsPACMan.cpp",
+    "nsPreloadedStream.cpp",
+    "nsProtocolProxyService.cpp",
+    "nsProxyInfo.cpp",
+    "nsRedirectHistoryEntry.cpp",
+    "nsRequestObserverProxy.cpp",
+    "nsSerializationHelper.cpp",
+    "nsServerSocket.cpp",
+    "nsSimpleNestedURI.cpp",
+    "nsSimpleStreamListener.cpp",
+    "nsSimpleURI.cpp",
+    "nsSocketTransport2.cpp",
+    "nsSocketTransportService2.cpp",
+    "nsStandardURL.cpp",
+    "nsStreamListenerTee.cpp",
+    "nsStreamListenerWrapper.cpp",
+    "nsStreamLoader.cpp",
+    "nsStreamTransportService.cpp",
+    "nsSyncStreamListener.cpp",
+    "nsTransportUtils.cpp",
+    "nsUDPSocket.cpp",
+    "PollableEvent.cpp",
+    "Predictor.cpp",
+    "ProtocolHandlerInfo.cpp",
+    "ProxyAutoConfig.cpp",
+    "RedirectChannelRegistrar.cpp",
+    "RequestContextService.cpp",
+    "SimpleBuffer.cpp",
+    "SimpleChannel.cpp",
+    "SimpleChannelParent.cpp",
+    "SSLTokensCache.cpp",
+    "ThrottleQueue.cpp",
+    "Tickler.cpp",
+    "TLSServerSocket.cpp",
+    "TRRLoadInfo.cpp",
+]
+
+if CONFIG["FUZZING"]:
+    SOURCES += [
+        "FuzzyLayer.cpp",
+        "FuzzySecurityInfo.cpp",
+        "FuzzySocketControl.cpp",
+    ]
+
+if CONFIG["FUZZING_INTERFACES"] and CONFIG["LIBFUZZER"]:
+    include("/tools/fuzzing/libfuzzer-flags.mozbuild")
+    SOURCES += [
+        "nsMediaFragmentURIParser.cpp",
+        "nsURLHelper.cpp",
+        "nsURLParsers.cpp",
+    ]
+    SOURCES["nsMediaFragmentURIParser.cpp"].flags += libfuzzer_flags
+    SOURCES["nsURLHelper.cpp"].flags += libfuzzer_flags
+    SOURCES["nsURLParsers.cpp"].flags += libfuzzer_flags
+else:
+    UNIFIED_SOURCES += [
+        "nsMediaFragmentURIParser.cpp",
+        "nsURLHelper.cpp",
+        "nsURLParsers.cpp",
+    ]
+
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
+    SOURCES += [
+        "nsURLHelperWin.cpp",
+        "ShutdownLayer.cpp",
+    ]
+elif CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    SOURCES += [
+        "nsURLHelperOSX.cpp",
+    ]
+else:
+    SOURCES += [
+        "nsURLHelperUnix.cpp",
+    ]
+
+# nsINetworkInfoService support.
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
+    SOURCES += [
+        "NetworkInfoServiceWindows.cpp",
+        "nsNetworkInfoService.cpp",
+    ]
+elif CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    SOURCES += [
+        "NetworkInfoServiceCocoa.cpp",
+        "nsNetworkInfoService.cpp",
+    ]
+elif CONFIG["OS_ARCH"] == "Linux":
+    SOURCES += [
+        "NetworkInfoServiceLinux.cpp",
+        "nsNetworkInfoService.cpp",
+    ]
+
+EXTRA_JS_MODULES += [
+    "NetUtil.sys.mjs",
+]
+
+DIRS += ["mozurl", "rust-helper", "http-sfv"]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
+
+LOCAL_INCLUDES += [
+    "!/xpcom/components",
+    "/docshell/base",
+    "/dom/base",
+    "/js/xpconnect/src",
+    "/netwerk/dns",
+    "/netwerk/protocol/http",
+    "/netwerk/protocol/webtransport",
+    "/netwerk/socket",
+    "/netwerk/url-classifier",
+    "/security/manager/ssl",
+    "/xpcom/components",
+]
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    LOCAL_INCLUDES += [
+        "/xpcom/base",
+    ]
+
+GeneratedFile(
+    "ascii_pac_utils.inc", script="makecppstring.py", inputs=["ascii_pac_utils.js"]
+)
diff --git a/netwerk/base/mozIThirdPartyUtil.idl b/netwerk/base/mozIThirdPartyUtil.idl
new file mode 100644
index 0000000000..0c029942d8
--- /dev/null
+++ b/netwerk/base/mozIThirdPartyUtil.idl
@@ -0,0 +1,231 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface mozIDOMWindowProxy;
+interface nsIChannel;
+interface nsIPrincipal;
+interface nsILoadInfo;
+
+%{C++
+
+#include "mozilla/EnumSet.h"
+
+enum class ThirdPartyAnalysis {
+  IsForeign,
+  IsThirdPartyTrackingResource,
+  IsThirdPartySocialTrackingResource,
+  IsStorageAccessPermissionGranted,
+};
+
+using ThirdPartyAnalysisResult = mozilla::EnumSet<ThirdPartyAnalysis>;
+
+typedef bool (*RequireThirdPartyCheck)(nsILoadInfo*);
+
+%}
+
+native ThirdPartyAnalysisResult(ThirdPartyAnalysisResult);
+native RequireThirdPartyCheck(RequireThirdPartyCheck);
+
+/**
+ * Utility functions for determining whether a given URI, channel, or window
+ * hierarchy is third party with respect to a known URI.
+ */
+[scriptable, builtinclass, uuid(fd82700e-ffb4-4932-b7d6-08f0b5697dda)]
+interface mozIThirdPartyUtil : nsISupports
+{
+  /**
+   * isThirdPartyURI
+   *
+   * Determine whether two URIs are third party with respect to each other.
+   * This is determined by computing the base domain for both URIs. If they can
+   * be determined, and the base domains match, the request is defined as first
+   * party. If it cannot be determined because one or both URIs do not have a
+   * base domain (for instance, in the case of IP addresses, host aliases such
+   * as 'localhost', or a file:// URI), an exact string comparison on host is
+   * performed.
+   *
+   * For example, the URI "http://mail.google.com/" is not third party with
+   * respect to "http://images.google.com/", but "http://mail.yahoo.com/" and
+   * "http://192.168.1.1/" are.
+   *
+   * @return true if aFirstURI is third party with respect to aSecondURI.
+   *
+   * @throws if either URI is null, has a malformed host, or has an empty host
+   *         and is not a file:// URI.
+   */
+  boolean isThirdPartyURI(in nsIURI aFirstURI, in nsIURI aSecondURI);
+
+  /**
+   * isThirdPartyWindow
+   *
+   * Determine whether the given window hierarchy is third party. This is done
+   * as follows:
+   *
+   * 1) Obtain the URI of the principal associated with 'aWindow'. Call this the
+   *    'bottom URI'.
+   * 2) If 'aURI' is provided, determine if it is third party with respect to
+   *    the bottom URI. If so, return.
+   * 3) Find the same-type parent window, if there is one, and its URI.
+   *    Determine whether it is third party with respect to the bottom URI. If
+   *    so, return.
+   *
+   * Therefore, each level in the window hierarchy is tested. (This means that
+   * nested iframes with different base domains, even though the bottommost and
+   * topmost URIs might be equal, will be considered third party.)
+   *
+   * @param aWindow
+   *        The bottommost window in the hierarchy.
+   * @param aURI
+   *        A URI to test against. If null, the URI of the principal
+   *        associated with 'aWindow' will be used.
+   *
+   * For example, if 'aURI' is "http://mail.google.com/", 'aWindow' has a URI
+   * of "http://google.com/", and its parent is the topmost content window with
+   * a URI of "http://mozilla.com", the result will be true.
+   *
+   * @return true if 'aURI' is third party with respect to any of the URIs
+   *         associated with aWindow and its same-type parents.
+   *
+   * @throws if aWindow is null; the same-type parent of any window in the
+   *         hierarchy cannot be determined; or the URI associated with any
+   *         window in the hierarchy is null, has a malformed host, or has an
+   *         empty host and is not a file:// URI.
+   *
+   * @see isThirdPartyURI
+   */
+  boolean isThirdPartyWindow(in mozIDOMWindowProxy aWindow, [optional] in nsIURI aURI);
+
+  /**
+   * isThirdPartyChannel
+   *
+   * Determine whether the given channel and its content window hierarchy is
+   * third party. This is done as follows:
+   *
+   * 1) If 'aChannel' is an nsIHttpChannel and has the
+   *    'forceAllowThirdPartyCookie' property set, then:
+   *    a) If 'aURI' is null, return false.
+   *    b) Otherwise, find the URI of the channel, determine whether it is
+   *       foreign with respect to 'aURI', and return.
+   * 2) Find the URI of the channel and determine whether it is third party with
+   *    respect to the URI of the channel. If so, return.
+   * 3) Obtain the bottommost nsIDOMWindow, and its same-type parent if it
+   *    exists, from the channel's notification callbacks. Then:
+   *    a) If the parent is the same as the bottommost window, and the channel
+   *       has the LOAD_DOCUMENT_URI flag set, return false. This represents the
+   *       case where a toplevel load is occurring and the window's URI has not
+   *       yet been updated. (We have already checked that 'aURI' is not foreign
+   *       with respect to the channel URI.)
+   *    b) Otherwise, return the result of isThirdPartyWindow with arguments
+   *       of the channel's bottommost window and the channel URI, respectively.
+   *
+   * Therefore, both the channel's URI and each level in the window hierarchy
+   * associated with the channel is tested.
+   *
+   * @param aChannel
+   *        The channel associated with the load.
+   * @param aURI
+   *        A URI to test against. If null, the URI of the channel will be used.
+   *
+   * For example, if 'aURI' is "http://mail.google.com/", 'aChannel' has a URI
+   * of "http://google.com/", and its parent is the topmost content window with
+   * a URI of "http://mozilla.com", the result will be true.
+   *
+   * @return true if aURI is third party with respect to the channel URI or any
+   *         of the URIs associated with the same-type window hierarchy of the
+   *         channel.
+   *
+   * @throws if 'aChannel' is null; the channel has no notification callbacks or
+   *         an associated window; or isThirdPartyWindow throws.
+   *
+   * @see isThirdPartyWindow
+   */
+  boolean isThirdPartyChannel(in nsIChannel aChannel, [optional] in nsIURI aURI);
+
+  /**
+   * getBaseDomain
+   *
+   * Get the base domain for aHostURI; e.g. for "www.bbc.co.uk", this would be
+   * "bbc.co.uk". Only properly-formed URI's are tolerated, though a trailing
+   * dot may be present. If aHostURI is an IP address, an alias such as
+   * 'localhost', an eTLD such as 'co.uk', or the empty string, aBaseDomain will
+   * be the exact host. The result of this function should only be used in exact
+   * string comparisons, since substring comparisons will not be valid for the
+   * special cases elided above.
+   *
+   * @param aHostURI
+   *        The URI to analyze.
+   *
+   * @return the base domain.
+   */
+  AUTF8String getBaseDomain(in nsIURI aHostURI);
+
+  /**
+   * NOTE: Long term, this method won't be needed once bug 922464 is fixed which
+   * will make it possible to parse all URI's off the main thread.
+   *
+   * getBaseDomainFromSchemeHost
+   *
+   * Get the base domain for aScheme and aHost. Otherwise identical to
+   * getBaseDomain().
+   *
+   * @param aScheme
+   *        The scheme to analyze.
+   *
+   * @param aAsciiHost
+   *        The host to analyze.
+   *
+   * @return the base domain.
+   */
+  AUTF8String getBaseDomainFromSchemeHost(in AUTF8String aScheme,
+                                          in AUTF8String aAsciiHost);
+
+  /**
+   * getURIFromWindow
+   *
+   * Returns the URI associated with the script object principal for the
+   * window.
+   */
+  nsIURI getURIFromWindow(in mozIDOMWindowProxy aWindow);
+
+  /**
+   * getPrincipalFromWindow
+   *
+   * Returns the script object principal for the window.
+   */
+  nsIPrincipal getPrincipalFromWindow(in mozIDOMWindowProxy aWindow);
+
+  /**
+   * getTopWindowForChannel
+   *
+   * Returns the top-level window associated with the given channel.
+   */
+  [noscript]
+  mozIDOMWindowProxy getTopWindowForChannel(in nsIChannel aChannel, [optional] in nsIURI aURIBeingLoaded);
+
+  /*
+   * Performs a full analysis of a channel.
+   *
+   * aChannel the input channel
+   * aNotify whether to send content blocking notifications if access control checks fail
+   * aURI optional URI to check for (the channel URI will be used instead if not provided)
+   * aRequireThirdPartyCheck a functor used to determine whether the load info requires third-party checks
+   */
+  [noscript, notxpcom]
+  ThirdPartyAnalysisResult analyzeChannel(in nsIChannel aChannel,
+                                          in boolean aNotify,
+                                          [optional] in nsIURI aURI,
+                                          [optional] in RequireThirdPartyCheck aRequireThirdPartyCheck,
+                                          out uint32_t aRejectedReason);
+};
+
+%{ C++
+/**
+ * The mozIThirdPartyUtil implementation is an XPCOM service registered
+ * under the ContractID:
+ */
+#define THIRDPARTYUTIL_CONTRACTID "@mozilla.org/thirdpartyutil;1"
+%}
diff --git a/netwerk/base/mozurl/.gitignore b/netwerk/base/mozurl/.gitignore
new file mode 100644
index 0000000000..4fffb2f89c
--- /dev/null
+++ b/netwerk/base/mozurl/.gitignore
@@ -0,0 +1,2 @@
+/target
+/Cargo.lock
diff --git a/netwerk/base/mozurl/Cargo.toml b/netwerk/base/mozurl/Cargo.toml
new file mode 100644
index 0000000000..0eaccad0b8
--- /dev/null
+++ b/netwerk/base/mozurl/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "mozurl"
+version = "0.0.1"
+authors = ["Nika Layzell <nika@thelayzells.com>"]
+license = "MPL-2.0"
+
+[dependencies]
+url = "2.0"
+nserror = { path = "../../../xpcom/rust/nserror" }
+nsstring = { path = "../../../xpcom/rust/nsstring" }
+xpcom = { path = "../../../xpcom/rust/xpcom" }
+uuid = { version = "1.0", features = ["v4"] }
diff --git a/netwerk/base/mozurl/MozURL.cpp b/netwerk/base/mozurl/MozURL.cpp
new file mode 100644
index 0000000000..47a679164a
--- /dev/null
+++ b/netwerk/base/mozurl/MozURL.cpp
@@ -0,0 +1,12 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/StaticPrefs_security.h"
+
+extern "C" {
+
+bool Gecko_StrictFileOriginPolicy() {
+  return mozilla::StaticPrefs::security_fileuri_strict_origin_policy();
+}
+}
diff --git a/netwerk/base/mozurl/MozURL.h b/netwerk/base/mozurl/MozURL.h
new file mode 100644
index 0000000000..ddd91c1b0c
--- /dev/null
+++ b/netwerk/base/mozurl/MozURL.h
@@ -0,0 +1,231 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozURL_h__
+#define mozURL_h__
+
+#include "mozilla/net/MozURL_ffi.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/Result.h"
+
+namespace mozilla {
+namespace net {
+
+// This class provides a thread-safe, immutable URL parser.
+// As long as there is RefPtr to the object, you may use it on any thread.
+// The constructor is private. One can instantiate the object by
+// calling the Init() method as such:
+//
+// RefPtr<MozURL> url;
+// nsAutoCString href("http://example.com/path?query#ref");
+// nsresult rv = MozURL::Init(getter_AddRefs(url), href);
+// if (NS_SUCCEEDED(rv)) { /* use url */ }
+//
+// When changing the URL is needed, you need to call the Mutate() method.
+// This gives you a Mutator object, on which you can perform setter operations.
+// Calling Finalize() on the Mutator will result in a new MozURL and a status
+// code. If any of the setter operations failed, it will be reflected in the
+// status code, and a null MozURL.
+//
+// Note: In the case of a domain name containing non-ascii characters,
+// GetSpec and GetHostname will return the IDNA(punycode) version of the host.
+// Also note that for now, MozURL only supports the UTF-8 charset.
+//
+// Implementor Note: This type is only a holder for methods in C++, and does not
+// reflect the actual layout of the type.
+class MozURL final {
+ public:
+  static nsresult Init(MozURL** aURL, const nsACString& aSpec,
+                       const MozURL* aBaseURL = nullptr) {
+    return mozurl_new(aURL, &aSpec, aBaseURL);
+  }
+
+  nsDependentCSubstring Spec() const { return mozurl_spec(this); }
+  nsDependentCSubstring Scheme() const { return mozurl_scheme(this); }
+  nsDependentCSubstring Username() const { return mozurl_username(this); }
+  nsDependentCSubstring Password() const { return mozurl_password(this); }
+  // Will return the hostname of URL. If the hostname is an IPv6 address,
+  // it will be enclosed in square brackets, such as `[::1]`
+  nsDependentCSubstring Host() const { return mozurl_host(this); }
+  // Will return the port number, if specified, or -1
+  int32_t Port() const { return mozurl_port(this); }
+  int32_t RealPort() const { return mozurl_real_port(this); }
+  // If the URL's port number is equal to the default port, will only return the
+  // hostname, otherwise it will return a string of the form `{host}:{port}`
+  // See: https://url.spec.whatwg.org/#default-port
+  nsDependentCSubstring HostPort() const { return mozurl_host_port(this); }
+  nsDependentCSubstring FilePath() const { return mozurl_filepath(this); }
+  nsDependentCSubstring Path() const { return mozurl_path(this); }
+  nsDependentCSubstring Query() const { return mozurl_query(this); }
+  nsDependentCSubstring Ref() const { return mozurl_fragment(this); }
+  bool HasFragment() const { return mozurl_has_fragment(this); }
+  nsDependentCSubstring Directory() const { return mozurl_directory(this); }
+  nsDependentCSubstring PrePath() const { return mozurl_prepath(this); }
+  nsDependentCSubstring SpecNoRef() const { return mozurl_spec_no_ref(this); }
+
+  // This matches the definition of origins and base domains in nsIPrincipal for
+  // almost all URIs (some rare file:// URIs don't match and it would be hard to
+  // fix them). It definitely matches nsIPrincipal for URIs used in quota
+  // manager and there are checks in quota manager and its clients that prevent
+  // different definitions (see QuotaManager::IsPrincipalInfoValid).
+  // See also TestMozURL.cpp which enumerates a huge pile of URIs and checks
+  // that origin and base domain definitions are in sync.
+  void Origin(nsACString& aOrigin) const { mozurl_origin(this, &aOrigin); }
+  nsresult BaseDomain(nsACString& aBaseDomain) const {
+    return mozurl_base_domain(this, &aBaseDomain);
+  }
+
+  nsresult GetCommonBase(const MozURL* aOther, MozURL** aCommon) const {
+    return mozurl_common_base(this, aOther, aCommon);
+  }
+  nsresult GetRelative(const MozURL* aOther, nsACString* aRelative) const {
+    return mozurl_relative(this, aOther, aRelative);
+  }
+
+  size_t SizeOf() { return mozurl_sizeof(this); }
+
+  class Mutator {
+   public:
+    // Calling this method will result in the creation of a new MozURL that
+    // adopts the mutator's mURL.
+    // If any of the setters failed with an error code, that error code will be
+    // returned here. It will also return an error code if Finalize is called
+    // more than once on the Mutator.
+    nsresult Finalize(MozURL** aURL) {
+      nsresult rv = GetStatus();
+      if (NS_SUCCEEDED(rv)) {
+        mURL.forget(aURL);
+      } else {
+        *aURL = nullptr;
+      }
+      return rv;
+    }
+
+    // These setter methods will return a reference to `this` so that you may
+    // chain setter operations as such:
+    //
+    // RefPtr<MozURL> url2;
+    // nsresult rv = url->Mutate().SetHostname("newhost"_ns)
+    //                            .SetFilePath("new/file/path"_ns)
+    //                            .Finalize(getter_AddRefs(url2));
+    // if (NS_SUCCEEDED(rv)) { /* use url2 */ }
+    Mutator& SetScheme(const nsACString& aScheme) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_scheme(mURL, &aScheme);
+      }
+      return *this;
+    }
+    Mutator& SetUsername(const nsACString& aUser) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_username(mURL, &aUser);
+      }
+      return *this;
+    }
+    Mutator& SetPassword(const nsACString& aPassword) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_password(mURL, &aPassword);
+      }
+      return *this;
+    }
+    Mutator& SetHostname(const nsACString& aHost) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_hostname(mURL, &aHost);
+      }
+      return *this;
+    }
+    Mutator& SetHostPort(const nsACString& aHostPort) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_host_port(mURL, &aHostPort);
+      }
+      return *this;
+    }
+    Mutator& SetFilePath(const nsACString& aPath) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_pathname(mURL, &aPath);
+      }
+      return *this;
+    }
+    Mutator& SetQuery(const nsACString& aQuery) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_query(mURL, &aQuery);
+      }
+      return *this;
+    }
+    Mutator& SetRef(const nsACString& aRef) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_fragment(mURL, &aRef);
+      }
+      return *this;
+    }
+    Mutator& SetPort(int32_t aPort) {
+      if (NS_SUCCEEDED(GetStatus())) {
+        mStatus = mozurl_set_port_no(mURL, aPort);
+      }
+      return *this;
+    }
+
+    // This method returns the status code of the setter operations.
+    // If any of the setters failed, it will return the code of the first error
+    // that occured. If none of the setters failed, it will return NS_OK.
+    // This method is useful to avoid doing expensive operations when the result
+    // would not be used because an error occurred. For example:
+    //
+    // RefPtr<MozURL> url2;
+    // MozURL::Mutator mut = url->Mutate();
+    // mut.SetScheme("!@#$"); // this would fail
+    // if (NS_SUCCEDED(mut.GetStatus())) {
+    //   nsAutoCString host(ExpensiveComputing());
+    //   rv = mut.SetHostname(host).Finalize(getter_AddRefs(url2));
+    // }
+    // if (NS_SUCCEEDED(rv)) { /* use url2 */ }
+    nsresult GetStatus() { return mURL ? mStatus : NS_ERROR_NOT_AVAILABLE; }
+
+    static Result<Mutator, nsresult> FromSpec(
+        const nsACString& aSpec, const MozURL* aBaseURL = nullptr) {
+      Mutator m = Mutator(aSpec, aBaseURL);
+      if (m.mURL) {
+        MOZ_ASSERT(NS_SUCCEEDED(m.mStatus));
+        return m;
+      }
+
+      MOZ_ASSERT(NS_FAILED(m.mStatus));
+      return Err(m.mStatus);
+    }
+
+   private:
+    explicit Mutator(MozURL* aUrl) : mStatus(NS_OK) {
+      mozurl_clone(aUrl, getter_AddRefs(mURL));
+    }
+
+    // This is only used to create a mutator from a string without cloning it
+    // so we avoid a pointless copy in FromSpec. It is important that we
+    // check the value of mURL afterwards.
+    explicit Mutator(const nsACString& aSpec,
+                     const MozURL* aBaseURL = nullptr) {
+      mStatus = mozurl_new(getter_AddRefs(mURL), &aSpec, aBaseURL);
+    }
+    RefPtr<MozURL> mURL;
+    nsresult mStatus;
+    friend class MozURL;
+  };
+
+  Mutator Mutate() { return Mutator(this); }
+
+  // AddRef and Release are non-virtual on this type, and always call into rust.
+  void AddRef() { mozurl_addref(this); }
+  void Release() { mozurl_release(this); }
+
+ private:
+  // Make it a compile time error for C++ code to ever create, destruct, or copy
+  // MozURL objects. All of these operations will be performed by rust.
+  MozURL();  /* never defined */
+  ~MozURL(); /* never defined */
+  MozURL(const MozURL&) = delete;
+  MozURL& operator=(const MozURL&) = delete;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozURL_h__
diff --git a/netwerk/base/mozurl/cbindgen.toml b/netwerk/base/mozurl/cbindgen.toml
new file mode 100644
index 0000000000..bb5fdbd08f
--- /dev/null
+++ b/netwerk/base/mozurl/cbindgen.toml
@@ -0,0 +1,61 @@
+header = """/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* The MozURL type is implemented in Rust code, and uses extern "C" FFI calls to
+ * operate on the internal data structure. This file contains C declarations of
+ * these files.
+
+ * WARNING: DO NOT CALL ANY OF THESE FUNCTIONS. USE |MozURL| INSTEAD! */
+ """
+autogen_warning = """/* DO NOT MODIFY THIS MANUALLY! This file was generated using cbindgen. */
+
+namespace mozilla {
+namespace net {
+class MozURL;
+}  // namespace net
+}  // namespace mozilla
+
+extern "C" {
+
+// FFI-compatible string slice struct used internally by MozURL.
+// Coerces to nsDependentCSubstring.
+struct MozURLSpecSlice {
+  char* mData;
+  uint32_t mLen;
+
+  operator nsDependentCSubstring() {
+    return nsDependentCSubstring(mData, mLen);
+  }
+};
+
+nsresult mozurl_new(mozilla::net::MozURL** aResult, const nsACString* aSpec,
+                    /* optional */ const mozilla::net::MozURL* aBase);
+
+void mozurl_clone(const mozilla::net::MozURL* aThis,
+                  mozilla::net::MozURL** aResult);
+
+nsresult mozurl_common_base(const mozilla::net::MozURL* aUrl1,
+                            const mozilla::net::MozURL* aUrl2,
+                            mozilla::net::MozURL** aResult);
+}
+
+"""
+
+include_guard = "mozilla_net_MozURL_ffi_h"
+include_version = true
+braces = "SameLine"
+line_length = 100
+tab_width = 2
+language = "C++"
+namespaces = []
+includes = ["nsError.h", "nsString.h"]
+
+[export]
+exclude = ["Gecko_StrictFileOriginPolicy", "MozURL", "SpecSlice", "mozurl_new", "mozurl_clone", "mozurl_common_base"]
+item_types = ["globals", "enums", "structs", "unions", "typedefs", "opaque", "functions", "constants"]
+
+
+[export.rename]
+"SpecSlice" = "MozURLSpecSlice"
+"MozURL" = "mozilla::net::MozURL"
diff --git a/netwerk/base/mozurl/moz.build b/netwerk/base/mozurl/moz.build
new file mode 100644
index 0000000000..0a4e522b5a
--- /dev/null
+++ b/netwerk/base/mozurl/moz.build
@@ -0,0 +1,22 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS.mozilla.net += [
+    "MozURL.h",
+]
+
+SOURCES += [
+    "MozURL.cpp",
+]
+
+FINAL_LIBRARY = "xul"
+
+if CONFIG["COMPILE_ENVIRONMENT"]:
+    CbindgenHeader("MozURL_ffi.h", inputs=["/netwerk/base/mozurl"])
+
+    EXPORTS.mozilla.net += [
+        "!MozURL_ffi.h",
+    ]
diff --git a/netwerk/base/mozurl/src/lib.rs b/netwerk/base/mozurl/src/lib.rs
new file mode 100644
index 0000000000..7b73311e73
--- /dev/null
+++ b/netwerk/base/mozurl/src/lib.rs
@@ -0,0 +1,564 @@
+/* -*- Mode: rust; rust-indent-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+extern crate url;
+use url::quirks;
+use url::{ParseOptions, Position, Url};
+
+extern crate nsstring;
+use nsstring::{nsACString, nsCString};
+
+extern crate nserror;
+use nserror::*;
+
+extern crate xpcom;
+use xpcom::interfaces::mozIThirdPartyUtil;
+use xpcom::{AtomicRefcnt, RefCounted, RefPtr};
+
+extern crate uuid;
+use uuid::Uuid;
+
+use std::fmt::Write;
+use std::marker::PhantomData;
+use std::mem;
+use std::ops;
+use std::ptr;
+use std::str;
+
+extern "C" {
+    fn Gecko_StrictFileOriginPolicy() -> bool;
+}
+
+/// Helper macro. If the expression $e is Ok(t) evaluates to t, otherwise,
+/// returns NS_ERROR_MALFORMED_URI.
+macro_rules! try_or_malformed {
+    ($e:expr) => {
+        match $e {
+            Ok(v) => v,
+            Err(_) => return NS_ERROR_MALFORMED_URI,
+        }
+    };
+}
+
+fn parser<'a>() -> ParseOptions<'a> {
+    Url::options()
+}
+
+fn default_port(scheme: &str) -> Option<u16> {
+    match scheme {
+        "ftp" => Some(21),
+        "gopher" => Some(70),
+        "http" => Some(80),
+        "https" => Some(443),
+        "ws" => Some(80),
+        "wss" => Some(443),
+        "rtsp" => Some(443),
+        "moz-anno" => Some(443),
+        "android" => Some(443),
+        _ => None,
+    }
+}
+
+/// A slice into the backing string. This type is only valid as long as the
+/// MozURL which it was pulled from is valid. In C++, this type implicitly
+/// converts to a nsDependentCString, and is an implementation detail.
+///
+/// This type exists because, unlike &str, this type is safe to return over FFI.
+#[repr(C)]
+pub struct SpecSlice<'a> {
+    data: *const u8,
+    len: u32,
+    _marker: PhantomData<&'a [u8]>,
+}
+
+impl<'a> From<&'a str> for SpecSlice<'a> {
+    fn from(s: &'a str) -> SpecSlice<'a> {
+        assert!(s.len() < u32::max_value() as usize);
+        SpecSlice {
+            data: s.as_ptr(),
+            len: s.len() as u32,
+            _marker: PhantomData,
+        }
+    }
+}
+
+/// The MozURL reference-counted threadsafe URL type. This type intentionally
+/// implements no XPCOM interfaces, and all method calls are non-virtual.
+#[repr(C)]
+pub struct MozURL {
+    pub url: Url,
+    refcnt: AtomicRefcnt,
+}
+
+impl MozURL {
+    pub fn from_url(url: Url) -> RefPtr<MozURL> {
+        // Actually allocate the URL on the heap. This is the only place we actually
+        // create a MozURL, other than in clone().
+        unsafe {
+            RefPtr::from_raw(Box::into_raw(Box::new(MozURL {
+                url: url,
+                refcnt: AtomicRefcnt::new(),
+            })))
+            .unwrap()
+        }
+    }
+}
+
+impl ops::Deref for MozURL {
+    type Target = Url;
+    fn deref(&self) -> &Url {
+        &self.url
+    }
+}
+impl ops::DerefMut for MozURL {
+    fn deref_mut(&mut self) -> &mut Url {
+        &mut self.url
+    }
+}
+
+// Memory Management for MozURL
+#[no_mangle]
+pub unsafe extern "C" fn mozurl_addref(url: &MozURL) {
+    url.refcnt.inc();
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozurl_release(url: &MozURL) {
+    let rc = url.refcnt.dec();
+    if rc == 0 {
+        mem::drop(Box::from_raw(url as *const MozURL as *mut MozURL));
+    }
+}
+
+// xpcom::RefPtr support
+unsafe impl RefCounted for MozURL {
+    unsafe fn addref(&self) {
+        mozurl_addref(self);
+    }
+    unsafe fn release(&self) {
+        mozurl_release(self);
+    }
+}
+
+// Allocate a new MozURL object with a RefCnt of 1, and store a pointer to it
+// into url.
+#[no_mangle]
+pub extern "C" fn mozurl_new(
+    result: &mut *const MozURL,
+    spec: &nsACString,
+    base: Option<&MozURL>,
+) -> nsresult {
+    *result = ptr::null_mut();
+
+    let spec = try_or_malformed!(str::from_utf8(spec));
+    let url = if let Some(base) = base {
+        try_or_malformed!(base.url.join(spec))
+    } else {
+        try_or_malformed!(parser().parse(spec))
+    };
+
+    MozURL::from_url(url).forget(result);
+    NS_OK
+}
+
+/// Allocate a new MozURL object which is a clone of the original, and store a
+/// pointer to it into newurl.
+#[no_mangle]
+pub extern "C" fn mozurl_clone(url: &MozURL, newurl: &mut *const MozURL) {
+    MozURL::from_url(url.url.clone()).forget(newurl);
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_spec(url: &MozURL) -> SpecSlice {
+    url.as_ref().into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_scheme(url: &MozURL) -> SpecSlice {
+    url.scheme().into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_username(url: &MozURL) -> SpecSlice {
+    if url.cannot_be_a_base() {
+        "".into()
+    } else {
+        url.username().into()
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_password(url: &MozURL) -> SpecSlice {
+    url.password().unwrap_or("").into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_host(url: &MozURL) -> SpecSlice {
+    url.host_str().unwrap_or("").into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_port(url: &MozURL) -> i32 {
+    // NOTE: Gecko uses -1 to represent the default port.
+    url.port().map(|p| p as i32).unwrap_or(-1)
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_real_port(url: &MozURL) -> i32 {
+    url.port()
+        .or_else(|| default_port(url.scheme()))
+        .map(|p| p as i32)
+        .unwrap_or(-1)
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_host_port(url: &MozURL) -> SpecSlice {
+    (&url[Position::BeforeHost..Position::BeforePath]).into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_filepath(url: &MozURL) -> SpecSlice {
+    url.path().into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_path(url: &MozURL) -> SpecSlice {
+    (&url[Position::BeforePath..]).into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_query(url: &MozURL) -> SpecSlice {
+    url.query().unwrap_or("").into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_fragment(url: &MozURL) -> SpecSlice {
+    url.fragment().unwrap_or("").into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_spec_no_ref(url: &MozURL) -> SpecSlice {
+    (&url[..Position::AfterQuery]).into()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_has_fragment(url: &MozURL) -> bool {
+    url.fragment().is_some()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_directory(url: &MozURL) -> SpecSlice {
+    if let Some(position) = url.path().rfind('/') {
+        url.path()[..position + 1].into()
+    } else {
+        url.path().into()
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_prepath(url: &MozURL) -> SpecSlice {
+    (&url[..Position::BeforePath]).into()
+}
+
+fn get_origin(url: &MozURL) -> Option<String> {
+    match url.scheme() {
+        "blob" | "ftp" | "http" | "https" | "ws" | "wss" => {
+            Some(url.origin().ascii_serialization())
+        }
+        "indexeddb" | "moz-extension" | "resource" => {
+            let host = url.host_str().unwrap_or("");
+
+            let port = url.port().or_else(|| default_port(url.scheme()));
+
+            if port == default_port(url.scheme()) {
+                Some(format!("{}://{}", url.scheme(), host))
+            } else {
+                Some(format!("{}://{}:{}", url.scheme(), host, port.unwrap()))
+            }
+        }
+        "file" => {
+            if unsafe { Gecko_StrictFileOriginPolicy() } {
+                Some(url[..Position::AfterPath].to_owned())
+            } else {
+                Some("file://UNIVERSAL_FILE_URI_ORIGIN".to_owned())
+            }
+        }
+        "about" | "moz-safe-about" => Some(url[..Position::AfterPath].to_owned()),
+        _ => None,
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_origin(url: &MozURL, origin: &mut nsACString) {
+    let origin_str = if !url.as_ref().starts_with("about:blank") {
+        get_origin(url)
+    } else {
+        None
+    };
+
+    let origin_str = origin_str.unwrap_or_else(|| {
+        // nsIPrincipal stores the uuid, so the same uuid is returned everytime.
+        // We can't do that for MozURL because it can be used across threads.
+        // Storing uuid would mutate the object which would cause races between
+        // threads.
+        format!("moz-nullprincipal:{{{}}}", Uuid::new_v4())
+    });
+
+    // NOTE: Try to re-use the allocation we got from rust-url, and transfer
+    // ownership of the buffer to C++.
+    let mut o = nsCString::from(origin_str);
+    origin.take_from(&mut o);
+}
+
+fn get_base_domain(url: &MozURL) -> Result<Option<String>, nsresult> {
+    match url.scheme() {
+        "ftp" | "http" | "https" | "moz-extension" | "resource" => {
+            let third_party_util: RefPtr<mozIThirdPartyUtil> =
+                xpcom::components::ThirdPartyUtil::service()
+                    .map_err(|_| NS_ERROR_ILLEGAL_DURING_SHUTDOWN)?;
+
+            let scheme = nsCString::from(url.scheme());
+
+            let mut host_str = url.host_str().unwrap_or("");
+
+            if host_str.starts_with('[') && host_str.ends_with(']') {
+                host_str = &host_str[1..host_str.len() - 1];
+            }
+
+            let host = nsCString::from(host_str);
+
+            unsafe {
+                let mut string = nsCString::new();
+                third_party_util
+                    .GetBaseDomainFromSchemeHost(&*scheme, &*host, &mut *string)
+                    .to_result()?;
+
+                // We know that GetBaseDomainFromSchemeHost returns AUTF8String, so just
+                // use unwrap().
+                Ok(Some(String::from_utf8(string.to_vec()).unwrap()))
+            }
+        }
+        "ws" | "wss" => Ok(Some(url.as_ref().to_owned())),
+        "file" => {
+            if unsafe { Gecko_StrictFileOriginPolicy() } {
+                Ok(Some(url.path().to_owned()))
+            } else {
+                Ok(Some("UNIVERSAL_FILE_URI_ORIGIN".to_owned()))
+            }
+        }
+        "about" | "moz-safe-about" | "indexeddb" => Ok(Some(url.as_ref().to_owned())),
+        _ => Ok(None),
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_base_domain(url: &MozURL, base_domain: &mut nsACString) -> nsresult {
+    let base_domain_str = if !url.as_ref().starts_with("about:blank") {
+        match get_base_domain(url) {
+            Ok(domain) => domain,
+            Err(rv) => return rv,
+        }
+    } else {
+        None
+    };
+
+    let base_domain_str = base_domain_str.unwrap_or_else(|| {
+        // See the comment in mozurl_origin about why we return a new uuid for
+        // "moz-nullprincipals".
+        format!("{{{}}}", Uuid::new_v4())
+    });
+
+    let mut bd = nsCString::from(base_domain_str);
+    base_domain.take_from(&mut bd);
+
+    NS_OK
+}
+
+// Helper macro for debug asserting that we're the only reference to MozURL.
+macro_rules! debug_assert_mut {
+    ($e:expr) => {
+        debug_assert_eq!($e.refcnt.get(), 1, "Cannot mutate an aliased MozURL!");
+    };
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_scheme(url: &mut MozURL, scheme: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let scheme = try_or_malformed!(str::from_utf8(scheme));
+    try_or_malformed!(quirks::set_protocol(url, scheme));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_username(url: &mut MozURL, username: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let username = try_or_malformed!(str::from_utf8(username));
+    try_or_malformed!(quirks::set_username(url, username));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_password(url: &mut MozURL, password: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let password = try_or_malformed!(str::from_utf8(password));
+    try_or_malformed!(quirks::set_password(url, password));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_host_port(url: &mut MozURL, hostport: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let hostport = try_or_malformed!(str::from_utf8(hostport));
+    try_or_malformed!(quirks::set_host(url, hostport));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_hostname(url: &mut MozURL, host: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let host = try_or_malformed!(str::from_utf8(host));
+    try_or_malformed!(quirks::set_hostname(url, host));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_port_no(url: &mut MozURL, new_port: i32) -> nsresult {
+    debug_assert_mut!(url);
+    if url.cannot_be_a_base() {
+        return NS_ERROR_MALFORMED_URI;
+    }
+
+    let port = match new_port {
+        new if new < 0 || u16::max_value() as i32 <= new => None,
+        new if Some(new as u16) == default_port(url.scheme()) => None,
+        new => Some(new as u16),
+    };
+    try_or_malformed!(url.set_port(port));
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_pathname(url: &mut MozURL, path: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let path = try_or_malformed!(str::from_utf8(path));
+    quirks::set_pathname(url, path);
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_query(url: &mut MozURL, query: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let query = try_or_malformed!(str::from_utf8(query));
+    quirks::set_search(url, query);
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_set_fragment(url: &mut MozURL, fragment: &nsACString) -> nsresult {
+    debug_assert_mut!(url);
+    let fragment = try_or_malformed!(str::from_utf8(fragment));
+    quirks::set_hash(url, fragment);
+    NS_OK
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_sizeof(url: &MozURL) -> usize {
+    debug_assert_mut!(url);
+    mem::size_of::<MozURL>() + url.as_str().len()
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_common_base(
+    url1: &MozURL,
+    url2: &MozURL,
+    result: &mut *const MozURL,
+) -> nsresult {
+    *result = ptr::null();
+    if url1.url == url2.url {
+        RefPtr::new(url1).forget(result);
+        return NS_OK;
+    }
+
+    if url1.scheme() != url2.scheme()
+        || url1.host() != url2.host()
+        || url1.username() != url2.username()
+        || url1.password() != url2.password()
+        || url1.port() != url2.port()
+    {
+        return NS_OK;
+    }
+
+    match (url1.path_segments(), url2.path_segments()) {
+        (Some(path1), Some(path2)) => {
+            // Take the shared prefix of path segments
+            let mut url = url1.url.clone();
+            if let Ok(mut segs) = url.path_segments_mut() {
+                segs.clear();
+                segs.extend(path1.zip(path2).take_while(|&(a, b)| a == b).map(|p| p.0));
+            } else {
+                return NS_OK;
+            }
+
+            MozURL::from_url(url).forget(result);
+            NS_OK
+        }
+        _ => NS_OK,
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn mozurl_relative(
+    url1: &MozURL,
+    url2: &MozURL,
+    result: &mut nsACString,
+) -> nsresult {
+    if url1.url == url2.url {
+        result.truncate();
+        return NS_OK;
+    }
+
+    if url1.scheme() != url2.scheme()
+        || url1.host() != url2.host()
+        || url1.username() != url2.username()
+        || url1.password() != url2.password()
+        || url1.port() != url2.port()
+    {
+        result.assign(url2.as_ref());
+        return NS_OK;
+    }
+
+    match (url1.path_segments(), url2.path_segments()) {
+        (Some(mut path1), Some(mut path2)) => {
+            // Exhaust the part of the iterators that match
+            while let (Some(ref p1), Some(ref p2)) = (path1.next(), path2.next()) {
+                if p1 != p2 {
+                    break;
+                }
+            }
+
+            result.truncate();
+            for _ in path1 {
+                result.append("../");
+            }
+            for p2 in path2 {
+                result.append(p2);
+                result.append("/");
+            }
+        }
+        _ => {
+            result.assign(url2.as_ref());
+        }
+    }
+    NS_OK
+}
+
+/// This type is used by nsStandardURL
+#[no_mangle]
+pub extern "C" fn rusturl_parse_ipv6addr(input: &nsACString, addr: &mut nsACString) -> nsresult {
+    let ip6 = try_or_malformed!(str::from_utf8(input));
+    let host = try_or_malformed!(url::Host::parse(ip6));
+    let _ = write!(addr, "{}", host);
+    NS_OK
+}
diff --git a/netwerk/base/netCore.h b/netwerk/base/netCore.h
new file mode 100644
index 0000000000..258cc5cb58
--- /dev/null
+++ b/netwerk/base/netCore.h
@@ -0,0 +1,14 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __netCore_h__
+#define __netCore_h__
+
+#include "nsError.h"
+
+// Where most necko status messages come from:
+#define NECKO_MSGS_URL "chrome://necko/locale/necko.properties"
+
+#endif  // __netCore_h__
diff --git a/netwerk/base/nsASocketHandler.h b/netwerk/base/nsASocketHandler.h
new file mode 100644
index 0000000000..c68da7c359
--- /dev/null
+++ b/netwerk/base/nsASocketHandler.h
@@ -0,0 +1,102 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsASocketHandler_h__
+#define nsASocketHandler_h__
+
+#include "nsError.h"
+#include "nsINetAddr.h"
+#include "nsISupports.h"
+#include "prio.h"
+
+// socket handler used by nsISocketTransportService.
+// methods are only called on the socket thread.
+
+class nsASocketHandler : public nsISupports {
+ public:
+  nsASocketHandler() = default;
+
+  //
+  // this condition variable will be checked to determine if the socket
+  // handler should be detached.  it must only be accessed on the socket
+  // thread.
+  //
+  nsresult mCondition{NS_OK};
+
+  //
+  // these flags can only be modified on the socket transport thread.
+  // the socket transport service will check these flags before calling
+  // PR_Poll.
+  //
+  uint16_t mPollFlags{0};
+
+  //
+  // this value specifies the maximum amount of time in seconds that may be
+  // spent waiting for activity on this socket.  if this timeout is reached,
+  // then OnSocketReady will be called with outFlags = -1.
+  //
+  // the default value for this member is UINT16_MAX, which disables the
+  // timeout error checking.  (i.e., a timeout value of UINT16_MAX is
+  // never reached.)
+  //
+  uint16_t mPollTimeout{UINT16_MAX};
+
+  bool mIsPrivate{false};
+
+  //
+  // called to service a socket
+  //
+  // params:
+  //   socketRef - socket identifier
+  //   fd        - socket file descriptor
+  //   outFlags  - value of PR_PollDesc::out_flags after PR_Poll returns
+  //               or -1 if a timeout occurred
+  //
+  virtual void OnSocketReady(PRFileDesc* fd, int16_t outFlags) = 0;
+
+  //
+  // called when a socket is no longer under the control of the socket
+  // transport service.  the socket handler may close the socket at this
+  // point.  after this call returns, the handler will no longer be owned
+  // by the socket transport service.
+  //
+  virtual void OnSocketDetached(PRFileDesc* fd) = 0;
+
+  //
+  // called to determine if the socket is for a local peer.
+  // when used for server sockets, indicates if it only accepts local
+  // connections.
+  //
+  virtual void IsLocal(bool* aIsLocal) = 0;
+
+  //
+  // called to determine if this socket should not be terminated when Gecko
+  // is turned offline. This is mostly useful for the debugging server
+  // socket.
+  //
+  virtual void KeepWhenOffline(bool* aKeepWhenOffline) {
+    *aKeepWhenOffline = false;
+  }
+
+  //
+  // called when global pref for keepalive has changed.
+  //
+  virtual void OnKeepaliveEnabledPrefChange(bool aEnabled) {}
+
+  //
+  // called to determine the NetAddr. addr can only be assumed to be initialized
+  // when NS_OK is returned
+  //
+  virtual nsresult GetRemoteAddr(mozilla::net::NetAddr* addr) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  //
+  // returns the number of bytes sent/transmitted over the socket
+  //
+  virtual uint64_t ByteCountSent() = 0;
+  virtual uint64_t ByteCountReceived() = 0;
+};
+
+#endif  // !nsASocketHandler_h__
diff --git a/netwerk/base/nsAsyncRedirectVerifyHelper.cpp b/netwerk/base/nsAsyncRedirectVerifyHelper.cpp
new file mode 100644
index 0000000000..7a10d4d3f0
--- /dev/null
+++ b/netwerk/base/nsAsyncRedirectVerifyHelper.cpp
@@ -0,0 +1,279 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Logging.h"
+#include "mozilla/SpinEventLoopUntil.h"
+#include "nsAsyncRedirectVerifyHelper.h"
+#include "nsThreadUtils.h"
+#include "nsNetUtil.h"
+
+#include "nsIOService.h"
+#include "nsIChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsILoadInfo.h"
+
+namespace mozilla {
+namespace net {
+
+static LazyLogModule gRedirectLog("nsRedirect");
+#undef LOG
+#define LOG(args) MOZ_LOG(gRedirectLog, LogLevel::Debug, args)
+
+NS_IMPL_ISUPPORTS(nsAsyncRedirectVerifyHelper, nsIAsyncVerifyRedirectCallback,
+                  nsIRunnable, nsINamed)
+
+class nsAsyncVerifyRedirectCallbackEvent : public Runnable {
+ public:
+  nsAsyncVerifyRedirectCallbackEvent(nsIAsyncVerifyRedirectCallback* cb,
+                                     nsresult result)
+      : Runnable("nsAsyncVerifyRedirectCallbackEvent"),
+        mCallback(cb),
+        mResult(result) {}
+
+  NS_IMETHOD Run() override {
+    LOG(
+        ("nsAsyncVerifyRedirectCallbackEvent::Run() "
+         "callback to %p with result %" PRIx32,
+         mCallback.get(), static_cast<uint32_t>(mResult)));
+    (void)mCallback->OnRedirectVerifyCallback(mResult);
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIAsyncVerifyRedirectCallback> mCallback;
+  nsresult mResult;
+};
+
+nsAsyncRedirectVerifyHelper::~nsAsyncRedirectVerifyHelper() {
+  NS_ASSERTION(NS_FAILED(mResult) || mExpectedCallbacks == 0,
+               "Did not receive all required callbacks!");
+}
+
+nsresult nsAsyncRedirectVerifyHelper::Init(
+    nsIChannel* oldChan, nsIChannel* newChan, uint32_t flags,
+    nsIEventTarget* mainThreadEventTarget, bool synchronize) {
+  LOG(
+      ("nsAsyncRedirectVerifyHelper::Init() "
+       "oldChan=%p newChan=%p",
+       oldChan, newChan));
+  mOldChan = oldChan;
+  mNewChan = newChan;
+  mFlags = flags;
+  mCallbackEventTarget = NS_IsMainThread() && mainThreadEventTarget
+                             ? mainThreadEventTarget
+                             : GetCurrentSerialEventTarget();
+
+  if (!(flags & (nsIChannelEventSink::REDIRECT_INTERNAL |
+                 nsIChannelEventSink::REDIRECT_STS_UPGRADE))) {
+    nsCOMPtr<nsILoadInfo> loadInfo = oldChan->LoadInfo();
+    if (loadInfo->GetDontFollowRedirects()) {
+      ExplicitCallback(NS_BINDING_ABORTED);
+      return NS_OK;
+    }
+  }
+
+  if (synchronize) mWaitingForRedirectCallback = true;
+
+  nsCOMPtr<nsIRunnable> runnable = this;
+  nsresult rv;
+  rv = mainThreadEventTarget
+           ? mainThreadEventTarget->Dispatch(runnable.forget())
+           : GetMainThreadSerialEventTarget()->Dispatch(runnable.forget());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (synchronize) {
+    if (!SpinEventLoopUntil("nsAsyncRedirectVerifyHelper::Init"_ns,
+                            [&]() { return !mWaitingForRedirectCallback; })) {
+      return NS_ERROR_UNEXPECTED;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncRedirectVerifyHelper::OnRedirectVerifyCallback(nsresult result) {
+  LOG(
+      ("nsAsyncRedirectVerifyHelper::OnRedirectVerifyCallback() "
+       "result=%" PRIx32 " expectedCBs=%u mResult=%" PRIx32,
+       static_cast<uint32_t>(result), mExpectedCallbacks,
+       static_cast<uint32_t>(mResult)));
+
+  MOZ_DIAGNOSTIC_ASSERT(
+      mExpectedCallbacks > 0,
+      "OnRedirectVerifyCallback called more times than expected");
+  if (mExpectedCallbacks <= 0) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  --mExpectedCallbacks;
+
+  // If response indicates failure we may call back immediately
+  if (NS_FAILED(result)) {
+    // We chose to store the first failure-value (as opposed to the last)
+    if (NS_SUCCEEDED(mResult)) mResult = result;
+
+    // If InitCallback() has been called, just invoke the callback and
+    // return. Otherwise it will be invoked from InitCallback()
+    if (mCallbackInitiated) {
+      ExplicitCallback(mResult);
+      return NS_OK;
+    }
+  }
+
+  // If the expected-counter is in balance and InitCallback() was called, all
+  // sinks have agreed that the redirect is ok and we can invoke our callback
+  if (mCallbackInitiated && mExpectedCallbacks == 0) {
+    ExplicitCallback(mResult);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAsyncRedirectVerifyHelper::DelegateOnChannelRedirect(
+    nsIChannelEventSink* sink, nsIChannel* oldChannel, nsIChannel* newChannel,
+    uint32_t flags) {
+  LOG(
+      ("nsAsyncRedirectVerifyHelper::DelegateOnChannelRedirect() "
+       "sink=%p expectedCBs=%u mResult=%" PRIx32,
+       sink, mExpectedCallbacks, static_cast<uint32_t>(mResult)));
+
+  ++mExpectedCallbacks;
+
+  if (IsOldChannelCanceled()) {
+    LOG(
+        ("  old channel has been canceled, cancel the redirect by "
+         "emulating OnRedirectVerifyCallback..."));
+    (void)OnRedirectVerifyCallback(NS_BINDING_ABORTED);
+    return NS_BINDING_ABORTED;
+  }
+
+  nsresult rv =
+      sink->AsyncOnChannelRedirect(oldChannel, newChannel, flags, this);
+
+  LOG(("  result=%" PRIx32 " expectedCBs=%u", static_cast<uint32_t>(rv),
+       mExpectedCallbacks));
+
+  // If the sink returns failure from this call the redirect is vetoed. We
+  // emulate a callback from the sink in this case in order to perform all
+  // the necessary logic.
+  if (NS_FAILED(rv)) {
+    LOG(("  emulating OnRedirectVerifyCallback..."));
+    (void)OnRedirectVerifyCallback(rv);
+  }
+
+  return rv;  // Return the actual status since our caller may need it
+}
+
+void nsAsyncRedirectVerifyHelper::ExplicitCallback(nsresult result) {
+  LOG(
+      ("nsAsyncRedirectVerifyHelper::ExplicitCallback() "
+       "result=%" PRIx32
+       " expectedCBs=%u mCallbackInitiated=%u mResult=%" PRIx32,
+       static_cast<uint32_t>(result), mExpectedCallbacks, mCallbackInitiated,
+       static_cast<uint32_t>(mResult)));
+
+  nsCOMPtr<nsIAsyncVerifyRedirectCallback> callback(
+      do_QueryInterface(mOldChan));
+
+  if (!callback || !mCallbackEventTarget) {
+    LOG(
+        ("nsAsyncRedirectVerifyHelper::ExplicitCallback() "
+         "callback=%p mCallbackEventTarget=%p",
+         callback.get(), mCallbackEventTarget.get()));
+    return;
+  }
+
+  mCallbackInitiated = false;  // reset to ensure only one callback
+  mWaitingForRedirectCallback = false;
+
+  // Now, dispatch the callback on the event-target which called Init()
+  nsCOMPtr<nsIRunnable> event =
+      new nsAsyncVerifyRedirectCallbackEvent(callback, result);
+  if (!event) {
+    NS_WARNING(
+        "nsAsyncRedirectVerifyHelper::ExplicitCallback() "
+        "failed creating callback event!");
+    return;
+  }
+  nsresult rv = mCallbackEventTarget->Dispatch(event, NS_DISPATCH_NORMAL);
+  if (NS_FAILED(rv)) {
+    NS_WARNING(
+        "nsAsyncRedirectVerifyHelper::ExplicitCallback() "
+        "failed dispatching callback event!");
+  } else {
+    LOG(
+        ("nsAsyncRedirectVerifyHelper::ExplicitCallback() "
+         "dispatched callback event=%p",
+         event.get()));
+  }
+}
+
+void nsAsyncRedirectVerifyHelper::InitCallback() {
+  LOG(
+      ("nsAsyncRedirectVerifyHelper::InitCallback() "
+       "expectedCBs=%d mResult=%" PRIx32,
+       mExpectedCallbacks, static_cast<uint32_t>(mResult)));
+
+  mCallbackInitiated = true;
+
+  // Invoke the callback if we are done
+  if (mExpectedCallbacks == 0) ExplicitCallback(mResult);
+}
+
+NS_IMETHODIMP
+nsAsyncRedirectVerifyHelper::GetName(nsACString& aName) {
+  aName.AssignLiteral("nsAsyncRedirectVerifyHelper");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncRedirectVerifyHelper::Run() {
+  /* If the channel got canceled after it fired AsyncOnChannelRedirect
+   * and before we got here, mostly because docloader load has been canceled,
+   * we must completely ignore this notification and prevent any further
+   * notification.
+   */
+  if (IsOldChannelCanceled()) {
+    ExplicitCallback(NS_BINDING_ABORTED);
+    return NS_OK;
+  }
+
+  // First, the global observer
+  NS_ASSERTION(gIOService, "Must have an IO service at this point");
+  LOG(("nsAsyncRedirectVerifyHelper::Run() calling gIOService..."));
+  nsresult rv =
+      gIOService->AsyncOnChannelRedirect(mOldChan, mNewChan, mFlags, this);
+  if (NS_FAILED(rv)) {
+    ExplicitCallback(rv);
+    return NS_OK;
+  }
+
+  // Now, the per-channel observers
+  nsCOMPtr<nsIChannelEventSink> sink;
+  NS_QueryNotificationCallbacks(mOldChan, sink);
+  if (sink) {
+    LOG(("nsAsyncRedirectVerifyHelper::Run() calling sink..."));
+    rv = DelegateOnChannelRedirect(sink, mOldChan, mNewChan, mFlags);
+  }
+
+  // All invocations to AsyncOnChannelRedirect has been done - call
+  // InitCallback() to flag this
+  InitCallback();
+  return NS_OK;
+}
+
+bool nsAsyncRedirectVerifyHelper::IsOldChannelCanceled() {
+  if (!mOldChan) {
+    return false;
+  }
+  bool canceled;
+  nsresult rv = mOldChan->GetCanceled(&canceled);
+  return NS_SUCCEEDED(rv) && canceled;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsAsyncRedirectVerifyHelper.h b/netwerk/base/nsAsyncRedirectVerifyHelper.h
new file mode 100644
index 0000000000..3e1afa8c69
--- /dev/null
+++ b/netwerk/base/nsAsyncRedirectVerifyHelper.h
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsAsyncRedirectVerifyHelper_h
+#define nsAsyncRedirectVerifyHelper_h
+
+#include "nsIRunnable.h"
+#include "nsIChannelEventSink.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsINamed.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/Attributes.h"
+
+class nsIChannel;
+
+namespace mozilla {
+namespace net {
+
+/**
+ * This class simplifies call of OnChannelRedirect of IOService and
+ * the sink bound with the channel being redirected while the result of
+ * redirect decision is returned through the callback.
+ */
+class nsAsyncRedirectVerifyHelper final
+    : public nsIRunnable,
+      public nsINamed,
+      public nsIAsyncVerifyRedirectCallback {
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSINAMED
+  NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
+
+ public:
+  nsAsyncRedirectVerifyHelper() = default;
+
+  /*
+   * Calls AsyncOnChannelRedirect() on the given sink with the given
+   * channels and flags. Keeps track of number of async callbacks to expect.
+   */
+  nsresult DelegateOnChannelRedirect(nsIChannelEventSink* sink,
+                                     nsIChannel* oldChannel,
+                                     nsIChannel* newChannel, uint32_t flags);
+
+  /**
+   * Initialize and run the chain of AsyncOnChannelRedirect calls. OldChannel
+   * is QI'ed for nsIAsyncVerifyRedirectCallback. The result of the redirect
+   * decision is passed through this interface back to the oldChannel.
+   *
+   * @param oldChan
+   *    channel being redirected, MUST implement
+   *    nsIAsyncVerifyRedirectCallback
+   * @param newChan
+   *    target of the redirect channel
+   * @param flags
+   *    redirect flags
+   * @param mainThreadEventTarget
+   *    a labeled event target for dispatching runnables
+   * @param synchronize
+   *    set to TRUE if you want the Init method wait synchronously for
+   *    all redirect callbacks
+   */
+  nsresult Init(nsIChannel* oldChan, nsIChannel* newChan, uint32_t flags,
+                nsIEventTarget* mainThreadEventTarget,
+                bool synchronize = false);
+
+ protected:
+  nsCOMPtr<nsIChannel> mOldChan;
+  nsCOMPtr<nsIChannel> mNewChan;
+  uint32_t mFlags{0};
+  bool mWaitingForRedirectCallback{false};
+  nsCOMPtr<nsIEventTarget> mCallbackEventTarget;
+  bool mCallbackInitiated{false};
+  int32_t mExpectedCallbacks{0};
+  nsresult mResult{NS_OK};  // value passed to callback
+
+  void InitCallback();
+
+  /**
+   * Calls back to |oldChan| as described in Init()
+   */
+  void ExplicitCallback(nsresult result);
+
+ private:
+  ~nsAsyncRedirectVerifyHelper();
+
+  bool IsOldChannelCanceled();
+};
+
+/*
+ * Helper to make the call-stack handle some control-flow for us
+ */
+class nsAsyncRedirectAutoCallback {
+ public:
+  explicit nsAsyncRedirectAutoCallback(
+      nsIAsyncVerifyRedirectCallback* aCallback)
+      : mCallback(aCallback) {
+    mResult = NS_OK;
+  }
+  ~nsAsyncRedirectAutoCallback() {
+    if (mCallback) mCallback->OnRedirectVerifyCallback(mResult);
+  }
+  /*
+   * Call this is you want it to call back with a different result-code
+   */
+  void SetResult(nsresult aRes) { mResult = aRes; }
+  /*
+   * Call this is you want to avoid the callback
+   */
+  void DontCallback() { mCallback = nullptr; }
+
+ private:
+  nsIAsyncVerifyRedirectCallback* mCallback;
+  nsresult mResult;
+};
+
+}  // namespace net
+}  // namespace mozilla
+#endif
diff --git a/netwerk/base/nsAsyncStreamCopier.cpp b/netwerk/base/nsAsyncStreamCopier.cpp
new file mode 100644
index 0000000000..de8363d17d
--- /dev/null
+++ b/netwerk/base/nsAsyncStreamCopier.cpp
@@ -0,0 +1,405 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsAsyncStreamCopier.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIOService.h"
+#include "nsIEventTarget.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "nsNetUtil.h"
+#include "nsNetCID.h"
+#include "nsIBufferedStreams.h"
+#include "nsIRequestObserver.h"
+#include "mozilla/Logging.h"
+
+using namespace mozilla;
+using namespace mozilla::net;
+
+#undef LOG
+//
+// MOZ_LOG=nsStreamCopier:5
+//
+static LazyLogModule gStreamCopierLog("nsStreamCopier");
+#define LOG(args) MOZ_LOG(gStreamCopierLog, mozilla::LogLevel::Debug, args)
+
+/**
+ * An event used to perform initialization off the main thread.
+ */
+class AsyncApplyBufferingPolicyEvent final : public Runnable {
+ public:
+  /**
+   * @param aCopier
+   *        The nsAsyncStreamCopier requesting the information.
+   */
+  explicit AsyncApplyBufferingPolicyEvent(nsAsyncStreamCopier* aCopier)
+      : mozilla::Runnable("AsyncApplyBufferingPolicyEvent"),
+        mCopier(aCopier),
+        mTarget(GetCurrentSerialEventTarget()) {}
+
+  NS_IMETHOD Run() override {
+    nsresult rv = mCopier->ApplyBufferingPolicy();
+    if (NS_FAILED(rv)) {
+      mCopier->Cancel(rv);
+      return NS_OK;
+    }
+
+    rv = mTarget->Dispatch(
+        NewRunnableMethod("nsAsyncStreamCopier::AsyncCopyInternal", mCopier,
+                          &nsAsyncStreamCopier::AsyncCopyInternal),
+        NS_DISPATCH_NORMAL);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    if (NS_FAILED(rv)) {
+      mCopier->Cancel(rv);
+    }
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsAsyncStreamCopier> mCopier;
+  nsCOMPtr<nsIEventTarget> mTarget;
+};
+
+//-----------------------------------------------------------------------------
+
+nsAsyncStreamCopier::nsAsyncStreamCopier()
+    : mChunkSize(nsIOService::gDefaultSegmentSize) {
+  LOG(("Creating nsAsyncStreamCopier @%p\n", this));
+}
+
+nsAsyncStreamCopier::~nsAsyncStreamCopier() {
+  LOG(("Destroying nsAsyncStreamCopier @%p\n", this));
+}
+
+bool nsAsyncStreamCopier::IsComplete(nsresult* status) {
+  MutexAutoLock lock(mLock);
+  if (status) *status = mStatus;
+  return !mIsPending;
+}
+
+nsIRequest* nsAsyncStreamCopier::AsRequest() {
+  return static_cast<nsIRequest*>(static_cast<nsIAsyncStreamCopier*>(this));
+}
+
+void nsAsyncStreamCopier::Complete(nsresult status) {
+  LOG(("nsAsyncStreamCopier::Complete [this=%p status=%" PRIx32 "]\n", this,
+       static_cast<uint32_t>(status)));
+
+  nsCOMPtr<nsIRequestObserver> observer;
+  nsCOMPtr<nsISupports> ctx;
+  {
+    MutexAutoLock lock(mLock);
+    mCopierCtx = nullptr;
+
+    if (mIsPending) {
+      mIsPending = false;
+      mStatus = status;
+
+      // setup OnStopRequest callback and release references...
+      observer = mObserver;
+      mObserver = nullptr;
+    }
+  }
+
+  if (observer) {
+    LOG(("  calling OnStopRequest [status=%" PRIx32 "]\n",
+         static_cast<uint32_t>(status)));
+    observer->OnStopRequest(AsRequest(), status);
+  }
+}
+
+void nsAsyncStreamCopier::OnAsyncCopyComplete(void* closure, nsresult status) {
+  // AddRef'd in AsyncCopy. Will be released at the end of the method.
+  RefPtr<nsAsyncStreamCopier> self = dont_AddRef((nsAsyncStreamCopier*)closure);
+  self->Complete(status);
+}
+
+//-----------------------------------------------------------------------------
+// nsISupports
+
+// We cannot use simply NS_IMPL_ISUPPORTSx as both
+// nsIAsyncStreamCopier and nsIAsyncStreamCopier2 implement nsIRequest
+
+NS_IMPL_ADDREF(nsAsyncStreamCopier)
+NS_IMPL_RELEASE(nsAsyncStreamCopier)
+NS_INTERFACE_TABLE_HEAD(nsAsyncStreamCopier)
+  NS_INTERFACE_TABLE_BEGIN
+    NS_INTERFACE_TABLE_ENTRY(nsAsyncStreamCopier, nsIAsyncStreamCopier)
+    NS_INTERFACE_TABLE_ENTRY(nsAsyncStreamCopier, nsIAsyncStreamCopier2)
+    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsAsyncStreamCopier, nsIRequest,
+                                       nsIAsyncStreamCopier)
+    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsAsyncStreamCopier, nsISupports,
+                                       nsIAsyncStreamCopier)
+  NS_INTERFACE_TABLE_END
+NS_INTERFACE_TABLE_TAIL
+
+//-----------------------------------------------------------------------------
+// nsIRequest
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::GetName(nsACString& name) {
+  name.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::IsPending(bool* result) {
+  *result = !IsComplete();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::GetStatus(nsresult* status) {
+  IsComplete(status);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsAsyncStreamCopier::SetCanceledReason(
+    const nsACString& aReason) {
+  return nsIAsyncStreamCopier::SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsAsyncStreamCopier::GetCanceledReason(nsACString& aReason) {
+  return nsIAsyncStreamCopier::GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsAsyncStreamCopier::CancelWithReason(nsresult aStatus,
+                                                    const nsACString& aReason) {
+  return nsIAsyncStreamCopier::CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::Cancel(nsresult status) {
+  nsCOMPtr<nsISupports> copierCtx;
+  {
+    MutexAutoLock lock(mLock);
+    if (!mIsPending) {
+      return NS_OK;
+    }
+    copierCtx.swap(mCopierCtx);
+  }
+
+  if (NS_SUCCEEDED(status)) {
+    NS_WARNING("cancel with non-failure status code");
+    status = NS_BASE_STREAM_CLOSED;
+  }
+
+  if (copierCtx) NS_CancelAsyncCopy(copierCtx, status);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::Suspend() {
+  MOZ_ASSERT_UNREACHABLE("nsAsyncStreamCopier::Suspend");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::Resume() {
+  MOZ_ASSERT_UNREACHABLE("nsAsyncStreamCopier::Resume");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::GetLoadFlags(nsLoadFlags* aLoadFlags) {
+  *aLoadFlags = LOAD_NORMAL;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::SetLoadFlags(nsLoadFlags aLoadFlags) { return NS_OK; }
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return nsIAsyncStreamCopier::GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return nsIAsyncStreamCopier::SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  *aLoadGroup = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::SetLoadGroup(nsILoadGroup* aLoadGroup) { return NS_OK; }
+
+// Can't be accessed by multiple threads yet
+nsresult nsAsyncStreamCopier::InitInternal(
+    nsIInputStream* source, nsIOutputStream* sink, nsIEventTarget* target,
+    uint32_t chunkSize, bool closeSource,
+    bool closeSink) MOZ_NO_THREAD_SAFETY_ANALYSIS {
+  NS_ASSERTION(!mSource && !mSink, "Init() called more than once");
+  if (chunkSize == 0) {
+    chunkSize = nsIOService::gDefaultSegmentSize;
+  }
+  mChunkSize = chunkSize;
+
+  mSource = source;
+  mSink = sink;
+  mCloseSource = closeSource;
+  mCloseSink = closeSink;
+
+  if (target) {
+    mTarget = target;
+  } else {
+    nsresult rv;
+    mTarget = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsIAsyncStreamCopier
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::Init(nsIInputStream* source, nsIOutputStream* sink,
+                          nsIEventTarget* target, bool sourceBuffered,
+                          bool sinkBuffered, uint32_t chunkSize,
+                          bool closeSource, bool closeSink) {
+  NS_ASSERTION(sourceBuffered || sinkBuffered,
+               "at least one stream must be buffered");
+  mMode = sourceBuffered ? NS_ASYNCCOPY_VIA_READSEGMENTS
+                         : NS_ASYNCCOPY_VIA_WRITESEGMENTS;
+
+  return InitInternal(source, sink, target, chunkSize, closeSource, closeSink);
+}
+
+//-----------------------------------------------------------------------------
+// nsIAsyncStreamCopier2
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::Init(nsIInputStream* source, nsIOutputStream* sink,
+                          nsIEventTarget* target, uint32_t chunkSize,
+                          bool closeSource, bool closeSink) {
+  mShouldSniffBuffering = true;
+
+  return InitInternal(source, sink, target, chunkSize, closeSource, closeSink);
+}
+
+/**
+ * Detect whether the input or the output stream is buffered,
+ * bufferize one of them if neither is buffered.
+ */
+nsresult nsAsyncStreamCopier::ApplyBufferingPolicy() {
+  // This function causes I/O, it must not be executed on the main
+  // thread.
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  if (NS_OutputStreamIsBuffered(mSink)) {
+    // Sink is buffered, no need to perform additional buffering
+    mMode = NS_ASYNCCOPY_VIA_WRITESEGMENTS;
+    return NS_OK;
+  }
+  if (NS_InputStreamIsBuffered(mSource)) {
+    // Source is buffered, no need to perform additional buffering
+    mMode = NS_ASYNCCOPY_VIA_READSEGMENTS;
+    return NS_OK;
+  }
+
+  // No buffering, let's buffer the sink
+  nsresult rv;
+  nsCOMPtr<nsIBufferedOutputStream> sink =
+      do_CreateInstance(NS_BUFFEREDOUTPUTSTREAM_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = sink->Init(mSink, mChunkSize);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mMode = NS_ASYNCCOPY_VIA_WRITESEGMENTS;
+  mSink = sink;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// Both nsIAsyncStreamCopier and nsIAsyncStreamCopier2
+
+NS_IMETHODIMP
+nsAsyncStreamCopier::AsyncCopy(nsIRequestObserver* observer, nsISupports* ctx) {
+  LOG(("nsAsyncStreamCopier::AsyncCopy [this=%p observer=%p]\n", this,
+       observer));
+
+  NS_ASSERTION(mSource && mSink, "not initialized");
+  nsresult rv;
+
+  if (observer) {
+    // build proxy for observer events
+    rv = NS_NewRequestObserverProxy(getter_AddRefs(mObserver), observer, ctx);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  // from this point forward, AsyncCopy is going to return NS_OK.  any errors
+  // will be reported via OnStopRequest.
+  {
+    MutexAutoLock lock(mLock);
+    mIsPending = true;
+  }
+
+  if (mObserver) {
+    rv = mObserver->OnStartRequest(AsRequest());
+    if (NS_FAILED(rv)) Cancel(rv);
+  }
+
+  if (!mShouldSniffBuffering) {
+    // No buffer sniffing required, let's proceed
+    AsyncCopyInternal();
+    return NS_OK;
+  }
+
+  if (NS_IsMainThread()) {
+    // Don't perform buffer sniffing on the main thread
+    nsCOMPtr<nsIRunnable> event = new AsyncApplyBufferingPolicyEvent(this);
+    rv = mTarget->Dispatch(event, NS_DISPATCH_NORMAL);
+    if (NS_FAILED(rv)) {
+      Cancel(rv);
+    }
+    return NS_OK;
+  }
+
+  // We're not going to block the main thread, so let's sniff here
+  rv = ApplyBufferingPolicy();
+  if (NS_FAILED(rv)) {
+    Cancel(rv);
+  }
+  AsyncCopyInternal();
+  return NS_OK;
+}
+
+// Launch async copy.
+// All errors are reported through the observer.
+void nsAsyncStreamCopier::AsyncCopyInternal() {
+  MOZ_ASSERT(mMode == NS_ASYNCCOPY_VIA_READSEGMENTS ||
+             mMode == NS_ASYNCCOPY_VIA_WRITESEGMENTS);
+
+  nsresult rv;
+  // We want to receive progress notifications; release happens in
+  // OnAsyncCopyComplete.
+  RefPtr<nsAsyncStreamCopier> self = this;
+  {
+    MutexAutoLock lock(mLock);
+    rv = NS_AsyncCopy(mSource, mSink, mTarget, mMode, mChunkSize,
+                      OnAsyncCopyComplete, this, mCloseSource, mCloseSink,
+                      getter_AddRefs(mCopierCtx));
+  }
+  if (NS_FAILED(rv)) {
+    Cancel(rv);
+    return;  // release self
+  }
+
+  Unused << self.forget();  // Will be released in OnAsyncCopyComplete
+}
diff --git a/netwerk/base/nsAsyncStreamCopier.h b/netwerk/base/nsAsyncStreamCopier.h
new file mode 100644
index 0000000000..120218c3c7
--- /dev/null
+++ b/netwerk/base/nsAsyncStreamCopier.h
@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsAsyncStreamCopier_h__
+#define nsAsyncStreamCopier_h__
+
+#include "nsIAsyncStreamCopier.h"
+#include "nsIAsyncStreamCopier2.h"
+#include "mozilla/Mutex.h"
+#include "nsStreamUtils.h"
+#include "nsCOMPtr.h"
+
+class nsIRequestObserver;
+
+//-----------------------------------------------------------------------------
+
+class nsAsyncStreamCopier final : public nsIAsyncStreamCopier,
+                                  nsIAsyncStreamCopier2 {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSIASYNCSTREAMCOPIER
+
+  // nsIAsyncStreamCopier2
+  // We declare it by hand instead of NS_DECL_NSIASYNCSTREAMCOPIER2
+  // as nsIAsyncStreamCopier2 duplicates methods of nsIAsyncStreamCopier
+  NS_IMETHOD Init(nsIInputStream* aSource, nsIOutputStream* aSink,
+                  nsIEventTarget* aTarget, uint32_t aChunkSize,
+                  bool aCloseSource, bool aCloseSink) override;
+
+  nsAsyncStreamCopier();
+
+  //-------------------------------------------------------------------------
+  // these methods may be called on any thread
+
+  bool IsComplete(nsresult* status = nullptr);
+  void Complete(nsresult status);
+
+ private:
+  virtual ~nsAsyncStreamCopier();
+
+  nsresult InitInternal(nsIInputStream* source, nsIOutputStream* sink,
+                        nsIEventTarget* target, uint32_t chunkSize,
+                        bool closeSource, bool closeSink);
+
+  static void OnAsyncCopyComplete(void*, nsresult);
+
+  void AsyncCopyInternal();
+  nsresult ApplyBufferingPolicy();
+  nsIRequest* AsRequest();
+
+  nsCOMPtr<nsIInputStream> mSource;
+  nsCOMPtr<nsIOutputStream> mSink;
+
+  nsCOMPtr<nsIRequestObserver> mObserver;
+
+  nsCOMPtr<nsIEventTarget> mTarget;
+
+  nsCOMPtr<nsISupports> mCopierCtx MOZ_GUARDED_BY(mLock);
+
+  mozilla::Mutex mLock{"nsAsyncStreamCopier.mLock"};
+
+  nsAsyncCopyMode mMode{NS_ASYNCCOPY_VIA_READSEGMENTS};
+  uint32_t mChunkSize;  // only modified in Init
+  nsresult mStatus MOZ_GUARDED_BY(mLock){NS_OK};
+  bool mIsPending MOZ_GUARDED_BY(mLock){false};
+  bool mCloseSource MOZ_GUARDED_BY(mLock){false};
+  bool mCloseSink MOZ_GUARDED_BY(mLock){false};
+  bool mShouldSniffBuffering{false};  // only modified in Init
+
+  friend class ProceedWithAsyncCopy;
+  friend class AsyncApplyBufferingPolicyEvent;
+};
+
+#endif  // !nsAsyncStreamCopier_h__
diff --git a/netwerk/base/nsAuthInformationHolder.cpp b/netwerk/base/nsAuthInformationHolder.cpp
new file mode 100644
index 0000000000..11cf7626ce
--- /dev/null
+++ b/netwerk/base/nsAuthInformationHolder.cpp
@@ -0,0 +1,61 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsAuthInformationHolder.h"
+
+NS_IMPL_ISUPPORTS(nsAuthInformationHolder, nsIAuthInformation)
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetFlags(uint32_t* aFlags) {
+  *aFlags = mFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetRealm(nsAString& aRealm) {
+  aRealm = mRealm;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetAuthenticationScheme(nsACString& aScheme) {
+  aScheme = mAuthType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetUsername(nsAString& aUserName) {
+  aUserName = mUser;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::SetUsername(const nsAString& aUserName) {
+  if (!(mFlags & ONLY_PASSWORD)) mUser = aUserName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetPassword(nsAString& aPassword) {
+  aPassword = mPassword;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::SetPassword(const nsAString& aPassword) {
+  mPassword = aPassword;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::GetDomain(nsAString& aDomain) {
+  aDomain = mDomain;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthInformationHolder::SetDomain(const nsAString& aDomain) {
+  if (mFlags & NEED_DOMAIN) mDomain = aDomain;
+  return NS_OK;
+}
diff --git a/netwerk/base/nsAuthInformationHolder.h b/netwerk/base/nsAuthInformationHolder.h
new file mode 100644
index 0000000000..48054d9413
--- /dev/null
+++ b/netwerk/base/nsAuthInformationHolder.h
@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSAUTHINFORMATIONHOLDER_H_
+#define NSAUTHINFORMATIONHOLDER_H_
+
+#include "nsIAuthInformation.h"
+#include "nsString.h"
+
+class nsAuthInformationHolder : public nsIAuthInformation {
+ protected:
+  virtual ~nsAuthInformationHolder() = default;
+
+ public:
+  // aAuthType must be ASCII
+  nsAuthInformationHolder(uint32_t aFlags, const nsString& aRealm,
+                          const nsACString& aAuthType)
+      : mFlags(aFlags), mRealm(aRealm), mAuthType(aAuthType) {}
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIAUTHINFORMATION
+
+  const nsString& User() const { return mUser; }
+  const nsString& Password() const { return mPassword; }
+  const nsString& Domain() const { return mDomain; }
+
+  /**
+   * This method can be used to initialize the username when the
+   * ONLY_PASSWORD flag is set.
+   */
+  void SetUserInternal(const nsString& aUsername) { mUser = aUsername; }
+
+ private:
+  nsString mUser;
+  nsString mPassword;
+  nsString mDomain;
+
+  uint32_t mFlags;
+  nsString mRealm;
+  nsCString mAuthType;
+};
+
+#endif
diff --git a/netwerk/base/nsBase64Encoder.cpp b/netwerk/base/nsBase64Encoder.cpp
new file mode 100644
index 0000000000..621dd2c4ec
--- /dev/null
+++ b/netwerk/base/nsBase64Encoder.cpp
@@ -0,0 +1,54 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsBase64Encoder.h"
+
+#include "mozilla/Base64.h"
+
+NS_IMPL_ISUPPORTS(nsBase64Encoder, nsIOutputStream)
+
+NS_IMETHODIMP
+nsBase64Encoder::Close() { return NS_OK; }
+
+NS_IMETHODIMP
+nsBase64Encoder::Flush() { return NS_OK; }
+
+NS_IMETHODIMP
+nsBase64Encoder::StreamStatus() { return NS_OK; }
+
+NS_IMETHODIMP
+nsBase64Encoder::Write(const char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  mData.Append(aBuf, aCount);
+  *_retval = aCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBase64Encoder::WriteFrom(nsIInputStream* aStream, uint32_t aCount,
+                           uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBase64Encoder::WriteSegments(nsReadSegmentFun aReader, void* aClosure,
+                               uint32_t aCount, uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBase64Encoder::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = false;
+  return NS_OK;
+}
+
+nsresult nsBase64Encoder::Finish(nsACString& result) {
+  nsresult rv = mozilla::Base64Encode(mData, result);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Free unneeded memory and allow reusing the object
+  mData.Truncate();
+  return NS_OK;
+}
diff --git a/netwerk/base/nsBase64Encoder.h b/netwerk/base/nsBase64Encoder.h
new file mode 100644
index 0000000000..b74d3c9b5a
--- /dev/null
+++ b/netwerk/base/nsBase64Encoder.h
@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSBASE64ENCODER_H_
+#define NSBASE64ENCODER_H_
+
+#include "nsIOutputStream.h"
+#include "nsString.h"
+#include "mozilla/Attributes.h"
+
+/**
+ * A base64 encoder. Usage: Instantiate class, write to it using
+ * Write(), then call Finish() to get the base64-encoded data.
+ */
+class nsBase64Encoder final : public nsIOutputStream {
+ public:
+  nsBase64Encoder() = default;
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+
+  nsresult Finish(nsACString& _result);
+
+ private:
+  ~nsBase64Encoder() = default;
+
+  /// The data written to this stream. nsCString can deal fine with
+  /// binary data.
+  nsCString mData;
+};
+
+#endif
diff --git a/netwerk/base/nsBaseChannel.cpp b/netwerk/base/nsBaseChannel.cpp
new file mode 100644
index 0000000000..3ce7fb9d4b
--- /dev/null
+++ b/netwerk/base/nsBaseChannel.cpp
@@ -0,0 +1,951 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 sts=2 ts=8 et tw=80 : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsBaseChannel.h"
+#include "nsContentUtils.h"
+#include "nsURLHelper.h"
+#include "nsNetCID.h"
+#include "nsMimeTypes.h"
+#include "nsUnknownDecoder.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsMimeTypes.h"
+#include "nsICancelable.h"
+#include "nsIChannelEventSink.h"
+#include "nsIStreamConverterService.h"
+#include "nsChannelClassifier.h"
+#include "nsAsyncRedirectVerifyHelper.h"
+#include "nsProxyRelease.h"
+#include "nsXULAppAPI.h"
+#include "nsContentSecurityManager.h"
+#include "LoadInfo.h"
+#include "nsServiceManagerUtils.h"
+#include "nsRedirectHistoryEntry.h"
+#include "mozilla/AntiTrackingUtils.h"
+#include "mozilla/BasePrincipal.h"
+
+using namespace mozilla;
+
+// This class is used to suspend a request across a function scope.
+class ScopedRequestSuspender {
+ public:
+  explicit ScopedRequestSuspender(nsIRequest* request) : mRequest(request) {
+    if (mRequest && NS_FAILED(mRequest->Suspend())) {
+      NS_WARNING("Couldn't suspend pump");
+      mRequest = nullptr;
+    }
+  }
+  ~ScopedRequestSuspender() {
+    if (mRequest) mRequest->Resume();
+  }
+
+ private:
+  nsIRequest* mRequest;
+};
+
+// Used to suspend data events from mRequest within a function scope.  This is
+// usually needed when a function makes callbacks that could process events.
+#define SUSPEND_PUMP_FOR_SCOPE() \
+  ScopedRequestSuspender pump_suspender__(mRequest)
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel
+
+nsBaseChannel::nsBaseChannel() : NeckoTargetHolder(nullptr) {
+  mContentType.AssignLiteral(UNKNOWN_CONTENT_TYPE);
+}
+
+nsBaseChannel::~nsBaseChannel() {
+  NS_ReleaseOnMainThread("nsBaseChannel::mLoadInfo", mLoadInfo.forget());
+}
+
+nsresult nsBaseChannel::Redirect(nsIChannel* newChannel, uint32_t redirectFlags,
+                                 bool openNewChannel) {
+  SUSPEND_PUMP_FOR_SCOPE();
+
+  // Transfer properties
+
+  newChannel->SetLoadGroup(mLoadGroup);
+  newChannel->SetNotificationCallbacks(mCallbacks);
+  newChannel->SetLoadFlags(mLoadFlags | LOAD_REPLACE);
+
+  // make a copy of the loadinfo, append to the redirectchain
+  // and set it on the new channel
+  nsSecurityFlags secFlags =
+      mLoadInfo->GetSecurityFlags() & ~nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  nsCOMPtr<nsILoadInfo> newLoadInfo =
+      static_cast<net::LoadInfo*>(mLoadInfo.get())
+          ->CloneWithNewSecFlags(secFlags);
+
+  bool isInternalRedirect =
+      (redirectFlags & (nsIChannelEventSink::REDIRECT_INTERNAL |
+                        nsIChannelEventSink::REDIRECT_STS_UPGRADE));
+
+  newLoadInfo->AppendRedirectHistoryEntry(this, isInternalRedirect);
+
+  // Ensure the channel's loadInfo's result principal URI so that it's
+  // either non-null or updated to the redirect target URI.
+  // We must do this because in case the loadInfo's result principal URI
+  // is null, it would be taken from OriginalURI of the channel.  But we
+  // overwrite it with the whole redirect chain first URI before opening
+  // the target channel, hence the information would be lost.
+  // If the protocol handler that created the channel wants to use
+  // the originalURI of the channel as the principal URI, it has left
+  // the result principal URI on the load info null.
+  nsCOMPtr<nsIURI> resultPrincipalURI;
+
+  nsCOMPtr<nsILoadInfo> existingLoadInfo = newChannel->LoadInfo();
+  if (existingLoadInfo) {
+    existingLoadInfo->GetResultPrincipalURI(getter_AddRefs(resultPrincipalURI));
+  }
+  if (!resultPrincipalURI) {
+    newChannel->GetOriginalURI(getter_AddRefs(resultPrincipalURI));
+  }
+
+  newLoadInfo->SetResultPrincipalURI(resultPrincipalURI);
+
+  newChannel->SetLoadInfo(newLoadInfo);
+
+  // Preserve the privacy bit if it has been overridden
+  if (mPrivateBrowsingOverriden) {
+    nsCOMPtr<nsIPrivateBrowsingChannel> newPBChannel =
+        do_QueryInterface(newChannel);
+    if (newPBChannel) {
+      newPBChannel->SetPrivate(mPrivateBrowsing);
+    }
+  }
+
+  if (nsCOMPtr<nsIWritablePropertyBag> bag = ::do_QueryInterface(newChannel)) {
+    nsHashPropertyBag::CopyFrom(bag, static_cast<nsIPropertyBag2*>(this));
+  }
+
+  // Notify consumer, giving chance to cancel redirect.
+
+  auto redirectCallbackHelper = MakeRefPtr<net::nsAsyncRedirectVerifyHelper>();
+
+  bool checkRedirectSynchronously = !openNewChannel;
+  nsCOMPtr<nsIEventTarget> target = GetNeckoTarget();
+
+  mRedirectChannel = newChannel;
+  mRedirectFlags = redirectFlags;
+  mOpenRedirectChannel = openNewChannel;
+  nsresult rv = redirectCallbackHelper->Init(
+      this, newChannel, redirectFlags, target, checkRedirectSynchronously);
+  if (NS_FAILED(rv)) return rv;
+
+  if (checkRedirectSynchronously && NS_FAILED(mStatus)) return mStatus;
+
+  return NS_OK;
+}
+
+nsresult nsBaseChannel::ContinueRedirect() {
+  // Make sure to do this _after_ making all the OnChannelRedirect calls
+  mRedirectChannel->SetOriginalURI(OriginalURI());
+
+  // If we fail to open the new channel, then we want to leave this channel
+  // unaffected, so we defer tearing down our channel until we have succeeded
+  // with the redirect.
+
+  if (mOpenRedirectChannel) {
+    nsresult rv = NS_OK;
+    rv = mRedirectChannel->AsyncOpen(mListener);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  mRedirectChannel = nullptr;
+
+  // close down this channel
+  Cancel(NS_BINDING_REDIRECTED);
+  ChannelDone();
+
+  return NS_OK;
+}
+
+bool nsBaseChannel::HasContentTypeHint() const {
+  NS_ASSERTION(!Pending(), "HasContentTypeHint called too late");
+  return !mContentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE);
+}
+
+nsresult nsBaseChannel::BeginPumpingData() {
+  nsresult rv;
+
+  rv = BeginAsyncRead(this, getter_AddRefs(mRequest),
+                      getter_AddRefs(mCancelableAsyncRequest));
+  if (NS_SUCCEEDED(rv)) {
+    MOZ_ASSERT(mRequest || mCancelableAsyncRequest,
+               "should have got a request or cancelable");
+    mPumpingData = true;
+    return NS_OK;
+  }
+  if (rv != NS_ERROR_NOT_IMPLEMENTED) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIInputStream> stream;
+  nsCOMPtr<nsIChannel> channel;
+  rv = OpenContentStream(true, getter_AddRefs(stream), getter_AddRefs(channel));
+  if (NS_FAILED(rv)) return rv;
+
+  NS_ASSERTION(!stream || !channel, "Got both a channel and a stream?");
+
+  if (channel) {
+    nsCOMPtr<nsIRunnable> runnable = new RedirectRunnable(this, channel);
+    rv = Dispatch(runnable.forget());
+    if (NS_SUCCEEDED(rv)) mWaitingOnAsyncRedirect = true;
+    return rv;
+  }
+
+  // By assigning mPump, we flag this channel as pending (see Pending).  It's
+  // important that the pending flag is set when we call into the stream (the
+  // call to AsyncRead results in the stream's AsyncWait method being called)
+  // and especially when we call into the loadgroup.  Our caller takes care to
+  // release mPump if we return an error.
+
+  nsCOMPtr<nsISerialEventTarget> target = GetNeckoTarget();
+  rv = nsInputStreamPump::Create(getter_AddRefs(mPump), stream, 0, 0, true,
+                                 target);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mPumpingData = true;
+  mRequest = mPump;
+  rv = mPump->AsyncRead(this);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  RefPtr<BlockingPromise> promise;
+  rv = ListenerBlockingPromise(getter_AddRefs(promise));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (promise) {
+    mPump->Suspend();
+
+    RefPtr<nsBaseChannel> self(this);
+
+    promise->Then(
+        target, __func__,
+        [self, this](nsresult rv) {
+          MOZ_ASSERT(mPump);
+          MOZ_ASSERT(NS_SUCCEEDED(rv));
+          mPump->Resume();
+        },
+        [self, this](nsresult rv) {
+          MOZ_ASSERT(mPump);
+          MOZ_ASSERT(NS_FAILED(rv));
+          Cancel(rv);
+          mPump->Resume();
+        });
+  }
+
+  return NS_OK;
+}
+
+void nsBaseChannel::HandleAsyncRedirect(nsIChannel* newChannel) {
+  NS_ASSERTION(!mPumpingData, "Shouldn't have gotten here");
+
+  nsresult rv = mStatus;
+  if (NS_SUCCEEDED(mStatus)) {
+    rv = Redirect(newChannel, nsIChannelEventSink::REDIRECT_TEMPORARY, true);
+    if (NS_SUCCEEDED(rv)) {
+      // OnRedirectVerifyCallback will be called asynchronously
+      return;
+    }
+  }
+
+  ContinueHandleAsyncRedirect(rv);
+}
+
+void nsBaseChannel::ContinueHandleAsyncRedirect(nsresult result) {
+  mWaitingOnAsyncRedirect = false;
+
+  if (NS_FAILED(result)) Cancel(result);
+
+  if (NS_FAILED(result) && mListener) {
+    // Notify our consumer ourselves
+    mListener->OnStartRequest(this);
+    mListener->OnStopRequest(this, mStatus);
+    ChannelDone();
+  }
+
+  if (mLoadGroup) mLoadGroup->RemoveRequest(this, nullptr, mStatus);
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+  CallbacksChanged();
+}
+
+void nsBaseChannel::ClassifyURI() {
+  // For channels created in the child process, delegate to the parent to
+  // classify URIs.
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
+  if (NS_ShouldClassifyChannel(this)) {
+    auto classifier = MakeRefPtr<net::nsChannelClassifier>(this);
+    classifier->Start();
+  }
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsISupports
+
+NS_IMPL_ADDREF(nsBaseChannel)
+NS_IMPL_RELEASE(nsBaseChannel)
+
+NS_INTERFACE_MAP_BEGIN(nsBaseChannel)
+  NS_INTERFACE_MAP_ENTRY(nsIRequest)
+  NS_INTERFACE_MAP_ENTRY(nsIChannel)
+  NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableRequest)
+  NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
+  NS_INTERFACE_MAP_ENTRY(nsITransportEventSink)
+  NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+  NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+  NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableStreamListener)
+  NS_INTERFACE_MAP_ENTRY(nsIAsyncVerifyRedirectCallback)
+  NS_INTERFACE_MAP_ENTRY(nsIPrivateBrowsingChannel)
+NS_INTERFACE_MAP_END_INHERITING(nsHashPropertyBag)
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsIRequest
+
+NS_IMETHODIMP
+nsBaseChannel::GetName(nsACString& result) {
+  if (!mURI) {
+    result.Truncate();
+    return NS_OK;
+  }
+  return mURI->GetSpec(result);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::IsPending(bool* result) {
+  *result = Pending();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetStatus(nsresult* status) {
+  if (mRequest && NS_SUCCEEDED(mStatus)) {
+    mRequest->GetStatus(status);
+  } else {
+    *status = mStatus;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsBaseChannel::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsBaseChannel::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsBaseChannel::CancelWithReason(nsresult aStatus,
+                                              const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::Cancel(nsresult status) {
+  // Ignore redundant cancelation
+  if (mCanceled) {
+    return NS_OK;
+  }
+
+  mCanceled = true;
+  mStatus = status;
+
+  if (mCancelableAsyncRequest) {
+    mCancelableAsyncRequest->Cancel(status);
+  }
+
+  if (mRequest) {
+    mRequest->Cancel(status);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::Suspend() {
+  NS_ENSURE_TRUE(mPumpingData, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mRequest, NS_ERROR_NOT_IMPLEMENTED);
+  return mRequest->Suspend();
+}
+
+NS_IMETHODIMP
+nsBaseChannel::Resume() {
+  NS_ENSURE_TRUE(mPumpingData, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mRequest, NS_ERROR_NOT_IMPLEMENTED);
+  return mRequest->Resume();
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetLoadFlags(nsLoadFlags* aLoadFlags) {
+  *aLoadFlags = mLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetLoadFlags(nsLoadFlags aLoadFlags) {
+  mLoadFlags = aLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  nsCOMPtr<nsILoadGroup> loadGroup(mLoadGroup);
+  loadGroup.forget(aLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetLoadGroup(nsILoadGroup* aLoadGroup) {
+  if (!CanSetLoadGroup(aLoadGroup)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mLoadGroup = aLoadGroup;
+  CallbacksChanged();
+  UpdatePrivateBrowsing();
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsIChannel
+
+NS_IMETHODIMP
+nsBaseChannel::GetOriginalURI(nsIURI** aURI) {
+  RefPtr<nsIURI> uri = OriginalURI();
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetOriginalURI(nsIURI* aURI) {
+  NS_ENSURE_ARG_POINTER(aURI);
+  mOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetURI(nsIURI** aURI) {
+  nsCOMPtr<nsIURI> uri(mURI);
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetOwner(nsISupports** aOwner) {
+  nsCOMPtr<nsISupports> owner(mOwner);
+  owner.forget(aOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetOwner(nsISupports* aOwner) {
+  mOwner = aOwner;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetLoadInfo(nsILoadInfo* aLoadInfo) {
+  MOZ_RELEASE_ASSERT(aLoadInfo, "loadinfo can't be null");
+  mLoadInfo = aLoadInfo;
+
+  // Need to update |mNeckoTarget| when load info has changed.
+  SetupNeckoTarget();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetLoadInfo(nsILoadInfo** aLoadInfo) {
+  nsCOMPtr<nsILoadInfo> loadInfo(mLoadInfo);
+  loadInfo.forget(aLoadInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetIsDocument(bool* aIsDocument) {
+  return NS_GetIsDocumentChannel(this, aIsDocument);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetNotificationCallbacks(nsIInterfaceRequestor** aCallbacks) {
+  nsCOMPtr<nsIInterfaceRequestor> callbacks(mCallbacks);
+  callbacks.forget(aCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetNotificationCallbacks(nsIInterfaceRequestor* aCallbacks) {
+  if (!CanSetCallbacks(aCallbacks)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mCallbacks = aCallbacks;
+  CallbacksChanged();
+  UpdatePrivateBrowsing();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetSecurityInfo(nsITransportSecurityInfo** aSecurityInfo) {
+  *aSecurityInfo = do_AddRef(mSecurityInfo).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentType(nsACString& aContentType) {
+  aContentType = mContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetContentType(const nsACString& aContentType) {
+  // mContentCharset is unchanged if not parsed
+  bool dummy;
+  net_ParseContentType(aContentType, mContentType, mContentCharset, &dummy);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentCharset(nsACString& aContentCharset) {
+  aContentCharset = mContentCharset;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetContentCharset(const nsACString& aContentCharset) {
+  mContentCharset = aContentCharset;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentDisposition(uint32_t* aContentDisposition) {
+  // preserve old behavior, fail unless explicitly set.
+  if (mContentDispositionHint == UINT32_MAX) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  *aContentDisposition = mContentDispositionHint;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetContentDisposition(uint32_t aContentDisposition) {
+  mContentDispositionHint = aContentDisposition;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentDispositionFilename(
+    nsAString& aContentDispositionFilename) {
+  if (!mContentDispositionFilename) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  aContentDispositionFilename = *mContentDispositionFilename;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetContentDispositionFilename(
+    const nsAString& aContentDispositionFilename) {
+  mContentDispositionFilename =
+      MakeUnique<nsString>(aContentDispositionFilename);
+
+  // For safety reasons ensure the filename doesn't contain null characters and
+  // replace them with underscores. We may later pass the extension to system
+  // MIME APIs that expect null terminated strings.
+  mContentDispositionFilename->ReplaceChar(char16_t(0), '_');
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentDispositionHeader(
+    nsACString& aContentDispositionHeader) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetContentLength(int64_t* aContentLength) {
+  *aContentLength = mContentLength;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::SetContentLength(int64_t aContentLength) {
+  mContentLength = aContentLength;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::Open(nsIInputStream** aStream) {
+  nsCOMPtr<nsIStreamListener> listener;
+  nsresult rv =
+      nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_TRUE(mURI, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(!mPumpingData, NS_ERROR_IN_PROGRESS);
+  NS_ENSURE_TRUE(!mWasOpened, NS_ERROR_IN_PROGRESS);
+
+  nsCOMPtr<nsIChannel> chan;
+  rv = OpenContentStream(false, aStream, getter_AddRefs(chan));
+  NS_ASSERTION(!chan || !*aStream, "Got both a channel and a stream?");
+  if (NS_SUCCEEDED(rv) && chan) {
+    rv = Redirect(chan, nsIChannelEventSink::REDIRECT_INTERNAL, false);
+    if (NS_FAILED(rv)) return rv;
+    rv = chan->Open(aStream);
+  } else if (rv == NS_ERROR_NOT_IMPLEMENTED) {
+    return NS_ImplementChannelOpen(this, aStream);
+  }
+
+  if (NS_SUCCEEDED(rv)) {
+    mWasOpened = true;
+    ClassifyURI();
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::AsyncOpen(nsIStreamListener* aListener) {
+  nsCOMPtr<nsIStreamListener> listener = aListener;
+
+  nsresult rv =
+      nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  MOZ_ASSERT(
+      mLoadInfo->GetSecurityMode() == 0 ||
+          mLoadInfo->GetInitialSecurityCheckDone() ||
+          (mLoadInfo->GetSecurityMode() ==
+               nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL &&
+           mLoadInfo->GetLoadingPrincipal() &&
+           mLoadInfo->GetLoadingPrincipal()->IsSystemPrincipal()),
+      "security flags in loadInfo but doContentSecurityCheck() not called");
+
+  NS_ENSURE_TRUE(mURI, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(!mPumpingData, NS_ERROR_IN_PROGRESS);
+  NS_ENSURE_TRUE(!mWasOpened, NS_ERROR_ALREADY_OPENED);
+  NS_ENSURE_ARG(listener);
+
+  SetupNeckoTarget();
+
+  // Skip checking for chrome:// sub-resources.
+  nsAutoCString scheme;
+  mURI->GetScheme(scheme);
+  if (!scheme.EqualsLiteral("file")) {
+    NS_CompareLoadInfoAndLoadContext(this);
+  }
+
+  // Ensure that this is an allowed port before proceeding.
+  rv = NS_CheckPortSafety(mURI);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  AntiTrackingUtils::UpdateAntiTrackingInfoForChannel(this);
+
+  // Store the listener and context early so that OpenContentStream and the
+  // stream's AsyncWait method (called by AsyncRead) can have access to them
+  // via the StreamListener methods.  However, since
+  // this typically introduces a reference cycle between this and the listener,
+  // we need to be sure to break the reference if this method does not succeed.
+  mListener = listener;
+
+  // This method assigns mPump as a side-effect.  We need to clear mPump if
+  // this method fails.
+  rv = BeginPumpingData();
+  if (NS_FAILED(rv)) {
+    mPump = nullptr;
+    mRequest = nullptr;
+    mPumpingData = false;
+    ChannelDone();
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  // At this point, we are going to return success no matter what.
+
+  mWasOpened = true;
+
+  SUSPEND_PUMP_FOR_SCOPE();
+
+  if (mLoadGroup) mLoadGroup->AddRequest(this, nullptr);
+
+  ClassifyURI();
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsITransportEventSink
+
+NS_IMETHODIMP
+nsBaseChannel::OnTransportStatus(nsITransport* transport, nsresult status,
+                                 int64_t progress, int64_t progressMax) {
+  // In some cases, we may wish to suppress transport-layer status events.
+
+  if (!mPumpingData || NS_FAILED(mStatus)) {
+    return NS_OK;
+  }
+
+  SUSPEND_PUMP_FOR_SCOPE();
+
+  // Lazily fetch mProgressSink
+  if (!mProgressSink) {
+    if (mQueriedProgressSink) {
+      return NS_OK;
+    }
+    GetCallback(mProgressSink);
+    mQueriedProgressSink = true;
+    if (!mProgressSink) {
+      return NS_OK;
+    }
+  }
+
+  if (!HasLoadFlag(LOAD_BACKGROUND)) {
+    nsAutoString statusArg;
+    if (GetStatusArg(status, statusArg)) {
+      mProgressSink->OnStatus(this, status, statusArg.get());
+    }
+  }
+
+  if (progress) {
+    mProgressSink->OnProgress(this, progress, progressMax);
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsIInterfaceRequestor
+
+NS_IMETHODIMP
+nsBaseChannel::GetInterface(const nsIID& iid, void** result) {
+  NS_QueryNotificationCallbacks(mCallbacks, mLoadGroup, iid, result);
+  return *result ? NS_OK : NS_ERROR_NO_INTERFACE;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsIRequestObserver
+
+static void CallTypeSniffers(void* aClosure, const uint8_t* aData,
+                             uint32_t aCount) {
+  nsIChannel* chan = static_cast<nsIChannel*>(aClosure);
+
+  nsAutoCString newType;
+  NS_SniffContent(NS_CONTENT_SNIFFER_CATEGORY, chan, aData, aCount, newType);
+  if (!newType.IsEmpty()) {
+    chan->SetContentType(newType);
+  }
+}
+
+static void CallUnknownTypeSniffer(void* aClosure, const uint8_t* aData,
+                                   uint32_t aCount) {
+  nsIChannel* chan = static_cast<nsIChannel*>(aClosure);
+
+  RefPtr<nsUnknownDecoder> sniffer = new nsUnknownDecoder();
+
+  nsAutoCString detected;
+  nsresult rv = sniffer->GetMIMETypeFromContent(chan, aData, aCount, detected);
+  if (NS_SUCCEEDED(rv)) chan->SetContentType(detected);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::OnStartRequest(nsIRequest* request) {
+  MOZ_ASSERT_IF(mRequest, request == mRequest);
+  MOZ_ASSERT_IF(mCancelableAsyncRequest, !mRequest);
+
+  nsAutoCString scheme;
+  mURI->GetScheme(scheme);
+
+  if (mPump && !scheme.EqualsLiteral("ftp")) {
+    // If our content type is unknown, use the content type
+    // sniffer. If the sniffer is not available for some reason, then we just
+    // keep going as-is.
+    if (NS_SUCCEEDED(mStatus) &&
+        mContentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
+      mPump->PeekStream(CallUnknownTypeSniffer, static_cast<nsIChannel*>(this));
+    }
+
+    // Now, the general type sniffers. Skip this if we have none.
+    if (mLoadFlags & LOAD_CALL_CONTENT_SNIFFERS) {
+      mPump->PeekStream(CallTypeSniffers, static_cast<nsIChannel*>(this));
+    }
+  }
+
+  SUSPEND_PUMP_FOR_SCOPE();
+
+  if (mListener) {  // null in case of redirect
+    return mListener->OnStartRequest(this);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::OnStopRequest(nsIRequest* request, nsresult status) {
+  // If both mStatus and status are failure codes, we keep mStatus as-is since
+  // that is consistent with our GetStatus and Cancel methods.
+  if (NS_SUCCEEDED(mStatus)) mStatus = status;
+
+  // Cause Pending to return false.
+  mPump = nullptr;
+  mRequest = nullptr;
+  mCancelableAsyncRequest = nullptr;
+  mPumpingData = false;
+
+  if (mListener) {  // null in case of redirect
+    mListener->OnStopRequest(this, mStatus);
+  }
+  ChannelDone();
+
+  // No need to suspend pump in this scope since we will not be receiving
+  // any more events from it.
+
+  if (mLoadGroup) mLoadGroup->RemoveRequest(this, nullptr, mStatus);
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+  CallbacksChanged();
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel::nsIStreamListener
+
+NS_IMETHODIMP
+nsBaseChannel::OnDataAvailable(nsIRequest* request, nsIInputStream* stream,
+                               uint64_t offset, uint32_t count) {
+  SUSPEND_PUMP_FOR_SCOPE();
+
+  nsresult rv = mListener->OnDataAvailable(this, stream, offset, count);
+  if (mSynthProgressEvents && NS_SUCCEEDED(rv)) {
+    int64_t prog = offset + count;
+    if (NS_IsMainThread()) {
+      OnTransportStatus(nullptr, NS_NET_STATUS_READING, prog, mContentLength);
+    } else {
+      class OnTransportStatusAsyncEvent : public Runnable {
+        RefPtr<nsBaseChannel> mChannel;
+        int64_t mProgress;
+        int64_t mContentLength;
+
+       public:
+        OnTransportStatusAsyncEvent(nsBaseChannel* aChannel, int64_t aProgress,
+                                    int64_t aContentLength)
+            : Runnable("OnTransportStatusAsyncEvent"),
+              mChannel(aChannel),
+              mProgress(aProgress),
+              mContentLength(aContentLength) {}
+
+        NS_IMETHOD Run() override {
+          return mChannel->OnTransportStatus(nullptr, NS_NET_STATUS_READING,
+                                             mProgress, mContentLength);
+        }
+      };
+
+      nsCOMPtr<nsIRunnable> runnable =
+          new OnTransportStatusAsyncEvent(this, prog, mContentLength);
+      Dispatch(runnable.forget());
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::OnRedirectVerifyCallback(nsresult result) {
+  if (NS_SUCCEEDED(result)) result = ContinueRedirect();
+
+  if (NS_FAILED(result) && !mWaitingOnAsyncRedirect) {
+    if (NS_SUCCEEDED(mStatus)) mStatus = result;
+    return NS_OK;
+  }
+
+  if (mWaitingOnAsyncRedirect) ContinueHandleAsyncRedirect(result);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseChannel::RetargetDeliveryTo(nsISerialEventTarget* aEventTarget) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  NS_ENSURE_TRUE(mRequest, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIThreadRetargetableRequest> req;
+  if (mAllowThreadRetargeting) {
+    req = do_QueryInterface(mRequest);
+  }
+
+  NS_ENSURE_TRUE(req, NS_ERROR_NOT_IMPLEMENTED);
+
+  return req->RetargetDeliveryTo(aEventTarget);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::GetDeliveryTarget(nsISerialEventTarget** aEventTarget) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  NS_ENSURE_TRUE(mRequest, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIThreadRetargetableRequest> req;
+  req = do_QueryInterface(mRequest);
+
+  NS_ENSURE_TRUE(req, NS_ERROR_NOT_IMPLEMENTED);
+  return req->GetDeliveryTarget(aEventTarget);
+}
+
+NS_IMETHODIMP
+nsBaseChannel::CheckListenerChain() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!mAllowThreadRetargeting) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  nsCOMPtr<nsIThreadRetargetableStreamListener> listener =
+      do_QueryInterface(mListener);
+  if (!listener) {
+    return NS_ERROR_NO_INTERFACE;
+  }
+
+  return listener->CheckListenerChain();
+}
+
+NS_IMETHODIMP nsBaseChannel::GetCanceled(bool* aCanceled) {
+  *aCanceled = mCanceled;
+  return NS_OK;
+}
+
+void nsBaseChannel::SetupNeckoTarget() {
+  mNeckoTarget =
+      nsContentUtils::GetEventTargetByLoadInfo(mLoadInfo, TaskCategory::Other);
+}
diff --git a/netwerk/base/nsBaseChannel.h b/netwerk/base/nsBaseChannel.h
new file mode 100644
index 0000000000..cacb74231b
--- /dev/null
+++ b/netwerk/base/nsBaseChannel.h
@@ -0,0 +1,310 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsBaseChannel_h__
+#define nsBaseChannel_h__
+
+#include "mozilla/Maybe.h"
+#include "mozilla/MozPromise.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/net/NeckoTargetHolder.h"
+#include "mozilla/net/PrivateBrowsingChannel.h"
+#include "nsHashPropertyBag.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsIChannel.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsILoadGroup.h"
+#include "nsILoadInfo.h"
+#include "nsIProgressEventSink.h"
+#include "nsIStreamListener.h"
+#include "nsIThreadRetargetableRequest.h"
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsITransport.h"
+#include "nsITransportSecurityInfo.h"
+#include "nsIURI.h"
+#include "nsInputStreamPump.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "nsCOMPtr.h"
+
+class nsIInputStream;
+class nsICancelable;
+
+//-----------------------------------------------------------------------------
+// nsBaseChannel is designed to be subclassed.  The subclass is responsible for
+// implementing the OpenContentStream method, which will be called by the
+// nsIChannel::AsyncOpen and nsIChannel::Open implementations.
+//
+// nsBaseChannel implements nsIInterfaceRequestor to provide a convenient way
+// for subclasses to query both the nsIChannel::notificationCallbacks and
+// nsILoadGroup::notificationCallbacks for supported interfaces.
+//
+// nsBaseChannel implements nsITransportEventSink to support progress & status
+// notifications generated by the transport layer.
+
+class nsBaseChannel
+    : public nsHashPropertyBag,
+      public nsIChannel,
+      public nsIThreadRetargetableRequest,
+      public nsIInterfaceRequestor,
+      public nsITransportEventSink,
+      public nsIAsyncVerifyRedirectCallback,
+      public mozilla::net::PrivateBrowsingChannel<nsBaseChannel>,
+      public mozilla::net::NeckoTargetHolder,
+      protected nsIStreamListener,
+      protected nsIThreadRetargetableStreamListener {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSICHANNEL
+  NS_DECL_NSIINTERFACEREQUESTOR
+  NS_DECL_NSITRANSPORTEVENTSINK
+  NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
+  NS_DECL_NSITHREADRETARGETABLEREQUEST
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+
+  nsBaseChannel();
+
+ protected:
+  // -----------------------------------------------
+  // Methods to be implemented by the derived class:
+
+  virtual ~nsBaseChannel();
+
+  using BlockingPromise = mozilla::MozPromise<nsresult, nsresult, true>;
+
+ private:
+  // Implemented by subclass to supply data stream.  The parameter, async, is
+  // true when called from nsIChannel::AsyncOpen and false otherwise.  When
+  // async is true, the resulting stream will be used with a nsIInputStreamPump
+  // instance.  This means that if it is a non-blocking stream that supports
+  // nsIAsyncInputStream that it will be read entirely on the main application
+  // thread, and its AsyncWait method will be called whenever ReadSegments
+  // returns NS_BASE_STREAM_WOULD_BLOCK.  Otherwise, if the stream is blocking,
+  // then it will be read on one of the background I/O threads, and it does not
+  // need to implement ReadSegments.  If async is false, this method may return
+  // NS_ERROR_NOT_IMPLEMENTED to cause the basechannel to implement Open in
+  // terms of AsyncOpen (see NS_ImplementChannelOpen).
+  // A callee is allowed to return an nsIChannel instead of an nsIInputStream.
+  // That case will be treated as a redirect to the new channel.  By default
+  // *channel will be set to null by the caller, so callees who don't want to
+  // return one an just not touch it.
+  virtual nsresult OpenContentStream(bool async, nsIInputStream** stream,
+                                     nsIChannel** channel) = 0;
+
+  // Implemented by subclass to begin pumping data for an async channel, in
+  // lieu of returning a stream. If implemented, OpenContentStream will never
+  // be called for async channels. If not implemented, AsyncOpen will fall
+  // back to OpenContentStream.
+  //
+  // On success, the callee must begin pumping data to the stream listener,
+  // and at some point call OnStartRequest followed by OnStopRequest.
+  //
+  // Additionally, when a successful nsresult is returned, then the subclass
+  // should be setting  through its two out params either:
+  // - a request object, which may be used to suspend, resume, and cancel
+  //   the underlying request.
+  // - or a cancelable object (e.g. when a request can't be returned right away
+  //   due to some async work needed to retrieve it). which may be used to
+  //   cancel the underlying request (e.g. because the channel has been
+  //   canceled)
+  //
+  // Not returning a request or cancelable leads to potentially leaking the
+  // an underling stream pump (which would keep to be pumping data even after
+  // the channel has been canceled and nothing is going to handle the data
+  // available, e.g. see Bug 1706594).
+  virtual nsresult BeginAsyncRead(nsIStreamListener* listener,
+                                  nsIRequest** request,
+                                  nsICancelable** cancelableRequest) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  // This method may return a promise that will keep the input stream pump
+  // suspended until the promise is resolved or rejected.  On resolution the
+  // pump is resumed.  On rejection the channel is canceled with the resulting
+  // error and then the pump is also resumed to propagate the error to the
+  // channel listener.  Use it to do any asynchronous/background tasks you need
+  // to finish prior calling OnStartRequest of the listener.  This method is
+  // called right after OpenContentStream() with async == true, after the input
+  // stream pump has already been called asyncRead().
+  virtual nsresult ListenerBlockingPromise(BlockingPromise** aPromise) {
+    NS_ENSURE_ARG(aPromise);
+    *aPromise = nullptr;
+    return NS_OK;
+  }
+
+  // The basechannel calls this method from its OnTransportStatus method to
+  // determine whether to call nsIProgressEventSink::OnStatus in addition to
+  // nsIProgressEventSink::OnProgress.  This method may be overriden by the
+  // subclass to enable nsIProgressEventSink::OnStatus events.  If this method
+  // returns true, then the statusArg out param specifies the "statusArg" value
+  // to pass to the OnStatus method.  By default, OnStatus messages are
+  // suppressed.  The status parameter passed to this method is the status value
+  // from the OnTransportStatus method.
+  virtual bool GetStatusArg(nsresult status, nsString& statusArg) {
+    return false;
+  }
+
+  // Called when the callbacks available to this channel may have changed.
+  virtual void OnCallbacksChanged() {}
+
+  // Called when our channel is done, to allow subclasses to drop resources.
+  virtual void OnChannelDone() {}
+
+ public:
+  // ----------------------------------------------
+  // Methods provided for use by the derived class:
+
+  // Redirect to another channel.  This method takes care of notifying
+  // observers of this redirect as well as of opening the new channel, if asked
+  // to do so.  It also cancels |this| with the status code
+  // NS_BINDING_REDIRECTED.  A failure return from this method means that the
+  // redirect could not be performed (no channel was opened; this channel
+  // wasn't canceled.)  The redirectFlags parameter consists of the flag values
+  // defined on nsIChannelEventSink.
+  nsresult Redirect(nsIChannel* newChannel, uint32_t redirectFlags,
+                    bool openNewChannel);
+
+  // Tests whether a type hint was set. Subclasses can use this to decide
+  // whether to call SetContentType.
+  // NOTE: This is only reliable if the subclass didn't itself call
+  // SetContentType, and should also not be called after OpenContentStream.
+  bool HasContentTypeHint() const;
+
+  // The URI member should be initialized before the channel is used, and then
+  // it should never be changed again until the channel is destroyed.
+  nsIURI* URI() { return mURI; }
+  void SetURI(nsIURI* uri) {
+    NS_ASSERTION(uri, "must specify a non-null URI");
+    NS_ASSERTION(!mURI, "must not modify URI");
+    NS_ASSERTION(!mOriginalURI, "how did that get set so early?");
+    mURI = uri;
+    mOriginalURI = uri;
+  }
+  nsIURI* OriginalURI() { return mOriginalURI; }
+
+  // The security info is a property of the transport-layer, which should be
+  // assigned by the subclass.
+  nsITransportSecurityInfo* SecurityInfo() { return mSecurityInfo; }
+  void SetSecurityInfo(nsITransportSecurityInfo* info) { mSecurityInfo = info; }
+
+  // Test the load flags
+  bool HasLoadFlag(uint32_t flag) { return (mLoadFlags & flag) != 0; }
+
+  // This is a short-cut to calling nsIRequest::IsPending()
+  virtual bool Pending() const {
+    return mPumpingData || mWaitingOnAsyncRedirect;
+  }
+
+  // Helper function for querying the channel's notification callbacks.
+  template <class T>
+  void GetCallback(nsCOMPtr<T>& result) {
+    GetInterface(NS_GET_TEMPLATE_IID(T), getter_AddRefs(result));
+  }
+
+  // If a subclass does not want to feed transport-layer progress events to the
+  // base channel via nsITransportEventSink, then it may set this flag to cause
+  // the base channel to synthesize progress events when it receives data from
+  // the content stream.  By default, progress events are not synthesized.
+  void EnableSynthesizedProgressEvents(bool enable) {
+    mSynthProgressEvents = enable;
+  }
+
+  // Some subclasses may wish to manually insert a stream listener between this
+  // and the channel's listener.  The following methods make that possible.
+  void SetStreamListener(nsIStreamListener* listener) { mListener = listener; }
+  nsIStreamListener* StreamListener() { return mListener; }
+
+ protected:
+  void DisallowThreadRetargeting() { mAllowThreadRetargeting = false; }
+
+  virtual void SetupNeckoTarget();
+
+ private:
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSIREQUESTOBSERVER
+
+  // Called to setup mPump and call AsyncRead on it.
+  nsresult BeginPumpingData();
+
+  // Called when the callbacks available to this channel may have changed.
+  void CallbacksChanged() {
+    mProgressSink = nullptr;
+    mQueriedProgressSink = false;
+    OnCallbacksChanged();
+  }
+
+  // Called when our channel is done.  This should drop no-longer-needed
+  // pointers.
+  void ChannelDone() {
+    mListener = nullptr;
+    OnChannelDone();
+  }
+
+  // Handle an async redirect callback.  This will only be called if we
+  // returned success from AsyncOpen while posting a redirect runnable.
+  void HandleAsyncRedirect(nsIChannel* newChannel);
+  void ContinueHandleAsyncRedirect(nsresult result);
+  nsresult ContinueRedirect();
+
+  // start URI classifier if requested
+  void ClassifyURI();
+
+  class RedirectRunnable : public mozilla::Runnable {
+   public:
+    RedirectRunnable(nsBaseChannel* chan, nsIChannel* newChannel)
+        : mozilla::Runnable("nsBaseChannel::RedirectRunnable"),
+          mChannel(chan),
+          mNewChannel(newChannel) {
+      MOZ_ASSERT(newChannel, "Must have channel to redirect to");
+    }
+
+    NS_IMETHOD Run() override {
+      mChannel->HandleAsyncRedirect(mNewChannel);
+      return NS_OK;
+    }
+
+   private:
+    RefPtr<nsBaseChannel> mChannel;
+    nsCOMPtr<nsIChannel> mNewChannel;
+  };
+  friend class RedirectRunnable;
+
+  RefPtr<nsInputStreamPump> mPump;
+  RefPtr<nsIRequest> mRequest;
+  nsCOMPtr<nsICancelable> mCancelableAsyncRequest;
+  bool mPumpingData{false};
+  nsCOMPtr<nsIProgressEventSink> mProgressSink;
+  nsCOMPtr<nsIURI> mOriginalURI;
+  nsCOMPtr<nsISupports> mOwner;
+  nsCOMPtr<nsITransportSecurityInfo> mSecurityInfo;
+  nsCOMPtr<nsIChannel> mRedirectChannel;
+  uint32_t mLoadFlags{LOAD_NORMAL};
+  bool mQueriedProgressSink{true};
+  bool mSynthProgressEvents{false};
+  bool mAllowThreadRetargeting{true};
+  bool mWaitingOnAsyncRedirect{false};
+  bool mOpenRedirectChannel{false};
+  uint32_t mRedirectFlags{0};
+
+ protected:
+  nsCString mContentType;
+  nsCString mContentCharset;
+  nsCOMPtr<nsIURI> mURI;
+  nsCOMPtr<nsILoadGroup> mLoadGroup;
+  nsCOMPtr<nsILoadInfo> mLoadInfo;
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsIStreamListener> mListener;
+  nsresult mStatus{NS_OK};
+  uint32_t mContentDispositionHint{UINT32_MAX};
+  mozilla::UniquePtr<nsString> mContentDispositionFilename;
+  int64_t mContentLength{-1};
+  bool mWasOpened{false};
+  bool mCanceled{false};
+
+  friend class mozilla::net::PrivateBrowsingChannel<nsBaseChannel>;
+};
+
+#endif  // !nsBaseChannel_h__
diff --git a/netwerk/base/nsBaseContentStream.cpp b/netwerk/base/nsBaseContentStream.cpp
new file mode 100644
index 0000000000..d59145f463
--- /dev/null
+++ b/netwerk/base/nsBaseContentStream.cpp
@@ -0,0 +1,127 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsBaseContentStream.h"
+#include "nsStreamUtils.h"
+
+//-----------------------------------------------------------------------------
+
+void nsBaseContentStream::DispatchCallback(bool async) {
+  if (!mCallback) return;
+
+  // It's important to clear mCallback and mCallbackTarget up-front because the
+  // OnInputStreamReady implementation may call our AsyncWait method.
+
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  if (async) {
+    callback = NS_NewInputStreamReadyEvent(
+        "nsBaseContentStream::DispatchCallback", mCallback, mCallbackTarget);
+    mCallback = nullptr;
+  } else {
+    callback.swap(mCallback);
+  }
+  mCallbackTarget = nullptr;
+
+  callback->OnInputStreamReady(this);
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseContentStream::nsISupports
+
+NS_IMPL_ADDREF(nsBaseContentStream)
+NS_IMPL_RELEASE(nsBaseContentStream)
+
+// We only support nsIAsyncInputStream when we are in non-blocking mode.
+NS_INTERFACE_MAP_BEGIN(nsBaseContentStream)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mNonBlocking)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
+NS_INTERFACE_MAP_END
+
+//-----------------------------------------------------------------------------
+// nsBaseContentStream::nsIInputStream
+
+NS_IMETHODIMP
+nsBaseContentStream::Close() {
+  return IsClosed() ? NS_OK : CloseWithStatus(NS_BASE_STREAM_CLOSED);
+}
+
+NS_IMETHODIMP
+nsBaseContentStream::Available(uint64_t* result) {
+  *result = 0;
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsBaseContentStream::StreamStatus() { return mStatus; }
+
+NS_IMETHODIMP
+nsBaseContentStream::Read(char* buf, uint32_t count, uint32_t* result) {
+  return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
+}
+
+NS_IMETHODIMP
+nsBaseContentStream::ReadSegments(nsWriteSegmentFun fun, void* closure,
+                                  uint32_t count, uint32_t* result) {
+  *result = 0;
+
+  if (mStatus == NS_BASE_STREAM_CLOSED) return NS_OK;
+
+  // No data yet
+  if (!IsClosed() && IsNonBlocking()) return NS_BASE_STREAM_WOULD_BLOCK;
+
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsBaseContentStream::IsNonBlocking(bool* result) {
+  *result = mNonBlocking;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsBaseContentStream::nsIAsyncInputStream
+
+NS_IMETHODIMP
+nsBaseContentStream::CloseWithStatus(nsresult status) {
+  if (IsClosed()) return NS_OK;
+
+  NS_ENSURE_ARG(NS_FAILED(status));
+  mStatus = status;
+
+  DispatchCallback();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseContentStream::AsyncWait(nsIInputStreamCallback* callback, uint32_t flags,
+                               uint32_t requestedCount,
+                               nsIEventTarget* target) {
+  // Our _only_ consumer is nsInputStreamPump, so we simplify things here by
+  // making assumptions about how we will be called.
+  NS_ASSERTION(target, "unexpected parameter");
+  NS_ASSERTION(flags == 0, "unexpected parameter");
+  NS_ASSERTION(requestedCount == 0, "unexpected parameter");
+
+#ifdef DEBUG
+  bool correctThread;
+  target->IsOnCurrentThread(&correctThread);
+  NS_ASSERTION(correctThread, "event target must be on the current thread");
+#endif
+
+  mCallback = callback;
+  mCallbackTarget = target;
+
+  if (!mCallback) return NS_OK;
+
+  // If we're already closed, then dispatch this callback immediately.
+  if (IsClosed()) {
+    DispatchCallback();
+    return NS_OK;
+  }
+
+  OnCallbackPending();
+  return NS_OK;
+}
diff --git a/netwerk/base/nsBaseContentStream.h b/netwerk/base/nsBaseContentStream.h
new file mode 100644
index 0000000000..13a3766857
--- /dev/null
+++ b/netwerk/base/nsBaseContentStream.h
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsBaseContentStream_h__
+#define nsBaseContentStream_h__
+
+#include "nsIAsyncInputStream.h"
+#include "nsIEventTarget.h"
+#include "nsCOMPtr.h"
+
+//-----------------------------------------------------------------------------
+// nsBaseContentStream is designed to be subclassed with the intention of being
+// used to satisfy the nsBaseChannel::OpenContentStream method.
+//
+// The subclass typically overrides the default Available, ReadSegments and
+// CloseWithStatus methods.  By default, Read is implemented in terms of
+// ReadSegments, and Close is implemented in terms of CloseWithStatus.  If
+// CloseWithStatus is overriden, then the subclass will usually want to call
+// the base class' CloseWithStatus method before returning.
+//
+// If the stream is non-blocking, then readSegments may return the exception
+// NS_BASE_STREAM_WOULD_BLOCK if there is no data available and the stream is
+// not at the "end-of-file" or already closed.  This error code must not be
+// returned from the Available implementation.  When the caller receives this
+// error code, he may choose to call the stream's AsyncWait method, in which
+// case the base stream will have a non-null PendingCallback.  When the stream
+// has data or encounters an error, it should be sure to dispatch a pending
+// callback if one exists (see DispatchCallback).  The implementation of the
+// base stream's CloseWithStatus (and Close) method will ensure that any
+// pending callback is dispatched.  It is the responsibility of the subclass
+// to ensure that the pending callback is dispatched when it wants to have its
+// ReadSegments method called again.
+
+class nsBaseContentStream : public nsIAsyncInputStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+
+  explicit nsBaseContentStream(bool nonBlocking)
+      : mStatus(NS_OK), mNonBlocking(nonBlocking) {}
+
+  nsresult Status() { return mStatus; }
+  bool IsNonBlocking() { return mNonBlocking; }
+  bool IsClosed() { return NS_FAILED(mStatus); }
+
+  // Called to test if the stream has a pending callback.
+  bool HasPendingCallback() { return mCallback != nullptr; }
+
+  // The current dispatch target (may be null) for the pending callback if any.
+  nsIEventTarget* CallbackTarget() { return mCallbackTarget; }
+
+  // Called to dispatch a pending callback.  If there is no pending callback,
+  // then this function does nothing.  Pass true to this function to cause the
+  // callback to occur asynchronously; otherwise, the callback will happen
+  // before this function returns.
+  void DispatchCallback(bool async = true);
+
+  // Helper function to make code more self-documenting.
+  void DispatchCallbackSync() { DispatchCallback(false); }
+
+ protected:
+  virtual ~nsBaseContentStream() = default;
+
+ private:
+  // Called from the base stream's AsyncWait method when a pending callback
+  // is installed on the stream.
+  virtual void OnCallbackPending() {}
+
+ private:
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  nsCOMPtr<nsIEventTarget> mCallbackTarget;
+  nsresult mStatus;
+  bool mNonBlocking;
+};
+
+#endif  // nsBaseContentStream_h__
diff --git a/netwerk/base/nsBufferedStreams.cpp b/netwerk/base/nsBufferedStreams.cpp
new file mode 100644
index 0000000000..2606352cc4
--- /dev/null
+++ b/netwerk/base/nsBufferedStreams.cpp
@@ -0,0 +1,1197 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsBufferedStreams.h"
+#include "nsStreamUtils.h"
+#include "nsNetCID.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIEventTarget.h"
+#include "nsThreadUtils.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/ipc/InputStreamUtils.h"
+#include <algorithm>
+
+#ifdef DEBUG_brendan
+#  define METERING
+#endif
+
+#ifdef METERING
+#  include <stdio.h>
+#  define METER(x) x
+#  define MAX_BIG_SEEKS 20
+
+static struct {
+  uint32_t mSeeksWithinBuffer;
+  uint32_t mSeeksOutsideBuffer;
+  uint32_t mBufferReadUponSeek;
+  uint32_t mBufferUnreadUponSeek;
+  uint32_t mBytesReadFromBuffer;
+  uint32_t mBigSeekIndex;
+  struct {
+    int64_t mOldOffset;
+    int64_t mNewOffset;
+  } mBigSeek[MAX_BIG_SEEKS];
+} bufstats;
+#else
+#  define METER(x) /* nothing */
+#endif
+
+using namespace mozilla::ipc;
+using namespace mozilla;
+
+////////////////////////////////////////////////////////////////////////////////
+// nsBufferedStream
+
+nsBufferedStream::~nsBufferedStream() { Close(); }
+
+NS_IMPL_ADDREF(nsBufferedStream)
+NS_IMPL_RELEASE(nsBufferedStream)
+
+NS_INTERFACE_MAP_BEGIN(nsBufferedStream)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsITellableStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISeekableStream, mSeekable)
+NS_INTERFACE_MAP_END
+
+nsresult nsBufferedStream::Init(nsISupports* aStream, uint32_t bufferSize) {
+  NS_ASSERTION(aStream, "need to supply a stream");
+  NS_ASSERTION(mStream == nullptr, "already inited");
+  mStream = aStream;  // we keep a reference until nsBufferedStream::Close
+  mBufferSize = bufferSize;
+  mBufferStartOffset = 0;
+  mCursor = 0;
+  nsCOMPtr<nsISeekableStream> seekable = do_QueryInterface(mStream);
+  mSeekable = seekable;
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  mBuffer = new (mozilla::fallible) char[bufferSize];
+  if (mBuffer == nullptr) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  return NS_OK;
+}
+
+void nsBufferedStream::Close() {
+  // Drop the reference from nsBufferedStream::Init()
+  mStream = nullptr;
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  if (mBuffer) {
+    delete[] mBuffer;
+    mBuffer = nullptr;
+    mBufferSize = 0;
+    mBufferStartOffset = 0;
+    mCursor = 0;
+    mFillPoint = 0;
+  }
+#ifdef METERING
+  {
+    static FILE* tfp;
+    if (!tfp) {
+      tfp = fopen("/tmp/bufstats", "w");
+      if (tfp) {
+        setvbuf(tfp, nullptr, _IOLBF, 0);
+      }
+    }
+    if (tfp) {
+      fprintf(tfp, "seeks within buffer:    %u\n", bufstats.mSeeksWithinBuffer);
+      fprintf(tfp, "seeks outside buffer:   %u\n",
+              bufstats.mSeeksOutsideBuffer);
+      fprintf(tfp, "buffer read on seek:    %u\n",
+              bufstats.mBufferReadUponSeek);
+      fprintf(tfp, "buffer unread on seek:  %u\n",
+              bufstats.mBufferUnreadUponSeek);
+      fprintf(tfp, "bytes read from buffer: %u\n",
+              bufstats.mBytesReadFromBuffer);
+      for (uint32_t i = 0; i < bufstats.mBigSeekIndex; i++) {
+        fprintf(tfp, "bigseek[%u] = {old: %u, new: %u}\n", i,
+                bufstats.mBigSeek[i].mOldOffset,
+                bufstats.mBigSeek[i].mNewOffset);
+      }
+    }
+  }
+#endif
+}
+
+NS_IMETHODIMP
+nsBufferedStream::Seek(int32_t whence, int64_t offset) {
+  if (mStream == nullptr) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  // If the underlying stream isn't a random access store, then fail early.
+  // We could possibly succeed for the case where the seek position denotes
+  // something that happens to be read into the buffer, but that would make
+  // the failure data-dependent.
+  nsresult rv;
+  nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("mStream doesn't QI to nsISeekableStream");
+    return rv;
+  }
+
+  int64_t absPos = 0;
+  switch (whence) {
+    case nsISeekableStream::NS_SEEK_SET:
+      absPos = offset;
+      break;
+    case nsISeekableStream::NS_SEEK_CUR:
+      absPos = mBufferStartOffset;
+      absPos += mCursor;
+      absPos += offset;
+      break;
+    case nsISeekableStream::NS_SEEK_END:
+      absPos = -1;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("bogus seek whence parameter");
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  // Let mCursor point into the existing buffer if the new position is
+  // between the current cursor and the mFillPoint "fencepost" -- the
+  // client may never get around to a Read or Write after this Seek.
+  // Read and Write worry about flushing and filling in that event.
+  // But if we're at EOF, make sure to pass the seek through to the
+  // underlying stream, because it may have auto-closed itself and
+  // needs to reopen.
+  uint32_t offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
+  if (offsetInBuffer <= mFillPoint && !mEOF) {
+    METER(bufstats.mSeeksWithinBuffer++);
+    mCursor = offsetInBuffer;
+    return NS_OK;
+  }
+
+  METER(bufstats.mSeeksOutsideBuffer++);
+  METER(bufstats.mBufferReadUponSeek += mCursor);
+  METER(bufstats.mBufferUnreadUponSeek += mFillPoint - mCursor);
+  rv = Flush();
+  if (NS_FAILED(rv)) {
+#ifdef DEBUG
+    NS_WARNING(
+        "(debug) Flush returned error within nsBufferedStream::Seek, so we "
+        "exit early.");
+#endif
+    return rv;
+  }
+
+  rv = ras->Seek(whence, offset);
+  if (NS_FAILED(rv)) {
+#ifdef DEBUG
+    NS_WARNING(
+        "(debug) Error: ras->Seek() returned error within "
+        "nsBufferedStream::Seek, so we exit early.");
+#endif
+    return rv;
+  }
+
+  mEOF = false;
+
+  // Recompute whether the offset we're seeking to is in our buffer.
+  // Note that we need to recompute because Flush() might have
+  // changed mBufferStartOffset.
+  offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
+  if (offsetInBuffer <= mFillPoint) {
+    // It's safe to just set mCursor to offsetInBuffer.  In particular, we
+    // want to avoid calling Fill() here since we already have the data that
+    // was seeked to and calling Fill() might auto-close our underlying
+    // stream in some cases.
+    mCursor = offsetInBuffer;
+    return NS_OK;
+  }
+
+  METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
+            bufstats.mBigSeek[bufstats.mBigSeekIndex]
+                .mOldOffset = mBufferStartOffset + int64_t(mCursor));
+  const int64_t minus1 = -1;
+  if (absPos == minus1) {
+    // then we had the SEEK_END case, above
+    int64_t tellPos;
+    rv = ras->Tell(&tellPos);
+    mBufferStartOffset = tellPos;
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  } else {
+    mBufferStartOffset = absPos;
+  }
+  METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
+            bufstats.mBigSeek[bufstats.mBigSeekIndex++]
+                .mNewOffset = mBufferStartOffset);
+
+  mFillPoint = mCursor = 0;
+
+  // If we seeked back to the start, then don't fill the buffer
+  // right now in case this is a lazily-opened file stream.
+  // We'll fill on the first read, like we did initially.
+  if (whence == nsISeekableStream::NS_SEEK_SET && offset == 0) {
+    return NS_OK;
+  }
+  return Fill();
+}
+
+NS_IMETHODIMP
+nsBufferedStream::Tell(int64_t* result) {
+  if (mStream == nullptr) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  int64_t result64 = mBufferStartOffset;
+  result64 += mCursor;
+  *result = result64;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedStream::SetEOF() {
+  if (mStream == nullptr) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ras->SetEOF();
+  if (NS_SUCCEEDED(rv)) {
+    mEOF = true;
+  }
+
+  return rv;
+}
+
+nsresult nsBufferedStream::GetData(nsISupports** aResult) {
+  nsCOMPtr<nsISupports> stream(mStream);
+  stream.forget(aResult);
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsBufferedInputStream
+
+NS_IMPL_ADDREF_INHERITED(nsBufferedInputStream, nsBufferedStream)
+NS_IMPL_RELEASE_INHERITED(nsBufferedInputStream, nsBufferedStream)
+
+NS_IMPL_CLASSINFO(nsBufferedInputStream, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_BUFFEREDINPUTSTREAM_CID)
+
+NS_INTERFACE_MAP_BEGIN(nsBufferedInputStream)
+  // Unfortunately there isn't a macro that combines ambiguous and conditional,
+  // and as far as I can tell, no other class would need such a macro.
+  if (mIsAsyncInputStream && aIID.Equals(NS_GET_IID(nsIInputStream))) {
+    foundInterface =
+        static_cast<nsIInputStream*>(static_cast<nsIAsyncInputStream*>(this));
+  } else if (!mIsAsyncInputStream && aIID.Equals(NS_GET_IID(nsIInputStream))) {
+    foundInterface = static_cast<nsIInputStream*>(
+        static_cast<nsIBufferedInputStream*>(this));
+  } else
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIBufferedInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIBufferedInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIIPCSerializableInputStream,
+                                     mIsIPCSerializable)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mIsAsyncInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback,
+                                     mIsAsyncInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream,
+                                     mIsCloneableInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLength, mIsInputStreamLength)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStreamLength,
+                                     mIsAsyncInputStreamLength)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLengthCallback,
+                                     mIsAsyncInputStreamLength)
+  NS_IMPL_QUERY_CLASSINFO(nsBufferedInputStream)
+NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)
+
+NS_IMPL_CI_INTERFACE_GETTER(nsBufferedInputStream, nsIInputStream,
+                            nsIBufferedInputStream, nsISeekableStream,
+                            nsITellableStream, nsIStreamBufferAccess)
+
+nsresult nsBufferedInputStream::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsBufferedInputStream> stream = new nsBufferedInputStream();
+  return stream->QueryInterface(aIID, aResult);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Init(nsIInputStream* stream, uint32_t bufferSize) {
+  nsresult rv = nsBufferedStream::Init(stream, bufferSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  {
+    nsCOMPtr<nsIIPCSerializableInputStream> stream = do_QueryInterface(mStream);
+    mIsIPCSerializable = !!stream;
+  }
+
+  {
+    nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream);
+    mIsAsyncInputStream = !!stream;
+  }
+
+  {
+    nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+    mIsCloneableInputStream = !!stream;
+  }
+
+  {
+    nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
+    mIsInputStreamLength = !!stream;
+  }
+
+  {
+    nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
+    mIsAsyncInputStreamLength = !!stream;
+  }
+
+  return NS_OK;
+}
+
+already_AddRefed<nsIInputStream> nsBufferedInputStream::GetInputStream() {
+  // A non-null mStream implies Init() has been called.
+  MOZ_ASSERT(mStream);
+
+  nsIInputStream* out = nullptr;
+  DebugOnly<nsresult> rv = QueryInterface(NS_GET_IID(nsIInputStream),
+                                          reinterpret_cast<void**>(&out));
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+  MOZ_ASSERT(out);
+
+  return already_AddRefed<nsIInputStream>(out);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Close() {
+  nsresult rv = NS_OK;
+  if (mStream) {
+    rv = Source()->Close();
+    if (NS_FAILED(rv)) {
+      NS_WARNING(
+          "(debug) Error: Source()->Close() returned error in "
+          "bsBuffedInputStream::Close().");
+    }
+  }
+
+  nsBufferedStream::Close();
+  return rv;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Available(uint64_t* result) {
+  *result = 0;
+
+  if (!mStream) {
+    return NS_OK;
+  }
+
+  uint64_t avail = mFillPoint - mCursor;
+
+  uint64_t tmp;
+  nsresult rv = Source()->Available(&tmp);
+  if (NS_SUCCEEDED(rv)) {
+    avail += tmp;
+  }
+
+  if (avail) {
+    *result = avail;
+    return NS_OK;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::StreamStatus() {
+  if (!mStream) {
+    return NS_OK;
+  }
+
+  if (mFillPoint - mCursor) {
+    return NS_OK;
+  }
+
+  return Source()->StreamStatus();
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Read(char* buf, uint32_t count, uint32_t* result) {
+  if (mBufferDisabled) {
+    if (!mStream) {
+      *result = 0;
+      return NS_OK;
+    }
+    nsresult rv = Source()->Read(buf, count, result);
+    if (NS_SUCCEEDED(rv)) {
+      mBufferStartOffset += *result;  // so nsBufferedStream::Tell works
+      if (*result == 0) {
+        mEOF = true;
+      }
+    }
+    return rv;
+  }
+
+  return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                    uint32_t count, uint32_t* result) {
+  *result = 0;
+
+  if (!mStream) {
+    return NS_OK;
+  }
+
+  nsresult rv = NS_OK;
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  while (count > 0) {
+    uint32_t amt = std::min(count, mFillPoint - mCursor);
+    if (amt > 0) {
+      uint32_t read = 0;
+      rv = writer(static_cast<nsIBufferedInputStream*>(this), closure,
+                  mBuffer + mCursor, *result, amt, &read);
+      if (NS_FAILED(rv)) {
+        // errors returned from the writer end here!
+        rv = NS_OK;
+        break;
+      }
+      *result += read;
+      count -= read;
+      mCursor += read;
+    } else {
+      rv = Fill();
+      if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
+        break;
+      }
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      if (mFillPoint == mCursor) {
+        break;
+      }
+    }
+  }
+  return (*result > 0) ? NS_OK : rv;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::IsNonBlocking(bool* aNonBlocking) {
+  if (mStream) {
+    return Source()->IsNonBlocking(aNonBlocking);
+  }
+  return NS_ERROR_NOT_INITIALIZED;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Fill() {
+  if (mBufferDisabled) {
+    return NS_OK;
+  }
+  NS_ENSURE_TRUE(mStream, NS_ERROR_NOT_INITIALIZED);
+
+  RecursiveMutexAutoLock lock(mBufferMutex);
+
+  nsresult rv;
+  int32_t rem = int32_t(mFillPoint - mCursor);
+  if (rem > 0) {
+    // slide the remainder down to the start of the buffer
+    // |<------------->|<--rem-->|<--->|
+    // b               c         f     s
+    memcpy(mBuffer, mBuffer + mCursor, rem);
+  }
+  mBufferStartOffset += mCursor;
+  mFillPoint = rem;
+  mCursor = 0;
+
+  uint32_t amt;
+  rv = Source()->Read(mBuffer + mFillPoint, mBufferSize - mFillPoint, &amt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (amt == 0) {
+    mEOF = true;
+  }
+
+  mFillPoint += amt;
+  return NS_OK;
+}
+
+NS_IMETHODIMP_(char*)
+nsBufferedInputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) {
+  NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
+  if (mGetBufferCount != 0) {
+    return nullptr;
+  }
+
+  if (mBufferDisabled) {
+    return nullptr;
+  }
+
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  char* buf = mBuffer + mCursor;
+  uint32_t rem = mFillPoint - mCursor;
+  if (rem == 0) {
+    if (NS_FAILED(Fill())) {
+      return nullptr;
+    }
+    buf = mBuffer + mCursor;
+    rem = mFillPoint - mCursor;
+  }
+
+  uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
+  if (mod) {
+    uint32_t pad = aAlignMask + 1 - mod;
+    if (pad > rem) {
+      return nullptr;
+    }
+
+    memset(buf, 0, pad);
+    mCursor += pad;
+    buf += pad;
+    rem -= pad;
+  }
+
+  if (aLength > rem) {
+    return nullptr;
+  }
+  mGetBufferCount++;
+  return buf;
+}
+
+NS_IMETHODIMP_(void)
+nsBufferedInputStream::PutBuffer(char* aBuffer, uint32_t aLength) {
+  NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
+  if (--mGetBufferCount != 0) {
+    return;
+  }
+
+  NS_ASSERTION(mCursor + aLength <= mFillPoint, "PutBuffer botch");
+  mCursor += aLength;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::DisableBuffering() {
+  NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
+  NS_ASSERTION(mGetBufferCount == 0,
+               "DisableBuffer call between GetBuffer and PutBuffer!");
+  if (mGetBufferCount != 0) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Empty the buffer so nsBufferedStream::Tell works.
+  mBufferStartOffset += mCursor;
+  mFillPoint = mCursor = 0;
+  mBufferDisabled = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::EnableBuffering() {
+  NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
+  mBufferDisabled = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::GetUnbufferedStream(nsISupports** aStream) {
+  // Empty the buffer so subsequent i/o trumps any buffered data.
+  mBufferStartOffset += mCursor;
+  mFillPoint = mCursor = 0;
+
+  nsCOMPtr<nsISupports> stream = mStream;
+  stream.forget(aStream);
+  return NS_OK;
+}
+
+void nsBufferedInputStream::SerializedComplexity(uint32_t aMaxSize,
+                                                 uint32_t* aSizeUsed,
+                                                 uint32_t* aPipes,
+                                                 uint32_t* aTransferables) {
+  if (mStream) {
+    nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream);
+    MOZ_ASSERT(stream);
+
+    InputStreamHelper::SerializedComplexity(stream, aMaxSize, aSizeUsed, aPipes,
+                                            aTransferables);
+  }
+}
+
+void nsBufferedInputStream::Serialize(InputStreamParams& aParams,
+                                      uint32_t aMaxSize, uint32_t* aSizeUsed) {
+  MOZ_ASSERT(aSizeUsed);
+  *aSizeUsed = 0;
+
+  BufferedInputStreamParams params;
+
+  if (mStream) {
+    nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream);
+    MOZ_ASSERT(stream);
+
+    InputStreamParams wrappedParams;
+    InputStreamHelper::SerializeInputStream(stream, wrappedParams, aMaxSize,
+                                            aSizeUsed);
+
+    params.optionalStream().emplace(wrappedParams);
+  }
+
+  params.bufferSize() = mBufferSize;
+
+  aParams = params;
+}
+
+bool nsBufferedInputStream::Deserialize(const InputStreamParams& aParams) {
+  if (aParams.type() != InputStreamParams::TBufferedInputStreamParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const BufferedInputStreamParams& params =
+      aParams.get_BufferedInputStreamParams();
+  const Maybe<InputStreamParams>& wrappedParams = params.optionalStream();
+
+  nsCOMPtr<nsIInputStream> stream;
+  if (wrappedParams.isSome()) {
+    stream = InputStreamHelper::DeserializeInputStream(wrappedParams.ref());
+    if (!stream) {
+      NS_WARNING("Failed to deserialize wrapped stream!");
+      return false;
+    }
+  }
+
+  nsresult rv = Init(stream, params.bufferSize());
+  NS_ENSURE_SUCCESS(rv, false);
+
+  return true;
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::CloseWithStatus(nsresult aStatus) { return Close(); }
+
+NS_IMETHODIMP
+nsBufferedInputStream::AsyncWait(nsIInputStreamCallback* aCallback,
+                                 uint32_t aFlags, uint32_t aRequestedCount,
+                                 nsIEventTarget* aEventTarget) {
+  nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream);
+  if (!stream) {
+    // Stream is probably closed. Callback, if not nullptr, can be executed
+    // immediately
+    if (!aCallback) {
+      return NS_OK;
+    }
+
+    if (aEventTarget) {
+      nsCOMPtr<nsIInputStreamCallback> callable = NS_NewInputStreamReadyEvent(
+          "nsBufferedInputStream::OnInputStreamReady", aCallback, aEventTarget);
+      return callable->OnInputStreamReady(this);
+    }
+
+    aCallback->OnInputStreamReady(this);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIInputStreamCallback> callback = aCallback ? this : nullptr;
+  {
+    MutexAutoLock lock(mMutex);
+
+    if (NS_WARN_IF(mAsyncWaitCallback && aCallback &&
+                   mAsyncWaitCallback != aCallback)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mAsyncWaitCallback = aCallback;
+  }
+
+  return stream->AsyncWait(callback, aFlags, aRequestedCount, aEventTarget);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  {
+    MutexAutoLock lock(mMutex);
+
+    // We have been canceled in the meanwhile.
+    if (!mAsyncWaitCallback) {
+      return NS_OK;
+    }
+
+    callback.swap(mAsyncWaitCallback);
+  }
+
+  MOZ_ASSERT(callback);
+  return callback->OnInputStreamReady(this);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::GetData(nsIInputStream** aResult) {
+  nsCOMPtr<nsISupports> stream;
+  nsBufferedStream::GetData(getter_AddRefs(stream));
+  nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(stream);
+  inputStream.forget(aResult);
+  return NS_OK;
+}
+
+// nsICloneableInputStream interface
+
+NS_IMETHODIMP
+nsBufferedInputStream::GetCloneable(bool* aCloneable) {
+  *aCloneable = false;
+
+  RecursiveMutexAutoLock lock(mBufferMutex);
+
+  // If we don't have the buffer, the inputStream has been already closed.
+  // If mBufferStartOffset is not 0, the stream has been seeked or read.
+  // In both case the cloning is not supported.
+  if (!mBuffer || mBufferStartOffset) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+
+  // GetCloneable is infallible.
+  NS_ENSURE_TRUE(stream, NS_OK);
+
+  return stream->GetCloneable(aCloneable);
+}
+
+NS_IMETHODIMP
+nsBufferedInputStream::Clone(nsIInputStream** aResult) {
+  RecursiveMutexAutoLock lock(mBufferMutex);
+
+  if (!mBuffer || mBufferStartOffset) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+  NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIInputStream> clonedStream;
+  nsresult rv = stream->Clone(getter_AddRefs(clonedStream));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIBufferedInputStream> bis = new nsBufferedInputStream();
+  rv = bis->Init(clonedStream, mBufferSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aResult =
+      static_cast<nsBufferedInputStream*>(bis.get())->GetInputStream().take();
+
+  return NS_OK;
+}
+
+// nsIInputStreamLength
+
+NS_IMETHODIMP
+nsBufferedInputStream::Length(int64_t* aLength) {
+  nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
+  NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE);
+
+  return stream->Length(aLength);
+}
+
+// nsIAsyncInputStreamLength
+
+NS_IMETHODIMP
+nsBufferedInputStream::AsyncLengthWait(nsIInputStreamLengthCallback* aCallback,
+                                       nsIEventTarget* aEventTarget) {
+  nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
+  if (!stream) {
+    // Stream is probably closed. Callback, if not nullptr, can be executed
+    // immediately
+    if (aCallback) {
+      const RefPtr<nsBufferedInputStream> self = this;
+      const nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback;
+      nsCOMPtr<nsIRunnable> runnable = NS_NewRunnableFunction(
+          "nsBufferedInputStream::OnInputStreamLengthReady",
+          [self, callback] { callback->OnInputStreamLengthReady(self, -1); });
+
+      if (aEventTarget) {
+        aEventTarget->Dispatch(runnable, NS_DISPATCH_NORMAL);
+      } else {
+        runnable->Run();
+      }
+    }
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback ? this : nullptr;
+  {
+    MutexAutoLock lock(mMutex);
+    mAsyncInputStreamLengthCallback = aCallback;
+  }
+
+  MOZ_ASSERT(stream);
+  return stream->AsyncLengthWait(callback, aEventTarget);
+}
+
+// nsIInputStreamLengthCallback
+
+NS_IMETHODIMP
+nsBufferedInputStream::OnInputStreamLengthReady(
+    nsIAsyncInputStreamLength* aStream, int64_t aLength) {
+  nsCOMPtr<nsIInputStreamLengthCallback> callback;
+  {
+    MutexAutoLock lock(mMutex);
+    // We have been canceled in the meanwhile.
+    if (!mAsyncInputStreamLengthCallback) {
+      return NS_OK;
+    }
+
+    callback.swap(mAsyncInputStreamLengthCallback);
+  }
+
+  MOZ_ASSERT(callback);
+  return callback->OnInputStreamLengthReady(this, aLength);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsBufferedOutputStream
+
+NS_IMPL_ADDREF_INHERITED(nsBufferedOutputStream, nsBufferedStream)
+NS_IMPL_RELEASE_INHERITED(nsBufferedOutputStream, nsBufferedStream)
+// This QI uses NS_INTERFACE_MAP_ENTRY_CONDITIONAL to check for
+// non-nullness of mSafeStream.
+NS_INTERFACE_MAP_BEGIN(nsBufferedOutputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIOutputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISafeOutputStream, mSafeStream)
+  NS_INTERFACE_MAP_ENTRY(nsIBufferedOutputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
+NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)
+
+nsresult nsBufferedOutputStream::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsBufferedOutputStream> stream = new nsBufferedOutputStream();
+  return stream->QueryInterface(aIID, aResult);
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::Init(nsIOutputStream* stream, uint32_t bufferSize) {
+  // QI stream to an nsISafeOutputStream, to see if we should support it
+  mSafeStream = do_QueryInterface(stream);
+
+  return nsBufferedStream::Init(stream, bufferSize);
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::Close() {
+  if (!mStream) {
+    return NS_OK;
+  }
+
+  nsresult rv1, rv2 = NS_OK;
+
+  rv1 = Flush();
+
+#ifdef DEBUG
+  if (NS_FAILED(rv1)) {
+    NS_WARNING(
+        "(debug) Flush() inside nsBufferedOutputStream::Close() returned error "
+        "(rv1).");
+  }
+#endif
+
+  // If we fail to Flush all the data, then we close anyway and drop the
+  // remaining data in the buffer. We do this because it's what Unix does
+  // for fclose and close. However, we report the error from Flush anyway.
+  if (mStream) {
+    rv2 = Sink()->Close();
+#ifdef DEBUG
+    if (NS_FAILED(rv2)) {
+      NS_WARNING(
+          "(debug) Sink->Close() inside nsBufferedOutputStream::Close() "
+          "returned error (rv2).");
+    }
+#endif
+  }
+  nsBufferedStream::Close();
+
+  if (NS_FAILED(rv1)) {
+    return rv1;
+  }
+  if (NS_FAILED(rv2)) {
+    return rv2;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::StreamStatus() {
+  return mStream ? Sink()->StreamStatus() : NS_BASE_STREAM_CLOSED;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::Write(const char* buf, uint32_t count,
+                              uint32_t* result) {
+  nsresult rv = NS_OK;
+  uint32_t written = 0;
+  *result = 0;
+  if (!mStream) {
+    // We special case this situation.
+    // We should catch the failure, NS_BASE_STREAM_CLOSED ASAP, here.
+    // If we don't, eventually Flush() is called in the while loop below
+    // after so many writes.
+    // However, Flush() returns NS_OK when mStream is null (!!),
+    // and we don't get a meaningful error, NS_BASE_STREAM_CLOSED,
+    // soon enough when we use buffered output.
+#ifdef DEBUG
+    NS_WARNING(
+        "(info) nsBufferedOutputStream::Write returns NS_BASE_STREAM_CLOSED "
+        "immediately (mStream==null).");
+#endif
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  while (count > 0) {
+    uint32_t amt = std::min(count, mBufferSize - mCursor);
+    if (amt > 0) {
+      memcpy(mBuffer + mCursor, buf + written, amt);
+      written += amt;
+      count -= amt;
+      mCursor += amt;
+      if (mFillPoint < mCursor) mFillPoint = mCursor;
+    } else {
+      NS_ASSERTION(mFillPoint, "loop in nsBufferedOutputStream::Write!");
+      rv = Flush();
+      if (NS_FAILED(rv)) {
+#ifdef DEBUG
+        NS_WARNING(
+            "(debug) Flush() returned error in nsBufferedOutputStream::Write.");
+#endif
+        break;
+      }
+    }
+  }
+  *result = written;
+  return (written > 0) ? NS_OK : rv;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::Flush() {
+  nsresult rv;
+  uint32_t amt;
+  if (!mStream) {
+    // Stream already cancelled/flushed; probably because of previous error.
+    return NS_OK;
+  }
+  // optimize : some code within C-C needs to call Seek -> Flush() often.
+  if (mFillPoint == 0) {
+    return NS_OK;
+  }
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  rv = Sink()->Write(mBuffer, mFillPoint, &amt);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mBufferStartOffset += amt;
+  if (amt == mFillPoint) {
+    mFillPoint = mCursor = 0;
+    return NS_OK;  // flushed everything
+  }
+
+  // slide the remainder down to the start of the buffer
+  // |<-------------->|<---|----->|
+  // b                a    c      s
+  uint32_t rem = mFillPoint - amt;
+  memmove(mBuffer, mBuffer + amt, rem);
+  mFillPoint = mCursor = rem;
+  return NS_ERROR_FAILURE;  // didn't flush all
+}
+
+// nsISafeOutputStream
+NS_IMETHODIMP
+nsBufferedOutputStream::Finish() {
+  // flush the stream, to write out any buffered data...
+  nsresult rv1 = nsBufferedOutputStream::Flush();
+  nsresult rv2 = NS_OK;
+
+  if (NS_FAILED(rv1)) {
+    NS_WARNING(
+        "(debug) nsBufferedOutputStream::Flush() failed in "
+        "nsBufferedOutputStream::Finish()! Possible dataloss.");
+
+    rv2 = Sink()->Close();
+    if (NS_FAILED(rv2)) {
+      NS_WARNING(
+          "(debug) Sink()->Close() failed in nsBufferedOutputStream::Finish()! "
+          "Possible dataloss.");
+    }
+  } else {
+    rv2 = mSafeStream->Finish();
+    if (NS_FAILED(rv2)) {
+      NS_WARNING(
+          "(debug) mSafeStream->Finish() failed within "
+          "nsBufferedOutputStream::Flush()! Possible dataloss.");
+    }
+  }
+
+  // ... and close the buffered stream, so any further attempts to flush/close
+  // the buffered stream won't cause errors.
+  nsBufferedStream::Close();
+
+  // We want to return the errors precisely from Finish()
+  // and mimick the existing error handling in
+  // nsBufferedOutputStream::Close() as reference.
+
+  if (NS_FAILED(rv1)) {
+    return rv1;
+  }
+  if (NS_FAILED(rv2)) {
+    return rv2;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::WriteFrom(nsIInputStream* inStr, uint32_t count,
+                                  uint32_t* _retval) {
+  return WriteSegments(NS_CopyStreamToSegment, inStr, count, _retval);
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::WriteSegments(nsReadSegmentFun reader, void* closure,
+                                      uint32_t count, uint32_t* _retval) {
+  *_retval = 0;
+  nsresult rv;
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  while (count > 0) {
+    uint32_t left = std::min(count, mBufferSize - mCursor);
+    if (left == 0) {
+      rv = Flush();
+      if (NS_FAILED(rv)) {
+        return (*_retval > 0) ? NS_OK : rv;
+      }
+
+      continue;
+    }
+
+    uint32_t read = 0;
+    rv = reader(this, closure, mBuffer + mCursor, *_retval, left, &read);
+
+    if (NS_FAILED(rv)) {  // If we have read some data, return ok
+      return (*_retval > 0) ? NS_OK : rv;
+    }
+    mCursor += read;
+    *_retval += read;
+    count -= read;
+    mFillPoint = std::max(mFillPoint, mCursor);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::IsNonBlocking(bool* aNonBlocking) {
+  if (mStream) {
+    return Sink()->IsNonBlocking(aNonBlocking);
+  }
+  return NS_ERROR_NOT_INITIALIZED;
+}
+
+NS_IMETHODIMP_(char*)
+nsBufferedOutputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) {
+  NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
+  if (mGetBufferCount != 0) {
+    return nullptr;
+  }
+
+  if (mBufferDisabled) {
+    return nullptr;
+  }
+
+  RecursiveMutexAutoLock lock(mBufferMutex);
+  char* buf = mBuffer + mCursor;
+  uint32_t rem = mBufferSize - mCursor;
+  if (rem == 0) {
+    if (NS_FAILED(Flush())) {
+      return nullptr;
+    }
+    buf = mBuffer + mCursor;
+    rem = mBufferSize - mCursor;
+  }
+
+  uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
+  if (mod) {
+    uint32_t pad = aAlignMask + 1 - mod;
+    if (pad > rem) {
+      return nullptr;
+    }
+
+    memset(buf, 0, pad);
+    mCursor += pad;
+    buf += pad;
+    rem -= pad;
+  }
+
+  if (aLength > rem) {
+    return nullptr;
+  }
+  mGetBufferCount++;
+  return buf;
+}
+
+NS_IMETHODIMP_(void)
+nsBufferedOutputStream::PutBuffer(char* aBuffer, uint32_t aLength) {
+  NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
+  if (--mGetBufferCount != 0) {
+    return;
+  }
+
+  NS_ASSERTION(mCursor + aLength <= mBufferSize, "PutBuffer botch");
+  mCursor += aLength;
+  if (mFillPoint < mCursor) {
+    mFillPoint = mCursor;
+  }
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::DisableBuffering() {
+  NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
+  NS_ASSERTION(mGetBufferCount == 0,
+               "DisableBuffer call between GetBuffer and PutBuffer!");
+  if (mGetBufferCount != 0) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Empty the buffer so nsBufferedStream::Tell works.
+  nsresult rv = Flush();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mBufferDisabled = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::EnableBuffering() {
+  NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
+  mBufferDisabled = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::GetUnbufferedStream(nsISupports** aStream) {
+  // Empty the buffer so subsequent i/o trumps any buffered data.
+  if (mFillPoint) {
+    nsresult rv = Flush();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  nsCOMPtr<nsISupports> stream = mStream;
+  stream.forget(aStream);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBufferedOutputStream::GetData(nsIOutputStream** aResult) {
+  nsCOMPtr<nsISupports> stream;
+  nsBufferedStream::GetData(getter_AddRefs(stream));
+  nsCOMPtr<nsIOutputStream> outputStream = do_QueryInterface(stream);
+  outputStream.forget(aResult);
+  return NS_OK;
+}
+#undef METER
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/netwerk/base/nsBufferedStreams.h b/netwerk/base/nsBufferedStreams.h
new file mode 100644
index 0000000000..5c5c7c07e7
--- /dev/null
+++ b/netwerk/base/nsBufferedStreams.h
@@ -0,0 +1,165 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsBufferedStreams_h__
+#define nsBufferedStreams_h__
+
+#include "nsIBufferedStreams.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsISafeOutputStream.h"
+#include "nsISeekableStream.h"
+#include "nsIStreamBufferAccess.h"
+#include "nsCOMPtr.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsIAsyncInputStream.h"
+#include "nsICloneableInputStream.h"
+#include "nsIInputStreamLength.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/RecursiveMutex.h"
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsBufferedStream : public nsISeekableStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+
+  nsBufferedStream() = default;
+
+  void Close();
+
+ protected:
+  virtual ~nsBufferedStream();
+
+  nsresult Init(nsISupports* stream, uint32_t bufferSize);
+  nsresult GetData(nsISupports** aResult);
+  NS_IMETHOD Fill() = 0;
+  NS_IMETHOD Flush() = 0;
+
+  uint32_t mBufferSize{0};
+  char* mBuffer MOZ_GUARDED_BY(mBufferMutex){nullptr};
+
+  mozilla::RecursiveMutex mBufferMutex{"nsBufferedStream::mBufferMutex"};
+
+  // mBufferStartOffset is the offset relative to the start of mStream.
+  int64_t mBufferStartOffset{0};
+
+  // mCursor is the read cursor for input streams, or write cursor for
+  // output streams, and is relative to mBufferStartOffset.
+  uint32_t mCursor{0};
+
+  // mFillPoint is the amount available in the buffer for input streams,
+  // or the high watermark of bytes written into the buffer, and therefore
+  // is relative to mBufferStartOffset.
+  uint32_t mFillPoint{0};
+
+  nsCOMPtr<nsISupports> mStream;  // cast to appropriate subclass
+
+  bool mBufferDisabled{false};
+  bool mEOF{false};  // True if mStream is at EOF
+  bool mSeekable{true};
+  uint8_t mGetBufferCount{0};
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsBufferedInputStream final : public nsBufferedStream,
+                                    public nsIBufferedInputStream,
+                                    public nsIStreamBufferAccess,
+                                    public nsIIPCSerializableInputStream,
+                                    public nsIAsyncInputStream,
+                                    public nsIInputStreamCallback,
+                                    public nsICloneableInputStream,
+                                    public nsIInputStreamLength,
+                                    public nsIAsyncInputStreamLength,
+                                    public nsIInputStreamLengthCallback {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIBUFFEREDINPUTSTREAM
+  NS_DECL_NSISTREAMBUFFERACCESS
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMLENGTH
+  NS_DECL_NSIASYNCINPUTSTREAMLENGTH
+  NS_DECL_NSIINPUTSTREAMLENGTHCALLBACK
+
+  nsBufferedInputStream() : nsBufferedStream() {}
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+  nsIInputStream* Source() { return (nsIInputStream*)mStream.get(); }
+
+  /**
+   * If there's a reference/pointer to an nsBufferedInputStream BEFORE calling
+   * Init() AND the intent is to ultimately convert/assign that
+   * reference/pointer to an nsIInputStream, DO NOT use that initial
+   * reference/pointer. Instead, use the value of QueryInterface-ing to an
+   * nsIInputStream (and, again, the QueryInterface must be performed after
+   * Init()). This is because nsBufferedInputStream has multiple underlying
+   * nsIInputStreams (one from nsIBufferedInputStream and one from
+   * nsIAsyncInputStream), and the correct base nsIInputStream to use will be
+   * unknown until the final value of mIsAsyncInputStream is set in Init().
+   *
+   * This method, however, does just that but also hides the QI details and
+   * will assert if called before Init().
+   */
+  already_AddRefed<nsIInputStream> GetInputStream();
+
+ protected:
+  virtual ~nsBufferedInputStream() = default;
+
+  NS_IMETHOD Fill() override;
+  NS_IMETHOD Flush() override { return NS_OK; }  // no-op for input streams
+
+  mozilla::Mutex mMutex MOZ_UNANNOTATED{"nsBufferedInputStream::mMutex"};
+
+  // This value is protected by mutex.
+  nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback;
+
+  // This value is protected by mutex.
+  nsCOMPtr<nsIInputStreamLengthCallback> mAsyncInputStreamLengthCallback;
+
+  bool mIsIPCSerializable{true};
+  bool mIsAsyncInputStream{false};
+  bool mIsCloneableInputStream{false};
+  bool mIsInputStreamLength{false};
+  bool mIsAsyncInputStreamLength{false};
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsBufferedOutputStream : public nsBufferedStream,
+                               public nsISafeOutputStream,
+                               public nsIBufferedOutputStream,
+                               public nsIStreamBufferAccess {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIOUTPUTSTREAM
+  NS_DECL_NSISAFEOUTPUTSTREAM
+  NS_DECL_NSIBUFFEREDOUTPUTSTREAM
+  NS_DECL_NSISTREAMBUFFERACCESS
+
+  nsBufferedOutputStream() : nsBufferedStream() {}
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+  nsIOutputStream* Sink() { return (nsIOutputStream*)mStream.get(); }
+
+ protected:
+  virtual ~nsBufferedOutputStream() { nsBufferedOutputStream::Close(); }
+
+  NS_IMETHOD Fill() override { return NS_OK; }  // no-op for output streams
+
+  nsCOMPtr<nsISafeOutputStream> mSafeStream;  // QI'd from mStream
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif  // nsBufferedStreams_h__
diff --git a/netwerk/base/nsDNSPrefetch.cpp b/netwerk/base/nsDNSPrefetch.cpp
new file mode 100644
index 0000000000..4c5a3a0fd6
--- /dev/null
+++ b/netwerk/base/nsDNSPrefetch.cpp
@@ -0,0 +1,164 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsDNSPrefetch.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+
+#include "nsIDNSAdditionalInfo.h"
+#include "nsIDNSListener.h"
+#include "nsIDNSService.h"
+#include "nsIDNSByTypeRecord.h"
+#include "nsICancelable.h"
+#include "nsIURI.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Preferences.h"
+
+static mozilla::StaticRefPtr<nsIDNSService> sDNSService;
+
+nsresult nsDNSPrefetch::Initialize(nsIDNSService* aDNSService) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  sDNSService = aDNSService;
+  return NS_OK;
+}
+
+nsresult nsDNSPrefetch::Shutdown() {
+  sDNSService = nullptr;
+  return NS_OK;
+}
+
+nsDNSPrefetch::nsDNSPrefetch(nsIURI* aURI,
+                             mozilla::OriginAttributes& aOriginAttributes,
+                             nsIRequest::TRRMode aTRRMode,
+                             nsIDNSListener* aListener, bool storeTiming)
+    : mOriginAttributes(aOriginAttributes),
+      mStoreTiming(storeTiming),
+      mTRRMode(aTRRMode),
+      mListener(do_GetWeakReference(aListener)) {
+  aURI->GetAsciiHost(mHostname);
+  aURI->GetPort(&mPort);
+}
+
+nsDNSPrefetch::nsDNSPrefetch(nsIURI* aURI,
+                             mozilla::OriginAttributes& aOriginAttributes,
+                             nsIRequest::TRRMode aTRRMode)
+    : mOriginAttributes(aOriginAttributes),
+      mStoreTiming(false),
+      mTRRMode(aTRRMode),
+      mListener(nullptr) {
+  aURI->GetAsciiHost(mHostname);
+}
+
+nsresult nsDNSPrefetch::Prefetch(nsIDNSService::DNSFlags flags) {
+  if (mHostname.IsEmpty()) return NS_ERROR_NOT_AVAILABLE;
+
+  if (!sDNSService) return NS_ERROR_NOT_AVAILABLE;
+
+  nsCOMPtr<nsICancelable> tmpOutstanding;
+
+  if (mStoreTiming) mStartTimestamp = mozilla::TimeStamp::Now();
+  // If AsyncResolve fails, for example because prefetching is disabled,
+  // then our timing will be useless. However, in such a case,
+  // mEndTimestamp will be a null timestamp and callers should check
+  // TimingsValid() before using the timing.
+  nsCOMPtr<nsIEventTarget> target = mozilla::GetCurrentSerialEventTarget();
+
+  flags |= nsIDNSService::GetFlagsFromTRRMode(mTRRMode);
+
+  return sDNSService->AsyncResolveNative(
+      mHostname, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+      flags | nsIDNSService::RESOLVE_SPECULATE, nullptr, this, target,
+      mOriginAttributes, getter_AddRefs(tmpOutstanding));
+}
+
+nsresult nsDNSPrefetch::PrefetchLow(nsIDNSService::DNSFlags aFlags) {
+  return Prefetch(nsIDNSService::RESOLVE_PRIORITY_LOW | aFlags);
+}
+
+nsresult nsDNSPrefetch::PrefetchMedium(nsIDNSService::DNSFlags aFlags) {
+  return Prefetch(nsIDNSService::RESOLVE_PRIORITY_MEDIUM | aFlags);
+}
+
+nsresult nsDNSPrefetch::PrefetchHigh(nsIDNSService::DNSFlags aFlags) {
+  return Prefetch(aFlags);
+}
+
+namespace {
+
+class HTTPSRRListener final : public nsIDNSListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSLISTENER
+
+  explicit HTTPSRRListener(
+      std::function<void(nsIDNSHTTPSSVCRecord*)>&& aCallback)
+      : mResultCallback(std::move(aCallback)) {}
+
+ private:
+  ~HTTPSRRListener() = default;
+  std::function<void(nsIDNSHTTPSSVCRecord*)> mResultCallback;
+};
+
+NS_IMPL_ISUPPORTS(HTTPSRRListener, nsIDNSListener)
+
+NS_IMETHODIMP
+HTTPSRRListener::OnLookupComplete(nsICancelable* aRequest, nsIDNSRecord* aRec,
+                                  nsresult aStatus) {
+  if (NS_FAILED(aStatus)) {
+    mResultCallback(nullptr);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDNSHTTPSSVCRecord> httpsRecord = do_QueryInterface(aRec);
+  mResultCallback(httpsRecord);
+  return NS_OK;
+}
+
+};  // namespace
+
+nsresult nsDNSPrefetch::FetchHTTPSSVC(
+    bool aRefreshDNS, bool aPrefetch,
+    std::function<void(nsIDNSHTTPSSVCRecord*)>&& aCallback) {
+  if (!sDNSService) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<nsIEventTarget> target = mozilla::GetCurrentSerialEventTarget();
+  nsIDNSService::DNSFlags flags = nsIDNSService::GetFlagsFromTRRMode(mTRRMode);
+  if (aRefreshDNS) {
+    flags |= nsIDNSService::RESOLVE_BYPASS_CACHE;
+  }
+  if (aPrefetch) {
+    flags |= nsIDNSService::RESOLVE_SPECULATE;
+  }
+
+  nsCOMPtr<nsICancelable> tmpOutstanding;
+  nsCOMPtr<nsIDNSListener> listener = new HTTPSRRListener(std::move(aCallback));
+  nsCOMPtr<nsIDNSAdditionalInfo> info;
+  if (mPort != -1) {
+    sDNSService->NewAdditionalInfo(""_ns, mPort, getter_AddRefs(info));
+  }
+  return sDNSService->AsyncResolveNative(
+      mHostname, nsIDNSService::RESOLVE_TYPE_HTTPSSVC, flags, info, listener,
+      target, mOriginAttributes, getter_AddRefs(tmpOutstanding));
+}
+
+NS_IMPL_ISUPPORTS(nsDNSPrefetch, nsIDNSListener)
+
+NS_IMETHODIMP
+nsDNSPrefetch::OnLookupComplete(nsICancelable* request, nsIDNSRecord* rec,
+                                nsresult status) {
+  if (mStoreTiming) {
+    mEndTimestamp = mozilla::TimeStamp::Now();
+  }
+  nsCOMPtr<nsIDNSListener> listener = do_QueryReferent(mListener);
+  if (listener) {
+    listener->OnLookupComplete(request, rec, status);
+  }
+
+  return NS_OK;
+}
diff --git a/netwerk/base/nsDNSPrefetch.h b/netwerk/base/nsDNSPrefetch.h
new file mode 100644
index 0000000000..7cad00b588
--- /dev/null
+++ b/netwerk/base/nsDNSPrefetch.h
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsDNSPrefetch_h___
+#define nsDNSPrefetch_h___
+
+#include <functional>
+
+#include "nsIWeakReferenceUtils.h"
+#include "nsString.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/BasePrincipal.h"
+
+#include "nsIDNSListener.h"
+#include "nsIRequest.h"
+#include "nsIDNSService.h"
+
+class nsIURI;
+class nsIDNSHTTPSSVCRecord;
+
+class nsDNSPrefetch final : public nsIDNSListener {
+  ~nsDNSPrefetch() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSLISTENER
+
+  nsDNSPrefetch(nsIURI* aURI, mozilla::OriginAttributes& aOriginAttributes,
+                nsIRequest::TRRMode aTRRMode, nsIDNSListener* aListener,
+                bool storeTiming);
+  // For fetching HTTPS RR.
+  nsDNSPrefetch(nsIURI* aURI, mozilla::OriginAttributes& aOriginAttributes,
+                nsIRequest::TRRMode aTRRMode);
+  bool TimingsValid() const {
+    return !mStartTimestamp.IsNull() && !mEndTimestamp.IsNull();
+  }
+  // Only use the two timings if TimingsValid() returns true
+  const mozilla::TimeStamp& StartTimestamp() const { return mStartTimestamp; }
+  const mozilla::TimeStamp& EndTimestamp() const { return mEndTimestamp; }
+
+  static nsresult Initialize(nsIDNSService* aDNSService);
+  static nsresult Shutdown();
+
+  // Call one of the following methods to start the Prefetch.
+  nsresult PrefetchHigh(
+      nsIDNSService::DNSFlags = nsIDNSService::RESOLVE_DEFAULT_FLAGS);
+  nsresult PrefetchMedium(
+      nsIDNSService::DNSFlags = nsIDNSService::RESOLVE_DEFAULT_FLAGS);
+  nsresult PrefetchLow(
+      nsIDNSService::DNSFlags = nsIDNSService::RESOLVE_DEFAULT_FLAGS);
+
+  nsresult FetchHTTPSSVC(
+      bool aRefreshDNS, bool aPrefetch,
+      std::function<void(nsIDNSHTTPSSVCRecord*)>&& aCallback);
+
+ private:
+  nsCString mHostname;
+  int32_t mPort{-1};
+  mozilla::OriginAttributes mOriginAttributes;
+  bool mStoreTiming;
+  nsIRequest::TRRMode mTRRMode;
+  mozilla::TimeStamp mStartTimestamp;
+  mozilla::TimeStamp mEndTimestamp;
+  nsWeakPtr mListener;
+
+  nsresult Prefetch(nsIDNSService::DNSFlags flags);
+};
+
+#endif
diff --git a/netwerk/base/nsDirectoryIndexStream.cpp b/netwerk/base/nsDirectoryIndexStream.cpp
new file mode 100644
index 0000000000..51f30a2fca
--- /dev/null
+++ b/netwerk/base/nsDirectoryIndexStream.cpp
@@ -0,0 +1,304 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set sw=2 sts=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+
+  The converts a filesystem directory into an "HTTP index" stream per
+  Lou Montulli's original spec:
+
+  http://www.mozilla.org/projects/netlib/dirindexformat.html
+
+ */
+
+#include "nsEscape.h"
+#include "nsDirectoryIndexStream.h"
+#include "mozilla/Logging.h"
+#include "prtime.h"
+#include "nsIFile.h"
+#include "nsURLHelper.h"
+#include "nsNativeCharsetUtils.h"
+
+// NOTE: This runs on the _file transport_ thread.
+// The problem is that now that we're actually doing something with the data,
+// we want to do stuff like i18n sorting. However, none of the collation stuff
+// is threadsafe.
+// So THIS CODE IS ASCII ONLY!!!!!!!! This is no worse than the current
+// behaviour, though. See bug 99382.
+
+using namespace mozilla;
+static LazyLogModule gLog("nsDirectoryIndexStream");
+
+nsDirectoryIndexStream::nsDirectoryIndexStream() {
+  MOZ_LOG(gLog, LogLevel::Debug, ("nsDirectoryIndexStream[%p]: created", this));
+}
+
+static int compare(nsIFile* aElement1, nsIFile* aElement2, void* aData) {
+  if (!NS_IsNativeUTF8()) {
+    // don't check for errors, because we can't report them anyway
+    nsAutoString name1, name2;
+    aElement1->GetLeafName(name1);
+    aElement2->GetLeafName(name2);
+
+    // Note - we should do the collation to do sorting. Why don't we?
+    // Because that is _slow_. Using TestProtocols to list file:///dev/
+    // goes from 3 seconds to 22. (This may be why nsXULSortService is
+    // so slow as well).
+    // Does this have bad effects? Probably, but since nsXULTree appears
+    // to use the raw RDF literal value as the sort key (which ammounts to an
+    // strcmp), it won't be any worse, I think.
+    // This could be made faster, by creating the keys once,
+    // but CompareString could still be smarter - see bug 99383 - bbaetz
+    // NB - 99393 has been WONTFIXed. So if the I18N code is ever made
+    // threadsafe so that this matters, we'd have to pass through a
+    // struct { nsIFile*, uint8_t* } with the pre-calculated key.
+    return Compare(name1, name2);
+  }
+
+  nsAutoCString name1, name2;
+  aElement1->GetNativeLeafName(name1);
+  aElement2->GetNativeLeafName(name2);
+
+  return Compare(name1, name2);
+}
+
+nsresult nsDirectoryIndexStream::Init(nsIFile* aDir) {
+  nsresult rv;
+  bool isDir;
+  rv = aDir->IsDirectory(&isDir);
+  if (NS_FAILED(rv)) return rv;
+  MOZ_ASSERT(isDir, "not a directory");
+  if (!isDir) return NS_ERROR_ILLEGAL_VALUE;
+
+  if (MOZ_LOG_TEST(gLog, LogLevel::Debug)) {
+    MOZ_LOG(gLog, LogLevel::Debug,
+            ("nsDirectoryIndexStream[%p]: initialized on %s", this,
+             aDir->HumanReadablePath().get()));
+  }
+
+  // Sigh. We have to allocate on the heap because there are no
+  // assignment operators defined.
+  nsCOMPtr<nsIDirectoryEnumerator> iter;
+  rv = aDir->GetDirectoryEntries(getter_AddRefs(iter));
+  if (NS_FAILED(rv)) return rv;
+
+  // Now lets sort, because clients expect it that way
+  // XXX - should we do so here, or when the first item is requested?
+  // XXX - use insertion sort instead?
+
+  nsCOMPtr<nsIFile> file;
+  while (NS_SUCCEEDED(iter->GetNextFile(getter_AddRefs(file))) && file) {
+    mArray.AppendObject(file);  // addrefs
+  }
+
+  mArray.Sort(compare, nullptr);
+
+  mBuf.AppendLiteral("300: ");
+  nsAutoCString url;
+  rv = net_GetURLSpecFromFile(aDir, url);
+  if (NS_FAILED(rv)) return rv;
+  mBuf.Append(url);
+  mBuf.Append('\n');
+
+  mBuf.AppendLiteral("200: filename content-length last-modified file-type\n");
+
+  return NS_OK;
+}
+
+nsDirectoryIndexStream::~nsDirectoryIndexStream() {
+  MOZ_LOG(gLog, LogLevel::Debug,
+          ("nsDirectoryIndexStream[%p]: destroyed", this));
+}
+
+nsresult nsDirectoryIndexStream::Create(nsIFile* aDir,
+                                        nsIInputStream** aResult) {
+  RefPtr<nsDirectoryIndexStream> result = new nsDirectoryIndexStream();
+  if (!result) return NS_ERROR_OUT_OF_MEMORY;
+
+  nsresult rv = result->Init(aDir);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  result.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(nsDirectoryIndexStream, nsIInputStream)
+
+// The below routines are proxied to the UI thread!
+NS_IMETHODIMP
+nsDirectoryIndexStream::Close() {
+  mStatus = NS_BASE_STREAM_CLOSED;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDirectoryIndexStream::Available(uint64_t* aLength) {
+  if (NS_FAILED(mStatus)) return mStatus;
+
+  // If there's data in our buffer, use that
+  if (mOffset < (int32_t)mBuf.Length()) {
+    *aLength = mBuf.Length() - mOffset;
+    return NS_OK;
+  }
+
+  // Returning one byte is not ideal, but good enough
+  *aLength = (mPos < mArray.Count()) ? 1 : 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDirectoryIndexStream::StreamStatus() { return mStatus; }
+
+NS_IMETHODIMP
+nsDirectoryIndexStream::Read(char* aBuf, uint32_t aCount,
+                             uint32_t* aReadCount) {
+  if (mStatus == NS_BASE_STREAM_CLOSED) {
+    *aReadCount = 0;
+    return NS_OK;
+  }
+  if (NS_FAILED(mStatus)) return mStatus;
+
+  uint32_t nread = 0;
+
+  // If anything is enqueued (or left-over) in mBuf, then feed it to
+  // the reader first.
+  while (mOffset < (int32_t)mBuf.Length() && aCount != 0) {
+    *(aBuf++) = char(mBuf.CharAt(mOffset++));
+    --aCount;
+    ++nread;
+  }
+
+  // Room left?
+  if (aCount > 0) {
+    mOffset = 0;
+    mBuf.Truncate();
+
+    // Okay, now we'll suck stuff off of our iterator into the mBuf...
+    while (uint32_t(mBuf.Length()) < aCount) {
+      bool more = mPos < mArray.Count();
+      if (!more) break;
+
+      // don't addref, for speed - an addref happened when it
+      // was placed in the array, so it's not going to go stale
+      nsIFile* current = mArray.ObjectAt(mPos);
+      ++mPos;
+
+      if (MOZ_LOG_TEST(gLog, LogLevel::Debug)) {
+        MOZ_LOG(gLog, LogLevel::Debug,
+                ("nsDirectoryIndexStream[%p]: iterated %s", this,
+                 current->HumanReadablePath().get()));
+      }
+
+      // rjc: don't return hidden files/directories!
+      // bbaetz: why not?
+      nsresult rv;
+#ifndef XP_UNIX
+      bool hidden = false;
+      current->IsHidden(&hidden);
+      if (hidden) {
+        MOZ_LOG(gLog, LogLevel::Debug,
+                ("nsDirectoryIndexStream[%p]: skipping hidden file/directory",
+                 this));
+        continue;
+      }
+#endif
+
+      int64_t fileSize = 0;
+      current->GetFileSize(&fileSize);
+
+      PRTime fileInfoModifyTime = 0;
+      current->GetLastModifiedTime(&fileInfoModifyTime);
+      fileInfoModifyTime *= PR_USEC_PER_MSEC;
+
+      mBuf.AppendLiteral("201: ");
+
+      // The "filename" field
+      if (!NS_IsNativeUTF8()) {
+        nsAutoString leafname;
+        rv = current->GetLeafName(leafname);
+        if (NS_FAILED(rv)) return rv;
+
+        nsAutoCString escaped;
+        if (!leafname.IsEmpty() &&
+            NS_Escape(NS_ConvertUTF16toUTF8(leafname), escaped, url_Path)) {
+          mBuf.Append(escaped);
+          mBuf.Append(' ');
+        }
+      } else {
+        nsAutoCString leafname;
+        rv = current->GetNativeLeafName(leafname);
+        if (NS_FAILED(rv)) return rv;
+
+        nsAutoCString escaped;
+        if (!leafname.IsEmpty() && NS_Escape(leafname, escaped, url_Path)) {
+          mBuf.Append(escaped);
+          mBuf.Append(' ');
+        }
+      }
+
+      // The "content-length" field
+      mBuf.AppendInt(fileSize, 10);
+      mBuf.Append(' ');
+
+      // The "last-modified" field
+      PRExplodedTime tm;
+      PR_ExplodeTime(fileInfoModifyTime, PR_GMTParameters, &tm);
+      {
+        char buf[64];
+        PR_FormatTimeUSEnglish(
+            buf, sizeof(buf), "%a,%%20%d%%20%b%%20%Y%%20%H:%M:%S%%20GMT ", &tm);
+        mBuf.Append(buf);
+      }
+
+      // The "file-type" field
+      bool isFile = true;
+      current->IsFile(&isFile);
+      if (isFile) {
+        mBuf.AppendLiteral("FILE ");
+      } else {
+        bool isDir;
+        rv = current->IsDirectory(&isDir);
+        if (NS_FAILED(rv)) return rv;
+        if (isDir) {
+          mBuf.AppendLiteral("DIRECTORY ");
+        } else {
+          bool isLink;
+          rv = current->IsSymlink(&isLink);
+          if (NS_FAILED(rv)) return rv;
+          if (isLink) {
+            mBuf.AppendLiteral("SYMBOLIC-LINK ");
+          }
+        }
+      }
+
+      mBuf.Append('\n');
+    }
+
+    // ...and once we've either run out of directory entries, or
+    // filled up the buffer, then we'll push it to the reader.
+    while (mOffset < (int32_t)mBuf.Length() && aCount != 0) {
+      *(aBuf++) = char(mBuf.CharAt(mOffset++));
+      --aCount;
+      ++nread;
+    }
+  }
+
+  *aReadCount = nread;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDirectoryIndexStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                     uint32_t count, uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDirectoryIndexStream::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = false;
+  return NS_OK;
+}
diff --git a/netwerk/base/nsDirectoryIndexStream.h b/netwerk/base/nsDirectoryIndexStream.h
new file mode 100644
index 0000000000..6bdebc7cfe
--- /dev/null
+++ b/netwerk/base/nsDirectoryIndexStream.h
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsDirectoryIndexStream_h__
+#define nsDirectoryIndexStream_h__
+
+#include "mozilla/Attributes.h"
+
+#include "nsString.h"
+#include "nsIInputStream.h"
+#include "nsCOMArray.h"
+
+class nsIFile;
+
+class nsDirectoryIndexStream final : public nsIInputStream {
+ private:
+  nsCString mBuf;
+  int32_t mOffset{0};
+  nsresult mStatus{NS_OK};
+
+  int32_t mPos{0};             // position within mArray
+  nsCOMArray<nsIFile> mArray;  // file objects within the directory
+
+  nsDirectoryIndexStream();
+  /**
+   * aDir will only be used on the calling thread.
+   */
+  nsresult Init(nsIFile* aDir);
+  ~nsDirectoryIndexStream();
+
+ public:
+  /**
+   * aDir will only be used on the calling thread.
+   */
+  static nsresult Create(nsIFile* aDir, nsIInputStream** aResult);
+
+  // nsISupportsInterface
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  // nsIInputStream interface
+  NS_DECL_NSIINPUTSTREAM
+};
+
+#endif  // nsDirectoryIndexStream_h__
diff --git a/netwerk/base/nsDownloader.cpp b/netwerk/base/nsDownloader.cpp
new file mode 100644
index 0000000000..b6d3240226
--- /dev/null
+++ b/netwerk/base/nsDownloader.cpp
@@ -0,0 +1,98 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsDownloader.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsNetUtil.h"
+#include "nsCRTGlue.h"
+
+nsDownloader::~nsDownloader() {
+  if (mLocation && mLocationIsTemp) {
+    // release the sink first since it may still hold an open file
+    // descriptor to mLocation.  this needs to happen before the
+    // file can be removed otherwise the Remove call will fail.
+    if (mSink) {
+      mSink->Close();
+      mSink = nullptr;
+    }
+
+    nsresult rv = mLocation->Remove(false);
+    if (NS_FAILED(rv)) NS_ERROR("unable to remove temp file");
+  }
+}
+
+NS_IMPL_ISUPPORTS(nsDownloader, nsIDownloader, nsIStreamListener,
+                  nsIRequestObserver)
+
+NS_IMETHODIMP
+nsDownloader::Init(nsIDownloadObserver* observer, nsIFile* location) {
+  mObserver = observer;
+  mLocation = location;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDownloader::OnStartRequest(nsIRequest* request) {
+  nsresult rv;
+  if (!mLocation) {
+    nsCOMPtr<nsIFile> location;
+    rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(location));
+    if (NS_FAILED(rv)) return rv;
+
+    char buf[13];
+    NS_MakeRandomString(buf, 8);
+    memcpy(buf + 8, ".tmp", 5);
+    rv = location->AppendNative(nsDependentCString(buf, 12));
+    if (NS_FAILED(rv)) return rv;
+
+    rv = location->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
+    if (NS_FAILED(rv)) return rv;
+
+    location.swap(mLocation);
+    mLocationIsTemp = true;
+  }
+
+  rv = NS_NewLocalFileOutputStream(getter_AddRefs(mSink), mLocation);
+  if (NS_FAILED(rv)) return rv;
+
+  // we could wrap this output stream with a buffered output stream,
+  // but it shouldn't be necessary since we will be writing large
+  // chunks given to us via OnDataAvailable.
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDownloader::OnStopRequest(nsIRequest* request, nsresult status) {
+  if (mSink) {
+    mSink->Close();
+    mSink = nullptr;
+  }
+
+  mObserver->OnDownloadComplete(this, request, status, mLocation);
+  mObserver = nullptr;
+
+  return NS_OK;
+}
+
+nsresult nsDownloader::ConsumeData(nsIInputStream* in, void* closure,
+                                   const char* fromRawSegment,
+                                   uint32_t toOffset, uint32_t count,
+                                   uint32_t* writeCount) {
+  nsDownloader* self = (nsDownloader*)closure;
+  if (self->mSink) return self->mSink->Write(fromRawSegment, count, writeCount);
+
+  *writeCount = count;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDownloader::OnDataAvailable(nsIRequest* request, nsIInputStream* inStr,
+                              uint64_t sourceOffset, uint32_t count) {
+  uint32_t n;
+  return inStr->ReadSegments(ConsumeData, this, count, &n);
+}
diff --git a/netwerk/base/nsDownloader.h b/netwerk/base/nsDownloader.h
new file mode 100644
index 0000000000..fe95dd6ac2
--- /dev/null
+++ b/netwerk/base/nsDownloader.h
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsDownloader_h__
+#define nsDownloader_h__
+
+#include "nsIDownloader.h"
+#include "nsCOMPtr.h"
+
+class nsIFile;
+class nsIOutputStream;
+
+class nsDownloader : public nsIDownloader {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIDOWNLOADER
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  nsDownloader() = default;
+
+ protected:
+  virtual ~nsDownloader();
+
+  static nsresult ConsumeData(nsIInputStream* in, void* closure,
+                              const char* fromRawSegment, uint32_t toOffset,
+                              uint32_t count, uint32_t* writeCount);
+
+  nsCOMPtr<nsIDownloadObserver> mObserver;
+  nsCOMPtr<nsIFile> mLocation;
+  nsCOMPtr<nsIOutputStream> mSink;
+  bool mLocationIsTemp{false};
+};
+
+#endif  // nsDownloader_h__
diff --git a/netwerk/base/nsFileStreams.cpp b/netwerk/base/nsFileStreams.cpp
new file mode 100644
index 0000000000..32281f6d02
--- /dev/null
+++ b/netwerk/base/nsFileStreams.cpp
@@ -0,0 +1,1031 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ipc/IPCMessageUtils.h"
+
+#if defined(XP_UNIX)
+#  include <unistd.h>
+#elif defined(XP_WIN)
+#  include <windows.h>
+#  include "nsILocalFileWin.h"
+#else
+// XXX add necessary include file for ftruncate (or equivalent)
+#endif
+
+#include "private/pprio.h"
+#include "prerror.h"
+
+#include "IOActivityMonitor.h"
+#include "nsFileStreams.h"
+#include "nsIFile.h"
+#include "nsReadLine.h"
+#include "nsIClassInfoImpl.h"
+#include "nsLiteralString.h"
+#include "nsSocketTransport2.h"  // for ErrorAccordingToNSPR()
+#include "mozilla/ipc/InputStreamUtils.h"
+#include "mozilla/ipc/RandomAccessStreamParams.h"
+#include "mozilla/Unused.h"
+#include "mozilla/FileUtils.h"
+#include "mozilla/UniquePtr.h"
+#include "nsNetCID.h"
+#include "nsXULAppAPI.h"
+
+using FileHandleType = mozilla::ipc::FileDescriptor::PlatformHandleType;
+
+using namespace mozilla::ipc;
+using namespace mozilla::net;
+
+using mozilla::DebugOnly;
+using mozilla::Maybe;
+using mozilla::Nothing;
+using mozilla::Some;
+
+////////////////////////////////////////////////////////////////////////////////
+// nsFileStreamBase
+
+nsFileStreamBase::~nsFileStreamBase() {
+  // We don't want to try to rewrind the stream when shutting down.
+  mBehaviorFlags &= ~nsIFileInputStream::REOPEN_ON_REWIND;
+
+  Close();
+}
+
+NS_IMPL_ISUPPORTS(nsFileStreamBase, nsISeekableStream, nsITellableStream,
+                  nsIFileMetadata)
+
+NS_IMETHODIMP
+nsFileStreamBase::Seek(int32_t whence, int64_t offset) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int64_t cnt = PR_Seek64(mFD, offset, (PRSeekWhence)whence);
+  if (cnt == int64_t(-1)) {
+    return NS_ErrorAccordingToNSPR();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileStreamBase::Tell(int64_t* result) {
+  if (mState == eDeferredOpen && !(mOpenParams.ioFlags & PR_APPEND)) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int64_t cnt = PR_Seek64(mFD, 0, PR_SEEK_CUR);
+  if (cnt == int64_t(-1)) {
+    return NS_ErrorAccordingToNSPR();
+  }
+  *result = cnt;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileStreamBase::SetEOF() {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+#if defined(XP_UNIX)
+  // Some system calls require an EOF offset.
+  int64_t offset;
+  rv = Tell(&offset);
+  if (NS_FAILED(rv)) return rv;
+#endif
+
+#if defined(XP_UNIX)
+  if (ftruncate(PR_FileDesc2NativeHandle(mFD), offset) != 0) {
+    NS_ERROR("ftruncate failed");
+    return NS_ERROR_FAILURE;
+  }
+#elif defined(XP_WIN)
+  if (!SetEndOfFile((HANDLE)PR_FileDesc2NativeHandle(mFD))) {
+    NS_ERROR("SetEndOfFile failed");
+    return NS_ERROR_FAILURE;
+  }
+#else
+  // XXX not implemented
+#endif
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileStreamBase::GetSize(int64_t* _retval) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  PRFileInfo64 info;
+  if (PR_GetOpenFileInfo64(mFD, &info) == PR_FAILURE) {
+    return NS_BASE_STREAM_OSERROR;
+  }
+
+  *_retval = int64_t(info.size);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileStreamBase::GetLastModified(int64_t* _retval) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  PRFileInfo64 info;
+  if (PR_GetOpenFileInfo64(mFD, &info) == PR_FAILURE) {
+    return NS_BASE_STREAM_OSERROR;
+  }
+
+  int64_t modTime = int64_t(info.modifyTime);
+  if (modTime == 0) {
+    *_retval = 0;
+  } else {
+    *_retval = modTime / int64_t(PR_USEC_PER_MSEC);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileStreamBase::GetFileDescriptor(PRFileDesc** _retval) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *_retval = mFD;
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::Close() {
+  if (mState == eClosed) {
+    return NS_OK;
+  }
+
+  CleanUpOpen();
+
+  nsresult rv = NS_OK;
+  if (mFD) {
+    if (PR_Close(mFD) == PR_FAILURE) rv = NS_BASE_STREAM_OSERROR;
+    mFD = nullptr;
+    mState = eClosed;
+  }
+  return rv;
+}
+
+nsresult nsFileStreamBase::Available(uint64_t* aResult) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // PR_Available with files over 4GB returns an error, so we have to
+  // use the 64-bit version of PR_Available.
+  int64_t avail = PR_Available64(mFD);
+  if (avail == -1) {
+    return NS_ErrorAccordingToNSPR();
+  }
+
+  // If available is greater than 4GB, return 4GB
+  *aResult = (uint64_t)avail;
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::Read(char* aBuf, uint32_t aCount,
+                                uint32_t* aResult) {
+  nsresult rv = DoPendingOpen();
+  if (rv == NS_BASE_STREAM_CLOSED) {
+    *aResult = 0;
+    return NS_OK;
+  }
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  int32_t bytesRead = PR_Read(mFD, aBuf, aCount);
+  if (bytesRead == -1) {
+    return NS_ErrorAccordingToNSPR();
+  }
+
+  *aResult = bytesRead;
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::ReadSegments(nsWriteSegmentFun aWriter,
+                                        void* aClosure, uint32_t aCount,
+                                        uint32_t* aResult) {
+  // ReadSegments is not implemented because it would be inefficient when
+  // the writer does not consume all data.  If you want to call ReadSegments,
+  // wrap a BufferedInputStream around the file stream.  That will call
+  // Read().
+
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsFileStreamBase::IsNonBlocking(bool* aNonBlocking) {
+  *aNonBlocking = false;
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::Flush(void) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int32_t cnt = PR_Sync(mFD);
+  if (cnt == -1) {
+    return NS_ErrorAccordingToNSPR();
+  }
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::StreamStatus() {
+  switch (mState) {
+    case eUnitialized:
+      MOZ_CRASH("This should not happen.");
+      return NS_ERROR_FAILURE;
+
+    case eDeferredOpen:
+      return NS_OK;
+
+    case eOpened:
+      MOZ_ASSERT(mFD);
+      if (NS_WARN_IF(!mFD)) {
+        return NS_ERROR_FAILURE;
+      }
+      return NS_OK;
+
+    case eClosed:
+      MOZ_ASSERT(!mFD);
+      return NS_BASE_STREAM_CLOSED;
+
+    case eError:
+      return mErrorValue;
+  }
+
+  MOZ_CRASH("Invalid mState value.");
+  return NS_ERROR_FAILURE;
+}
+
+nsresult nsFileStreamBase::Write(const char* buf, uint32_t count,
+                                 uint32_t* result) {
+  nsresult rv = DoPendingOpen();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  int32_t cnt = PR_Write(mFD, buf, count);
+  if (cnt == -1) {
+    return NS_ErrorAccordingToNSPR();
+  }
+  *result = cnt;
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::WriteFrom(nsIInputStream* inStr, uint32_t count,
+                                     uint32_t* _retval) {
+  MOZ_ASSERT_UNREACHABLE("WriteFrom (see source comment)");
+  return NS_ERROR_NOT_IMPLEMENTED;
+  // File streams intentionally do not support this method.
+  // If you need something like this, then you should wrap
+  // the file stream using nsIBufferedOutputStream
+}
+
+nsresult nsFileStreamBase::WriteSegments(nsReadSegmentFun reader, void* closure,
+                                         uint32_t count, uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+  // File streams intentionally do not support this method.
+  // If you need something like this, then you should wrap
+  // the file stream using nsIBufferedOutputStream
+}
+
+nsresult nsFileStreamBase::MaybeOpen(nsIFile* aFile, int32_t aIoFlags,
+                                     int32_t aPerm, bool aDeferred) {
+  NS_ENSURE_STATE(aFile);
+
+  mOpenParams.ioFlags = aIoFlags;
+  mOpenParams.perm = aPerm;
+
+  if (aDeferred) {
+    // Clone the file, as it may change between now and the deferred open
+    nsCOMPtr<nsIFile> file;
+    nsresult rv = aFile->Clone(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mOpenParams.localFile = std::move(file);
+    NS_ENSURE_TRUE(mOpenParams.localFile, NS_ERROR_UNEXPECTED);
+
+    mState = eDeferredOpen;
+    return NS_OK;
+  }
+
+  mOpenParams.localFile = aFile;
+
+  // Following call open() at main thread.
+  // Main thread might be blocked, while open a remote file.
+  return DoOpen();
+}
+
+void nsFileStreamBase::CleanUpOpen() { mOpenParams.localFile = nullptr; }
+
+nsresult nsFileStreamBase::DoOpen() {
+  MOZ_ASSERT(mState == eDeferredOpen || mState == eUnitialized ||
+             mState == eClosed);
+  NS_ASSERTION(!mFD, "Already have a file descriptor!");
+  NS_ASSERTION(mOpenParams.localFile, "Must have a file to open");
+
+  PRFileDesc* fd;
+  nsresult rv;
+
+  if (mOpenParams.ioFlags & PR_CREATE_FILE) {
+    nsCOMPtr<nsIFile> parent;
+    mOpenParams.localFile->GetParent(getter_AddRefs(parent));
+
+    // Result doesn't need to be checked. If the file's parent path does not
+    // exist, make it. If it does exist, do nothing.
+    if (parent) {
+      mozilla::Unused << parent->Create(nsIFile::DIRECTORY_TYPE, 0755);
+    }
+  }
+
+#ifdef XP_WIN
+  if (mBehaviorFlags & nsIFileInputStream::SHARE_DELETE) {
+    nsCOMPtr<nsILocalFileWin> file = do_QueryInterface(mOpenParams.localFile);
+    MOZ_ASSERT(file);
+
+    rv = file->OpenNSPRFileDescShareDelete(mOpenParams.ioFlags,
+                                           mOpenParams.perm, &fd);
+  } else
+#endif  // XP_WIN
+  {
+    rv = mOpenParams.localFile->OpenNSPRFileDesc(mOpenParams.ioFlags,
+                                                 mOpenParams.perm, &fd);
+  }
+
+  if (rv == NS_OK && IOActivityMonitor::IsActive()) {
+    auto nativePath = mOpenParams.localFile->NativePath();
+    if (!nativePath.IsEmpty()) {
+// registering the file to the activity monitor
+#ifdef XP_WIN
+      // 16 bits unicode
+      IOActivityMonitor::MonitorFile(
+          fd, NS_ConvertUTF16toUTF8(nativePath.get()).get());
+#else
+      // 8 bit unicode
+      IOActivityMonitor::MonitorFile(fd, nativePath.get());
+#endif
+    }
+  }
+
+  CleanUpOpen();
+
+  if (NS_FAILED(rv)) {
+    mState = eError;
+    mErrorValue = rv;
+    return rv;
+  }
+
+  mFD = fd;
+  mState = eOpened;
+
+  return NS_OK;
+}
+
+nsresult nsFileStreamBase::DoPendingOpen() {
+  switch (mState) {
+    case eUnitialized:
+      MOZ_CRASH("This should not happen.");
+      return NS_ERROR_FAILURE;
+
+    case eDeferredOpen:
+      return DoOpen();
+
+    case eOpened:
+      MOZ_ASSERT(mFD);
+      if (NS_WARN_IF(!mFD)) {
+        return NS_ERROR_FAILURE;
+      }
+      return NS_OK;
+
+    case eClosed:
+      MOZ_ASSERT(!mFD);
+      return NS_BASE_STREAM_CLOSED;
+
+    case eError:
+      return mErrorValue;
+  }
+
+  MOZ_CRASH("Invalid mState value.");
+  return NS_ERROR_FAILURE;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsFileInputStream
+
+NS_IMPL_ADDREF_INHERITED(nsFileInputStream, nsFileStreamBase)
+NS_IMPL_RELEASE_INHERITED(nsFileInputStream, nsFileStreamBase)
+
+NS_IMPL_CLASSINFO(nsFileInputStream, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_LOCALFILEINPUTSTREAM_CID)
+
+NS_INTERFACE_MAP_BEGIN(nsFileInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIFileInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsILineInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIIPCSerializableInputStream)
+  NS_IMPL_QUERY_CLASSINFO(nsFileInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream, IsCloneable())
+NS_INTERFACE_MAP_END_INHERITING(nsFileStreamBase)
+
+NS_IMPL_CI_INTERFACE_GETTER(nsFileInputStream, nsIInputStream,
+                            nsIFileInputStream, nsISeekableStream,
+                            nsITellableStream, nsILineInputStream)
+
+nsresult nsFileInputStream::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsFileInputStream> stream = new nsFileInputStream();
+  return stream->QueryInterface(aIID, aResult);
+}
+
+nsresult nsFileInputStream::Open(nsIFile* aFile, int32_t aIOFlags,
+                                 int32_t aPerm) {
+  nsresult rv = NS_OK;
+
+  // If the previous file is open, close it
+  if (mFD) {
+    rv = Close();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  // Open the file
+  if (aIOFlags == -1) aIOFlags = PR_RDONLY;
+  if (aPerm == -1) aPerm = 0;
+
+  return MaybeOpen(aFile, aIOFlags, aPerm,
+                   mBehaviorFlags & nsIFileInputStream::DEFER_OPEN);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Init(nsIFile* aFile, int32_t aIOFlags, int32_t aPerm,
+                        int32_t aBehaviorFlags) {
+  NS_ENSURE_TRUE(!mFD, NS_ERROR_ALREADY_INITIALIZED);
+  NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
+                 NS_ERROR_ALREADY_INITIALIZED);
+
+  mBehaviorFlags = aBehaviorFlags;
+  mState = eUnitialized;
+
+  mFile = aFile;
+  mIOFlags = aIOFlags;
+  mPerm = aPerm;
+
+  return Open(aFile, aIOFlags, aPerm);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Close() {
+  // If this stream has already been closed, do nothing.
+  if (mState == eClosed) {
+    return NS_OK;
+  }
+
+  // Get the cache position at the time the file was close. This allows
+  // NS_SEEK_CUR on a closed file that has been opened with
+  // REOPEN_ON_REWIND.
+  if (mBehaviorFlags & REOPEN_ON_REWIND) {
+    // Get actual position. Not one modified by subclasses
+    nsFileStreamBase::Tell(&mCachedPosition);
+  }
+
+  // explicitly clear mLineBuffer in case this stream is reopened
+  mLineBuffer = nullptr;
+  return nsFileStreamBase::Close();
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  nsresult rv = nsFileStreamBase::Read(aBuf, aCount, _retval);
+  if (rv == NS_ERROR_FILE_NOT_FOUND) {
+    // Don't warn if this is a deffered file not found.
+    return rv;
+  }
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Check if we're at the end of file and need to close
+  if (mBehaviorFlags & CLOSE_ON_EOF && *_retval == 0) {
+    Close();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileInputStream::ReadLine(nsACString& aLine, bool* aResult) {
+  if (!mLineBuffer) {
+    mLineBuffer = mozilla::MakeUnique<nsLineBuffer<char>>();
+  }
+  return NS_ReadLine(this, mLineBuffer.get(), aLine, aResult);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Seek(int32_t aWhence, int64_t aOffset) {
+  return SeekInternal(aWhence, aOffset);
+}
+
+nsresult nsFileInputStream::SeekInternal(int32_t aWhence, int64_t aOffset,
+                                         bool aClearBuf) {
+  nsresult rv = DoPendingOpen();
+  if (rv != NS_OK && rv != NS_BASE_STREAM_CLOSED) {
+    return rv;
+  }
+
+  if (aClearBuf) {
+    mLineBuffer = nullptr;
+  }
+
+  if (rv == NS_BASE_STREAM_CLOSED) {
+    if (mBehaviorFlags & REOPEN_ON_REWIND) {
+      rv = Open(mFile, mIOFlags, mPerm);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // If the file was closed, and we do a relative seek, use the
+      // position we cached when we closed the file to seek to the right
+      // location.
+      if (aWhence == NS_SEEK_CUR) {
+        aWhence = NS_SEEK_SET;
+        aOffset += mCachedPosition;
+      }
+      // If we're trying to seek to the start then we're done, so
+      // return early to avoid Seek from calling DoPendingOpen and
+      // opening the underlying file earlier than necessary.
+      if (aWhence == NS_SEEK_SET && aOffset == 0) {
+        return NS_OK;
+      }
+    } else {
+      return NS_BASE_STREAM_CLOSED;
+    }
+  }
+
+  return nsFileStreamBase::Seek(aWhence, aOffset);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Tell(int64_t* aResult) {
+  return nsFileStreamBase::Tell(aResult);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Available(uint64_t* aResult) {
+  return nsFileStreamBase::Available(aResult);
+}
+
+NS_IMETHODIMP
+nsFileInputStream::StreamStatus() { return nsFileStreamBase::StreamStatus(); }
+
+void nsFileInputStream::SerializedComplexity(uint32_t aMaxSize,
+                                             uint32_t* aSizeUsed,
+                                             uint32_t* aPipes,
+                                             uint32_t* aTransferables) {
+  *aTransferables = 1;
+}
+
+void nsFileInputStream::Serialize(InputStreamParams& aParams, uint32_t aMaxSize,
+                                  uint32_t* aSizeUsed) {
+  MOZ_ASSERT(aSizeUsed);
+  *aSizeUsed = 0;
+
+  FileInputStreamParams params;
+
+  if (NS_SUCCEEDED(DoPendingOpen())) {
+    MOZ_ASSERT(mFD);
+    FileHandleType fd = FileHandleType(PR_FileDesc2NativeHandle(mFD));
+    NS_ASSERTION(fd, "This should never be null!");
+
+    params.fileDescriptor() = FileDescriptor(fd);
+
+    Close();
+  } else {
+    NS_WARNING(
+        "This file has not been opened (or could not be opened). "
+        "Sending an invalid file descriptor to the other process!");
+
+    params.fileDescriptor() = FileDescriptor();
+  }
+
+  int32_t behaviorFlags = mBehaviorFlags;
+
+  // The receiving process (or thread) is going to have an open file
+  // descriptor automatically so transferring this flag is meaningless.
+  behaviorFlags &= ~nsIFileInputStream::DEFER_OPEN;
+
+  params.behaviorFlags() = behaviorFlags;
+  params.ioFlags() = mIOFlags;
+
+  aParams = params;
+}
+
+bool nsFileInputStream::Deserialize(const InputStreamParams& aParams) {
+  NS_ASSERTION(!mFD, "Already have a file descriptor?!");
+  NS_ASSERTION(mState == nsFileStreamBase::eUnitialized, "Deferring open?!");
+  NS_ASSERTION(!mFile, "Should never have a file here!");
+  NS_ASSERTION(!mPerm, "This should always be 0!");
+
+  if (aParams.type() != InputStreamParams::TFileInputStreamParams) {
+    NS_WARNING("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const FileInputStreamParams& params = aParams.get_FileInputStreamParams();
+
+  const FileDescriptor& fd = params.fileDescriptor();
+
+  if (fd.IsValid()) {
+    auto rawFD = fd.ClonePlatformHandle();
+    PRFileDesc* fileDesc = PR_ImportFile(PROsfd(rawFD.release()));
+    if (!fileDesc) {
+      NS_WARNING("Failed to import file handle!");
+      return false;
+    }
+    mFD = fileDesc;
+    mState = eOpened;
+  } else {
+    NS_WARNING("Received an invalid file descriptor!");
+    mState = eError;
+    mErrorValue = NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  mBehaviorFlags = params.behaviorFlags();
+
+  if (!XRE_IsParentProcess()) {
+    // A child process shouldn't close when it reads the end because it will
+    // not be able to reopen the file later.
+    mBehaviorFlags &= ~nsIFileInputStream::CLOSE_ON_EOF;
+
+    // A child process will not be able to reopen the file so this flag is
+    // meaningless.
+    mBehaviorFlags &= ~nsIFileInputStream::REOPEN_ON_REWIND;
+  }
+
+  mIOFlags = params.ioFlags();
+
+  return true;
+}
+
+bool nsFileInputStream::IsCloneable() const {
+  // This inputStream is cloneable only if has been created using Init() and
+  // it owns a nsIFile. This is not true when it is deserialized from IPC.
+  return XRE_IsParentProcess() && mFile;
+}
+
+NS_IMETHODIMP
+nsFileInputStream::GetCloneable(bool* aCloneable) {
+  *aCloneable = IsCloneable();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileInputStream::Clone(nsIInputStream** aResult) {
+  MOZ_ASSERT(IsCloneable());
+  return NS_NewLocalFileInputStream(aResult, mFile, mIOFlags, mPerm,
+                                    mBehaviorFlags);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsFileOutputStream
+
+NS_IMPL_ISUPPORTS_INHERITED(nsFileOutputStream, nsFileStreamBase,
+                            nsIOutputStream, nsIFileOutputStream)
+
+nsresult nsFileOutputStream::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsFileOutputStream> stream = new nsFileOutputStream();
+  return stream->QueryInterface(aIID, aResult);
+}
+
+NS_IMETHODIMP
+nsFileOutputStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
+                         int32_t behaviorFlags) {
+  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
+  NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
+                 NS_ERROR_ALREADY_INITIALIZED);
+
+  mBehaviorFlags = behaviorFlags;
+  mState = eUnitialized;
+
+  if (ioFlags == -1) ioFlags = PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE;
+  if (perm <= 0) perm = 0664;
+
+  return MaybeOpen(file, ioFlags, perm,
+                   mBehaviorFlags & nsIFileOutputStream::DEFER_OPEN);
+}
+
+nsresult nsFileOutputStream::InitWithFileDescriptor(
+    const mozilla::ipc::FileDescriptor& aFd) {
+  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
+  NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
+                 NS_ERROR_ALREADY_INITIALIZED);
+
+  if (aFd.IsValid()) {
+    auto rawFD = aFd.ClonePlatformHandle();
+    PRFileDesc* fileDesc = PR_ImportFile(PROsfd(rawFD.release()));
+    if (!fileDesc) {
+      NS_WARNING("Failed to import file handle!");
+      return NS_ERROR_FAILURE;
+    }
+    mFD = fileDesc;
+    mState = eOpened;
+  } else {
+    mState = eError;
+    mErrorValue = NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileOutputStream::Preallocate(int64_t aLength) {
+  if (!mFD) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mozilla::fallocate(mFD, aLength)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsAtomicFileOutputStream
+
+NS_IMPL_ISUPPORTS_INHERITED(nsAtomicFileOutputStream, nsFileOutputStream,
+                            nsISafeOutputStream, nsIOutputStream,
+                            nsIFileOutputStream)
+
+NS_IMETHODIMP
+nsAtomicFileOutputStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
+                               int32_t behaviorFlags) {
+  // While `PR_APPEND` is not supported, `-1` is used as `ioFlags` parameter
+  // in some places, and `PR_APPEND | PR_TRUNCATE` does not require appending
+  // to existing file. So, throw an exception only if `PR_APPEND` is
+  // explicitly specified without `PR_TRUNCATE`.
+  if ((ioFlags & PR_APPEND) && !(ioFlags & PR_TRUNCATE)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  return nsFileOutputStream::Init(file, ioFlags, perm, behaviorFlags);
+}
+
+nsresult nsAtomicFileOutputStream::DoOpen() {
+  // Make sure mOpenParams.localFile will be empty if we bail somewhere in
+  // this function
+  nsCOMPtr<nsIFile> file;
+  file.swap(mOpenParams.localFile);
+
+  if (!file) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  nsresult rv = file->Exists(&mTargetFileExists);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Can't tell if target file exists");
+    mTargetFileExists =
+        true;  // Safer to assume it exists - we just do more work.
+  }
+
+  // follow symlinks, for two reasons:
+  // 1) if a user has deliberately set up a profile file as a symlink, we
+  //    honor it
+  // 2) to make the MoveToNative() in Finish() an atomic operation (which may
+  //    not be the case if moving across directories on different
+  //    filesystems).
+  nsCOMPtr<nsIFile> tempResult;
+  rv = file->Clone(getter_AddRefs(tempResult));
+  if (NS_SUCCEEDED(rv) && mTargetFileExists) {
+    tempResult->Normalize();
+  }
+
+  if (NS_SUCCEEDED(rv) && mTargetFileExists) {
+    // Abort if |file| is not writable; it won't work as an output stream.
+    bool isWritable;
+    if (NS_SUCCEEDED(file->IsWritable(&isWritable)) && !isWritable) {
+      return NS_ERROR_FILE_ACCESS_DENIED;
+    }
+
+    uint32_t origPerm;
+    if (NS_FAILED(file->GetPermissions(&origPerm))) {
+      NS_ERROR("Can't get permissions of target file");
+      origPerm = mOpenParams.perm;
+    }
+
+    // XXX What if |perm| is more restrictive then |origPerm|?
+    // This leaves the user supplied permissions as they were.
+    rv = tempResult->CreateUnique(nsIFile::NORMAL_FILE_TYPE, origPerm);
+  }
+  if (NS_SUCCEEDED(rv)) {
+    // nsFileOutputStream::DoOpen will work on the temporary file, so we
+    // prepare it and place it in mOpenParams.localFile.
+    mOpenParams.localFile = tempResult;
+    mTempFile = tempResult;
+    mTargetFile = file;
+    rv = nsFileOutputStream::DoOpen();
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsAtomicFileOutputStream::Close() {
+  nsresult rv = nsFileOutputStream::Close();
+
+  // the consumer doesn't want the original file overwritten -
+  // so clean up by removing the temp file.
+  if (mTempFile) {
+    mTempFile->Remove(false);
+    mTempFile = nullptr;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsAtomicFileOutputStream::Finish() {
+  nsresult rv = nsFileOutputStream::Close();
+
+  // if there is no temp file, don't try to move it over the original target.
+  // It would destroy the targetfile if close() is called twice.
+  if (!mTempFile) return rv;
+
+  // Only overwrite if everything was ok, and the temp file could be closed.
+  if (NS_SUCCEEDED(mWriteResult) && NS_SUCCEEDED(rv)) {
+    NS_ENSURE_STATE(mTargetFile);
+
+    if (!mTargetFileExists) {
+      // If the target file did not exist when we were initialized, then the
+      // temp file we gave out was actually a reference to the target file.
+      // since we succeeded in writing to the temp file (and hence succeeded
+      // in writing to the target file), there is nothing more to do.
+#ifdef DEBUG
+      bool equal;
+      if (NS_FAILED(mTargetFile->Equals(mTempFile, &equal)) || !equal) {
+        NS_WARNING("mTempFile not equal to mTargetFile");
+      }
+#endif
+    } else {
+      nsAutoString targetFilename;
+      rv = mTargetFile->GetLeafName(targetFilename);
+      if (NS_SUCCEEDED(rv)) {
+        // This will replace target.
+        rv = mTempFile->MoveTo(nullptr, targetFilename);
+        if (NS_FAILED(rv)) mTempFile->Remove(false);
+      }
+    }
+  } else {
+    mTempFile->Remove(false);
+
+    // if writing failed, propagate the failure code to the caller.
+    if (NS_FAILED(mWriteResult)) rv = mWriteResult;
+  }
+  mTempFile = nullptr;
+  return rv;
+}
+
+NS_IMETHODIMP
+nsAtomicFileOutputStream::Write(const char* buf, uint32_t count,
+                                uint32_t* result) {
+  nsresult rv = nsFileOutputStream::Write(buf, count, result);
+  if (NS_SUCCEEDED(mWriteResult)) {
+    if (NS_FAILED(rv)) {
+      mWriteResult = rv;
+    } else if (count != *result) {
+      mWriteResult = NS_ERROR_LOSS_OF_SIGNIFICANT_DATA;
+    }
+
+    if (NS_FAILED(mWriteResult) && count > 0) {
+      NS_WARNING("writing to output stream failed! data may be lost");
+    }
+  }
+  return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsSafeFileOutputStream
+
+NS_IMETHODIMP
+nsSafeFileOutputStream::Finish() {
+  (void)Flush();
+  return nsAtomicFileOutputStream::Finish();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsFileRandomAccessStream
+
+nsresult nsFileRandomAccessStream::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsFileRandomAccessStream> stream = new nsFileRandomAccessStream();
+  return stream->QueryInterface(aIID, aResult);
+}
+
+NS_IMPL_ISUPPORTS_INHERITED(nsFileRandomAccessStream, nsFileStreamBase,
+                            nsIRandomAccessStream, nsIFileRandomAccessStream,
+                            nsIInputStream, nsIOutputStream)
+
+NS_IMETHODIMP
+nsFileRandomAccessStream::GetInputStream(nsIInputStream** aInputStream) {
+  nsCOMPtr<nsIInputStream> inputStream(this);
+
+  inputStream.forget(aInputStream);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFileRandomAccessStream::GetOutputStream(nsIOutputStream** aOutputStream) {
+  nsCOMPtr<nsIOutputStream> outputStream(this);
+
+  outputStream.forget(aOutputStream);
+  return NS_OK;
+}
+
+nsIInputStream* nsFileRandomAccessStream::InputStream() { return this; }
+
+nsIOutputStream* nsFileRandomAccessStream::OutputStream() { return this; }
+
+RandomAccessStreamParams nsFileRandomAccessStream::Serialize(
+    nsIInterfaceRequestor* aCallbacks) {
+  FileRandomAccessStreamParams params;
+
+  if (NS_SUCCEEDED(DoPendingOpen())) {
+    MOZ_ASSERT(mFD);
+    FileHandleType fd = FileHandleType(PR_FileDesc2NativeHandle(mFD));
+    MOZ_ASSERT(fd, "This should never be null!");
+
+    params.fileDescriptor() = FileDescriptor(fd);
+
+    Close();
+  } else {
+    NS_WARNING(
+        "This file has not been opened (or could not be opened). "
+        "Sending an invalid file descriptor to the other process!");
+
+    params.fileDescriptor() = FileDescriptor();
+  }
+
+  int32_t behaviorFlags = mBehaviorFlags;
+
+  // The receiving process (or thread) is going to have an open file
+  // descriptor automatically so transferring this flag is meaningless.
+  behaviorFlags &= ~nsIFileInputStream::DEFER_OPEN;
+
+  params.behaviorFlags() = behaviorFlags;
+
+  return params;
+}
+
+bool nsFileRandomAccessStream::Deserialize(
+    RandomAccessStreamParams& aStreamParams) {
+  MOZ_ASSERT(!mFD, "Already have a file descriptor?!");
+  MOZ_ASSERT(mState == nsFileStreamBase::eUnitialized, "Deferring open?!");
+
+  if (aStreamParams.type() !=
+      RandomAccessStreamParams::TFileRandomAccessStreamParams) {
+    NS_WARNING("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const FileRandomAccessStreamParams& params =
+      aStreamParams.get_FileRandomAccessStreamParams();
+
+  const FileDescriptor& fd = params.fileDescriptor();
+
+  if (fd.IsValid()) {
+    auto rawFD = fd.ClonePlatformHandle();
+    PRFileDesc* fileDesc = PR_ImportFile(PROsfd(rawFD.release()));
+    if (!fileDesc) {
+      NS_WARNING("Failed to import file handle!");
+      return false;
+    }
+    mFD = fileDesc;
+    mState = eOpened;
+  } else {
+    NS_WARNING("Received an invalid file descriptor!");
+    mState = eError;
+    mErrorValue = NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  mBehaviorFlags = params.behaviorFlags();
+
+  return true;
+}
+
+NS_IMETHODIMP
+nsFileRandomAccessStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
+                               int32_t behaviorFlags) {
+  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
+  NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
+                 NS_ERROR_ALREADY_INITIALIZED);
+
+  mBehaviorFlags = behaviorFlags;
+  mState = eUnitialized;
+
+  if (ioFlags == -1) ioFlags = PR_RDWR;
+  if (perm <= 0) perm = 0;
+
+  return MaybeOpen(file, ioFlags, perm,
+                   mBehaviorFlags & nsIFileRandomAccessStream::DEFER_OPEN);
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/netwerk/base/nsFileStreams.h b/netwerk/base/nsFileStreams.h
new file mode 100644
index 0000000000..d402bffb24
--- /dev/null
+++ b/netwerk/base/nsFileStreams.h
@@ -0,0 +1,292 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsFileStreams_h__
+#define nsFileStreams_h__
+
+#include "mozilla/UniquePtr.h"
+#include "nsIFileStreams.h"
+#include "nsIFile.h"
+#include "nsICloneableInputStream.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsIRandomAccessStream.h"
+#include "nsISafeOutputStream.h"
+#include "nsISeekableStream.h"
+#include "nsILineInputStream.h"
+#include "nsCOMPtr.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsReadLine.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace ipc {
+class FileDescriptor;
+}  // namespace ipc
+}  // namespace mozilla
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsFileStreamBase : public nsISeekableStream, public nsIFileMetadata {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+  NS_DECL_NSIFILEMETADATA
+
+  nsFileStreamBase() = default;
+
+ protected:
+  virtual ~nsFileStreamBase();
+
+  nsresult Close();
+  nsresult Available(uint64_t* aResult);
+  nsresult Read(char* aBuf, uint32_t aCount, uint32_t* aResult);
+  nsresult ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                        uint32_t aCount, uint32_t* _retval);
+  nsresult IsNonBlocking(bool* aNonBlocking);
+  nsresult Flush();
+  nsresult StreamStatus();
+  nsresult Write(const char* aBuf, uint32_t aCount, uint32_t* result);
+  nsresult WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
+                     uint32_t* _retval);
+  nsresult WriteSegments(nsReadSegmentFun aReader, void* aClosure,
+                         uint32_t aCount, uint32_t* _retval);
+
+  PRFileDesc* mFD{nullptr};
+
+  /**
+   * Flags describing our behavior.  See the IDL file for possible values.
+   */
+  int32_t mBehaviorFlags{0};
+
+  enum {
+    // This is the default value. It will be changed by Deserialize or Init.
+    eUnitialized,
+    // The opening has been deferred. See DEFER_OPEN.
+    eDeferredOpen,
+    // The file has been opened. mFD is not null.
+    eOpened,
+    // The file has been closed. mFD is null.
+    eClosed,
+    // Something bad happen in the Open() or in Deserialize(). The actual
+    // error value is stored in mErrorValue.
+    eError
+  } mState{eUnitialized};
+
+  struct OpenParams {
+    nsCOMPtr<nsIFile> localFile;
+    int32_t ioFlags = 0;
+    int32_t perm = 0;
+  };
+
+  /**
+   * Data we need to do an open.
+   */
+  OpenParams mOpenParams;
+
+  nsresult mErrorValue{NS_ERROR_FAILURE};
+
+  /**
+   * Prepares the data we need to open the file, and either does the open now
+   * by calling DoOpen(), or leaves it to be opened later by a call to
+   * DoPendingOpen().
+   */
+  nsresult MaybeOpen(nsIFile* aFile, int32_t aIoFlags, int32_t aPerm,
+                     bool aDeferred);
+
+  /**
+   * Cleans up data prepared in MaybeOpen.
+   */
+  void CleanUpOpen();
+
+  /**
+   * Open the file. This is called either from MaybeOpen (during Init)
+   * or from DoPendingOpen (if DEFER_OPEN is used when initializing this
+   * stream). The default behavior of DoOpen is to open the file and save the
+   * file descriptor.
+   */
+  virtual nsresult DoOpen();
+
+  /**
+   * Based on mState, this method does the opening, return an error, or do
+   * nothing. If the return value is not NS_OK, please, return it back to the
+   * callee.
+   */
+  inline nsresult DoPendingOpen();
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+// nsFileInputStream is cloneable only on the parent process because only there
+// it can open the same file multiple times.
+
+class nsFileInputStream : public nsFileStreamBase,
+                          public nsIFileInputStream,
+                          public nsILineInputStream,
+                          public nsIIPCSerializableInputStream,
+                          public nsICloneableInputStream {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIFILEINPUTSTREAM
+  NS_DECL_NSILINEINPUTSTREAM
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+
+  NS_IMETHOD Close() override;
+  NS_IMETHOD Tell(int64_t* aResult) override;
+  NS_IMETHOD Available(uint64_t* _retval) override;
+  NS_IMETHOD StreamStatus() override;
+  NS_IMETHOD Read(char* aBuf, uint32_t aCount, uint32_t* _retval) override;
+  NS_IMETHOD ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                          uint32_t aCount, uint32_t* _retval) override {
+    return nsFileStreamBase::ReadSegments(aWriter, aClosure, aCount, _retval);
+  }
+  NS_IMETHOD IsNonBlocking(bool* _retval) override {
+    return nsFileStreamBase::IsNonBlocking(_retval);
+  }
+
+  // Overrided from nsFileStreamBase
+  NS_IMETHOD Seek(int32_t aWhence, int64_t aOffset) override;
+
+  nsFileInputStream() : mLineBuffer(nullptr) {}
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+ protected:
+  virtual ~nsFileInputStream() = default;
+
+  nsresult SeekInternal(int32_t aWhence, int64_t aOffset,
+                        bool aClearBuf = true);
+
+  mozilla::UniquePtr<nsLineBuffer<char>> mLineBuffer;
+
+  /**
+   * The file being opened.
+   */
+  nsCOMPtr<nsIFile> mFile;
+  /**
+   * The IO flags passed to Init() for the file open.
+   */
+  int32_t mIOFlags{0};
+  /**
+   * The permissions passed to Init() for the file open.
+   */
+  int32_t mPerm{0};
+
+  /**
+   * Cached position for Tell for automatically reopening streams.
+   */
+  int64_t mCachedPosition{0};
+
+ protected:
+  /**
+   * Internal, called to open a file.  Parameters are the same as their
+   * Init() analogues.
+   */
+  nsresult Open(nsIFile* file, int32_t ioFlags, int32_t perm);
+
+  bool IsCloneable() const;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsFileOutputStream : public nsFileStreamBase, public nsIFileOutputStream {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIFILEOUTPUTSTREAM
+  NS_FORWARD_NSIOUTPUTSTREAM(nsFileStreamBase::)
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+  nsresult InitWithFileDescriptor(const mozilla::ipc::FileDescriptor& aFd);
+
+ protected:
+  virtual ~nsFileOutputStream() = default;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * A safe file output stream that overwrites the destination file only
+ * once writing is complete. This protects against incomplete writes
+ * due to the process or the thread being interrupted or crashed.
+ */
+class nsAtomicFileOutputStream : public nsFileOutputStream,
+                                 public nsISafeOutputStream {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSISAFEOUTPUTSTREAM
+
+  nsAtomicFileOutputStream() = default;
+
+  virtual nsresult DoOpen() override;
+
+  NS_IMETHOD Close() override;
+  NS_IMETHOD Write(const char* buf, uint32_t count, uint32_t* result) override;
+  NS_IMETHOD Init(nsIFile* file, int32_t ioFlags, int32_t perm,
+                  int32_t behaviorFlags) override;
+
+ protected:
+  virtual ~nsAtomicFileOutputStream() = default;
+
+  nsCOMPtr<nsIFile> mTargetFile;
+  nsCOMPtr<nsIFile> mTempFile;
+
+  bool mTargetFileExists{true};
+  nsresult mWriteResult{NS_OK};  // Internally set in Write()
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * A safe file output stream that overwrites the destination file only
+ * once writing + flushing is complete. This protects against more
+ * classes of software/hardware errors than nsAtomicFileOutputStream,
+ * at the expense of being more costly to the disk, OS and battery.
+ */
+class nsSafeFileOutputStream : public nsAtomicFileOutputStream {
+ public:
+  NS_IMETHOD Finish() override;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class nsFileRandomAccessStream : public nsFileStreamBase,
+                                 public nsIFileRandomAccessStream,
+                                 public nsIInputStream,
+                                 public nsIOutputStream {
+ public:
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_FORWARD_NSITELLABLESTREAM(nsFileStreamBase::)
+  NS_FORWARD_NSISEEKABLESTREAM(nsFileStreamBase::)
+  NS_DECL_NSIRANDOMACCESSSTREAM
+  NS_DECL_NSIFILERANDOMACCESSSTREAM
+  NS_FORWARD_NSIINPUTSTREAM(nsFileStreamBase::)
+
+  // Can't use NS_FORWARD_NSIOUTPUTSTREAM due to overlapping methods
+  // Close() and IsNonBlocking()
+  NS_IMETHOD Flush() override { return nsFileStreamBase::Flush(); }
+  NS_IMETHOD Write(const char* aBuf, uint32_t aCount,
+                   uint32_t* _retval) override {
+    return nsFileStreamBase::Write(aBuf, aCount, _retval);
+  }
+  NS_IMETHOD WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
+                       uint32_t* _retval) override {
+    return nsFileStreamBase::WriteFrom(aFromStream, aCount, _retval);
+  }
+  NS_IMETHOD WriteSegments(nsReadSegmentFun aReader, void* aClosure,
+                           uint32_t aCount, uint32_t* _retval) override {
+    return nsFileStreamBase::WriteSegments(aReader, aClosure, aCount, _retval);
+  }
+
+ protected:
+  virtual ~nsFileRandomAccessStream() = default;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif  // nsFileStreams_h__
diff --git a/netwerk/base/nsIArrayBufferInputStream.idl b/netwerk/base/nsIArrayBufferInputStream.idl
new file mode 100644
index 0000000000..1bf24d1d4b
--- /dev/null
+++ b/netwerk/base/nsIArrayBufferInputStream.idl
@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIInputStream.idl"
+
+/**
+ * nsIArrayBufferInputStream
+ *
+ * Provides scriptable methods for initializing a nsIInputStream
+ * implementation with an ArrayBuffer.
+ */
+[scriptable, builtinclass, uuid(3014dde6-aa1c-41db-87d0-48764a3710f6)]
+interface nsIArrayBufferInputStream : nsIInputStream
+{
+    /**
+     * SetData - assign an ArrayBuffer to the input stream.
+     *
+     * @param buffer    - stream data
+     * @param byteOffset - stream data offset
+     * @param byteLen - stream data length
+     */
+    void setData(in jsval buffer, in uint64_t byteOffset, in uint64_t byteLen);
+};
diff --git a/netwerk/base/nsIAsyncStreamCopier.idl b/netwerk/base/nsIAsyncStreamCopier.idl
new file mode 100644
index 0000000000..633fe72b6e
--- /dev/null
+++ b/netwerk/base/nsIAsyncStreamCopier.idl
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsIRequestObserver;
+interface nsIEventTarget;
+
+// You should prefer nsIAsyncStreamCopier2
+[scriptable, uuid(5a19ca27-e041-4aca-8287-eb248d4c50c0)]
+interface nsIAsyncStreamCopier : nsIRequest
+{
+    /**
+     * Initialize the stream copier.
+     *
+     * @param aSource
+     *        contains the data to be copied.
+     * @param aSink
+     *        specifies the destination for the data.
+     * @param aTarget
+     *        specifies the thread on which the copy will occur.  a null value
+     *        is permitted and will cause the copy to occur on an unspecified
+     *        background thread.
+     * @param aSourceBuffered
+     *        true if aSource implements ReadSegments.
+     * @param aSinkBuffered
+     *        true if aSink implements WriteSegments.
+     * @param aChunkSize
+     *        specifies how many bytes to read/write at a time.  this controls
+     *        the granularity of the copying.  it should match the segment size
+     *        of the "buffered" streams involved.
+     * @param aCloseSource
+     *        true if aSource should be closed after copying.
+     * @param aCloseSink
+     *        true if aSink should be closed after copying.
+     *
+     * NOTE: at least one of the streams must be buffered. If you do not know
+     * whether your streams are buffered, you should use nsIAsyncStreamCopier2
+     * instead.
+     */
+    void init(in nsIInputStream    aSource,
+              in nsIOutputStream   aSink,
+              in nsIEventTarget    aTarget,
+              in boolean           aSourceBuffered,
+              in boolean           aSinkBuffered,
+              in unsigned long     aChunkSize,
+              in boolean           aCloseSource,
+              in boolean           aCloseSink);
+
+    /**
+     * asyncCopy triggers the start of the copy.  The observer will be notified
+     * when the copy completes.
+     *
+     * @param aObserver
+     *        receives notifications.
+     * @param aObserverContext
+     *        passed to observer methods.
+     */
+    void asyncCopy(in nsIRequestObserver   aObserver,
+                   in nsISupports          aObserverContext);
+};
diff --git a/netwerk/base/nsIAsyncStreamCopier2.idl b/netwerk/base/nsIAsyncStreamCopier2.idl
new file mode 100644
index 0000000000..7de793f51e
--- /dev/null
+++ b/netwerk/base/nsIAsyncStreamCopier2.idl
@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsIRequestObserver;
+interface nsIEventTarget;
+
+[scriptable, uuid(a5b2decf-4ede-4801-8b38-e5fe5db46bf2)]
+interface nsIAsyncStreamCopier2 : nsIRequest
+{
+    /**
+     * Initialize the stream copier.
+     *
+     * If neither the source nor the sink are buffered, buffering will
+     * be automatically added to the sink.
+     *
+     *
+     * @param aSource
+     *        contains the data to be copied.
+     * @param aSink
+     *        specifies the destination for the data.
+     * @param aTarget
+     *        specifies the thread on which the copy will occur.  a null value
+     *        is permitted and will cause the copy to occur on an unspecified
+     *        background thread.
+     * @param aChunkSize
+     *        specifies how many bytes to read/write at a time.  this controls
+     *        the granularity of the copying.  it should match the segment size
+     *        of the "buffered" streams involved.
+     * @param aCloseSource
+     *        true if aSource should be closed after copying (this is generally
+     *        the desired behavior).
+     * @param aCloseSink
+     *        true if aSink should be closed after copying (this is generally
+     *        the desired behavior).
+     */
+  void init(in nsIInputStream    aSource,
+            in nsIOutputStream   aSink,
+            in nsIEventTarget    aTarget,
+            in unsigned long     aChunkSize,
+            in boolean           aCloseSource,
+            in boolean           aCloseSink);
+
+  /**
+   * asyncCopy triggers the start of the copy.  The observer will be notified
+   * when the copy completes.
+   *
+   * @param aObserver
+   *        receives notifications.
+   * @param aObserverContext
+   *        passed to observer methods.
+   */
+  void asyncCopy(in nsIRequestObserver   aObserver,
+                 in nsISupports          aObserverContext);
+};
diff --git a/netwerk/base/nsIAsyncVerifyRedirectCallback.idl b/netwerk/base/nsIAsyncVerifyRedirectCallback.idl
new file mode 100644
index 0000000000..8c81a142f8
--- /dev/null
+++ b/netwerk/base/nsIAsyncVerifyRedirectCallback.idl
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(8d171460-a716-41f1-92be-8c659db39b45)]
+interface nsIAsyncVerifyRedirectCallback : nsISupports
+{
+    /**
+     * Complement to nsIChannelEventSink asynchronous callback. The result of
+     * the redirect decision is passed through this callback.
+     *
+     * @param result
+     *    Result of the redirect veto decision. If FAILED the redirect has been
+     *    vetoed. If SUCCEEDED the redirect has been allowed by all consumers.
+     */
+    void onRedirectVerifyCallback(in nsresult result);
+};
diff --git a/netwerk/base/nsIAuthInformation.idl b/netwerk/base/nsIAuthInformation.idl
new file mode 100644
index 0000000000..a9a74891b1
--- /dev/null
+++ b/netwerk/base/nsIAuthInformation.idl
@@ -0,0 +1,117 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * A object that hold authentication information. The caller of
+ * nsIAuthPrompt2::promptUsernameAndPassword or
+ * nsIAuthPrompt2::promptPasswordAsync provides an object implementing this
+ * interface; the prompt implementation can then read the values here to prefill
+ * the dialog. After the user entered the authentication information, it should
+ * set the attributes of this object to indicate to the caller what was entered
+ * by the user.
+ */
+[scriptable, uuid(0d73639c-2a92-4518-9f92-28f71fea5f20)]
+interface nsIAuthInformation : nsISupports
+{
+  /** @name Flags */
+  /* @{ */
+  /**
+   * This dialog belongs to a network host.
+   */
+  const uint32_t AUTH_HOST = 1;
+
+  /**
+   * This dialog belongs to a proxy.
+   */
+  const uint32_t AUTH_PROXY = 2;
+
+  /**
+   * This dialog needs domain information. The user interface should show a
+   * domain field, prefilled with the domain attribute's value.
+   */
+  const uint32_t NEED_DOMAIN = 4;
+
+  /**
+   * This dialog only asks for password information. Authentication prompts
+   * SHOULD NOT show a username field. Attempts to change the username field
+   * will have no effect. nsIAuthPrompt2 implementations should, however, show
+   * its initial value to the user in some form. For example, a paragraph in
+   * the dialog might say "Please enter your password for user jsmith at
+   * server intranet".
+   *
+   * This flag is mutually exclusive with #NEED_DOMAIN.
+   */
+  const uint32_t ONLY_PASSWORD = 8;
+
+  /**
+   * We have already tried to log in for this channel
+   * (with auth values from a previous promptAuth call),
+   * but it failed, so we now ask the user to provide a new, correct login.
+   *
+   * @see also RFC 2616, Section 10.4.2
+   */
+  const uint32_t PREVIOUS_FAILED = 16;
+
+  /**
+   * A cross-origin sub-resource requests an authentication.
+   * The message presented to users must reflect that.
+   */
+  const uint32_t CROSS_ORIGIN_SUB_RESOURCE = 32;
+  /* @} */
+
+  /**
+   * Flags describing this dialog. A bitwise OR of the flag values
+   * above.
+   *
+   * It is possible that neither #AUTH_HOST nor #AUTH_PROXY are set.
+   *
+   * Auth prompts should ignore flags they don't understand; especially, they
+   * should not throw an exception because of an unsupported flag.
+   */
+  readonly attribute unsigned long flags;
+
+  /**
+   * The server-supplied realm of the authentication as defined in RFC 2617.
+   * Can be the empty string if the protocol does not support realms.
+   * Otherwise, this is a human-readable string like "Secret files".
+   */
+  readonly attribute AString realm;
+
+  /**
+   * The authentication scheme used for this request, if applicable. If the
+   * protocol for this authentication does not support schemes, this will be
+   * the empty string. Otherwise, this will be a string such as "basic" or
+   * "digest". This string will always be in lowercase.
+   */
+  readonly attribute AUTF8String authenticationScheme;
+
+  /**
+   * The initial value should be used to prefill the dialog or be shown
+   * in some other way to the user.
+   * On return, this parameter should contain the username entered by
+   * the user.
+   * This field can only be changed if the #ONLY_PASSWORD flag is not set.
+   */
+  attribute AString username;
+
+  /**
+   * The initial value should be used to prefill the dialog or be shown
+   * in some other way to the user.
+   * The password should not be shown in clear.
+   * On return, this parameter should contain the password entered by
+   * the user.
+   */
+  attribute AString password;
+
+  /**
+   * The initial value should be used to prefill the dialog or be shown
+   * in some other way to the user.
+   * On return, this parameter should contain the domain entered by
+   * the user.
+   * This attribute is only used if flags include #NEED_DOMAIN.
+   */
+  attribute AString domain;
+};
diff --git a/netwerk/base/nsIAuthModule.idl b/netwerk/base/nsIAuthModule.idl
new file mode 100644
index 0000000000..87985f2a57
--- /dev/null
+++ b/netwerk/base/nsIAuthModule.idl
@@ -0,0 +1,146 @@
+/* vim:set ts=4 sw=4 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+[uuid(6e35dbc0-49ef-4e2c-b1ea-b72ec64450a2)]
+interface nsIAuthModule : nsISupports
+{
+    /**
+     * Default behavior.
+     */
+    const unsigned long REQ_DEFAULT = 0;
+
+    /**
+     * Client and server will be authenticated.
+     */
+    const unsigned long REQ_MUTUAL_AUTH = (1 << 0);
+
+    /**
+     * The server is allowed to impersonate the client.  The REQ_MUTUAL_AUTH
+     * flag may also need to be specified in order for this flag to take
+     * effect.
+     */
+    const unsigned long REQ_DELEGATE = (1 << 1);
+
+    /**
+     * The authentication is required for a proxy connection.
+     */
+    const unsigned long REQ_PROXY_AUTH = (1 << 2);
+
+    /**
+     * Flags used for telemetry.
+     */
+    const unsigned long NTLM_MODULE_SAMBA_AUTH_PROXY = 0;
+    const unsigned long NTLM_MODULE_SAMBA_AUTH_DIRECT = 1;
+    const unsigned long NTLM_MODULE_WIN_API_PROXY = 2;
+    const unsigned long NTLM_MODULE_WIN_API_DIRECT = 3;
+    const unsigned long NTLM_MODULE_GENERIC_PROXY = 4;
+    const unsigned long NTLM_MODULE_GENERIC_DIRECT = 5;
+    const unsigned long NTLM_MODULE_KERBEROS_PROXY = 6;
+    const unsigned long NTLM_MODULE_KERBEROS_DIRECT = 7;
+
+    /** Other flags may be defined in the future */
+
+    /**
+     * Called to initialize an auth module.  The other methods cannot be called
+     * unless this method succeeds.
+     *
+     * @param aServiceName
+     *        the service name, which may be null if not applicable (e.g., for
+     *        NTLM, this parameter should be null).
+     * @param aServiceFlags
+     *        a bitwise-or of the REQ_ flags defined above (pass REQ_DEFAULT
+     *        for default behavior).
+     * @param aDomain
+     *        the authentication domain, which may be null if not applicable.
+     * @param aUsername
+     *        the user's login name
+     * @param aPassword
+     *        the user's password
+     */
+    void init(in ACString        aServiceName,
+              in unsigned long aServiceFlags,
+              in AString       aDomain,
+              in AString       aUsername,
+              in AString       aPassword);
+
+    /**
+     * Called to get the next token in a sequence of authentication steps.
+     *
+     * @param aInToken
+     *        A buffer containing the input token (e.g., a challenge from a
+     *        server).  This may be null.
+     * @param aInTokenLength
+     *        The length of the input token.
+     * @param aOutToken
+     *        If getNextToken succeeds, then aOutToken will point to a buffer
+     *        to be sent in response to the server challenge.  The length of
+     *        this buffer is given by aOutTokenLength.  The buffer at aOutToken
+     *        must be recycled with a call to free.
+     * @param aOutTokenLength
+     *        If getNextToken succeeds, then aOutTokenLength contains the
+     *        length of the buffer (number of bytes) pointed to by aOutToken.
+     */
+    void getNextToken([const] in voidPtr  aInToken,
+                      in unsigned long    aInTokenLength,
+                      out voidPtr         aOutToken,
+                      out unsigned long   aOutTokenLength);
+    /**
+     * Once a security context has been established through calls to GetNextToken()
+     * it may be used to protect data exchanged between client and server. Calls
+     * to Wrap() are used to protect items of data to be sent to the server.
+     *
+     * @param aInToken
+     *        A buffer containing the data to be sent to the server
+     * @param aInTokenLength
+     *        The length of the input token
+     * @param confidential
+     *        If set to true, Wrap() will encrypt the data, otherwise data will
+     *        just be integrity protected (checksummed)
+     * @param aOutToken
+     *        A buffer containing the resulting data to be sent to the server
+     * @param aOutTokenLength
+     *        The length of the output token buffer
+     *
+     * Wrap() may return NS_ERROR_NOT_IMPLEMENTED, if the underlying authentication
+     * mechanism does not support security layers.
+     */
+    void wrap([const] in voidPtr aInToken,
+              in unsigned long   aInTokenLength,
+              in boolean         confidential,
+              out voidPtr        aOutToken,
+              out unsigned long  aOutTokenLength);
+
+    /**
+     * Unwrap() is used to unpack, decrypt, and verify the checksums on data
+     * returned by a server when security layers are in use.
+     *
+     * @param aInToken
+     *        A buffer containing the data received from the server
+     * @param aInTokenLength
+     *        The length of the input token
+     * @param aOutToken
+     *        A buffer containing the plaintext data from the server
+     * @param aOutTokenLength
+     *        The length of the output token buffer
+     *
+     * Unwrap() may return NS_ERROR_NOT_IMPLEMENTED, if the underlying
+     * authentication mechanism does not support security layers.
+     */
+    void unwrap([const] in voidPtr aInToken,
+                in unsigned long   aInTokenLength,
+                out voidPtr        aOutToken,
+                out unsigned long  aOutTokenLength);
+
+%{C++
+    /**
+     * Create a new instance of an auth module.
+     *
+     * @param aType
+     *        The type of the auth module to be constructed.
+     */
+    static already_AddRefed<nsIAuthModule> CreateInstance(const char* aType);
+%}
+};
diff --git a/netwerk/base/nsIAuthPrompt.idl b/netwerk/base/nsIAuthPrompt.idl
new file mode 100644
index 0000000000..fbbac6ee9f
--- /dev/null
+++ b/netwerk/base/nsIAuthPrompt.idl
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIPrompt;
+
+[scriptable, uuid(358089f9-ee4b-4711-82fd-bcd07fc62061)]
+interface nsIAuthPrompt : nsISupports
+{
+    const uint32_t SAVE_PASSWORD_NEVER             = 0;
+    const uint32_t SAVE_PASSWORD_FOR_SESSION       = 1;
+    const uint32_t SAVE_PASSWORD_PERMANENTLY       = 2;
+
+    /**
+     * Puts up a text input dialog with OK and Cancel buttons.
+     * Note: prompt uses separate args for the "in" and "out" values of the
+     *       input field, whereas the other functions use a single inout arg.
+     * @param  dialogText    The title for the dialog.
+     * @param  text          The text to display in the dialog.
+     * @param  passwordRealm The "realm" the password belongs to: e.g.
+     *                       ldap://localhost/dc=test
+     * @param  savePassword  One of the SAVE_PASSWORD_* options above.
+     * @param  defaultText   The default text to display in the text input box.
+     * @param  result        The value entered by the user if OK was
+     *                       selected.
+     * @return true for OK, false for Cancel
+     */
+    boolean prompt(in wstring dialogTitle,
+                   in wstring text,
+                   in wstring passwordRealm,
+                   in uint32_t savePassword,
+                   in wstring defaultText,
+                   out wstring result);
+
+    /**
+     * Puts up a username/password dialog with OK and Cancel buttons.
+     * @param  dialogText    The title for the dialog.
+     * @param  text          The text to display in the dialog.
+     * @param  passwordRealm The "realm" the password belongs to: e.g.
+     *                       ldap://localhost/dc=test
+     * @param  savePassword  One of the SAVE_PASSWORD_* options above.
+     * @param  user          The username entered in the dialog.
+     * @param  pwd           The password entered by the user if OK was
+     *                       selected.
+     * @return true for OK, false for Cancel
+     */
+    boolean promptUsernameAndPassword(in wstring dialogTitle,
+                                      in wstring text,
+                                      in wstring passwordRealm,
+                                      in uint32_t savePassword,
+                                      inout wstring user,
+                                      inout wstring pwd);
+
+    /**
+     * Puts up an async username/password dialog with OK and Cancel buttons.
+     * @param  dialogText    The title for the dialog.
+     * @param  text          The text to display in the dialog.
+     * @param  passwordRealm The "realm" the password belongs to: e.g.
+     *                       ldap://localhost/dc=test
+     * @param  savePassword  One of the SAVE_PASSWORD_* options above.
+     * @param  user          The username entered in the dialog.
+     * @param  pwd           The password entered by the user if OK was
+     *                       selected.
+     * @return promise resolving to true for OK, false for Cancel
+     */
+    Promise asyncPromptUsernameAndPassword(in wstring dialogTitle,
+                                      in wstring text,
+                                      in wstring passwordRealm,
+                                      in uint32_t savePassword,
+                                      inout wstring user,
+                                      inout wstring pwd);
+
+    /**
+     * Puts up a password dialog with OK and Cancel buttons.
+     * @param  dialogText    The title for the dialog.
+     * @param  text          The text to display in the dialog.
+     * @param  passwordRealm The "realm" the password belongs to: e.g.
+     *                       ldap://localhost/dc=test. If a username is
+     *                       specified (http://user@site.com) it will be used
+     *                       when matching existing logins or saving new ones.
+     *                       If no username is specified, only password-only
+     *                       logins will be matched or saved.
+     *                       Note: if a username is specified, the username
+     *                       should be escaped.
+     * @param  savePassword  One of the SAVE_PASSWORD_* options above.
+     * @param  pwd           The password entered by the user if OK was
+     *                       selected.
+     * @return true for OK, false for Cancel
+     */
+    boolean promptPassword(in wstring dialogTitle,
+                           in wstring text,
+                           in wstring passwordRealm,
+                           in uint32_t savePassword,
+                           inout wstring pwd);
+
+    /**
+     * Puts up an async password dialog with OK and Cancel buttons.
+     * @param  dialogText    The title for the dialog.
+     * @param  text          The text to display in the dialog.
+     * @param  passwordRealm The "realm" the password belongs to: e.g.
+     *                       ldap://localhost/dc=test. If a username is
+     *                       specified (http://user@site.com) it will be used
+     *                       when matching existing logins or saving new ones.
+     *                       If no username is specified, only password-only
+     *                       logins will be matched or saved.
+     *                       Note: if a username is specified, the username
+     *                       should be escaped.
+     * @param  savePassword  One of the SAVE_PASSWORD_* options above.
+     * @param  pwd           The password entered by the user if OK was
+     *                       selected.
+     * @return promise resolving to true for OK, false for Cancel
+     */
+    Promise asyncPromptPassword(in wstring dialogTitle,
+                           in wstring text,
+                           in wstring passwordRealm,
+                           in uint32_t savePassword,
+                           inout wstring pwd);
+};
diff --git a/netwerk/base/nsIAuthPrompt2.idl b/netwerk/base/nsIAuthPrompt2.idl
new file mode 100644
index 0000000000..d94d50dfcc
--- /dev/null
+++ b/netwerk/base/nsIAuthPrompt2.idl
@@ -0,0 +1,104 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIAuthPromptCallback;
+interface nsIChannel;
+interface nsICancelable;
+interface nsIAuthInformation;
+
+/**
+ * An interface allowing to prompt for a username and password. This interface
+ * is usually acquired using getInterface on notification callbacks or similar.
+ * It can be used to prompt users for authentication information, either
+ * synchronously or asynchronously.
+ */
+[scriptable, uuid(651395EB-8612-4876-8AC0-A88D4DCE9E1E)]
+interface nsIAuthPrompt2 : nsISupports
+{
+  /** @name Security Levels */
+  /* @{ */
+  /**
+   * The password will be sent unencrypted. No security provided.
+   */
+  const uint32_t LEVEL_NONE = 0;
+  /**
+   * Password will be sent encrypted, but the connection is otherwise
+   * insecure.
+   */
+  const uint32_t LEVEL_PW_ENCRYPTED = 1;
+  /**
+   * The connection, both for password and data, is secure.
+   */
+  const uint32_t LEVEL_SECURE = 2;
+  /* @} */
+
+  /**
+   * Requests a username and a password. Implementations will commonly show a
+   * dialog with a username and password field, depending on flags also a
+   * domain field.
+   *
+   * @param aChannel
+   *        The channel that requires authentication.
+   * @param level
+   *        One of the level constants from above. See there for descriptions
+   *        of the levels.
+   * @param authInfo
+   *        Authentication information object. The implementation should fill in
+   *        this object with the information entered by the user before
+   *        returning.
+   *
+   * @retval true
+   *         Authentication can proceed using the values in the authInfo
+   *         object.
+   * @retval false
+   *         Authentication should be cancelled, usually because the user did
+   *         not provide username/password.
+   *
+   * @note   Exceptions thrown from this function will be treated like a
+   *         return value of false.
+   * @deprecated use asyncPromptAuth
+   */
+  boolean promptAuth(in nsIChannel aChannel,
+                     in uint32_t level,
+                     in nsIAuthInformation authInfo);
+
+  /**
+   * Asynchronously prompt the user for a username and password.
+   * This has largely the same semantics as promptUsernameAndPassword(),
+   * but must return immediately after calling and return the entered
+   * data in a callback.
+   *
+   * If the user closes the dialog using a cancel button or similar,
+   * the callback's nsIAuthPromptCallback::onAuthCancelled method must be
+   * called.
+   * Calling nsICancelable::cancel on the returned object SHOULD close the
+   * dialog and MUST call nsIAuthPromptCallback::onAuthCancelled on the provided
+   * callback.
+   *
+   * This implementation may:
+   *
+   *  1) Coalesce identical prompts.  This means prompts that are guaranteed to
+   *     want the same auth information from the user.  A single prompt will be
+   *     shown; then the callbacks for all the coalesced prompts will be notified
+   *     with the resulting auth information.
+   *  2) Serialize prompts that are all in the same "context" (this might mean
+   *     application-wide, for a given window, or something else depending on
+   *     the user interface) so that the user is not deluged with prompts.
+   *
+   * @throw
+   *     This method may throw any exception when the prompt fails to queue e.g
+   *     because of out-of-memory error. It must not throw when the prompt
+   *     could already be potentially shown to the user. In that case information
+   *     about the failure has to come through the callback. This way we
+   *     prevent multiple dialogs shown to the user because consumer may fall
+   *     back to synchronous prompt on synchronous failure of this method.
+   */
+  nsICancelable asyncPromptAuth(in nsIChannel aChannel,
+                                in nsIAuthPromptCallback aCallback,
+                                in nsISupports aContext,
+                                in uint32_t level,
+                                in nsIAuthInformation authInfo);
+};
diff --git a/netwerk/base/nsIAuthPromptAdapterFactory.idl b/netwerk/base/nsIAuthPromptAdapterFactory.idl
new file mode 100644
index 0000000000..e763d47146
--- /dev/null
+++ b/netwerk/base/nsIAuthPromptAdapterFactory.idl
@@ -0,0 +1,22 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIAuthPrompt;
+interface nsIAuthPrompt2;
+
+/**
+ * An interface for wrapping nsIAuthPrompt interfaces to make
+ * them usable via an nsIAuthPrompt2 interface.
+ */
+[scriptable, uuid(60e46383-bb9a-4860-8962-80d9c5c05ddc)]
+interface nsIAuthPromptAdapterFactory : nsISupports
+{
+  /**
+   * Wrap an object implementing nsIAuthPrompt so that it's usable via
+   * nsIAuthPrompt2.
+   */
+  nsIAuthPrompt2 createAdapter(in nsIAuthPrompt aPrompt);
+};
diff --git a/netwerk/base/nsIAuthPromptCallback.idl b/netwerk/base/nsIAuthPromptCallback.idl
new file mode 100644
index 0000000000..27f89f04c0
--- /dev/null
+++ b/netwerk/base/nsIAuthPromptCallback.idl
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIAuthInformation;
+
+/**
+ * Interface for callback methods for the asynchronous nsIAuthPrompt2 method.
+ * Callers MUST call exactly one method if nsIAuthPrompt2::promptPasswordAsync
+ * returns successfully. They MUST NOT call any method on this interface before
+ * promptPasswordAsync returns.
+ */
+[scriptable, uuid(bdc387d7-2d29-4cac-92f1-dd75d786631d)]
+interface nsIAuthPromptCallback : nsISupports
+{
+  /**
+   * Authentication information is available.
+   *
+   * @param aContext
+   *        The context as passed to promptPasswordAsync
+   * @param aAuthInfo
+   *        Authentication information. Must be the same object that was passed
+   *        to promptPasswordAsync.
+   *
+   * @note  Any exceptions thrown from this method should be ignored.
+   */
+  void onAuthAvailable(in nsISupports aContext,
+                       in nsIAuthInformation aAuthInfo);
+
+  /**
+   * Notification that the prompt was cancelled.
+   *
+   * @param aContext
+   *        The context that was passed to promptPasswordAsync.
+   * @param userCancel
+   *        If false, this prompt was cancelled by calling the
+   *        the cancel method on the nsICancelable; otherwise,
+   *        it was cancelled by the user.
+   */
+  void onAuthCancelled(in nsISupports aContext, in boolean userCancel);
+};
diff --git a/netwerk/base/nsIAuthPromptProvider.idl b/netwerk/base/nsIAuthPromptProvider.idl
new file mode 100644
index 0000000000..e8ff122ec2
--- /dev/null
+++ b/netwerk/base/nsIAuthPromptProvider.idl
@@ -0,0 +1,34 @@
+/* -*- Mode: idl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(bd9dc0fa-68ce-47d0-8859-6418c2ae8576)]
+interface nsIAuthPromptProvider : nsISupports
+{
+    /**
+     * Normal (non-proxy) prompt request.
+     */
+    const uint32_t PROMPT_NORMAL        = 0;
+
+    /**
+     * Proxy auth request.
+     */
+    const uint32_t PROMPT_PROXY         = 1;
+
+    /**
+     * Request a prompt interface for the given prompt reason;
+     * @throws NS_ERROR_NOT_AVAILABLE if no prompt is allowed or
+     * available for the given reason.
+     *
+     * @param aPromptReason   The reason for the auth prompt;
+     *                        one of #PROMPT_NORMAL or #PROMPT_PROXY
+     * @param iid             The desired interface, e.g.
+     *                        NS_GET_IID(nsIAuthPrompt2).
+     * @returns an nsIAuthPrompt2 interface, or throws NS_ERROR_NOT_AVAILABLE
+     */
+    void getAuthPrompt(in uint32_t aPromptReason, in nsIIDRef iid,
+                       [iid_is(iid),retval] out nsQIResult result);
+};
diff --git a/netwerk/base/nsIBackgroundFileSaver.idl b/netwerk/base/nsIBackgroundFileSaver.idl
new file mode 100644
index 0000000000..0b26852c28
--- /dev/null
+++ b/netwerk/base/nsIBackgroundFileSaver.idl
@@ -0,0 +1,183 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIArray;
+interface nsIBackgroundFileSaverObserver;
+interface nsIFile;
+
+/**
+ * Allows saving data to a file, while handling all the input/output on a
+ * background thread, including the initial file name assignment and any
+ * subsequent renaming of the target file.
+ *
+ * This interface is designed for file downloads.  Generally, they start in the
+ * temporary directory, while the user is selecting the final name.  Then, they
+ * are moved to the chosen target directory with a ".part" extension appended to
+ * the file name.  Finally, they are renamed when the download is completed.
+ *
+ * Components implementing both nsIBackgroundFileSaver and nsIStreamListener
+ * allow data to be fed using an implementation of OnDataAvailable that never
+ * blocks the calling thread.  They suspend the request that drives the stream
+ * listener in case too much data is being fed, and resume it when the data has
+ * been written.  Calling OnStopRequest does not necessarily close the target
+ * file, and the Finish method must be called to complete the operation.
+ *
+ * Components implementing both nsIBackgroundFileSaver and nsIAsyncOutputStream
+ * allow data to be fed directly to the non-blocking output stream, that however
+ * may return NS_BASE_STREAM_WOULD_BLOCK in case too much data is being fed.
+ * Closing the output stream does not necessarily close the target file, and the
+ * Finish method must be called to complete the operation.
+ *
+ * @remarks Implementations may require the consumer to always call Finish.  If
+ *          the object reference is released without calling Finish, a memory
+ *          leak may occur, and the target file might be kept locked. All
+ *          public methods of the interface may only be called from the main
+ *          thread.
+ */
+[scriptable, uuid(c43544a4-682c-4262-b407-2453d26e660d)]
+interface nsIBackgroundFileSaver : nsISupports
+{
+  /**
+   * This observer receives notifications when the target file name changes and
+   * when the operation completes, successfully or not.
+   *
+   * @remarks A strong reference to the observer is held.  Notification events
+   *          are dispatched to the thread that created the object that
+   *          implements nsIBackgroundFileSaver.
+   */
+  attribute nsIBackgroundFileSaverObserver observer;
+
+  /**
+   * An Array of Array of Array of bytes, representing a chain of
+   * X.509 certificates, the last of which signed the downloaded file.
+   * Each list may belong to a different signer and contain certificates
+   * all the way up to the root.
+   *
+   * @throws NS_ERROR_NOT_AVAILABLE
+   *         In case this is called before the onSaveComplete method has been
+   *         called to notify success, or enableSignatureInfo has not been
+   *         called.
+   */
+  readonly attribute Array<Array<Array<uint8_t> > > signatureInfo;
+
+  /**
+   * The SHA-256 hash, in raw bytes, associated with the data that was saved.
+   *
+   * In case the enableAppend method has been called, the hash computation
+   * includes the contents of the existing file, if any.
+   *
+   * @throws NS_ERROR_NOT_AVAILABLE
+   *         In case the enableSha256 method has not been called, or before the
+   *         onSaveComplete method has been called to notify success.
+   */
+  readonly attribute ACString sha256Hash;
+
+  /**
+   * Instructs the component to compute the signatureInfo of the target file,
+   * and make it available in the signatureInfo property.
+   *
+   * @remarks This must be set on the main thread before the first call to
+   *          setTarget.
+   */
+  void enableSignatureInfo();
+
+  /**
+   * Instructs the component to compute the SHA-256 hash of the target file, and
+   * make it available in the sha256Hash property.
+   *
+   * @remarks This must be set on the main thread before the first call to
+   *          setTarget.
+   */
+  void enableSha256();
+
+  /**
+   * Instructs the component to append data to the initial target file, that
+   * will be specified by the first call to the setTarget method, instead of
+   * overwriting the file.
+   *
+   * If the initial target file does not exist, this method has no effect.
+   *
+   * @remarks This must be set on the main thread before the first call to
+   *          setTarget.
+   */
+  void enableAppend();
+
+  /**
+   * Sets the name of the output file to be written.  The target can be changed
+   * after data has already been fed, in which case the existing file will be
+   * moved to the new destination.
+   *
+   * In case the specified file already exists, and this method is called for
+   * the first time, the file may be either overwritten or appended to, based on
+   * whether the enableAppend method was called.  Subsequent calls always
+   * overwrite the specified target file with the previously saved data.
+   *
+   * No file will be written until this function is called at least once.  It's
+   * recommended not to feed any data until the output file is set.
+   *
+   * If an input/output error occurs with the specified file, the save operation
+   * fails.  Failure is notified asynchronously through the observer.
+   *
+   * @param aTarget
+   *        New output file to be written.
+   * @param aKeepPartial
+   *        Indicates whether aFile should be kept as partially completed,
+   *        rather than deleted, if the operation fails or is canceled.  This is
+   *        generally set for downloads that use temporary ".part" files.
+   */
+  void setTarget(in nsIFile aTarget, in bool aKeepPartial);
+
+  /**
+   * Terminates access to the output file, then notifies the observer with the
+   * specified status code.  A failure code will force the operation to be
+   * canceled, in which case the output file will be deleted if requested.
+   *
+   * This forces the involved streams to be closed, thus no more data should be
+   * fed to the component after this method has been called.
+   *
+   * This is the last method that should be called on this object, and the
+   * target file name cannot be changed anymore after this method has been
+   * called.  Conversely, before calling this method, the file can still be
+   * renamed even if all the data has been fed.
+   *
+   * @param aStatus
+   *        Result code that determines whether the operation should succeed or
+   *        be canceled, and is notified to the observer.  If the operation
+   *        fails meanwhile for other reasons, or the observer has been already
+   *        notified of completion, this status code is ignored.
+   */
+  void finish(in nsresult aStatus);
+};
+
+[scriptable, uuid(ee7058c3-6e54-4411-b76b-3ce87b76fcb6)]
+interface nsIBackgroundFileSaverObserver : nsISupports
+{
+  /**
+   * Called when the name of the output file has been determined.  This function
+   * may be called more than once if the target file is renamed while saving.
+   *
+   * @param aSaver
+   *        Reference to the object that raised the notification.
+   * @param aTarget
+   *        Name of the file that is being written.
+   */
+  void onTargetChange(in nsIBackgroundFileSaver aSaver, in nsIFile aTarget);
+
+  /**
+   * Called when the operation completed, and the target file has been closed.
+   * If the operation succeeded, the target file is ready to be used, otherwise
+   * it might have been already deleted.
+   *
+   * @param aSaver
+   *        Reference to the object that raised the notification.
+   * @param aStatus
+   *        Result code that determines whether the operation succeeded or
+   *        failed, as well as the failure reason.
+   */
+  void onSaveComplete(in nsIBackgroundFileSaver aSaver, in nsresult aStatus);
+};
diff --git a/netwerk/base/nsIBufferedStreams.idl b/netwerk/base/nsIBufferedStreams.idl
new file mode 100644
index 0000000000..46f0112900
--- /dev/null
+++ b/netwerk/base/nsIBufferedStreams.idl
@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIInputStream.idl"
+#include "nsIOutputStream.idl"
+
+/**
+ * An input stream that reads ahead and keeps a buffer coming from another input
+ * stream so that fewer accesses to the underlying stream are necessary.
+ */
+[scriptable, builtinclass, uuid(616f5b48-da09-11d3-8cda-0060b0fc14a3)]
+interface nsIBufferedInputStream : nsIInputStream
+{
+    /**
+     * @param fillFromStream - add buffering to this stream
+     * @param bufferSize     - specifies the maximum buffer size
+     */
+    void init(in nsIInputStream fillFromStream,
+              in unsigned long bufferSize);
+
+    /**
+     * Get the wrapped data stream
+     */
+    readonly attribute nsIInputStream data;
+};
+
+/**
+ * An output stream that stores up data to write out to another output stream
+ * and does the entire write only when the buffer is full, so that fewer writes
+ * to the underlying output stream are necessary.
+ */
+[scriptable, builtinclass, uuid(6476378a-da09-11d3-8cda-0060b0fc14a3)]
+interface nsIBufferedOutputStream : nsIOutputStream
+{
+    /**
+     * @param sinkToStream - add buffering to this stream
+     * @param bufferSize   - specifies the maximum buffer size
+     */
+    void init(in nsIOutputStream sinkToStream,
+              in unsigned long bufferSize);
+
+    /**
+     * Get the wrapped data stream
+     */
+    readonly attribute nsIOutputStream data;
+};
diff --git a/netwerk/base/nsIByteRangeRequest.idl b/netwerk/base/nsIByteRangeRequest.idl
new file mode 100644
index 0000000000..4a10126d69
--- /dev/null
+++ b/netwerk/base/nsIByteRangeRequest.idl
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(C1B1F426-7E83-4759-9F88-0E1B17F49366)]
+interface nsIByteRangeRequest : nsISupports
+{
+    /**
+     * Returns true IFF this request is a byte range request, otherwise it
+     * returns false (This is effectively the same as checking to see if
+     * |startRequest| is zero and |endRange| is the content length.)
+     */
+    readonly attribute boolean isByteRangeRequest;
+
+    /**
+     * Absolute start position in remote file for this request.
+     */
+    readonly attribute long long startRange;
+
+    /**
+     * Absolute end postion in remote file for this request
+     */
+    readonly attribute long long endRange;
+};
diff --git a/netwerk/base/nsICacheInfoChannel.idl b/netwerk/base/nsICacheInfoChannel.idl
new file mode 100644
index 0000000000..b7bb44093c
--- /dev/null
+++ b/netwerk/base/nsICacheInfoChannel.idl
@@ -0,0 +1,207 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIAsyncOutputStream;
+interface nsIInputStream;
+
+%{C++
+#include "nsTArray.h"
+namespace mozilla {
+namespace net {
+class PreferredAlternativeDataTypeParams;
+}
+} // namespace mozilla
+%}
+
+[ref] native ConstPreferredAlternativeDataTypeArray(const nsTArray<mozilla::net::PreferredAlternativeDataTypeParams>);
+
+[scriptable, uuid(1fb8ccf2-5fa5-45ec-bc57-8c8022a5d0d3)]
+interface nsIInputStreamReceiver : nsISupports
+{
+  void onInputStreamReady(in nsIInputStream aStream);
+};
+
+[scriptable, builtinclass, uuid(72c34415-c6eb-48af-851f-772fa9ee5972)]
+interface nsICacheInfoChannel : nsISupports
+{
+  /**
+   * Get the number of times the cache entry has been opened. This attribute is
+   * equivalent to nsICachingChannel.cacheToken.fetchCount.
+   *
+   * @throws NS_ERROR_NOT_AVAILABLE if the cache entry or the alternate data
+   *         cache entry cannot be read.
+   */
+  readonly attribute uint32_t cacheTokenFetchCount;
+
+  /**
+   * Get expiration time from cache token. This attribute is equivalent to
+   * nsICachingChannel.cacheToken.expirationTime.
+   */
+  readonly attribute uint32_t cacheTokenExpirationTime;
+
+  /**
+   * TRUE if this channel's data is being loaded from the cache.  This value
+   * is undefined before the channel fires its OnStartRequest notification
+   * and after the channel fires its OnStopRequest notification.
+   */
+  boolean isFromCache();
+
+  /**
+   * Returns true if the channel raced the cache and network requests.
+   * In order to determine if the response is coming from the cache or the
+   * network, the consumer can check isFromCache().
+   * The method can only be called after the channel fires its OnStartRequest
+   * notification.
+   */
+  boolean isRacing();
+
+  /**
+   * The unique ID of the corresponding nsICacheEntry from which the response is
+   * retrieved. By comparing the returned value, we can judge whether the data
+   * of two distinct nsICacheInfoChannels is from the same nsICacheEntry. This
+   * scenario could be useful when verifying whether the alternative data from
+   * one nsICacheInfochannel matches the main data from another one.
+   *
+   * Note: NS_ERROR_NOT_AVAILABLE is thrown when a nsICacheInfoChannel has no
+   * valid corresponding nsICacheEntry.
+   */
+  uint64_t getCacheEntryId();
+
+  /**
+   * Set/get the cache key. This integer uniquely identifies the data in
+   * the cache for this channel.
+   *
+   * A cache key retrieved from a particular instance of nsICacheInfoChannel
+   * could be set on another instance of nsICacheInfoChannel provided the
+   * underlying implementations are compatible and provided the new
+   * channel instance was created with the same URI.  The implementation of
+   * nsICacheInfoChannel would be expected to use the cache entry identified
+   * by the cache token.  Depending on the value of nsIRequest::loadFlags,
+   * the cache entry may be validated, overwritten, or simply read.
+   *
+   * The cache key may be 0 indicating that the URI of the channel is
+   * sufficient to locate the same cache entry.  Setting a 0 cache key
+   * is likewise valid.
+   */
+  attribute unsigned long cacheKey;
+
+  /**
+   * Tells the channel to behave as if the LOAD_FROM_CACHE flag has been set,
+   * but without affecting the loads for the entire loadGroup in case of this
+   * channel being the default load group's channel.
+   */
+  attribute boolean allowStaleCacheContent;
+
+  /**
+   * Tells the priority for LOAD_CACHE is raised over LOAD_BYPASS_CACHE or
+   * LOAD_BYPASS_LOCAL_CACHE in case those flags are set at the same time.
+   */
+  attribute boolean preferCacheLoadOverBypass;
+
+  cenum PreferredAlternativeDataDeliveryType : 8 {
+    /**
+     * Do not deliver alternative data stream.
+     */
+    NONE = 0,
+
+    /**
+     * Deliver alternative data stream upon additional request.
+     */
+    ASYNC = 1,
+
+    /**
+     * Deliver alternative data stream during IPC parent/child serialization.
+     */
+    SERIALIZE = 2,
+  };
+
+  /**
+   * Tells the channel to be force validated during soft reload.
+   */
+  attribute boolean forceValidateCacheContent;
+
+  /**
+   * Calling this method instructs the channel to serve the alternative data
+   * if that was previously saved in the cache, otherwise it will serve the
+   * real data.
+   * @param type
+   *        a string identifying the alt-data format
+   * @param contentType
+   *        the contentType for which the preference applies.
+   *        an empty contentType means the preference applies for ANY contentType
+   * @param deliverAltData
+   *        if false, also if alt-data is available, the channel will deliver
+   *        the original data.
+   *
+   * The method may be called several times, with different type and contentType.
+   *
+   * Must be called before AsyncOpen.
+   */
+  void preferAlternativeDataType(in ACString type, in ACString contentType,
+                                 in nsICacheInfoChannel_PreferredAlternativeDataDeliveryType deliverAltData);
+
+  /**
+   * Get the preferred alternative data type set by preferAlternativeDataType().
+   * The returned types stand for the desired data type instead of the type of the
+   * information retrieved from the network stack.
+   */
+  [noscript, notxpcom, nostdcall]
+  ConstPreferredAlternativeDataTypeArray preferredAlternativeDataTypes();
+
+  /**
+   * Holds the type of the alternative data representation that the channel
+   * is returning.
+   * Is empty string if no alternative data representation was requested, or
+   * if the requested representation wasn't found in the cache.
+   * Can only be called during or after OnStartRequest.
+   */
+  readonly attribute ACString alternativeDataType;
+
+  /**
+   * If preferAlternativeDataType() has been called passing deliverAltData
+   * equal to false, this attribute will expose the alt-data inputStream if
+   * avaiable.
+   */
+  readonly attribute nsIInputStream alternativeDataInputStream;
+
+  /**
+   * Sometimes when the channel is delivering alt-data, we may want to somehow
+   * access the original content too. This method asynchronously opens the
+   * input stream and delivers it to the receiver.
+   */
+  void getOriginalInputStream(in nsIInputStreamReceiver aReceiver);
+
+  /**
+   * Opens and returns an output stream that a consumer may use to save an
+   * alternate representation of the data.
+   * Must be called after the OnStopRequest that delivered the real data.
+   * The consumer may choose to replace the saved alt representation.
+   * Opening the output stream will fail if there are any open input streams
+   * reading the already saved alt representation. After successfully opening
+   * an output stream, if there is an error before the entire alt data can be
+   * written successfully, the client must signal failure by passing an error
+   * code to CloseWithStatus().
+   *
+   * @param type
+   *        type of the alternative data representation
+   * @param predictedSize
+   *        Predicted size of the data that will be written. It's used to decide
+   *        whether the resulting entry would exceed size limit, in which case
+   *        an error is thrown. If the size isn't known in advance, -1 should be
+   *        passed.
+   */
+  nsIAsyncOutputStream openAlternativeOutputStream(in ACString type, in long long predictedSize);
+};
+
+%{ C++
+namespace mozilla {
+namespace net {
+
+using PreferredAlternativeDataDeliveryTypeIPC = nsICacheInfoChannel::PreferredAlternativeDataDeliveryType;
+
+}
+} // namespace mozilla
+%}
diff --git a/netwerk/base/nsICachingChannel.idl b/netwerk/base/nsICachingChannel.idl
new file mode 100644
index 0000000000..3623423ff7
--- /dev/null
+++ b/netwerk/base/nsICachingChannel.idl
@@ -0,0 +1,110 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsICacheInfoChannel.idl"
+
+interface nsIFile;
+
+/**
+ * A channel may optionally implement this interface to allow clients
+ * to affect its behavior with respect to how it uses the cache service.
+ *
+ * This interface provides:
+ *   1) Support for "stream as file" semantics (for JAR and plugins).
+ *   2) Support for "pinning" cached data in the cache (for printing and save-as).
+ *   3) Support for uniquely identifying cached data in cases when the URL
+ *      is insufficient (e.g., HTTP form submission).
+ */
+[scriptable, builtinclass, uuid(dd1d6122-5ecf-4fe4-8f0f-995e7ab3121a)]
+interface nsICachingChannel : nsICacheInfoChannel
+{
+    /**
+     * Set/get the cache token... uniquely identifies the data in the cache.
+     * Holding a reference to this token prevents the cached data from being
+     * removed.
+     *
+     * A cache token retrieved from a particular instance of nsICachingChannel
+     * could be set on another instance of nsICachingChannel provided the
+     * underlying implementations are compatible.  The implementation of
+     * nsICachingChannel would be expected to only read from the cache entry
+     * identified by the cache token and not try to validate it.
+     *
+     * The cache token can be QI'd to a nsICacheEntryInfo if more detail
+     * about the cache entry is needed (e.g., expiration time).
+     */
+    attribute nsISupports cacheToken;
+
+    /**
+     * Instructs the channel to only store the metadata of the entry, and not
+     * the content. When reading an existing entry, this automatically sets
+     * LOAD_ONLY_IF_MODIFIED flag.
+     * Must be called before asyncOpen().
+     */
+    attribute boolean cacheOnlyMetadata;
+
+    /**
+     * Tells the channel to use the pinning storage.
+     */
+    attribute boolean pin;
+
+    /**
+     * Overrides cache validation for a time specified in seconds.
+     *
+     * @param aSecondsToTheFuture
+     *
+     */
+    void forceCacheEntryValidFor(in unsigned long aSecondsToTheFuture);
+
+    /**************************************************************************
+     * Caching channel specific load flags:
+     */
+
+    /**
+     * This load flag inhibits fetching from the net.  An error of
+     * NS_ERROR_DOCUMENT_NOT_CACHED will be sent to the listener's
+     * onStopRequest if network IO is necessary to complete the request.
+     *
+     * This flag can be used to find out whether fetching this URL would
+     * cause validation of the cache entry via the network.
+     *
+     * Combining this flag with LOAD_BYPASS_LOCAL_CACHE will cause all
+     * loads to fail.
+     */
+    const unsigned long LOAD_NO_NETWORK_IO = 1 << 26;
+
+    /**
+     * This load flag causes the local cache to be skipped when fetching a
+     * request.  Unlike LOAD_BYPASS_CACHE, it does not force an end-to-end load
+     * (i.e., it does not affect proxy caches).
+     */
+    const unsigned long LOAD_BYPASS_LOCAL_CACHE = 1 << 28;
+
+    /**
+     * This load flag causes the local cache to be skipped if the request
+     * would otherwise block waiting to access the cache.
+     */
+    const unsigned long LOAD_BYPASS_LOCAL_CACHE_IF_BUSY = 1 << 29;
+
+    /**
+     * This load flag inhibits fetching from the net if the data in the cache
+     * has been evicted.  An error of NS_ERROR_DOCUMENT_NOT_CACHED will be sent
+     * to the listener's onStopRequest in this case.  This flag is set
+     * automatically when the application is offline.
+     */
+    const unsigned long LOAD_ONLY_FROM_CACHE = 1 << 30;
+
+    /**
+     * This load flag controls what happens when a document would be loaded
+     * from the cache to satisfy a call to AsyncOpen.  If this attribute is
+     * set to TRUE, then the document will not be loaded from the cache.  A
+     * stream listener can check nsICachingChannel::isFromCache to determine
+     * if the AsyncOpen will actually result in data being streamed.
+     *
+     * If this flag has been set, and the request can be satisfied via the
+     * cache, then the OnDataAvailable events will be skipped.  The listener
+     * will only see OnStartRequest followed by OnStopRequest.
+     */
+    const unsigned long LOAD_ONLY_IF_MODIFIED = 1 << 31;
+};
diff --git a/netwerk/base/nsICancelable.idl b/netwerk/base/nsICancelable.idl
new file mode 100644
index 0000000000..c558dc6e27
--- /dev/null
+++ b/netwerk/base/nsICancelable.idl
@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface provides a means to cancel an operation that is in progress.
+ */
+[scriptable, uuid(d94ac0a0-bb18-46b8-844e-84159064b0bd)]
+interface nsICancelable : nsISupports
+{
+  /**
+   * Call this method to request that this object abort whatever operation it
+   * may be performing.
+   *
+   * @param aReason
+   *        Pass a failure code to indicate the reason why this operation is
+   *        being canceled.  It is an error to pass a success code.
+   */
+  void cancel(in nsresult aReason);
+};
diff --git a/netwerk/base/nsICaptivePortalService.idl b/netwerk/base/nsICaptivePortalService.idl
new file mode 100644
index 0000000000..e4867765d7
--- /dev/null
+++ b/netwerk/base/nsICaptivePortalService.idl
@@ -0,0 +1,83 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(b5fd5629-d04c-4138-9529-9311f291ecd4)]
+interface nsICaptivePortalServiceCallback : nsISupports
+{
+  /**
+   * Invoke callbacks after captive portal detection finished.
+   */
+  void complete(in bool success, in nsresult error);
+};
+
+/**
+ * Service used for captive portal detection.
+ * The service is only active in the main process. It is also available in the
+ * content process, but only to mirror the captive portal state from the main
+ * process.
+ */
+[scriptable, uuid(bdbe0555-fc3d-4f7b-9205-c309ceb2d641)]
+interface nsICaptivePortalService : nsISupports
+{
+  const long UNKNOWN          = 0;
+  const long NOT_CAPTIVE      = 1;
+  const long UNLOCKED_PORTAL  = 2;
+  const long LOCKED_PORTAL    = 3;
+
+  /**
+   * Called from XPCOM to trigger a captive portal recheck.
+   * A network request will only be performed if no other checks are currently
+   * ongoing.
+   * Will not do anything if called in the content process.
+   */
+  void recheckCaptivePortal();
+
+  /**
+   * Returns the state of the captive portal.
+   */
+  readonly attribute long state;
+
+%{C++
+  int32_t State() {
+    int32_t result = nsICaptivePortalService::UNKNOWN;
+    GetState(&result);
+    return result;
+  }
+%}
+
+  /**
+   * Returns the time difference between NOW and the last time a request was
+   * completed in milliseconds.
+   */
+  readonly attribute unsigned long long lastChecked;
+};
+
+%{C++
+/**
+ * This observer notification will be emitted when the captive portal state
+ * changes. After receiving it, the ContentParent will send an IPC message
+ * to the ContentChild, which will set the state in the captive portal service
+ * in the child.
+ */
+#define NS_IPC_CAPTIVE_PORTAL_SET_STATE "ipc:network:captive-portal-set-state"
+
+/**
+ * This notification will be emitted when the captive portal service has
+ * determined that we can connect to the internet.
+ * The service will pass either "captive" if there is an unlocked captive portal
+ * present, or "clear" if no captive portal was detected.
+ * Note: this notification only gets sent in the parent process.
+ */
+#define NS_CAPTIVE_PORTAL_CONNECTIVITY "network:captive-portal-connectivity"
+
+/**
+ * Similar to NS_CAPTIVE_PORTAL_CONNECTIVITY but only gets dispatched when
+ * the connectivity changes from UNKNOWN to NOT_CAPTIVE or from LOCKED_PORTAL
+ * to UNLOCKED_PORTAL.
+ */
+#define NS_CAPTIVE_PORTAL_CONNECTIVITY_CHANGED "network:captive-portal-connectivity-changed"
+
+%}
diff --git a/netwerk/base/nsIChannel.idl b/netwerk/base/nsIChannel.idl
new file mode 100644
index 0000000000..2269c4faa8
--- /dev/null
+++ b/netwerk/base/nsIChannel.idl
@@ -0,0 +1,405 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+#include "nsILoadInfo.idl"
+
+interface nsIInputStream;
+interface nsIInterfaceRequestor;
+interface nsIStreamListener;
+interface nsITransportSecurityInfo;
+interface nsIURI;
+
+%{C++
+#include "nsCOMPtr.h"
+%}
+
+/**
+ * The nsIChannel interface allows clients to construct "GET" requests for
+ * specific protocols, and manage them in a uniform way.  Once a channel is
+ * created (via nsIIOService::newChannel), parameters for that request may
+ * be set by using the channel attributes, or by QI'ing to a subclass of
+ * nsIChannel for protocol-specific parameters.  Then, the URI can be fetched
+ * by calling nsIChannel::open or nsIChannel::asyncOpen.
+ *
+ * After a request has been completed, the channel is still valid for accessing
+ * protocol-specific results.  For example, QI'ing to nsIHttpChannel allows
+ * response headers to be retrieved for the corresponding http transaction.
+ *
+ * This interface must be used only from the XPCOM main thread.
+ */
+[scriptable, uuid(2c389865-23db-4aa7-9fe5-60cc7b00697e)]
+interface nsIChannel : nsIRequest
+{
+    /**
+     * The original URI used to construct the channel. This is used in
+     * the case of a redirect or URI "resolution" (e.g. resolving a
+     * resource: URI to a file: URI) so that the original pre-redirect
+     * URI can still be obtained.  This is never null.  Attempts to
+     * set it to null must throw.
+     *
+     * NOTE: this is distinctly different from the http Referer (referring URI),
+     * which is typically the page that contained the original URI (accessible
+     * from nsIHttpChannel).
+     *
+     * NOTE: originalURI isn't yet set on the new channel when
+     * asyncOnChannelRedirect is called.
+     */
+    attribute nsIURI originalURI;
+
+    /**
+     * The URI corresponding to the channel.  Its value is immutable.
+     */
+    readonly attribute nsIURI URI;
+
+    /**
+     * The owner, corresponding to the entity that is responsible for this
+     * channel.  Used by the security manager to grant or deny privileges to
+     * mobile code loaded from this channel.
+     *
+     * NOTE: this is a strong reference to the owner, so if the owner is also
+     * holding a strong reference to the channel, care must be taken to
+     * explicitly drop its reference to the channel.
+     */
+    attribute nsISupports owner;
+
+    /**
+     * The notification callbacks for the channel.  This is set by clients, who
+     * wish to provide a means to receive progress, status and protocol-specific
+     * notifications.  If this value is NULL, the channel implementation may use
+     * the notification callbacks from its load group.  The channel may also
+     * query the notification callbacks from its load group if its notification
+     * callbacks do not supply the requested interface.
+     *
+     * Interfaces commonly requested include: nsIProgressEventSink, nsIPrompt,
+     * and nsIAuthPrompt/nsIAuthPrompt2.
+     *
+     * When the channel is done, it must not continue holding references to
+     * this object.
+     *
+     * NOTE: A channel implementation should take care when "caching" an
+     * interface pointer queried from its notification callbacks.  If the
+     * notification callbacks are changed, then a cached interface pointer may
+     * become invalid and may therefore need to be re-queried.
+     */
+    attribute nsIInterfaceRequestor notificationCallbacks;
+
+    /**
+     * Transport-level security information (if any) corresponding to the
+     * channel.
+     *
+     * NOTE: In some circumstances TLS information is propagated onto
+     * non-nsIHttpChannel objects to indicate that their contents were likely
+     * delivered over TLS all the same.
+     *
+     * FIXME(bz, bug 1528449) is that still true now that
+     * document.open() doesn't do this?
+     */
+    readonly attribute nsITransportSecurityInfo securityInfo;
+
+    /**
+     * The MIME type of the channel's content if available.
+     *
+     * NOTE: the content type can often be wrongly specified (e.g., wrong file
+     * extension, wrong MIME type, wrong document type stored on a server, etc.),
+     * and the caller most likely wants to verify with the actual data.
+     *
+     * Setting contentType before the channel has been opened provides a hint
+     * to the channel as to what the MIME type is.  The channel may ignore this
+     * hint in deciding on the actual MIME type that it will report.
+     *
+     * Setting contentType after onStartRequest has been fired or after open()
+     * is called will override the type determined by the channel.
+     *
+     * Setting contentType between the time that asyncOpen() is called and the
+     * time when onStartRequest is fired has undefined behavior at this time.
+     *
+     * The value of the contentType attribute is a lowercase string.  A value
+     * assigned to this attribute will be parsed and normalized as follows:
+     *  1- any parameters (delimited with a ';') will be stripped.
+     *  2- if a charset parameter is given, then its value will replace the
+     *     the contentCharset attribute of the channel.
+     *  3- the stripped contentType will be lowercased.
+     * Any implementation of nsIChannel must follow these rules.
+     */
+    attribute ACString contentType;
+
+    /**
+     * The character set of the channel's content if available and if applicable.
+     * This attribute only applies to textual data.
+     *
+     * The value of the contentCharset attribute is a mixedcase string.
+     */
+    attribute ACString contentCharset;
+
+    /**
+     * The length of the data associated with the channel if available.  A value
+     * of -1 indicates that the content length is unknown. Note that this is a
+     * 64-bit value and obsoletes the "content-length" property used on some
+     * channels.
+     */
+    attribute int64_t contentLength;
+
+    /**
+     * Synchronously open the channel.
+     *
+     * @return blocking input stream to the channel's data.
+     *
+     * NOTE: nsIChannel implementations are not required to implement this
+     * method.  Moreover, since this method may block the calling thread, it
+     * should not be called on a thread that processes UI events.  Like any
+     * other nsIChannel method it must not be called on any thread other
+     * than the XPCOM main thread.
+     *
+     * NOTE: Implementations should throw NS_ERROR_IN_PROGRESS if the channel
+     * is reopened.
+     */
+    nsIInputStream open();
+
+    /**
+     * Asynchronously open this channel.  Data is fed to the specified stream
+     * listener as it becomes available.  The stream listener's methods are
+     * called on the thread that calls asyncOpen and are not called until
+     * after asyncOpen returns.  If asyncOpen returns successfully, the
+     * channel promises to call at least onStartRequest and onStopRequest.
+     *
+     * If the nsIRequest object passed to the stream listener's methods is not
+     * this channel, an appropriate onChannelRedirect notification needs to be
+     * sent to the notification callbacks before onStartRequest is called.
+     * Once onStartRequest is called, all following method calls on aListener
+     * will get the request that was passed to onStartRequest.
+     *
+     * If the channel's and loadgroup's notification callbacks do not provide
+     * an nsIChannelEventSink when onChannelRedirect would be called, that's
+     * equivalent to having called onChannelRedirect.
+     *
+     * If asyncOpen returns successfully, the channel is responsible for
+     * keeping itself alive until it has called onStopRequest on aListener or
+     * called onChannelRedirect.
+     *
+     * Implementations are allowed to synchronously add themselves to the
+     * associated load group (if any).
+     *
+     * NOTE: Implementations should throw NS_ERROR_ALREADY_OPENED if the
+     * channel is reopened.
+     * NOTE: Implementations should throw an error if the channel has been
+     * cancelled prior asyncOpen being called.
+     *
+     * @param aListener the nsIStreamListener implementation
+     * @see nsIChannelEventSink for onChannelRedirect
+     */
+    void asyncOpen(in nsIStreamListener aListener);
+
+    /**
+     * True if the channel has been canceled.
+     */
+    [must_use] readonly attribute boolean canceled;
+
+    /**************************************************************************
+     * Channel specific load flags:
+     *
+     * Bits 16-31 are reserved for future use by this interface or one of its
+     * derivatives (e.g., see nsICachingChannel).
+     */
+
+    /**
+     * Set (e.g., by the docshell) to indicate whether or not the channel
+     * corresponds to a document URI.
+     * While setting this flag is sufficient to mark a channel as a document
+     * load, _checking_ whether the channel is a document load requires the use
+     * of the new channel.isDocument
+     */
+    const unsigned long LOAD_DOCUMENT_URI = 1 << 16;
+
+    /**
+     * If the end consumer for this load has been retargeted after discovering
+     * its content, this flag will be set:
+     */
+    const unsigned long LOAD_RETARGETED_DOCUMENT_URI = 1 << 17;
+
+    /**
+     * This flag is set to indicate that this channel is replacing another
+     * channel.  This means that:
+     *
+     * 1) the stream listener this channel will be notifying was initially
+     *    passed to the asyncOpen method of some other channel
+     *
+     *   and
+     *
+     * 2) this channel's URI is a better identifier of the resource being
+     *    accessed than this channel's originalURI.
+     *
+     * This flag can be set, for example, for redirects or for cases when a
+     * single channel has multiple parts to it (and thus can follow
+     * onStopRequest with another onStartRequest/onStopRequest pair, each pair
+     * for a different request).
+     */
+    const unsigned long LOAD_REPLACE = 1 << 18;
+
+    /**
+     * Set (e.g., by the docshell) to indicate whether or not the channel
+     * corresponds to an initial document URI load (e.g., link click).
+     */
+    const unsigned long LOAD_INITIAL_DOCUMENT_URI = 1 << 19;
+
+    /**
+     * Set (e.g., by the URILoader) to indicate whether or not the end consumer
+     * for this load has been determined.
+     */
+    const unsigned long LOAD_TARGETED = 1 << 20;
+
+    /**
+     * If this flag is set, the channel should call the content sniffers as
+     * described in nsNetCID.h about NS_CONTENT_SNIFFER_CATEGORY.
+     *
+     * Note: Channels may ignore this flag; however, new channel implementations
+     * should only do so with good reason.
+     */
+    const unsigned long LOAD_CALL_CONTENT_SNIFFERS = 1 << 21;
+
+    /**
+     * This flag tells the channel to bypass URL classifier service check
+     * when opening the channel.
+     */
+    const unsigned long LOAD_BYPASS_URL_CLASSIFIER = 1 << 22;
+
+    /**
+     * If this flag is set, the media-type content sniffer will be allowed
+     * to override any server-set content-type. Otherwise it will only
+     * be allowed to override "no content type" and application/octet-stream.
+     */
+    const unsigned long LOAD_MEDIA_SNIFFER_OVERRIDES_CONTENT_TYPE = 1 << 23;
+
+    /**
+     * Set to let explicitely provided credentials be used over credentials
+     * we have cached previously. In some situations like form login using HTTP
+     * auth via XMLHttpRequest we need to let consumers override the cached
+     * credentials explicitely. For form login 403 response instead of 401 is
+     * usually used to prevent an auth dialog. But any code other then 401/7
+     * will leave original credentials in the cache and there is then no way
+     * to override them for the same user name.
+     */
+    const unsigned long LOAD_EXPLICIT_CREDENTIALS = 1 << 24;
+
+    /**
+     * Set to force bypass of any service worker interception of the channel.
+     */
+    const unsigned long LOAD_BYPASS_SERVICE_WORKER = 1 << 25;
+
+    // nsICachingChannel load flags begin at bit 26.
+
+    /**
+     * Access to the type implied or stated by the Content-Disposition header
+     * if available and if applicable. This allows determining inline versus
+     * attachment.
+     *
+     * Setting contentDisposition provides a hint to the channel about the
+     * disposition.  If the hint is DISPOSITION_ATTACHMENT and a normal
+     * Content-Disposition header is present, the hinted value will always be
+     * used. If the hint is DISPOSITION_FORCE_INLINE then the disposition is
+     * inline and the header is not used. The value from Content-Disposition
+     * header is only used when the hinted value is not DISPOSITION_INLINE or
+     * DISPOSITION_FORCE_INLINE.
+     * If the header is missing the hinted value will be used if set.
+     *
+     * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header either
+     * doesn't exist for this type of channel or is empty, and return
+     * DISPOSITION_ATTACHMENT if an invalid/noncompliant value is present.
+     */
+    attribute unsigned long contentDisposition;
+    const unsigned long DISPOSITION_INLINE = 0;
+    const unsigned long DISPOSITION_ATTACHMENT = 1;
+    const unsigned long DISPOSITION_FORCE_INLINE = 2;
+
+    /**
+     * Access to the filename portion of the Content-Disposition header if
+     * available and if applicable. This allows getting the preferred filename
+     * without having to parse it out yourself.
+     *
+     * Setting contentDispositionFilename provides a hint to the channel about
+     * the disposition.  If a normal Content-Disposition header is present its
+     * value will always be used.  If it is missing the hinted value will be
+     * used if set.
+     *
+     * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header doesn't
+     * exist for this type of channel, if the header is empty, if the header
+     * doesn't contain a filename portion, or the value of the filename
+     * attribute is empty/missing.
+     */
+    attribute AString contentDispositionFilename;
+
+    /**
+     * Access to the raw Content-Disposition header if available and applicable.
+     *
+     * Implementations should throw NS_ERROR_NOT_AVAILABLE if the header either
+     * doesn't exist for this type of channel or is empty.
+     *
+     * @deprecated Use contentDisposition/contentDispositionFilename instead.
+     */
+    readonly attribute ACString contentDispositionHeader;
+
+    /**
+     * The LoadInfo object contains information about a network load, why it
+     * was started, and how we plan on using the resulting response.
+     * If a network request is redirected, the new channel will receive a new
+     * LoadInfo object. The new object will contain mostly the same
+     * information as the pre-redirect one, but updated as appropriate.
+     * For detailed information about what parts of LoadInfo are updated on
+     * redirect, see documentation on individual properties.
+     */
+    attribute nsILoadInfo loadInfo;
+
+    /**
+     * Returns true if the channel is used to create a document.
+     * It returns true if the loadFlags have LOAD_DOCUMENT_URI set, or if
+     * LOAD_HTML_OBJECT_DATA is set and the channel has the appropriate
+     * MIME type.
+     * Note: May have the wrong value if called before OnStartRequest as we
+     * don't know the MIME type yet.
+     */
+    readonly attribute bool isDocument;
+
+%{ C++
+  inline bool IsDocument()
+  {
+    bool isDocument = false;
+    if (NS_SUCCEEDED(GetIsDocument(&isDocument)) && isDocument) {
+      return true;
+    }
+    return false;
+  }
+
+  inline already_AddRefed<nsILoadInfo> LoadInfo()
+  {
+    nsCOMPtr<nsILoadInfo> result;
+    mozilla::DebugOnly<nsresult> rv = GetLoadInfo(getter_AddRefs(result));
+    MOZ_ASSERT(NS_SUCCEEDED(rv) && result);
+    return result.forget();
+  }
+%}
+
+};
+
+[builtinclass, scriptable, uuid(1ebbff64-d742-4f4a-aad5-4df2d1eb937a)]
+interface nsIIdentChannel : nsIChannel
+{
+    /**
+     * Unique ID of the channel, shared between parent and child. Needed if
+     * the channel activity needs to be monitored across process boundaries,
+     * like in devtools net monitor. See bug 1274556.
+     */
+    [must_use] attribute uint64_t channelId;
+
+%{ C++
+  inline uint64_t ChannelId()
+  {
+    uint64_t value = 0;
+    if (NS_SUCCEEDED(GetChannelId(&value))) {
+      return value;
+    }
+    return 0;
+  }
+%}
+};
diff --git a/netwerk/base/nsIChannelEventSink.idl b/netwerk/base/nsIChannelEventSink.idl
new file mode 100644
index 0000000000..1f77cfb466
--- /dev/null
+++ b/netwerk/base/nsIChannelEventSink.idl
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:set ts=4 sw=4 sts=4 cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+interface nsIAsyncVerifyRedirectCallback;
+
+/**
+ * Implement this interface to receive control over various channel events.
+ * Channels will try to get this interface from a channel's
+ * notificationCallbacks or, if not available there, from the loadGroup's
+ * notificationCallbacks.
+ *
+ * These methods are called before onStartRequest.
+ */
+[scriptable, uuid(0197720d-37ed-4e75-8956-d0d296e4d8a6)]
+interface nsIChannelEventSink : nsISupports
+{
+    /**
+     * This is a temporary redirect. New requests for this resource should
+     * continue to use the URI of the old channel.
+     *
+     * The new URI may be identical to the old one.
+     */
+    const unsigned long REDIRECT_TEMPORARY = 1 << 0;
+
+    /**
+     * This is a permanent redirect. New requests for this resource should use
+     * the URI of the new channel (This might be an HTTP 301 reponse).
+     * If this flag is not set, this is a temporary redirect.
+     *
+     * The new URI may be identical to the old one.
+     */
+    const unsigned long REDIRECT_PERMANENT = 1 << 1;
+
+    /**
+     * This is an internal redirect, i.e. it was not initiated by the remote
+     * server, but is specific to the channel implementation.
+     *
+     * The new URI may be identical to the old one.
+     */
+    const unsigned long REDIRECT_INTERNAL = 1 << 2;
+
+    /**
+     * This is a special-cased redirect coming from hitting HSTS upgrade
+     * redirect from http to https only.  In some cases this type of redirect
+     * may be considered as safe despite not being the-same-origin redirect.
+     */
+    const unsigned long REDIRECT_STS_UPGRADE = 1 << 3;
+
+    /**
+     * Called when a redirect occurs. This may happen due to an HTTP 3xx status
+     * code. The purpose of this method is to notify the sink that a redirect
+     * is about to happen, but also to give the sink the right to veto the
+     * redirect by throwing or passing a failure-code in the callback.
+     *
+     * Note that vetoing the redirect simply means that |newChannel| will not
+     * be opened. It is important to understand that |oldChannel| will continue
+     * loading as if it received a HTTP 200, which includes notifying observers
+     * and possibly display or process content attached to the HTTP response.
+     * If the sink wants to prevent this loading it must explicitly deal with
+     * it, e.g. by calling |oldChannel->Cancel()|
+     *
+     * There is a certain freedom in implementing this method:
+     *
+     * If the return-value indicates success, a callback on |callback| is
+     * required. This callback can be done from within asyncOnChannelRedirect
+     * (effectively making the call synchronous) or at some point later
+     * (making the call asynchronous). Repeat: A callback must be done
+     * if this method returns successfully.
+     *
+     * If the return value indicates error (method throws an exception)
+     * the redirect is vetoed and no callback must be done. Repeat: No
+     * callback must be done if this method throws!
+     *
+     * NOTE: originalURI isn't yet set on the new channel when
+     * asyncOnChannelRedirect is called.
+     *
+     * @see nsIAsyncVerifyRedirectCallback::onRedirectVerifyCallback()
+     *
+     * @param oldChannel
+     *        The channel that's being redirected.
+     * @param newChannel
+     *        The new channel. This channel is not opened yet.
+     * @param flags
+     *        Flags indicating the type of redirect. A bitmask consisting
+     *        of flags from above.
+     *        One of REDIRECT_TEMPORARY and REDIRECT_PERMANENT will always be
+     *        set.
+     * @param callback
+     *        Object to inform about the async result of this method
+     *
+     * @throw <any> Throwing an exception will cause the redirect to be
+     *        cancelled
+     */
+    void asyncOnChannelRedirect(in nsIChannel oldChannel,
+                                in nsIChannel newChannel,
+                                in unsigned long flags,
+                                in nsIAsyncVerifyRedirectCallback callback);
+};
diff --git a/netwerk/base/nsIChildChannel.idl b/netwerk/base/nsIChildChannel.idl
new file mode 100644
index 0000000000..3b57013536
--- /dev/null
+++ b/netwerk/base/nsIChildChannel.idl
@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIStreamListener;
+
+/**
+ * Implemented by content side of IPC protocols.
+ */
+
+[scriptable, uuid(c45b92ae-4f07-41dd-b0ef-aa044eeabb1e)]
+interface nsIChildChannel : nsISupports
+{
+  /**
+   * Create the chrome side of the IPC protocol and join an existing 'real'
+   * channel on the parent process.  The id is provided by
+   * nsIRedirectChannelRegistrar on the chrome process and pushed to the child
+   * protocol as an argument to event starting a redirect.
+   *
+   * Primarilly used in HttpChannelChild::Redirect1Begin on a newly created
+   * child channel, where the new channel is intended to be created on the
+   * child process.
+   */
+  void connectParent(in uint32_t registrarId);
+
+  /**
+   * As AsyncOpen is called on the chrome process for redirect target channels,
+   * we have to inform the child side of the protocol of that fact by a special
+   * method.
+   */
+  void completeRedirectSetup(in nsIStreamListener aListener);
+};
diff --git a/netwerk/base/nsIClassOfService.idl b/netwerk/base/nsIClassOfService.idl
new file mode 100644
index 0000000000..5426eabbcc
--- /dev/null
+++ b/netwerk/base/nsIClassOfService.idl
@@ -0,0 +1,103 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsIClassOfService.idl
+ *
+ * Used to express class dependencies and characteristics - complimentary to
+ * nsISupportsPriority which is used to express weight
+ *
+ * Channels that implement this interface may make use of this
+ * information in different ways.
+ */
+
+// convenience class for passing around the class of service
+%{C++
+namespace mozilla::net {
+class ClassOfService;
+}
+%}
+native ClassOfService(mozilla::net::ClassOfService);
+
+[scriptable, uuid(1ccb58ec-5e07-4cf9-a30d-ac5490d23b41)]
+interface nsIClassOfService : nsISupports
+{
+  attribute unsigned long classFlags;
+  attribute bool incremental;
+
+  void clearClassFlags(in unsigned long flags);
+  void addClassFlags(in unsigned long flags);
+  void setClassOfService(in ClassOfService s);
+
+  // All these flags have a (de)prioritization effect.
+
+  // In the HTTP/1 world the priority is considered for all requests inside a so
+  // called 'Request Context' which is a context common to all sub-resources
+  // belonging to a single top level window (RequestContextService). Requests
+  // marked with the Leader flag are blocking (preventing from being sent to the
+  // server) all other resource loads except those marked with the Unblocked
+  // flag.  Other classes run in parallel - neither being blocked no ;r blocking.
+  // The Leader flag is used only for <head> blocking resources (sync and
+  // defer javascript resources and stylesheets.) Purpose is to deliver these
+  // first-paint and domcontentloaded blocking resources as soon as possbile.
+
+  // In the HTTP/2 world it's different. Priorities are done only per HTTP/2
+  // session, normally we have one session per one origin (including origin
+  // attributes!) Requests are dispatched (sent) immediately on an HTTP/2
+  // session. Each session has artificial streams (groups) relating to the class
+  // of service flags (Leader, Other, Background, Speculative, Follower,
+  // UrgentStart), each such a stream is given a different weight (only way to
+  // give a stream a priority in HTTP/2) reflecting the desired request group
+  // priority.  Actual request streams are then dependent on these artificial
+  // streams (groups). nsISupportsPriority of each request is passed as a weight
+  // on the HTTP/2 stream to prioritize streams in the same group. A stream can
+  // also be dependent on other stream. We have dependency of Followers on
+  // Leaders, hence everything set the Follower flag should be processed by the
+  // server after Leaders. Same for Speculative being dependent on Background. The
+  // tree is created and used here:
+  // https://searchfox.org/mozilla-central/rev/cc280c4be94ff8cf64a27cc9b3d6831ffa49fa45/netwerk/protocol/http/Http2Session.cpp#1053-1070
+  // https://searchfox.org/mozilla-central/rev/cc280c4be94ff8cf64a27cc9b3d6831ffa49fa45/netwerk/protocol/http/Http2Stream.cpp#1338
+  // For detailed description of how HTTP/2 server should handle the priorities
+  // and dependencies see:
+  // https://developers.google.com/web/fundamentals/performance/http2/#stream_prioritization
+  // Please note that the dependecies and weights we are sending to the server
+  // are only suggestions, the server may completely ignore it.
+
+  // Leaders (should) block all other resources except Unblocked.  This flag
+  // also priortizes HTTP cache reading queue by blocking all other cache
+  // requests.
+  const unsigned long Leader = 1 << 0;
+  // The Follower flag is currently unused!
+  const unsigned long Follower = 1 << 1;
+  // The Speculative flag is currently unused!
+  const unsigned long Speculative = 1 << 2;
+  // The Background flag is currently only used for Beacon.
+  const unsigned long Background = 1 << 3;
+  // Requests marked with this flag are not blocked by Leaders.  This is mainly
+  // used for probing-like XMLHttpRequests that may block delivery of head
+  // blocking resources, e.g. CSS files tailored for the UA.
+  const unsigned long Unblocked = 1 << 4;
+  // Throttleable flag allows response throttling of the resource load. Note
+  // that this functionality is currently disabled.
+  const unsigned long Throttleable = 1 << 5;
+  // UrgentStart makes the request temporarily extend HTTP/1 connection
+  // parallelism limits.  Used mainly for navigational requests (top level html)
+  // and any request considered coming from a user interaction to make reaction
+  // of the browser as fast as possible and not blocked.
+  const unsigned long UrgentStart = 1 << 6;
+  // Specifically disables throttling under any circumstances, used for media
+  // responses mainly.
+  const unsigned long DontThrottle = 1 << 7;
+  // Enforce tailing on this load; any of Leader, Unblocked, UrgentStart,
+  // TailForbidden overrule this flag (disable tailing.)
+  const unsigned long Tail = 1 << 8;
+  // Tailing may be engaged regardless if the load is marked Unblocked when some
+  // other conditions are met later, like when the load is found to be a
+  // tracker.
+  const unsigned long TailAllowed = 1 << 9;
+  // Tailing not allowed under any circumstances or combination of flags.
+  const unsigned long TailForbidden = 1 << 10;
+};
diff --git a/netwerk/base/nsIClassifiedChannel.idl b/netwerk/base/nsIClassifiedChannel.idl
new file mode 100644
index 0000000000..482c524cbf
--- /dev/null
+++ b/netwerk/base/nsIClassifiedChannel.idl
@@ -0,0 +1,201 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsIClassifiedChannel
+ *
+ * A channel may optionally implement this interface if it carries classified
+ * result information of channel classifier. The information contains, for
+ * example, the name of matched table and the name of matched provider.
+ */
+[builtinclass, scriptable, uuid(70cf6091-a1de-4aa8-8224-058f8964be31)]
+interface nsIClassifiedChannel : nsISupports
+{
+  /**
+   * Sets matched info of the classified channel.
+   *
+   * @param aList
+   *        Name of the Safe Browsing list that matched (e.g. goog-phish-shavar).
+   * @param aProvider
+   *        Name of the Safe Browsing provider that matched (e.g. google)
+   * @param aFullHash
+   *        Full hash of URL that matched Safe Browsing list.
+   */
+  void setMatchedInfo(in ACString aList,
+                      in ACString aProvider,
+                      in ACString aFullHash);
+
+  /**
+   * Name of the list that matched
+   */
+  readonly attribute ACString matchedList;
+
+  /**
+   * Name of provider that matched
+   */
+  readonly attribute ACString matchedProvider;
+
+  /**
+   * Full hash of URL that matched
+   */
+  readonly attribute ACString matchedFullHash;
+
+  /**
+   * Sets matched tracking info of the classified channel.
+   *
+   * @param aLists
+   *        Name of the Tracking Protection list that matched (e.g. content-track-digest256).
+   * @param aFullHash
+   *        Full hash of URLs that matched Tracking Protection list.
+   */
+  void setMatchedTrackingInfo(in Array<ACString> aLists,
+                              in Array<ACString> aFullHashes);
+
+  /**
+   * Name of the lists that matched
+   */
+  readonly attribute Array<ACString> matchedTrackingLists;
+
+  /**
+   * Full hash of URLs that matched
+   */
+  readonly attribute Array<ACString> matchedTrackingFullHashes;
+
+  /**
+   * Returns the classification flags if the channel has been processed by
+   * URL-Classifier features and is considered first-party.
+   */
+  [infallible] readonly attribute unsigned long firstPartyClassificationFlags;
+
+  /**
+   * Returns the classification flags if the channel has been processed by
+   * URL-Classifier features and is considered third-party with the top
+   * window URI.
+   */
+  [infallible] readonly attribute unsigned long thirdPartyClassificationFlags;
+
+  /*
+    * Returns the classification flags if the channel has been processed by
+    * URL-Classifier features. This value is equal to
+    * "firstPartyClassificationFlags || thirdPartyClassificationFlags".
+    *
+    * Note that top-level channels could be classified as well.
+    * In order to identify third-party resources specifically, use
+    * classificationThirdPartyFlags;
+    */
+  [infallible] readonly attribute unsigned long classificationFlags;
+
+  cenum ClassificationFlags : 32 {
+    /**
+     * The resource is on the fingerprinting list.
+     */
+    CLASSIFIED_FINGERPRINTING = 0x0001,
+    CLASSIFIED_FINGERPRINTING_CONTENT = 0x0080,
+
+    /**
+     * The resource is on the cryptomining list.
+     */
+    CLASSIFIED_CRYPTOMINING = 0x0002,
+    CLASSIFIED_CRYPTOMINING_CONTENT = 0x0100,
+
+    /**
+     * The following are about tracking annotation and are available only
+     * if the privacy.trackingprotection.annotate_channels pref.
+     * CLASSIFIED_TRACKING is set if we are not able to identify the
+     * type of classification.
+     */
+    CLASSIFIED_TRACKING = 0x0004,
+    CLASSIFIED_TRACKING_AD = 0x0008,
+    CLASSIFIED_TRACKING_ANALYTICS = 0x0010,
+    CLASSIFIED_TRACKING_SOCIAL = 0x0020,
+    CLASSIFIED_TRACKING_CONTENT = 0x0040,
+
+    /**
+     * The following are about social tracking.
+     */
+    CLASSIFIED_SOCIALTRACKING = 0x0200,
+    CLASSIFIED_SOCIALTRACKING_FACEBOOK = 0x0400,
+    CLASSIFIED_SOCIALTRACKING_LINKEDIN = 0x0800,
+    CLASSIFIED_SOCIALTRACKING_TWITTER = 0x1000,
+
+    /**
+     * The following are about email tracking.
+     */
+    CLASSIFIED_EMAILTRACKING = 0x2000,
+    CLASSIFIED_EMAILTRACKING_CONTENT = 0x4000,
+
+    /**
+     * This is exposed to help to identify tracking classification using the
+     * basic lists.
+     */
+    CLASSIFIED_ANY_BASIC_TRACKING = CLASSIFIED_TRACKING |
+      CLASSIFIED_TRACKING_AD | CLASSIFIED_TRACKING_ANALYTICS |
+      CLASSIFIED_TRACKING_SOCIAL | CLASSIFIED_FINGERPRINTING,
+
+    /**
+     * This is exposed to help to identify tracking classification using the
+     * strict lists.
+     */
+    CLASSIFIED_ANY_STRICT_TRACKING = CLASSIFIED_ANY_BASIC_TRACKING |
+      CLASSIFIED_TRACKING_CONTENT | CLASSIFIED_FINGERPRINTING_CONTENT,
+
+    /**
+     * This is exposed to help to identify social tracking classification
+     * flags.
+     */
+    CLASSIFIED_ANY_SOCIAL_TRACKING = CLASSIFIED_SOCIALTRACKING |
+      CLASSIFIED_SOCIALTRACKING_FACEBOOK |
+      CLASSIFIED_SOCIALTRACKING_LINKEDIN | CLASSIFIED_SOCIALTRACKING_TWITTER,
+  };
+
+  /**
+   * Returns true  if the channel has been processed by URL-Classifier features
+   * and is considered third-party with the top window URI, and if it has loaded
+   * a resource that is classified as a tracker.
+   *
+   * This is a helper attribute which returns the same value of
+   * (thirdPartyClassificationFlags & CLASSIFIED_ANY_BASIC_TRACKING) or
+   * (thirdPartyClassificationFlags & CLASSIFIED_ANY_STRICT_TRACKING) or
+   * (thirdPartyClassificationFlags & CLASSIFIED_ANY_SOCIAL_TRACKING)
+   */
+  boolean isThirdPartyTrackingResource();
+
+%{ C++
+  inline bool IsThirdPartyTrackingResource()
+  {
+    bool value = false;
+    if (NS_SUCCEEDED(IsThirdPartyTrackingResource(&value)) && value) {
+      return true;
+    }
+    return false;
+  }
+%}
+
+  /**
+   * Returns true if the channel has loaded a 3rd party resource that is
+   * classified as a social tracker.
+   *
+   * This is a helper attribute which returns the same value of
+   * (classificationFlags & CLASSIFIED_ANY_SOCIAL_TRACKING)
+   *
+   * Note that top-level channels could be marked as tracking
+   * resources. In order to identify third-party social tracking resources
+   * specifically, check the flags manually or add a new helper here.
+   */
+  boolean isThirdPartySocialTrackingResource();
+
+%{ C++
+  inline bool IsThirdPartySocialTrackingResource()
+  {
+    bool value = false;
+    if (NS_SUCCEEDED(IsThirdPartySocialTrackingResource(&value)) && value) {
+      return true;
+    }
+    return false;
+  }
+%}
+};
diff --git a/netwerk/base/nsIContentSniffer.idl b/netwerk/base/nsIContentSniffer.idl
new file mode 100644
index 0000000000..f9052b8e60
--- /dev/null
+++ b/netwerk/base/nsIContentSniffer.idl
@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIRequest;
+
+/**
+ * Content sniffer interface. Components implementing this interface can
+ * determine a MIME type from a chunk of bytes.
+ */
+[scriptable, uuid(a5772d1b-fc63-495e-a169-96e8d3311af0)]
+interface nsIContentSniffer : nsISupports
+{
+  /**
+   * Given a chunk of data, determines a MIME type. Information from the given
+   * request may be used in order to make a better decision.
+   *
+   * @param aRequest The request where this data came from. May be null.
+   * @param aData Data to check
+   * @param aLength Length of the data
+   *
+   * @return The content type
+   *
+   * @throw NS_ERROR_NOT_AVAILABLE if no MIME type could be determined.
+   *
+   * @note Implementations should consider the request read-only. Especially,
+   * they should not attempt to set the content type property that subclasses of
+   * nsIRequest might offer.
+   */
+  ACString getMIMETypeFromContent(in nsIRequest aRequest,
+                                  [const,array,size_is(aLength)] in octet aData,
+                                  in unsigned long aLength);
+};
diff --git a/netwerk/base/nsIDHCPClient.idl b/netwerk/base/nsIDHCPClient.idl
new file mode 100644
index 0000000000..1d986ebd52
--- /dev/null
+++ b/netwerk/base/nsIDHCPClient.idl
@@ -0,0 +1,19 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface allows the proxy code to access the DHCP Options in a platform-specific way
+ */
+[scriptable, uuid(aee75dc0-be1a-46b9-9e0c-31a6899c175c)]
+interface nsIDHCPClient : nsISupports
+{
+
+    /**
+    * returns the DHCP Option designated by the option parameter
+    */
+    ACString getOption(in uint8_t option);
+};
diff --git a/netwerk/base/nsIDashboard.idl b/netwerk/base/nsIDashboard.idl
new file mode 100644
index 0000000000..ae80a9e458
--- /dev/null
+++ b/netwerk/base/nsIDashboard.idl
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/* A JavaScript callback function that takes a JSON as its parameter.
+ * The returned JSON contains arrays with data
+ */
+[scriptable, function, uuid(19d7f24f-a95a-4fd9-87e2-d96e9e4b1f6d)]
+interface nsINetDashboardCallback : nsISupports
+{
+    void onDashboardDataAvailable(in jsval data);
+};
+
+/* The dashboard service.
+ * The async API returns JSONs, which hold arrays with the required info.
+ * Only one request of each type may be pending at any time.
+ */
+[scriptable, uuid(c79eb3c6-091a-45a6-8544-5a8d1ab79537)]
+interface nsIDashboard : nsISupports
+{
+    /* Arrays: host, port, tcp, active, socksent, sockreceived
+     * Values: sent, received  */
+    void requestSockets(in nsINetDashboardCallback cb);
+
+    /* Arrays: host, port, spdy, ssl
+     * Array of arrays: active, idle */
+    void requestHttpConnections(in nsINetDashboardCallback cb);
+
+    /* Arrays: hostport, encrypted, msgsent, msgreceived, sentsize, receivedsize */
+    void requestWebsocketConnections(in nsINetDashboardCallback cb);
+
+    /* Arrays: hostname, family, hostaddr, expiration */
+    void requestDNSInfo(in nsINetDashboardCallback cb);
+
+    /* aProtocol: a transport layer protocol:
+     *      ex: "ssl", "tcp", default is "tcp".
+     * aHost: the host's name
+     * aPort: the port which the connection will open on
+     * aTimeout: the timespan before the connection will be timed out */
+    void requestConnection(in ACString aHost, in unsigned long aPort,
+                           in string aProtocol, in unsigned long aTimeout,
+                           in nsINetDashboardCallback cb);
+
+    /* When true, the service will log websocket events */
+    attribute boolean enableLogging;
+
+    /* DNS resolver for host name
+     * aHost: host name */
+    void requestDNSLookup(in ACString aHost, in nsINetDashboardCallback cb);
+
+    /* Resolve HTTPS RRs for host name
+     * aHost: host name */
+    void requestDNSHTTPSRRLookup(in ACString aHost,
+                                 in nsINetDashboardCallback cb);
+
+    /**
+     * Asyncly returns stats regarding the "Race Cache With Network" feature.
+     */
+    void requestRcwnStats(in nsINetDashboardCallback cb);
+
+    AUTF8String getLogPath();
+};
diff --git a/netwerk/base/nsIDashboardEventNotifier.idl b/netwerk/base/nsIDashboardEventNotifier.idl
new file mode 100644
index 0000000000..933caf4371
--- /dev/null
+++ b/netwerk/base/nsIDashboardEventNotifier.idl
@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[uuid(24fdfcbe-54cb-4997-8392-3c476126ea3b)]
+interface nsIDashboardEventNotifier : nsISupports
+{
+    /* These methods are called to register a websocket event with the dashboard
+     *
+     * A host is identified by the (aHost, aSerial) pair.
+     * aHost: the host's name: example.com
+     * aSerial: a number that uniquely identifies the websocket
+     *
+     * aEncrypted: if the connection is encrypted
+     * aLength: the length of the message in bytes
+     */
+    void addHost(in ACString aHost, in unsigned long aSerial, in boolean aEncrypted);
+    void removeHost(in ACString aHost, in unsigned long aSerial);
+    void newMsgSent(in ACString aHost, in unsigned long aSerial, in unsigned long aLength);
+    void newMsgReceived(in ACString aHost, in unsigned long aSerial, in unsigned long aLength);
+};
diff --git a/netwerk/base/nsIDownloader.idl b/netwerk/base/nsIDownloader.idl
new file mode 100644
index 0000000000..c887c32c74
--- /dev/null
+++ b/netwerk/base/nsIDownloader.idl
@@ -0,0 +1,50 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+interface nsIFile;
+interface nsIDownloadObserver;
+
+/**
+ * nsIDownloader
+ *
+ * A downloader is a special implementation of a nsIStreamListener that will
+ * make the contents of the stream available as a file.  This may utilize the
+ * disk cache as an optimization to avoid an extra copy of the data on disk.
+ * The resulting file is valid from the time the downloader completes until
+ * the last reference to the downloader is released.
+ */
+[scriptable, uuid(fafe41a9-a531-4d6d-89bc-588a6522fb4e)]
+interface nsIDownloader : nsIStreamListener
+{
+    /**
+     * Initialize this downloader
+     *
+     * @param observer
+     *        the observer to be notified when the download completes.
+     * @param downloadLocation
+     *        the location where the stream contents should be written.
+     *        if null, the downloader will select a location and the
+     *        resulting file will be deleted (or otherwise made invalid)
+     *        when the downloader object is destroyed.  if an explicit
+     *        download location is specified then the resulting file will
+     *        not be deleted, and it will be the callers responsibility
+     *        to keep track of the file, etc.
+     */
+    void init(in nsIDownloadObserver observer,
+              in nsIFile             downloadLocation);
+};
+
+[scriptable, uuid(44b3153e-a54e-4077-a527-b0325e40924e)]
+interface nsIDownloadObserver : nsISupports
+{
+    /**
+     * Called to signal a download that has completed.
+     */
+    void onDownloadComplete(in nsIDownloader downloader,
+                            in nsIRequest    request,
+                            in nsresult      status,
+                            in nsIFile       result);
+};
diff --git a/netwerk/base/nsIEncodedChannel.idl b/netwerk/base/nsIEncodedChannel.idl
new file mode 100644
index 0000000000..a7571a0a92
--- /dev/null
+++ b/netwerk/base/nsIEncodedChannel.idl
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIUTF8StringEnumerator;
+interface nsIStreamListener;
+interface nsISupports;
+
+/**
+ * A channel interface which allows special handling of encoded content
+ */
+
+[scriptable, uuid(29c29ce6-8ce4-45e6-8d60-36c8fa3e255b)]
+interface nsIEncodedChannel : nsISupports
+{
+    /**
+     * This attribute holds the MIME types corresponding to the content
+     * encodings on the channel.  The enumerator returns nsISupportsCString
+     * objects.  The first one corresponds to the outermost encoding on the
+     * channel and then we work our way inward.  "identity" is skipped and not
+     * represented on the list.  Unknown encodings make the enumeration stop.
+     * If you want the actual Content-Encoding value, use
+     * getResponseHeader("Content-Encoding").
+     *
+     * When there is no Content-Encoding header, this property is null.
+     *
+     * Modifying the Content-Encoding header on the channel will cause
+     * this enumerator to have undefined behavior.  Don't do it.
+     *
+     * Also note that contentEncodings only exist during or after OnStartRequest.
+     * Calling contentEncodings before OnStartRequest is an error.
+     */
+    readonly attribute nsIUTF8StringEnumerator contentEncodings;
+
+    /**
+     * This attribute controls whether or not content conversion should be
+     * done per the Content-Encoding response header.  applyConversion can only
+     * be set before or during OnStartRequest.  Calling this during
+     * OnDataAvailable is an error.
+     *
+     * TRUE by default.
+     */
+    attribute boolean applyConversion;
+
+    /**
+     * This function will start converters if they are available.
+     * aNewNextListener will be nullptr if no converter is available.
+     */
+    void doApplyContentConversions(in nsIStreamListener aNextListener,
+                                   out nsIStreamListener aNewNextListener,
+                                   in nsISupports aCtxt);
+};
diff --git a/netwerk/base/nsIExternalProtocolHandler.idl b/netwerk/base/nsIExternalProtocolHandler.idl
new file mode 100644
index 0000000000..6f86dbb05a
--- /dev/null
+++ b/netwerk/base/nsIExternalProtocolHandler.idl
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIProtocolHandler.idl"
+
+[scriptable, uuid(0e61f3b2-34d7-4c79-bfdc-4860bc7341b7)]
+interface nsIExternalProtocolHandler: nsIProtocolHandler
+{
+    /**
+     * This method checks if the external handler exists for a given scheme.
+     *
+     * @param scheme external scheme.
+     * @return TRUE if the external handler exists for the input scheme, FALSE otherwise.
+     */
+    boolean externalAppExistsForScheme(in ACString scheme);
+};
diff --git a/netwerk/base/nsIFileStreams.idl b/netwerk/base/nsIFileStreams.idl
new file mode 100644
index 0000000000..026fa41bcf
--- /dev/null
+++ b/netwerk/base/nsIFileStreams.idl
@@ -0,0 +1,239 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIInputStream.idl"
+#include "nsIOutputStream.idl"
+#include "nsIRandomAccessStream.idl"
+
+interface nsIEventTarget;
+interface nsIFile;
+interface nsIFileMetadataCallback;
+
+%{C++
+struct PRFileDesc;
+%}
+
+[ptr] native PRFileDescPtr(PRFileDesc);
+
+/**
+ * An input stream that allows you to read from a file.
+ */
+[scriptable, builtinclass, uuid(e3d56a20-c7ec-11d3-8cda-0060b0fc14a3)]
+interface nsIFileInputStream : nsIInputStream
+{
+    /**
+     * @param file          file to read from
+     * @param ioFlags       file open flags listed in prio.h (see
+     *                      PR_Open documentation) or -1 to open the
+     *                      file in default mode (PR_RDONLY).
+     * @param perm          file mode bits listed in prio.h or -1 to
+     *                      use the default value (0)
+     * @param behaviorFlags flags specifying various behaviors of the class
+     *        (see enumerations in the class)
+     */
+    void init(in nsIFile file, in long ioFlags, in long perm,
+              in long behaviorFlags);
+
+    /**
+     * If this is set, the file will close automatically when the end of the
+     * file is reached.
+     */
+    const long CLOSE_ON_EOF = 1<<2;
+
+    /**
+     * If this is set, the file will be reopened whenever we reach the start of
+     * the file, either by doing a Seek(0, NS_SEEK_CUR), or by doing a relative
+     * seek that happen to reach the beginning of the file. If the file is
+     * already open and the seek occurs, it will happen naturally.  (The file
+     * will only be reopened if it is closed for some reason.)
+     */
+    const long REOPEN_ON_REWIND = 1<<3;
+
+    /**
+     * If this is set, the file will be opened (i.e., a call to
+     * PR_Open done) only when we do an actual operation on the stream,
+     * or more specifically, when one of the following is called:
+     *   - Seek
+     *   - Tell
+     *   - SetEOF
+     *   - Available
+     *   - Read
+     *   - ReadLine
+     *
+     * DEFER_OPEN is useful if we use the stream on a background
+     * thread, so that the opening and possible |stat|ing of the file
+     * happens there as well.
+     *
+     * @note Using this flag results in the file not being opened
+     *       during the call to Init.  This means that any errors that might
+     *       happen when this flag is not set would happen during the
+     *       first read.  Also, the file is not locked when Init is called,
+     *       so it might be deleted before we try to read from it.
+     */
+    const long DEFER_OPEN = 1<<4;
+
+    /**
+     * This flag has no effect and is totally ignored on any platform except
+     * Windows since this is the default behavior on POSIX systems. On Windows
+     * if this flag is set then the stream is opened in a special mode that
+     * allows the OS to delete the file from disk just like POSIX.
+     */
+    const long SHARE_DELETE = 1<<5;
+};
+
+/**
+ * An output stream that lets you stream to a file.
+ */
+[scriptable, builtinclass, uuid(e734cac9-1295-4e6f-9684-3ac4e1f91063)]
+interface nsIFileOutputStream : nsIOutputStream
+{
+    /**
+     * @param file          file to write to
+     * @param ioFlags       file open flags listed in prio.h (see
+     *                      PR_Open documentation) or -1 to open the
+     *                      file in default mode (PR_WRONLY |
+     *                      PR_CREATE_FILE | PR_TRUNCATE)
+     * @param perm          file mode bits listed in prio.h or -1 to
+     *                      use the default permissions (0664)
+     * @param behaviorFlags flags specifying various behaviors of the class
+     *        (currently none supported)
+     */
+    void init(in nsIFile file, in long ioFlags, in long perm,
+              in long behaviorFlags);
+
+    /**
+     * @param length        asks the operating system to allocate storage for
+     *                      this file of at least |length| bytes long, and
+     *                      set the file length to the corresponding size.
+     * @throws NS_ERROR_FAILURE if the preallocation fails.
+     * @throws NS_ERROR_NOT_INITIALIZED if the file is not opened.
+     */
+    [noscript] void preallocate(in long long length);
+
+    /**
+     * See the same constant in nsIFileInputStream. The deferred open will
+     * be performed when one of the following is called:
+     *   - Seek
+     *   - Tell
+     *   - SetEOF
+     *   - Write
+     *   - Flush
+     *
+     * @note Using this flag results in the file not being opened
+     *       during the call to Init.  This means that any errors that might
+     *       happen when this flag is not set would happen during the
+     *       first write, and if the file is to be created, then it will not
+     *       appear on the disk until the first write.
+     */
+    const long DEFER_OPEN = 1<<0;
+};
+
+/**
+ * A stream that allows you to read from a file or stream to a file.
+ */
+[scriptable, builtinclass, uuid(82cf605a-8393-4550-83ab-43cd5578e006)]
+interface nsIFileRandomAccessStream : nsIRandomAccessStream
+{
+    /**
+     * @param file          file to read from or stream to
+     * @param ioFlags       file open flags listed in prio.h (see
+     *                      PR_Open documentation) or -1 to open the
+     *                      file in default mode (PR_RDWR).
+     * @param perm          file mode bits listed in prio.h or -1 to
+     *                      use the default value (0)
+     * @param behaviorFlags flags specifying various behaviors of the class
+     *        (see enumerations in the class)
+     */
+    void init(in nsIFile file, in long ioFlags, in long perm,
+              in long behaviorFlags);
+
+    /**
+     * See the same constant in nsIFileInputStream. The deferred open will
+     * be performed when one of the following is called:
+     *   - Seek
+     *   - Tell
+     *   - SetEOF
+     *   - Available
+     *   - Read
+     *   - Flush
+     *   - Write
+     *   - GetSize
+     *   - GetLastModified
+     *
+     * @note Using this flag results in the file not being opened
+     *       during the call to Init.  This means that any errors that might
+     *       happen when this flag is not set would happen during the
+     *       first read or write. The file is not locked when Init is called,
+     *       so it might be deleted before we try to read from it and if the
+     *       file is to be created, then it will not appear on the disk until
+     *       the first write.
+     */
+    const long DEFER_OPEN = 1<<0;
+};
+
+/**
+ * An interface that allows you to get some metadata like file size and
+ * file last modified time. These methods and attributes can throw
+ * NS_BASE_STREAM_WOULD_BLOCK in case the informations are not available yet.
+ * If this happens, consider the use of nsIAsyncFileMetadata.
+ *
+ * If using nsIAsyncFileMetadata, you should retrieve any data via this
+ * interface before taking any action that might consume the underlying stream.
+ * For example, once Available(), Read(), or nsIAsyncInputStream::AsyncWait()
+ * are invoked, these methods may return NS_BASE_STREAM_CLOSED.  This will
+ * happen when using RemoteLazyInputStream with an underlying file stream, for
+ * example.
+ */
+[scriptable, builtinclass, uuid(07f679e4-9601-4bd1-b510-cd3852edb881)]
+interface nsIFileMetadata : nsISupports
+{
+    /**
+     * File size in bytes.
+     */
+    readonly attribute long long size;
+
+    /**
+     * File last modified time in milliseconds from midnight (00:00:00),
+     * January 1, 1970 Greenwich Mean Time (GMT).
+     */
+    readonly attribute long long lastModified;
+
+    /**
+     * The internal file descriptor. It can be used for memory mapping of the
+     * underlying file. Please use carefully! If this returns
+     * NS_BASE_STREAM_WOULD_BLOCK, consider the use of nsIAsyncFileMetadata.
+     */
+    [noscript] PRFileDescPtr getFileDescriptor();
+};
+
+[scriptable, builtinclass, uuid(de15b80b-29ba-4b7f-9220-a3d75b17ae8c)]
+interface nsIAsyncFileMetadata : nsIFileMetadata
+{
+    /**
+     * Asynchronously wait for the object to be ready.
+     *
+     * @param aCallback The callback will be used when the stream is ready to
+     *                  return File metadata. Use a nullptr to cancel a
+     *                  previous operation.
+     *
+     * @param aEventTarget The event target where aCallback will be executed.
+     *                     If aCallback is passed, aEventTarget cannot be null.
+     */
+    void asyncFileMetadataWait(in nsIFileMetadataCallback aCallback,
+                               in nsIEventTarget aEventTarget);
+};
+
+/**
+ * This is a companion interface for
+ * nsIAsyncFileMetadata::asyncFileMetadataWait.
+ */
+[function, scriptable, uuid(d01c7ead-7ba3-4726-b399-618ec8ec7057)]
+interface nsIFileMetadataCallback : nsISupports
+{
+    /**
+     * Called to indicate that the nsIFileMetadata object is ready.
+     */
+    void onFileMetadataReady(in nsIAsyncFileMetadata aObject);
+};
diff --git a/netwerk/base/nsIFileURL.idl b/netwerk/base/nsIFileURL.idl
new file mode 100644
index 0000000000..3c97a2e3af
--- /dev/null
+++ b/netwerk/base/nsIFileURL.idl
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIURL.idl"
+
+interface nsIFile;
+interface nsIURIMutator;
+
+/**
+ * nsIFileURL provides access to the underlying nsIFile object corresponding to
+ * an URL.  The URL scheme need not be file:, since other local protocols may
+ * map URLs to files (e.g., resource:).
+ */
+[scriptable, builtinclass, uuid(e91ac988-27c2-448b-b1a1-3822e1ef1987)]
+interface nsIFileURL : nsIURL
+{
+    /**
+     * Get the nsIFile corresponding to this URL.
+     *
+     *  - Returns a reference to an immutable object.  Callers must clone
+     *    before attempting to modify the returned nsIFile object.  NOTE: this
+     *    constraint might not be enforced at runtime, so beware!!
+     */
+    readonly attribute nsIFile file;
+};
+
+[scriptable, builtinclass, uuid(a588b6f2-d2b9-4024-84c7-be3368546b57)]
+interface nsIFileURLMutator : nsISupports
+{
+    /*
+     *  - Marks the inner URI implementation as one that supports nsIFileURL.
+     */
+    [must_use, noscript] void markFileURL();
+
+    /*
+     *  - Setter clones the nsIFile object (allowing the caller to safely modify
+     *    the nsIFile object after setting it on this interface).
+     */
+    [must_use, noscript] void setFile(in nsIFile aFile);
+};
diff --git a/netwerk/base/nsIForcePendingChannel.idl b/netwerk/base/nsIForcePendingChannel.idl
new file mode 100644
index 0000000000..714c83f52d
--- /dev/null
+++ b/netwerk/base/nsIForcePendingChannel.idl
@@ -0,0 +1,22 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsIForcePending interface exposes a function that enables overwriting of the normal
+ * behavior for the channel's IsPending(), forcing 'true' to be returned.
+ */
+
+[uuid(2ac3e1ca-049f-44c3-a519-f0681f51e9b1)]
+interface nsIForcePendingChannel : nsISupports
+{
+
+    /**
+     * forcePending(true) overrides the normal behavior for the
+     * channel's IsPending(), forcing 'true' to be returned. A call to
+     * forcePending(false) reverts IsPending() back to normal behavior.
+     */
+    void forcePending(in boolean aForcePending);
+};
diff --git a/netwerk/base/nsIFormPOSTActionChannel.idl b/netwerk/base/nsIFormPOSTActionChannel.idl
new file mode 100644
index 0000000000..870886390c
--- /dev/null
+++ b/netwerk/base/nsIFormPOSTActionChannel.idl
@@ -0,0 +1,17 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIUploadChannel.idl"
+
+/**
+ * nsIFormPOSTActionChannel
+ *
+ * Channel classes that want to be allowed for HTML form POST action must
+ * implement this interface.
+ */
+[scriptable, uuid(fc826b53-0db8-42b4-aa6a-5dd2cfca52a4)]
+interface nsIFormPOSTActionChannel : nsIUploadChannel
+{
+};
diff --git a/netwerk/base/nsIHttpAuthenticatorCallback.idl b/netwerk/base/nsIHttpAuthenticatorCallback.idl
new file mode 100644
index 0000000000..74fd3c97ab
--- /dev/null
+++ b/netwerk/base/nsIHttpAuthenticatorCallback.idl
@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[uuid(d989cb03-e446-4086-b9e6-46842cb97bd5)]
+interface nsIHttpAuthenticatorCallback : nsISupports
+{
+  /**
+   * Authentication data for a header is available.
+   *
+   * @param aCreds
+   *        Credentials which were obtained asynchonously.
+   * @param aFlags
+   *        Flags set by asynchronous call.
+   * @param aResult
+   *        Result status of credentials generation
+   * @param aSessionState
+   *        Modified session state to be passed to caller
+   * @param aContinuationState
+   *        Modified continuation state to be passed to caller
+   */
+  void onCredsGenerated(in ACString aCreds,
+                        in unsigned long aFlags,
+                        in nsresult aResult,
+                        in nsISupports aSessionsState,
+                        in nsISupports aContinuationState);
+
+};
diff --git a/netwerk/base/nsIHttpPushListener.idl b/netwerk/base/nsIHttpPushListener.idl
new file mode 100644
index 0000000000..f44605c000
--- /dev/null
+++ b/netwerk/base/nsIHttpPushListener.idl
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+interface nsIHttpChannel;
+
+/**
+ * nsIHttpPushListener
+ *
+ * Used for triggering when a HTTP/2 push is received.
+ *
+ */
+[scriptable, uuid(0d6ce59c-ad5d-4520-b4d3-09664868f279)]
+interface nsIHttpPushListener : nsISupports
+{
+  /**
+   * When provided as a notificationCallback to an httpChannel, this.onPush()
+   * will be invoked when there is a >= Http2 push to that
+   * channel. The push may be in progress.
+   *
+   * The consumer must start the new channel in the usual way by calling
+   * pushChannel.AsyncOpen with a nsIStreamListener object that
+   * will receive the normal sequence of OnStartRequest(),
+   * 0 to N OnDataAvailable(), and onStopRequest().
+   *
+   * The new channel can be canceled after the AsyncOpen if it is not wanted.
+   *
+   * @param associatedChannel
+   *        the monitor channel that was recieved on
+   * @param pushChannel
+   *        a channel to the resource which is being pushed
+   */
+  void onPush(in nsIHttpChannel associatedChannel,
+              in nsIHttpChannel pushChannel);
+};
diff --git a/netwerk/base/nsIIOService.idl b/netwerk/base/nsIIOService.idl
new file mode 100644
index 0000000000..6a4d58ceab
--- /dev/null
+++ b/netwerk/base/nsIIOService.idl
@@ -0,0 +1,354 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsIContentPolicy.idl"
+
+interface nsIProtocolHandler;
+interface nsIChannel;
+interface nsIURI;
+interface nsIFile;
+interface nsIPrincipal;
+interface nsILoadInfo;
+interface nsIWebTransport;
+
+webidl Node;
+
+%{C++
+#include "mozilla/Maybe.h"
+
+namespace mozilla {
+namespace dom {
+class ClientInfo;
+class ServiceWorkerDescriptor;
+} // namespace dom
+} // namespace mozilla
+%}
+
+[ref] native const_MaybeClientInfoRef(const mozilla::Maybe<mozilla::dom::ClientInfo>);
+[ref] native const_MaybeServiceWorkerDescriptorRef(const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>);
+
+/**
+ * nsIIOService provides a set of network utility functions.  This interface
+ * duplicates many of the nsIProtocolHandler methods in a protocol handler
+ * independent way (e.g., NewURI inspects the scheme in order to delegate
+ * creation of the new URI to the appropriate protocol handler).  nsIIOService
+ * also provides a set of URL parsing utility functions.  These are provided
+ * as a convenience to the programmer and in some cases to improve performance
+ * by eliminating intermediate data structures and interfaces.
+ */
+[scriptable, builtinclass, uuid(4286de5a-b2ea-446f-8f70-e2a461f42694)]
+interface nsIIOService : nsISupports
+{
+    /**
+     * Returns a protocol handler for a given URI scheme.
+     *
+     * @param aScheme the URI scheme
+     * @return reference to corresponding nsIProtocolHandler
+     */
+    nsIProtocolHandler getProtocolHandler(in string aScheme);
+
+    /**
+     * Returns the protocol flags for a given scheme.
+     *
+     * @param aScheme the URI scheme
+     * @return protocol flags for the corresponding protocol
+     */
+    unsigned long getProtocolFlags(in string aScheme);
+
+    /**
+     * Returns the dynamic protocol flags for a given URI.
+     *
+     * @param aURI the URI to get all dynamic flags for
+     * @return protocol flags for that URI
+     */
+    unsigned long getDynamicProtocolFlags(in nsIURI aURI);
+
+    /**
+     * Returns the default port for a given scheme.
+     *
+     * @param aScheme the URI scheme
+     * @return default port for the corresponding protocol
+     */
+    long getDefaultPort(in string aScheme);
+
+    /**
+     * This method constructs a new URI based on the scheme of the URI spec.
+     * QueryInterface can be used on the resulting URI object to obtain a more
+     * specific type of URI.
+     */
+    nsIURI newURI(in AUTF8String aSpec,
+                  [optional] in string aOriginCharset,
+                  [optional] in nsIURI aBaseURI);
+
+    /**
+     * This method constructs a new URI from a nsIFile.
+     *
+     * @param aFile specifies the file path
+     * @return reference to a new nsIURI object
+     *
+     * Note: in the future, for perf reasons we should allow
+     * callers to specify whether this is a file or directory by
+     * splitting this  into newDirURI() and newActualFileURI().
+     */
+    nsIURI newFileURI(in nsIFile aFile);
+
+    /**
+     * Converts an internal URI (e.g. one that has a username and password in
+     * it) into one which we can expose to the user, for example on the URL bar.
+     *
+     * @param  aURI The URI to be converted.
+     * @return nsIURI The converted, exposable URI.
+     */
+    nsIURI createExposableURI(in nsIURI aURI);
+
+    /**
+     * Creates a channel for a given URI.
+     *
+     * @param aURI
+     *        nsIURI from which to make a channel
+     * @param aLoadingNode
+     * @param aLoadingPrincipal
+     * @param aTriggeringPrincipal
+     * @param aSecurityFlags
+     * @param aContentPolicyType
+     *        These will be used as values for the nsILoadInfo object on the
+     *        created channel. For details, see nsILoadInfo in nsILoadInfo.idl
+     * @return reference to the new nsIChannel object
+     *
+     * Please note, if you provide both a loadingNode and a loadingPrincipal,
+     * then loadingPrincipal must be equal to loadingNode->NodePrincipal().
+     * But less error prone is to just supply a loadingNode.
+     *
+     * Keep in mind that URIs coming from a webpage should *never* use the
+     * systemPrincipal as the loadingPrincipal.
+     */
+    nsIChannel newChannelFromURI(in nsIURI aURI,
+                                 in Node aLoadingNode,
+                                 in nsIPrincipal aLoadingPrincipal,
+                                 in nsIPrincipal aTriggeringPrincipal,
+                                 in unsigned long aSecurityFlags,
+                                 in nsContentPolicyType aContentPolicyType);
+
+    [noscript, nostdcall, notxpcom]
+    nsresult NewChannelFromURIWithClientAndController(in nsIURI aURI,
+                                                      in Node aLoadingNode,
+                                                      in nsIPrincipal aLoadingPrincipal,
+                                                      in nsIPrincipal aTriggeringPrincipal,
+                                                      in const_MaybeClientInfoRef aLoadingClientInfo,
+                                                      in const_MaybeServiceWorkerDescriptorRef aController,
+                                                      in unsigned long aSecurityFlags,
+                                                      in nsContentPolicyType aContentPolicyType,
+                                                      in unsigned long aSandboxFlags,
+                                                      in boolean aSkipCheckForBrokenURLOrZeroSized,
+                                                      out nsIChannel aResult);
+
+    /**
+     * Equivalent to newChannelFromURI(aURI, aLoadingNode, ...)
+     */
+    nsIChannel newChannelFromURIWithLoadInfo(in nsIURI aURI,
+                                             in nsILoadInfo aLoadInfo);
+
+    /**
+     * Equivalent to newChannelFromURI(newURI(...))
+     */
+    nsIChannel newChannel(in AUTF8String aSpec,
+                          in string aOriginCharset,
+                          in nsIURI aBaseURI,
+                          in Node aLoadingNode,
+                          in nsIPrincipal aLoadingPrincipal,
+                          in nsIPrincipal aTriggeringPrincipal,
+                          in unsigned long aSecurityFlags,
+                          in nsContentPolicyType aContentPolicyType);
+
+    /**
+     * Creates a WebTransport.
+     */
+    nsIWebTransport newWebTransport();
+
+    /**
+     * Returns true if networking is in "offline" mode. When in offline mode,
+     * attempts to access the network will fail (although this does not
+     * necessarily correlate with whether there is actually a network
+     * available -- that's hard to detect without causing the dialer to
+     * come up).
+     *
+     * Changing this fires observer notifications ... see below.
+     */
+    attribute boolean offline;
+
+    /**
+     * Returns false if there are no interfaces for a network request
+     */
+    readonly attribute boolean connectivity;
+
+    /**
+     * Checks if a port number is banned. This involves consulting a list of
+     * unsafe ports, corresponding to network services that may be easily
+     * exploitable. If the given port is considered unsafe, then the protocol
+     * handler (corresponding to aScheme) will be asked whether it wishes to
+     * override the IO service's decision to block the port. This gives the
+     * protocol handler ultimate control over its own security policy while
+     * ensuring reasonable, default protection.
+     *
+     * @see nsIProtocolHandler::allowPort
+     */
+    boolean allowPort(in long aPort, in string aScheme);
+
+    /**
+     * Utility to extract the scheme from a URL string, consistently and
+     * according to spec (see RFC 2396).
+     *
+     * NOTE: Most URL parsing is done via nsIURI, and in fact the scheme
+     * can also be extracted from a URL string via nsIURI.  This method
+     * is provided purely as an optimization.
+     *
+     * @param aSpec the URL string to parse
+     * @return URL scheme, lowercase
+     *
+     * @throws NS_ERROR_MALFORMED_URI if URL string is not of the right form.
+     */
+    ACString extractScheme(in AUTF8String urlString);
+
+    /**
+     * Checks if a URI host is a local IPv4 or IPv6 address literal.
+     *
+     * @param nsIURI the URI that contains the hostname to check
+     * @return true if the URI hostname is a local IP address
+     */
+    boolean hostnameIsLocalIPAddress(in nsIURI aURI);
+
+    /**
+     * Checks if a URI host is a shared IPv4 address literal.
+     *
+     * @param nsIURI the URI that contains the hostname to check
+     * @return true if the URI hostname is a shared IP address
+     */
+    boolean hostnameIsSharedIPAddress(in nsIURI aURI);
+
+    /**
+     * While this is set, IOService will monitor an nsINetworkLinkService
+     * (if available) and set its offline status to "true" whenever
+     * isLinkUp is false.
+     *
+     * Applications that want to control changes to the IOService's offline
+     * status should set this to false, watch for network:link-status-changed
+     * broadcasts, and change nsIIOService::offline as they see fit. Note
+     * that this means during application startup, IOService may be offline
+     * if there is no link, until application code runs and can turn off
+     * this management.
+     */
+    attribute boolean manageOfflineStatus;
+
+    /**
+     * Creates a channel for a given URI.
+     *
+     * @param aURI
+     *        nsIURI from which to make a channel
+     * @param aProxyURI
+     *        nsIURI to use for proxy resolution. Can be null in which
+     *        case aURI is used
+     * @param aProxyFlags flags from nsIProtocolProxyService to use
+     *        when resolving proxies for this new channel
+     * @param aLoadingNode
+     * @param aLoadingPrincipal
+     * @param aTriggeringPrincipal
+     * @param aSecurityFlags
+     * @param aContentPolicyType
+     *        These will be used as values for the nsILoadInfo object on the
+     *        created channel. For details, see nsILoadInfo in nsILoadInfo.idl
+     * @return reference to the new nsIChannel object
+     *
+     * Please note, if you provide both a loadingNode and a loadingPrincipal,
+     * then loadingPrincipal must be equal to loadingNode->NodePrincipal().
+     * But less error prone is to just supply a loadingNode.
+     */
+    nsIChannel newChannelFromURIWithProxyFlags(in nsIURI aURI,
+                                               in nsIURI aProxyURI,
+                                               in unsigned long aProxyFlags,
+                                               in Node aLoadingNode,
+                                               in nsIPrincipal aLoadingPrincipal,
+                                               in nsIPrincipal aTriggeringPrincipal,
+                                               in unsigned long aSecurityFlags,
+                                               in nsContentPolicyType aContentPolicyType);
+
+    /**
+     * Return true if socket process is launched.
+     */
+    readonly attribute boolean socketProcessLaunched;
+
+    /**
+     * The pid for socket process.
+     */
+    readonly attribute unsigned long long socketProcessId;
+
+    /**
+     * Register a protocol handler at runtime, given protocol flags and a
+     * default port.
+     *
+     * Statically registered protocol handlers cannot be overridden, and an
+     * error will be returned if that is attempted.
+     *
+     * Runtime registered protocol handlers are never QueryInterface-ed into
+     * `nsIProtocolHandlerWithDynamicFlags`, so that interface will be ignored.
+     *
+     * @param aScheme the scheme handled by the protocol handler.
+     * @param aHandler the protocol handler instance.
+     * @param aProtocolFlags protocol flags for this protocol, see
+     *                       nsIProtocolHandler for values.
+     * @param aDefaultPort default port for this scheme, or -1.
+     */
+    void registerProtocolHandler(in ACString aScheme,
+                                 in nsIProtocolHandler aHandler,
+                                 in unsigned long aProtocolFlags,
+                                 in long aDefaultPort);
+
+    /**
+     * Unregister a protocol handler which was previously registered using
+     * registerProtocolHandler.
+     *
+     * @param aScheme the scheme to unregister a handler for.
+     */
+    void unregisterProtocolHandler(in ACString aScheme);
+};
+
+%{C++
+/**
+ * We send notifications through nsIObserverService with topic
+ * NS_IOSERVICE_GOING_OFFLINE_TOPIC and data NS_IOSERVICE_OFFLINE
+ * when 'offline' has changed from false to true, and we are about
+ * to shut down network services such as DNS. When those
+ * services have been shut down, we send a notification with
+ * topic NS_IOSERVICE_OFFLINE_STATUS_TOPIC and data
+ * NS_IOSERVICE_OFFLINE.
+ *
+ * When 'offline' changes from true to false, then after
+ * network services have been restarted, we send a notification
+ * with topic NS_IOSERVICE_OFFLINE_STATUS_TOPIC and data
+ * NS_IOSERVICE_ONLINE.
+ */
+#define NS_IOSERVICE_GOING_OFFLINE_TOPIC  "network:offline-about-to-go-offline"
+#define NS_IOSERVICE_OFFLINE_STATUS_TOPIC "network:offline-status-changed"
+#define NS_IOSERVICE_OFFLINE              "offline"
+#define NS_IOSERVICE_ONLINE               "online"
+
+%}
+
+[uuid(6633c0bf-d97a-428f-8ece-cb6a655fb95a)]
+interface nsIIOServiceInternal : nsISupports
+{
+    /**
+     * This is an internal method that should only be called from ContentChild
+     * in order to pass the connectivity state from the chrome process to the
+     * content process. It throws if called outside the content process.
+     */
+    void SetConnectivity(in boolean connectivity);
+
+    /**
+     * An internal method to asynchronously run our notifications that happen
+     * when we wake from sleep
+     */
+    void NotifyWakeup();
+};
diff --git a/netwerk/base/nsIIncrementalDownload.idl b/netwerk/base/nsIIncrementalDownload.idl
new file mode 100644
index 0000000000..3ae363c488
--- /dev/null
+++ b/netwerk/base/nsIIncrementalDownload.idl
@@ -0,0 +1,109 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+
+interface nsIURI;
+interface nsIFile;
+interface nsIRequestObserver;
+
+/**
+ * An incremental download object attempts to fetch a file piecemeal over time
+ * in an effort to minimize network bandwidth usage.
+ *
+ * Canceling a background download does not cause the file on disk to be
+ * deleted.
+ */
+[scriptable, uuid(6687823f-56c4-461d-93a1-7f6cb7dfbfba)]
+interface nsIIncrementalDownload : nsIRequest
+{
+  /**
+   * Initialize the incremental download object.  If the destination file
+   * already exists, then only the remaining portion of the file will be
+   * fetched.
+   *
+   * NOTE: The downloader will create the destination file if it does not
+   * already exist.  It will create the file with the permissions 0600 if
+   * needed.  To affect the permissions of the file, consumers of this
+   * interface may create an empty file at the specified destination prior to
+   * starting the incremental download.
+   *
+   * NOTE: Since this class may create a temporary file at the specified
+   * destination, it is advisable for the consumer of this interface to specify
+   * a file name for the destination that would not tempt the user into
+   * double-clicking it.  For example, it might be wise to append a file
+   * extension like ".part" to the end of the destination to protect users from
+   * accidentally running "blah.exe" before it is a complete file.
+   *
+   * @param uri
+   *        The URI to fetch.
+   * @param destination
+   *        The location where the file is to be stored.
+   * @param chunkSize
+   *        The size of the chunks to fetch.  A non-positive value results in
+   *        the default chunk size being used.
+   * @param intervalInSeconds
+   *        The amount of time to wait between fetching chunks.  Pass a
+   *        negative to use the default interval, or 0 to fetch the remaining
+   *        part of the file in one chunk.
+   */
+  void init(in nsIURI uri, in nsIFile destination, in long chunkSize,
+            in long intervalInSeconds);
+
+  /**
+   * The URI being fetched.
+   */
+  readonly attribute nsIURI URI;
+
+  /**
+   * The URI being fetched after any redirects have been followed.  This
+   * attribute is set just prior to calling OnStartRequest on the observer
+   * passed to the start method.
+   */
+  readonly attribute nsIURI finalURI;
+
+  /**
+   * The file where the download is being written.
+   */
+  readonly attribute nsIFile destination;
+
+  /**
+   * The total number of bytes for the requested file.  This attribute is set
+   * just prior to calling OnStartRequest on the observer passed to the start
+   * method.
+   *
+   * This attribute has a value of -1 if the total size is unknown.
+   */
+  readonly attribute long long totalSize;
+
+  /**
+   * The current number of bytes downloaded so far.  This attribute is set just
+   * prior to calling OnStartRequest on the observer passed to the start
+   * method.
+   *
+   * This attribute has a value of -1 if the current size is unknown.
+   */
+  readonly attribute long long currentSize;
+
+  /**
+   * Start the incremental download.
+   *
+   * @param observer
+   *        An observer to be notified of various events.  OnStartRequest is
+   *        called when finalURI and totalSize have been determined or when an
+   *        error occurs.  OnStopRequest is called when the file is completely
+   *        downloaded or when an error occurs.  If this object implements
+   *        nsIProgressEventSink, then its OnProgress method will be called as
+   *        data is written to the destination file.  If this object implements
+   *        nsIInterfaceRequestor, then it will be assigned as the underlying
+   *        channel's notification callbacks, which allows it to provide a
+   *        nsIAuthPrompt implementation if needed by the channel, for example.
+   * @param ctxt
+   *        User defined object forwarded to the observer's methods.
+   */
+  void start(in nsIRequestObserver observer,
+             in nsISupports ctxt);
+};
diff --git a/netwerk/base/nsIIncrementalStreamLoader.idl b/netwerk/base/nsIIncrementalStreamLoader.idl
new file mode 100644
index 0000000000..60aa9cfef5
--- /dev/null
+++ b/netwerk/base/nsIIncrementalStreamLoader.idl
@@ -0,0 +1,100 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+interface nsIRequest;
+interface nsIIncrementalStreamLoader;
+
+[scriptable, uuid(07c3d2cc-5454-4618-9f4f-cd93de9504a4)]
+interface nsIIncrementalStreamLoaderObserver : nsISupports
+{
+    /**
+     * Called when new data has arrived on the stream.
+     *
+     * @param loader the stream loader that loaded the stream.
+     * @param ctxt the context parameter of the underlying channel
+     * @param dataLength the length of the new data received
+     * @param data the contents of the new data received.
+     *
+     * This method will always be called asynchronously by the
+     * nsIIncrementalStreamLoader involved, on the thread that called the
+     * loader's init() method.
+     *
+     * If the observer wants to not accumulate all or portional of the data in
+     * the internal buffer, the consumedLength shall be set to the value of
+     * the dataLength or less. By default the consumedLength value is assumed 0.
+     * The data and dataLength reflect the non-consumed data and will be
+     * accumulated if consumedLength is not set.
+     *
+     * In comparison with onStreamComplete(), the data buffer cannot be
+     * adopted if this method returns NS_SUCCESS_ADOPTED_DATA.
+     */
+    void onIncrementalData(in nsIIncrementalStreamLoader loader,
+                           in nsISupports ctxt,
+                           in unsigned long dataLength,
+                           [const,array,size_is(dataLength)] in octet data,
+                           inout unsigned long consumedLength);
+
+    /**
+     * Called when the entire stream has been loaded.
+     *
+     * @param loader the stream loader that loaded the stream.
+     * @param ctxt the context parameter of the underlying channel
+     * @param status the status of the underlying channel
+     * @param resultLength the length of the data loaded
+     * @param result the data
+     *
+     * This method will always be called asynchronously by the
+     * nsIIncrementalStreamLoader involved, on the thread that called the
+     * loader's init() method.
+     *
+     * If the observer wants to take over responsibility for the
+     * data buffer (result), it returns NS_SUCCESS_ADOPTED_DATA
+     * in place of NS_OK as its success code. The loader will then
+     * "forget" about the data and not free() it after
+     * onStreamComplete() returns; observer must call free()
+     * when the data is no longer required.
+     */
+    void onStreamComplete(in nsIIncrementalStreamLoader loader,
+                          in nsISupports ctxt,
+                          in nsresult status,
+                          in unsigned long resultLength,
+                          [const,array,size_is(resultLength)] in octet result);
+};
+
+/**
+ * Asynchronously loads a channel into a memory buffer.
+ *
+ * To use this interface, first call init() with a nsIIncrementalStreamLoaderObserver
+ * that will be notified when the data has been loaded. Then call asyncOpen()
+ * on the channel with the nsIIncrementalStreamLoader as the listener. The context
+ * argument in the asyncOpen() call will be passed to the onStreamComplete()
+ * callback.
+ *
+ * XXX define behaviour for sizes >4 GB
+ */
+[scriptable, uuid(a023b060-ba23-431a-b449-2dd63e220554)]
+interface nsIIncrementalStreamLoader : nsIStreamListener
+{
+    /**
+     * Initialize this stream loader, and start loading the data.
+     *
+     * @param aObserver
+     *        An observer that will be notified when the data is complete.
+     */
+    void init(in nsIIncrementalStreamLoaderObserver aObserver);
+
+    /**
+     * Gets the number of bytes read so far.
+     */
+    readonly attribute unsigned long numBytesRead;
+
+    /**
+     * Gets the request that loaded this file.
+     * null after the request has finished loading.
+     */
+    readonly attribute nsIRequest request;
+};
diff --git a/netwerk/base/nsIInputStreamChannel.idl b/netwerk/base/nsIInputStreamChannel.idl
new file mode 100644
index 0000000000..9172a2b283
--- /dev/null
+++ b/netwerk/base/nsIInputStreamChannel.idl
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIInputStream;
+interface nsIURI;
+
+/**
+ * nsIInputStreamChannel
+ *
+ * This interface provides methods to initialize an input stream channel.
+ * The input stream channel serves as a data pump for an input stream.
+ */
+[scriptable, uuid(ea730238-4bfd-4015-8489-8f264d05b343)]
+interface nsIInputStreamChannel : nsISupports
+{
+    /**
+     * Sets the URI for this channel.  This must be called before the
+     * channel is opened, and it may only be called once.
+     */
+    void setURI(in nsIURI aURI);
+
+    /**
+     * Get/set the content stream
+     *
+     * This stream contains the data that will be pushed to the channel's
+     * stream listener.  If the stream is non-blocking and supports the
+     * nsIAsyncInputStream interface, then the stream will be read directly.
+     * Otherwise, the stream will be read on a background thread.
+     *
+     * This attribute must be set before the channel is opened, and it may
+     * only be set once.
+     *
+     * @throws NS_ERROR_IN_PROGRESS if the setter is called after the channel
+     * has been opened.
+     */
+    attribute nsIInputStream contentStream;
+
+    /**
+     * Get/set the srcdoc data string.  When the input stream channel is
+     * created to load a srcdoc iframe, this is set to hold the value of the
+     * srcdoc attribute.
+     *
+     * This should be the same value used to create contentStream, but this is
+     * not checked.
+     *
+     * Changing the value of this attribute will not otherwise affect the
+     * functionality of the channel or input stream.
+     */
+    attribute AString srcdocData;
+
+    /**
+     * Returns true if srcdocData has been set within the channel.
+     */
+    readonly attribute boolean isSrcdocChannel;
+
+    /**
+     * The base URI to be used for the channel.  Used when the base URI cannot
+     * be inferred by other means, for example when this is a srcdoc channel.
+     */
+    attribute nsIURI baseURI;
+};
diff --git a/netwerk/base/nsIInputStreamPump.idl b/netwerk/base/nsIInputStreamPump.idl
new file mode 100644
index 0000000000..2bd1ee1683
--- /dev/null
+++ b/netwerk/base/nsIInputStreamPump.idl
@@ -0,0 +1,66 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+
+interface nsIInputStream;
+interface nsISerialEventTarget;
+interface nsIStreamListener;
+
+/**
+ * nsIInputStreamPump
+ *
+ * This interface provides a means to configure and use a input stream pump
+ * instance.  The input stream pump will asynchronously read from an input
+ * stream, and push data to an nsIStreamListener instance.  It utilizes the
+ * current thread's nsIEventTarget in order to make reading from the stream
+ * asynchronous. A different thread can be used if the pump also implements
+ * nsIThreadRetargetableRequest.
+ *
+ * If the given stream supports nsIAsyncInputStream, then the stream pump will
+ * call the stream's AsyncWait method to drive the stream listener.  Otherwise,
+ * the stream will be read on a background thread utilizing the stream
+ * transport service.  More details are provided below.
+ */
+[scriptable, uuid(400F5468-97E7-4d2b-9C65-A82AECC7AE82)]
+interface nsIInputStreamPump : nsIRequest
+{
+    /**
+     * Initialize the input stream pump.
+     *
+     * @param aStream
+     *        contains the data to be read.  if the input stream is non-blocking,
+     *        then it will be QI'd to nsIAsyncInputStream.  if the QI succeeds
+     *        then the stream will be read directly.  otherwise, it will be read
+     *        on a background thread using the stream transport service.
+     * @param aSegmentSize
+     *        if the stream transport service is used, then this parameter
+     *        specifies the segment size for the stream transport's buffer.
+     *        pass 0 to specify the default value.
+     * @param aSegmentCount
+     *        if the stream transport service is used, then this parameter
+     *        specifies the segment count for the stream transport's buffer.
+     *        pass 0 to specify the default value.
+     * @param aCloseWhenDone
+     *        if true, the input stream will be closed after it has been read.
+     * @param aMainThreadTarget
+     *        a labeled main therad event target.
+     */
+    void init(in nsIInputStream aStream,
+              in unsigned long  aSegmentSize,
+              in unsigned long  aSegmentCount,
+              in boolean        aCloseWhenDone,
+              [optional] in nsISerialEventTarget aMainThreadTarget);
+
+    /**
+     * asyncRead causes the input stream to be read in chunks and delivered
+     * asynchronously to the listener via OnDataAvailable.
+     *
+     * @param aListener
+     *        receives notifications.
+     * @param aListenerContext
+     *        passed to listener methods.
+     */
+    void asyncRead(in nsIStreamListener aListener);
+};
diff --git a/netwerk/base/nsIInterceptionInfo.idl b/netwerk/base/nsIInterceptionInfo.idl
new file mode 100644
index 0000000000..d3c1b030ac
--- /dev/null
+++ b/netwerk/base/nsIInterceptionInfo.idl
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: ft=cpp tw=78 sw=2 et ts=2 sts=2 cin
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsIContentPolicy.idl"
+
+interface nsIPrincipal;
+interface nsIRedirectHistoryEntry;
+
+%{C++
+#include "nsTArray.h"
+%}
+
+[ref] native nsIRedirectHistoryEntryArray(const nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>);
+/**
+ * nsIInterceptionInfo is used to record the needed information of the
+ * InterceptedHttpChannel.
+ * This infomration need to be propagated to the new channel which created by
+ * FetchEvent.request or ServiceWorker NavigationPreload.
+ */
+[scriptable, builtinclass, uuid(8b9cd81f-3cd1-4f6a-9086-92a9bbf055f4)]
+interface nsIInterceptionInfo : nsISupports
+{
+  /**
+   * InterceptedHttpChannel's triggering principal
+   */
+  [noscript, notxpcom, nostdcall, binaryname(TriggeringPrincipal)]
+  nsIPrincipal binaryTriggeringPrincipal();
+
+  [noscript, notxpcom, nostdcall, binaryname(SetTriggeringPrincipal)]
+  void binarySetTriggeringPrincipal(in nsIPrincipal aPrincipal);
+
+  /**
+   * InterceptedHttpChannel's content policy type
+   */
+  [noscript, notxpcom, nostdcall, binaryname(ContentPolicyType)]
+  nsContentPolicyType binaryContentPolicyType();
+
+  [noscript, notxpcom, nostdcall, binaryname(ExternalContentPolicyType)]
+  nsContentPolicyType binaryExternalContentPolicyType();
+
+  [noscript, notxpcom, nostdcall, binaryname(SetContentPolicyType)]
+  void binarySetContentPolicyType(in nsContentPolicyType aContentPolicyType);
+
+%{ C++
+  inline ExtContentPolicyType GetExtContentPolicyType()
+  {
+    return static_cast<ExtContentPolicyType>(ExternalContentPolicyType());
+  }
+%}
+
+  /**
+   * The InterceptedHttpChannel's redirect chain
+   */
+  [noscript, notxpcom, nostdcall, binaryname(RedirectChain)]
+  nsIRedirectHistoryEntryArray binaryRedirectChain();
+
+  [noscript, notxpcom, nostdcall, binaryname(SetRedirectChain)]
+  void binarySetRedirectChain(
+      in nsIRedirectHistoryEntryArray aRedirectChain);
+
+  /**
+   * The InterceptedHttpChannel is a third party channel or not.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(FromThirdParty)]
+  bool binaryFromThirdParty();
+
+  [noscript, notxpcom, nostdcall, binaryname(SetFromThirdParty)]
+  void binarySetFromThirdParty(in bool aFromThirdParty);
+};
diff --git a/netwerk/base/nsILoadContextInfo.idl b/netwerk/base/nsILoadContextInfo.idl
new file mode 100644
index 0000000000..bbf2b5d48a
--- /dev/null
+++ b/netwerk/base/nsILoadContextInfo.idl
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{ C++
+#include "mozilla/BasePrincipal.h"
+%}
+native OriginAttributesNativePtr(const mozilla::OriginAttributes*);
+
+interface nsILoadContext;
+interface nsIDOMWindow;
+
+/**
+ * Helper interface to carry informatin about the load context
+ * encapsulating origin attributes and IsAnonymous, IsPrivite properties.
+ * It shall be used where nsILoadContext cannot be used or is not
+ * available.
+ */
+
+[scriptable, builtinclass, uuid(555e2f8a-a1f6-41dd-88ca-ed4ed6b98a22)]
+interface nsILoadContextInfo : nsISupports
+{
+  /**
+   * Whether the context is in a Private Browsing mode
+   */
+  readonly attribute boolean isPrivate;
+
+  /**
+   * Whether the load is initiated as anonymous
+   */
+  readonly attribute boolean isAnonymous;
+
+  /**
+   * OriginAttributes hiding all the security context attributes
+   */
+  [implicit_jscontext]
+  readonly attribute jsval originAttributes;
+  [noscript, notxpcom, nostdcall, binaryname(OriginAttributesPtr)]
+  OriginAttributesNativePtr binaryOriginAttributesPtr();
+
+%{C++
+  /**
+   * De-XPCOMed getters
+   */
+  bool IsPrivate()
+  {
+    bool pb;
+    GetIsPrivate(&pb);
+    return pb;
+  }
+
+  bool IsAnonymous()
+  {
+    bool anon;
+    GetIsAnonymous(&anon);
+    return anon;
+  }
+
+  bool Equals(nsILoadContextInfo *aOther)
+  {
+    return IsAnonymous() == aOther->IsAnonymous() &&
+           *OriginAttributesPtr() == *aOther->OriginAttributesPtr();
+  }
+%}
+};
+
+/**
+ * Since OriginAttributes struct limits the implementation of
+ * nsILoadContextInfo (that needs to be thread safe) to C++,
+ * we need a scriptable factory to create instances of that
+ * interface from JS.
+ */
+[scriptable, uuid(c1c7023d-4318-4f99-8307-b5ccf0558793)]
+interface nsILoadContextInfoFactory : nsISupports
+{
+  readonly attribute nsILoadContextInfo default;
+  readonly attribute nsILoadContextInfo private;
+  readonly attribute nsILoadContextInfo anonymous;
+  [implicit_jscontext]
+  nsILoadContextInfo custom(in boolean aAnonymous, in jsval aOriginAttributes);
+  nsILoadContextInfo fromLoadContext(in nsILoadContext aLoadContext, in boolean aAnonymous);
+  nsILoadContextInfo fromWindow(in nsIDOMWindow aWindow, in boolean aAnonymous);
+};
diff --git a/netwerk/base/nsILoadGroup.idl b/netwerk/base/nsILoadGroup.idl
new file mode 100644
index 0000000000..06e51e442b
--- /dev/null
+++ b/netwerk/base/nsILoadGroup.idl
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequest.idl"
+
+interface nsISimpleEnumerator;
+interface nsIRequestObserver;
+interface nsIInterfaceRequestor;
+interface nsIRequestContext;
+
+/**
+ * A load group maintains a collection of nsIRequest objects.
+ * This is used in lots of places where groups of requests need to be tracked.
+ * For example, Document::mDocumentLoadGroup is used to track all requests
+ * made for subdocuments in order to track page load progress and allow all
+ * requests made on behalf of the document to be stopped, etc.
+ */
+[builtinclass, scriptable, uuid(f0c87725-7a35-463c-9ceb-2c07f23406cc)]
+interface nsILoadGroup : nsIRequest
+{
+    /**
+     * The group observer is notified when requests are added to and removed
+     * from this load group.  The groupObserver is weak referenced.
+     */
+    attribute nsIRequestObserver groupObserver;
+
+    /**
+     * Accesses the default load request for the group.  Each time a number
+     * of requests are added to a group, the defaultLoadRequest may be set
+     * to indicate that all of the requests are related to a base request.
+     *
+     * The load group inherits its load flags from the default load request.
+     * If the default load request is NULL, then the group's load flags are
+     * not changed.
+     */
+    attribute nsIRequest defaultLoadRequest;
+
+    /**
+     * Adds a new request to the group.  This will cause the default load
+     * flags to be applied to the request.  If this is a foreground
+     * request then the groupObserver's onStartRequest will be called.
+     *
+     * If the request is the default load request or if the default load
+     * request is null, then the load group will inherit its load flags from
+     * the request.
+     */
+    void addRequest(in nsIRequest aRequest,
+                    in nsISupports aContext);
+
+    /**
+     * Removes a request from the group.  If this is a foreground request
+     * then the groupObserver's onStopRequest will be called.
+     *
+     * By the time this call ends, aRequest will have been removed from the
+     * loadgroup, even if this function throws an exception.
+     */
+    void removeRequest(in nsIRequest aRequest,
+                       in nsISupports aContext,
+                       in nsresult aStatus);
+
+    /**
+     * Returns the requests contained directly in this group.
+     * Enumerator element type: nsIRequest.
+     */
+    readonly attribute nsISimpleEnumerator requests;
+
+    /**
+     * Returns the count of "active" requests (ie. requests without the
+     * LOAD_BACKGROUND bit set).
+     */
+    readonly attribute unsigned long activeCount;
+
+    /**
+     * Notification callbacks for the load group.
+     */
+    attribute nsIInterfaceRequestor notificationCallbacks;
+
+    /**
+     * Context for managing things like js/css connection blocking,
+     * and per-tab connection grouping.
+     */
+    readonly attribute unsigned long long requestContextID;
+
+    /**
+     * The set of load flags that will be added to all new requests added to
+     * this group. Any existing requests in the load group are not modified,
+     * so it is expected these flags will be added before requests are added
+     * to the group - typically via nsIDocShell::defaultLoadFlags on a new
+     * docShell.
+     * Note that these flags are *not* added to the default request for the
+     * load group; it is expected the default request will already have these
+     * flags (again, courtesy of setting nsIDocShell::defaultLoadFlags before
+     * the docShell has created the default request.)
+     */
+    attribute nsLoadFlags defaultLoadFlags;
+
+    /**
+     * Returns true if the loadGroup belongs to a discarded context, such as, a
+     * terminated private browsing session.
+     */
+    [infallible]
+    readonly attribute boolean isBrowsingContextDiscarded;
+};
diff --git a/netwerk/base/nsILoadGroupChild.idl b/netwerk/base/nsILoadGroupChild.idl
new file mode 100644
index 0000000000..959913a474
--- /dev/null
+++ b/netwerk/base/nsILoadGroupChild.idl
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsILoadGroup;
+
+/**
+ * nsILoadGroupChild provides a hierarchy of load groups so that the
+ * root load group can be used to conceptually tie a series of loading
+ * operations into a logical whole while still leaving them separate
+ * for the purposes of cancellation and status events.
+ */
+
+[builtinclass, scriptable, uuid(02efe8e2-fbbc-4718-a299-b8a09c60bf6b)]
+interface nsILoadGroupChild : nsISupports
+{
+    /**
+     * The parent of this load group. It is stored with
+     * a nsIWeakReference/nsWeakPtr so there is no requirement for the
+     * parentLoadGroup to out live the child, nor will the child keep a
+     * reference count on the parent.
+     */
+    attribute nsILoadGroup parentLoadGroup;
+
+    /**
+     * The nsILoadGroup associated with this nsILoadGroupChild
+     */
+    readonly attribute nsILoadGroup childLoadGroup;
+
+    /**
+     * The rootLoadGroup is the recursive parent of this
+     * load group where parent is defined as parentlLoadGroup if set
+     * or childLoadGroup.loadGroup as a backup. (i.e. parentLoadGroup takes
+     * precedence.) The nsILoadGroup child is the root if neither parent
+     * nor loadgroup attribute is specified.
+     */
+    readonly attribute nsILoadGroup rootLoadGroup;
+};
diff --git a/netwerk/base/nsILoadInfo.idl b/netwerk/base/nsILoadInfo.idl
new file mode 100644
index 0000000000..79fdcc5e4d
--- /dev/null
+++ b/netwerk/base/nsILoadInfo.idl
@@ -0,0 +1,1488 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: ft=cpp tw=78 sw=2 et ts=2 sts=2 cin
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsIContentPolicy.idl"
+#include "nsIScriptSecurityManager.idl"
+#include "nsIInterceptionInfo.idl"
+
+interface nsIChannel;
+interface nsIContentSecurityPolicy;
+interface nsICookieJarSettings;
+interface nsICSPEventListener;
+interface nsINode;
+interface nsIPrincipal;
+interface nsIRedirectHistoryEntry;
+interface nsIURI;
+webidl Document;
+webidl BrowsingContext;
+native LoadContextRef(already_AddRefed<nsISupports>);
+%{C++
+#include "nsTArray.h"
+#include "mozilla/LoadTainting.h"
+#include "mozilla/OriginAttributes.h"
+#include "mozilla/UniquePtr.h"
+#include "nsStringFwd.h"
+
+namespace mozilla {
+namespace dom {
+class ClientInfo;
+class ClientSource;
+class PerformanceStorage;
+class ServiceWorkerDescriptor;
+} // namespace dom
+} // namespace mozilla
+%}
+
+[ref] native nsIRedirectHistoryEntryArray(const nsTArray<nsCOMPtr<nsIRedirectHistoryEntry>>);
+native OriginAttributes(mozilla::OriginAttributes);
+[ref] native const_OriginAttributesRef(const mozilla::OriginAttributes);
+[ref] native CStringArrayRef(const nsTArray<nsCString>);
+[ref] native StringArrayRef(const nsTArray<nsString>);
+[ref] native Uint64ArrayRef(const nsTArray<uint64_t>);
+[ref] native PrincipalArrayRef(const nsTArray<nsCOMPtr<nsIPrincipal>>);
+[ref] native const_ClientInfoRef(const mozilla::dom::ClientInfo);
+      native UniqueClientSource(mozilla::UniquePtr<mozilla::dom::ClientSource>);
+      native UniqueClientSourceMove(mozilla::UniquePtr<mozilla::dom::ClientSource>&&);
+[ref] native const_MaybeClientInfoRef(const mozilla::Maybe<mozilla::dom::ClientInfo>);
+[ref] native const_ServiceWorkerDescriptorRef(const mozilla::dom::ServiceWorkerDescriptor);
+[ref] native const_MaybeServiceWorkerDescriptorRef(const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>);
+[ptr] native PerformanceStoragePtr(mozilla::dom::PerformanceStorage);
+      native LoadTainting(mozilla::LoadTainting);
+      native CSPRef(already_AddRefed<nsIContentSecurityPolicy>);
+
+typedef unsigned long nsSecurityFlags;
+
+/**
+ * The LoadInfo object contains information about a network load, why it
+ * was started, and how we plan on using the resulting response.
+ * If a network request is redirected, the new channel will receive a new
+ * LoadInfo object. The new object will contain mostly the same
+ * information as the pre-redirect one, but updated as appropriate.
+ * For detailed information about what parts of LoadInfo are updated on
+ * redirect, see documentation on individual properties.
+ */
+[scriptable, builtinclass, uuid(ddc65bf9-2f60-41ab-b22a-4f1ae9efcd36)]
+interface nsILoadInfo : nsISupports
+{
+  /**
+   * The following five flags determine the security mode and hence what kind of
+   * security checks should be performed throughout the lifetime of the channel.
+   *
+   *    * SEC_REQUIRE_SAME_ORIGIN_INHERITS_SEC_CONTEXT
+   *    * SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED
+   *    * SEC_ALLOW_CROSS_ORIGIN_INHERITS_SEC_CONTEXT
+   *    * SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL
+   *    * SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT
+   *
+   * Exactly one of these flags are required to be set in order to allow
+   * the channel to perform the correct security checks (SOP, CORS, ...) and
+   * return the correct result principal. If none or more than one of these
+   * flags are set AsyncOpen will fail.
+   */
+
+   /**
+    * Warning: Never use this flag when creating a new channel!
+    * Only use this flag if you have to create a temporary LoadInfo
+    * for performing an explicit nsIContentPolicy check, like e.g.
+    * when loading something from the cache that needs an explicit
+    * nsIContentPolicy check. In all other cases pick one of the
+    * security flags underneath.
+    */
+  const unsigned long SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK = 0;
+
+  /*
+   * Enforce the same origin policy where loads inherit the principal.
+   * See the documentation for principalToInherit, which describes exactly what
+   * principal is inherited.
+   */
+  const unsigned long SEC_REQUIRE_SAME_ORIGIN_INHERITS_SEC_CONTEXT = (1<<0);
+
+  /*
+   * Enforce the same origin policy and data: loads are blocked.
+   */
+  const unsigned long SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED = (1<<1);
+
+  /**
+   * Allow loads from other origins. Loads which inherit the principal should
+   * see the documentation for principalToInherit, which describes exactly what
+   * principal is inherited.
+   *
+   * Commonly used by plain <img>, <video>, <link rel=stylesheet> etc.
+   */
+  const unsigned long SEC_ALLOW_CROSS_ORIGIN_INHERITS_SEC_CONTEXT = (1 << 2);
+
+  /**
+   * Allow loads from other origins. Loads from data: will be allowed,
+   * but the resulting resource will get a null principal.
+   * Used in blink/webkit for <iframe>s. Likely also the mode
+   * that should be used by most Chrome code.
+   */
+  const unsigned long SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL = (1<<3);
+
+  /**
+   * Allow loads from any origin, but require CORS for cross-origin loads.
+   * See the documentation for principalToInherit, which describes exactly what
+   * principal is inherited.
+   *
+   * Commonly used by <img crossorigin>, <video crossorigin>,
+   * XHR, fetch(), etc.
+   */
+  const unsigned long SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT = (1<<4);
+
+  /**
+   * Choose cookie policy. The default policy is equivalent to "INCLUDE" for
+   * SEC_REQUIRE_SAME_ORIGIN_* and SEC_ALLOW_CROSS_ORIGIN_* modes, and
+   * equivalent to "SAME_ORIGIN" for SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT mode.
+   *
+   * This means that if you want to perform a CORS load with credentials, pass
+   * SEC_COOKIES_INCLUDE.
+   *
+   * Note that these flags are still subject to the user's cookie policies.
+   * For example, if the user is blocking 3rd party cookies, those cookies
+   * will be blocked no matter which of these flags are set.
+   */
+  const unsigned long SEC_COOKIES_DEFAULT = (0 << 5);
+  const unsigned long SEC_COOKIES_INCLUDE = (1 << 5);
+  const unsigned long SEC_COOKIES_SAME_ORIGIN = (2 << 5);
+  const unsigned long SEC_COOKIES_OMIT = (3 << 5);
+
+  /**
+   * Force inheriting of the principal.  See the documentation for
+   * principalToInherit, which describes exactly what principal is inherited.
+   *
+   * Setting this flag will cause GetChannelResultPrincipal to return the
+   * principal to be inherited as the channel principal.
+   *
+   * This will happen independently of the scheme of the URI that the
+   * channel is loading.
+   *
+   * So if the principal that gets inherited is "http://a.com/", and the channel
+   * is loading the URI "http://b.com/whatever", GetChannelResultPrincipal
+   * will return a principal from "http://a.com/".
+   *
+   * This flag can not be used together with SANDBOXED_ORIGIN sandbox flag.  If
+   * both are passed to the LoadInfo constructor then this flag will be dropped.
+   * If you need to know whether this flag would have been present but was dropped
+   * due to sandboxing, check for the forceInheritPrincipalDropped flag.
+   */
+  const unsigned long SEC_FORCE_INHERIT_PRINCIPAL = (1<<7);
+
+  /**
+   * Inherit the Principal for about:blank.
+   */
+  const unsigned long SEC_ABOUT_BLANK_INHERITS = (1<<9);
+
+  /**
+   * Allow access to chrome: packages that are content accessible.
+   */
+  const unsigned long SEC_ALLOW_CHROME = (1<<10);
+
+  /**
+   * Disallow access to javascript: uris.
+   */
+  const unsigned long SEC_DISALLOW_SCRIPT = (1<<11);
+
+  /**
+   * Don't follow redirects. Instead the redirect response is returned
+   * as a successful response for the channel.
+   *
+   * Redirects not initiated by a server response, i.e. REDIRECT_INTERNAL and
+   * REDIRECT_STS_UPGRADE, are still followed.
+   *
+   * Note: If this flag is set and the channel response is a redirect, then
+   * the response body might not be available.
+   * This can happen if the redirect was cached.
+   */
+  const unsigned long SEC_DONT_FOLLOW_REDIRECTS = (1<<12);
+
+  /**
+   * Load an error page, it should be one of following : about:neterror,
+   * about:certerror, about:blocked, about:tabcrashed or about:restartrequired.
+   */
+  const unsigned long SEC_LOAD_ERROR_PAGE = (1<<13);
+
+  /**
+   * Force inheriting of the principal, overruling any owner that might be set
+   * on the channel. (Please note that channel.owner is deprecated and will be
+   * removed within Bug 1286838).  See the documentation for principalToInherit,
+   * which describes exactly what principal is inherited.
+   *
+   * Setting this flag will cause GetChannelResultPrincipal to return the
+   * principal to be inherited as the channel principal.
+   *
+   * This will happen independently of the scheme of the URI that the
+   * channel is loading.
+   */
+  const unsigned long SEC_FORCE_INHERIT_PRINCIPAL_OVERRULE_OWNER = (1<<14);
+
+  /**
+   * This is the principal of the network request's caller/requester where
+   * the resulting resource will be used. I.e. it is the principal which
+   * will get access to the result of the request. (Where "get access to"
+   * might simply mean "embed" depending on the type of resource that is
+   * loaded).
+   *
+   * For example for an image, it is the principal of the document where
+   * the image is rendered. For a stylesheet it is the principal of the
+   * document where the stylesheet will be applied.
+   *
+   * So if document at http://a.com/page.html loads an image from
+   * http://b.com/pic.jpg, then loadingPrincipal will be
+   * http://a.com/page.html.
+   *
+   * For <iframe> and <frame> loads, the LoadingPrincipal is the
+   * principal of the parent document. For top-level loads, the
+   * LoadingPrincipal is null. For all loads except top-level loads
+   * the LoadingPrincipal is never null.
+   *
+   * If the loadingPrincipal is the system principal, no security checks
+   * will be done at all. There will be no security checks on the initial
+   * load or any subsequent redirects. This means there will be no
+   * nsIContentPolicy checks or any CheckLoadURI checks. Because of
+   * this, never set the loadingPrincipal to the system principal when
+   * the URI to be loaded is controlled by a webpage.
+   * If the loadingPrincipal and triggeringPrincipal are both
+   * content principals, then we will always call into
+   * nsIContentPolicies and CheckLoadURI. The call to nsIContentPolicies
+   * and CheckLoadURI happen even if the URI to be loaded is same-origin
+   * with the loadingPrincipal or triggeringPrincipal.
+   */
+  readonly attribute nsIPrincipal loadingPrincipal;
+
+  /**
+   * A C++-friendly version of triggeringPrincipal.
+   *
+   * This is a bit awkward because we can't use
+   * binaryname(GetLoadingPrincipal).
+   */
+  [noscript, notxpcom, nostdcall]
+  nsIPrincipal virtualGetLoadingPrincipal();
+
+%{C++
+  nsIPrincipal* GetLoadingPrincipal() {
+    return VirtualGetLoadingPrincipal();
+  }
+%}
+
+  /**
+   * This is the principal which caused the network load to start. I.e.
+   * this is the principal which provided the URL to be loaded. This is
+   * often the same as the LoadingPrincipal, but there are a few cases
+   * where that's not true.
+   *
+   * For example for loads into an <iframe>, the LoadingPrincipal is always
+   * the principal of the parent document. However the triggeringPrincipal
+   * is the principal of the document which provided the URL that the
+   * <iframe> is navigating to. This could be the previous document inside
+   * the <iframe> which set document.location. Or a document elsewhere in
+   * the frame tree which contained a <a target="..."> which targetted the
+   * <iframe>.
+   *
+   * If a stylesheet links to a sub-resource, like an @imported stylesheet,
+   * or a background image, then the triggeringPrincipal is the principal
+   * of the stylesheet, while the LoadingPrincipal is the principal of the
+   * document being styled.
+   *
+   * The triggeringPrincipal is never null.
+   *
+   * If the triggeringPrincipal is the system principal, no security checks
+   * will be done at all. There will be no security checks on the initial
+   * load or any subsequent redirects. This means there will be no
+   * nsIContentPolicy checks or any CheckLoadURI checks. Because of
+   * this, never set the triggeringPrincipal to the system principal when
+   * the URI to be loaded is controlled by a webpage.
+   * If the loadingPrincipal and triggeringPrincipal are both
+   * content principals, then we will always call into
+   * nsIContentPolicies and CheckLoadURI. The call to nsIContentPolicies
+   * and CheckLoadURI happen even if the URI to be loaded is same-origin
+   * with the loadingPrincipal or triggeringPrincipal.
+   */
+  readonly attribute nsIPrincipal triggeringPrincipal;
+
+  /**
+   * A C++-friendly version of triggeringPrincipal.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(TriggeringPrincipal)]
+  nsIPrincipal binaryTriggeringPrincipal();
+
+  /**
+   * The remote type of the process which caused the network load to start. I.e.
+   * this is the remote type of the process which provided the URL to be loaded.
+   *
+   * For subresource loads, this should be the same as the process which will
+   * handle the response, however for document loads this may both be different
+   * than the final process, as well as different from the process which starts
+   * the navigation.
+   *
+   * This field is intentionally not perfectly preserved over IPC, and will be
+   * reset to the remote type of the sending process when sent from a content
+   * process to the parent process.
+   */
+  attribute AUTF8String triggeringRemoteType;
+
+  /**
+   * For non-document loads the principalToInherit is always null. For
+   * loads of type TYPE_DOCUMENT or TYPE_SUBDOCUMENT the principalToInherit
+   * might be null. If it's non null, then this is the principal that is
+   * inherited if a principal needs to be inherited. If the principalToInherit
+   * is null but the inherit flag is set, then the triggeringPrincipal is
+   * the principal that is inherited.
+   */
+  attribute nsIPrincipal principalToInherit;
+
+  /**
+   * A C++-friendly version of principalToInherit.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(PrincipalToInherit)]
+  nsIPrincipal binaryPrincipalToInherit();
+
+  /**
+   * Finds the correct principal to inherit for the given channel, based on
+   * the values of PrincipalToInherit and TriggeringPrincipal.
+   */
+  [noscript, notxpcom, nostdcall]
+  nsIPrincipal FindPrincipalToInherit(in nsIChannel aChannel);
+
+  /**
+   * This is the ownerDocument of the LoadingNode. Unless the LoadingNode
+   * is a Document, in which case the LoadingDocument is the same as the
+   * LoadingNode.
+   *
+   * For top-level loads, and for loads originating from workers, the
+   * LoadingDocument is null. When the LoadingDocument is not null, the
+   * LoadingPrincipal is set to the principal of the LoadingDocument.
+   */
+  readonly attribute Document loadingDocument;
+
+  /**
+   * A C++-friendly version of loadingDocument (loadingNode).
+   * This is the Node where the resulting resource will be used. I.e. it is
+   * the Node which will get access to the result of the request. (Where
+   * "get access to" might simply mean "embed" depending on the type of
+   * resource that is loaded).
+   *
+   * For example for an <img>/<video> it is the image/video element. For
+   * document loads inside <iframe> and <frame>s, the LoadingNode is the
+   * <iframe>/<frame> element. For an XMLHttpRequest, it is the Document
+   * which contained the JS which initiated the XHR. For a stylesheet, it
+   * is the Document that contains <link rel=stylesheet>.
+   *
+   * For loads triggered by the HTML pre-parser, the LoadingNode is the
+   * Document which is currently being parsed.
+   *
+   * For top-level loads, and for loads originating from workers, the
+   * LoadingNode is null. If the LoadingNode is non-null, then the
+   * LoadingPrincipal is the principal of the LoadingNode.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(LoadingNode)]
+  nsINode binaryLoadingNode();
+
+  /**
+   * A C++ friendly version of the loadingContext for toplevel loads.
+   * Most likely you want to query the ownerDocument or LoadingNode
+   * and not this context only available for TYPE_DOCUMENT loads.
+   * Please note that except for loads of TYPE_DOCUMENT, this
+   * ContextForTopLevelLoad will always return null.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(ContextForTopLevelLoad)]
+  LoadContextRef binaryContextForTopLevelLoad();
+
+  /**
+   * For all loads except loads of TYPE_DOCUMENT, the loadingContext
+   * simply returns the loadingNode. For loads of TYPE_DOCUMENT this
+   * will return the context available for top-level loads which
+   * do not have a loadingNode.
+   */
+  [binaryname(LoadingContextXPCOM)]
+  readonly attribute nsISupports loadingContext;
+
+  /**
+   * A C++ friendly version of the loadingContext.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(GetLoadingContext)]
+  LoadContextRef binaryGetLoadingContext();
+
+  /**
+   * The securityFlags of that channel.
+   */
+  readonly attribute nsSecurityFlags securityFlags;
+
+%{C++
+  inline nsSecurityFlags GetSecurityFlags()
+  {
+    nsSecurityFlags result;
+    mozilla::DebugOnly<nsresult> rv = GetSecurityFlags(&result);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return result;
+  }
+%}
+
+  /**
+   * The sandboxFlags of that channel.
+   */
+  [infallible] readonly attribute unsigned long sandboxFlags;
+
+  /**
+  *   The TriggingSandboxFlags are the SandboxFlags of the entity
+  *   responsible for causing the load to occur.
+  */
+  [infallible] attribute unsigned long triggeringSandboxFlags;
+
+  /**
+   * Allows to query only the security mode bits from above.
+   */
+  [infallible] readonly attribute unsigned long securityMode;
+
+  /**
+   * This flag is used for any browsing context where we should not sniff
+   * the content type. E.g if an iframe has the XCTO nosniff header, then
+   * that flag is set to true so we skip content sniffing for that browsing
+   * context.
+   */
+  [infallible] attribute boolean skipContentSniffing;
+
+  /**
+   * (default) If this flag is set, it has not yet been determined if the
+   * HTTPS-Only mode will upgrade the request.
+   */
+  const unsigned long HTTPS_ONLY_UNINITIALIZED = (1 << 0);
+
+  /**
+   * Indicates that the request will get upgraded, and the HTTPS-Only
+   * StreamListener got registered.
+   */
+  const unsigned long HTTPS_ONLY_UPGRADED_LISTENER_NOT_REGISTERED = (1 << 1);
+
+  /**
+   * Indicates that this is the first time the request gets upgraded, and thus
+   * the HTTPS-Only StreamListener hasn't been registered yet. Even though there
+   * might be multiple channels per request that have to be upgraded (e.g.,
+   * because of redirects), the StreamListener only has to be attached to one
+   * channel.
+   */
+  const unsigned long HTTPS_ONLY_UPGRADED_LISTENER_REGISTERED = (1 << 2);
+
+  /**
+   * This flag can be manually set if the HTTPS-Only mode should exempt the
+   * request and not upgrade it. (e.g in the case of OCSP.
+   */
+  const unsigned long HTTPS_ONLY_EXEMPT = (1 << 3);
+
+  /**
+   * This flag can only ever be set on top-level loads. It indicates
+   * that the top-level https connection succeeded. This flag is mostly
+   * used to counter time-outs which allows to cancel the channel
+   * if the https load has not started.
+   */
+  const unsigned long HTTPS_ONLY_TOP_LEVEL_LOAD_IN_PROGRESS = (1 << 4);
+
+   /**
+   * This flag can only ever be set on downloads. It indicates
+   * that the download https connection succeeded. This flag is mostly
+   * used to counter time-outs which allows to cancel the channel
+   * if the https load has not started.
+   */
+  const unsigned long HTTPS_ONLY_DOWNLOAD_IN_PROGRESS = (1 << 5);
+
+  /**
+   * This flag indicates that the request should not be logged to the
+   * console.
+   */
+  const unsigned long HTTPS_ONLY_DO_NOT_LOG_TO_CONSOLE = (1 << 6);
+
+  /**
+   * This flag indicates that the request was upgraded by https-first mode.
+   */
+  const unsigned long HTTPS_ONLY_UPGRADED_HTTPS_FIRST = (1 << 7);
+
+  /**
+   * This flag indicates that the request should not be blocked by ORB.
+   */
+  const unsigned long HTTPS_ONLY_BYPASS_ORB = (1 << 8);
+
+  /**
+   * Upgrade state of HTTPS-Only Mode. The flag HTTPS_ONLY_EXEMPT can get
+   * set on requests that should be excempt from an upgrade.
+   */
+  [infallible] attribute unsigned long httpsOnlyStatus;
+
+  /**
+   * Reflects whetehr this is an HTTP Strict Transport Security host
+   */
+[infallible] attribute boolean hstsStatus;
+
+  /**
+   * Returns true if at the time of the loadinfo construction the document
+   * that triggered this load has the bit hasValidTransientUserGestureActivation
+   * set or the load was triggered from External. (Mostly this bool is used
+   * in the context of Sec-Fetch-User.)
+   */
+  [infallible] attribute boolean hasValidUserGestureActivation;
+
+  /**
+   * We disallow the SystemPrincipal to initiate requests to
+   * the public web. This flag is to allow exceptions.
+   */
+  [infallible] attribute boolean allowDeprecatedSystemRequests;
+
+  /**
+   * Only ever returns true if the loadinfo is of TYPE_SCRIPT and
+   * the script was created by the HTML parser.
+   */
+  [infallible] attribute boolean parserCreatedScript;
+
+  /**
+   * True if this request is known to have been triggered by a user
+   * manually requesting the URI to be saved.
+   */
+  [infallible] attribute boolean isUserTriggeredSave;
+
+  /**
+   * True if this request is from DevTools.
+   */
+  [infallible] attribute boolean isInDevToolsContext;
+
+  /**
+   * True if this request is embedded in a context that can't be third-party
+   * (i.e. an iframe embedded in a cross-origin parent window). If this is
+   * false, then this request may be third-party if it's a third-party to
+   * loadingPrincipal.
+   */
+  [infallible] attribute boolean isInThirdPartyContext;
+
+  /**
+   * True if this request is a third party in respect to the top-level window.
+   *
+   * Note that this doesn't consider the parent window. I.e. It will still
+   * return false even in the case that the parent is cross-origin but the
+   * top-level is same-origin.
+   *
+   * This value would be set during opening the channel in parent and propagate
+   * to the channel in the content.
+   */
+  [infallible] attribute boolean isThirdPartyContextToTopWindow;
+
+  /**
+   * See the SEC_COOKIES_* flags above. This attribute will never return
+   * SEC_COOKIES_DEFAULT, but will instead return what the policy resolves to.
+   * I.e. SEC_COOKIES_SAME_ORIGIN for CORS mode, and SEC_COOKIES_INCLUDE
+   * otherwise.
+   */
+  [infallible] readonly attribute unsigned long cookiePolicy;
+
+  /**
+   * The cookie jar settings inherited from the top-level document's loadInfo.
+   * It cannot be null.
+   */
+  attribute nsICookieJarSettings cookieJarSettings;
+
+  cenum StoragePermissionState : 8 {
+    NoStoragePermission = 0,
+    HasStoragePermission = 1,
+    StoragePermissionAllowListed = 2,
+  };
+
+  /**
+   * The result of the storage permission check of the loading document. This
+   * value would be set during opening the channel.
+   */
+  [infallible] attribute nsILoadInfo_StoragePermissionState
+        storagePermission;
+
+  /**
+   * True if the load was triggered by a meta refresh.
+   */
+  [infallible] attribute boolean isMetaRefresh;
+
+  /**
+   * If forceInheritPrincipal is true, the data coming from the channel should
+   * inherit its principal, even when the data is loaded over http:// or another
+   * protocol that would normally use a URI-based principal.
+   *
+   * See the documentation for principalToInherit, which describes exactly what
+   * principal is inherited.
+   *
+   * This attribute will never be true when loadingSandboxed is true.
+   */
+  [infallible] readonly attribute boolean forceInheritPrincipal;
+
+  /**
+   * If forceInheritPrincipalOverruleOwner is true, the data coming from the
+   * channel should inherit the principal, even when the data is loaded over
+   * http:// or another protocol that would normally use a URI-based principal
+   * and even if the channel's .owner is not null.  This last is the difference
+   * between forceInheritPrincipalOverruleOwner and forceInheritPrincipal: the
+   * latter does _not_ overrule the .owner setting.
+   *
+   * See the documentation for principalToInherit, which describes exactly what
+   * principal is inherited.
+   */
+  [infallible] readonly attribute boolean forceInheritPrincipalOverruleOwner;
+
+  /**
+   * If loadingSandboxed is true, the data coming from the channel is
+   * being loaded sandboxed, so it should have a nonce origin and
+   * hence should use a NullPrincipal.
+   */
+  [infallible] readonly attribute boolean loadingSandboxed;
+
+  /**
+   * If aboutBlankInherits is true, then about:blank should inherit
+   * the principal.
+   */
+  [infallible] readonly attribute boolean aboutBlankInherits;
+
+  /**
+   * If allowChrome is true, then use nsIScriptSecurityManager::ALLOW_CHROME
+   * when calling CheckLoadURIWithPrincipal().
+   */
+  [infallible] readonly attribute boolean allowChrome;
+
+  /**
+   * If disallowScript is true, then use nsIScriptSecurityManager::DISALLOW_SCRIPT
+   * when calling CheckLoadURIWithPrincipal().
+   */
+  [infallible] readonly attribute boolean disallowScript;
+
+%{C++
+  uint32_t CheckLoadURIFlags() {
+    uint32_t flags = nsIScriptSecurityManager::STANDARD;
+    if (GetAllowChrome()) {
+      flags |= nsIScriptSecurityManager::ALLOW_CHROME;
+    }
+    if (GetDisallowScript()) {
+      flags |= nsIScriptSecurityManager::DISALLOW_SCRIPT;
+    }
+    return flags;
+  }
+%}
+
+  /**
+   * Returns true if SEC_DONT_FOLLOW_REDIRECTS is set.
+   */
+  [infallible] readonly attribute boolean dontFollowRedirects;
+
+  /**
+   * Returns true if SEC_LOAD_ERROR_PAGE is set.
+   */
+  [infallible] readonly attribute boolean loadErrorPage;
+
+  /**
+   * True if the load was initiated by a form request.
+   * This is important to know to handle the CSP directive navigate-to.
+   */
+  [infallible] attribute boolean isFormSubmission;
+
+  /**
+   * The external contentPolicyType of the channel, used for security checks
+   * like Mixed Content Blocking and Content Security Policy.
+   *
+   * Specifically, content policy types with _INTERNAL_ in their name will
+   * never get returned from this attribute.
+   */
+  readonly attribute nsContentPolicyType externalContentPolicyType;
+
+  /**
+   * CSP uses this parameter to send or not CSP violation events.
+   * Default value: true.
+   */
+  [infallible] attribute boolean sendCSPViolationEvents;
+
+%{ C++
+  inline ExtContentPolicyType GetExternalContentPolicyType()
+  {
+    nsContentPolicyType result;
+    mozilla::DebugOnly<nsresult> rv = GetExternalContentPolicyType(&result);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return static_cast<ExtContentPolicyType>(result);
+  }
+
+%}
+
+
+  /**
+   * The internal contentPolicyType of the channel, used for constructing
+   * RequestContext values when creating a fetch event for an intercepted
+   * channel.
+   *
+   * This should not be used for the purposes of security checks, since
+   * the content policy implementations cannot be expected to deal with
+   * _INTERNAL_ values.  Please use the contentPolicyType attribute above
+   * for that purpose.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(InternalContentPolicyType)]
+  nsContentPolicyType binaryInternalContentPolicyType();
+
+  readonly attribute nsContentPolicyType internalContentPolicyType;
+
+  /**
+   * Returns true if document or any of the documents ancestors
+   * up to the toplevel document make use of the CSP directive
+   * 'block-all-mixed-content'.
+   *
+   * Warning: If the loadingDocument is null, then the
+   * blockAllMixedContent is false.
+   */
+  [infallible] readonly attribute boolean blockAllMixedContent;
+
+  /**
+   * Returns true if document or any of the documents ancestors
+   * up to the toplevel document make use of the CSP directive
+   * 'upgrade-insecure-requests'.
+   *
+   * Warning: If the loadingDocument is null, then the
+   * upgradeInsecureRequests is false.
+   */
+  [infallible] readonly attribute boolean upgradeInsecureRequests;
+
+  /**
+   * Returns true if the the page is https and the content is upgradable from http
+   * requires 'security.mixed_content.upgrade_display_content' pref to be true.
+   * Currently this only upgrades display content but might be expanded to other loads.
+   * This is very similar in implementation to upgradeInsecureRequests but browser set.
+   */
+  [infallible] readonly attribute boolean browserUpgradeInsecureRequests;
+
+  /**
+   * Returns true if the display content was or will get upgraded from http to https.
+   * Requires 'security.mixed_content.upgrade_display_content' pref to be true.
+   * Flag is set purely to collect telemetry.
+   */
+  [infallible] attribute boolean browserDidUpgradeInsecureRequests;
+
+  /**
+   * Returns true if the the page is https and the content is upgradable from http
+   * requires 'security.mixed_content.upgrade_display_content' pref to be false.
+   * See browserUpgradeInsecureRequests for more details, this only happens
+   * when *not* upgrading purely for telemetry.
+   */
+  [infallible] readonly attribute boolean browserWouldUpgradeInsecureRequests;
+
+  /**
+   * If true, toplevel data: URI navigation is allowed
+   */
+  [infallible] attribute boolean forceAllowDataURI;
+
+  /**
+   * If true, insecure redirects to a data: URI are allowed.
+   */
+  [infallible] attribute boolean allowInsecureRedirectToDataURI;
+
+  /**
+   * If true, the content policy security check is excluded from web requests.
+   */
+  [infallible] attribute boolean skipContentPolicyCheckForWebRequest;
+
+  /**
+   * If true, this is the load of a frame's original src attribute
+   */
+  [infallible] attribute boolean originalFrameSrcLoad;
+
+  /**
+   * The SEC_FORCE_INHERIT_PRINCIPAL flag may be dropped when a load info
+   * object is created.  Specifically, it will be dropped if the SANDBOXED_ORIGIN
+   * sandbox flag is also present.  This flag is set if SEC_FORCE_INHERIT_PRINCIPAL
+   * was dropped.
+   */
+  [infallible] readonly attribute boolean forceInheritPrincipalDropped;
+
+  /**
+   * This is the inner window ID of the window in which the element being
+   * loaded lives.
+   *
+   * Note that this window ID can be 0 if the window is not
+   * available.
+   */
+  [infallible] readonly attribute unsigned long long innerWindowID;
+
+  /**
+   * The BrowsingContext performing the load for this nsILoadInfo object.
+   */
+  [infallible] readonly attribute unsigned long long browsingContextID;
+  [infallible] readonly attribute BrowsingContext browsingContext;
+
+  /**
+   * The BrowsingContext which the worker is associated.
+   *
+   * Note that this could be 0 if the load is not triggered in a WorkerScope.
+   * This value is only set and used in the parent process for some sitautions
+   * the channel is created in the parent process for Workers. Such as fetch().
+   * In content process, it is always 0.
+   * This value would not be propagated through IPC.
+   */
+  [infallible] attribute unsigned long long workerAssociatedBrowsingContextID;
+  [infallible] readonly attribute BrowsingContext workerAssociatedBrowsingContext;
+
+  /**
+   * Only when the element being loaded is <frame src="foo.html">
+   * (or, more generally, if the element QIs to nsFrameLoaderOwner),
+   * the frameBrowsingContext is the browsing context containing the
+   * foo.html document.
+   *
+   * Note: For other cases, frameBrowsingContextID is 0.
+   */
+  [infallible] readonly attribute unsigned long long frameBrowsingContextID;
+  [infallible] readonly attribute BrowsingContext frameBrowsingContext;
+
+  /**
+   * If the element being loaded is a nsFrameLoaderOwner,
+   * `targetBrowsingContext` is the Browsing Context which will contain the
+   * loading document (see `frameBrowsingContext`). Otherwise, it is the
+   * Browsing Context performing the load (see `browsingContext`).
+   */
+  [infallible] readonly attribute unsigned long long targetBrowsingContextID;
+  [infallible] readonly attribute BrowsingContext targetBrowsingContext;
+
+  /**
+   * Resets the PrincipalToInherit to a freshly created NullPrincipal
+   * which inherits the origin attributes from the loadInfo.
+   *
+   * WARNING: Please only use that function if you know exactly what
+   * you are doing!!!
+   */
+  void resetPrincipalToInheritToNullPrincipal();
+
+  /**
+   * Customized OriginAttributes within LoadInfo to allow overwriting of the
+   * default originAttributes from the loadingPrincipal.
+   *
+   * In chrome side, originAttributes.privateBrowsingId will always be 0 even if
+   * the usePrivateBrowsing is true, because chrome docshell won't set
+   * privateBrowsingId on origin attributes (See bug 1278664). This is to make
+   * sure nsILoadInfo and nsILoadContext have the same origin attributes.
+   */
+  [implicit_jscontext, binaryname(ScriptableOriginAttributes)]
+  attribute jsval originAttributes;
+
+  [noscript, nostdcall, binaryname(GetOriginAttributes)]
+  OriginAttributes binaryGetOriginAttributes();
+
+  [noscript, nostdcall, binaryname(SetOriginAttributes)]
+  void binarySetOriginAttributes(in const_OriginAttributesRef aOriginAttrs);
+
+%{ C++
+  inline mozilla::OriginAttributes GetOriginAttributes()
+  {
+    mozilla::OriginAttributes result;
+    mozilla::DebugOnly<nsresult> rv = GetOriginAttributes(&result);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return result;
+  }
+%}
+
+  /**
+   * Whenever a channel is evaluated by the ContentSecurityManager
+   * the first time, we set this flag to true to indicate that
+   * subsequent calls of AsyncOpen() do not have to enforce all
+   * security checks again. E.g., after a redirect there is no
+   * need to set up CORS again. We need this separate flag
+   * because the redirectChain might also contain internal
+   * redirects which might pollute the redirectChain so we can't
+   * rely on the size of the redirectChain-array to query whether
+   * a channel got redirected or not.
+   *
+   * Please note, once the flag is set to true it must remain true
+   * throughout the lifetime of the channel. Trying to set it
+   * to anything else than true will be discarded.
+   *
+   */
+  [infallible] attribute boolean initialSecurityCheckDone;
+
+  /**
+   * Returns true if the load was triggered from an external application
+   * (e.g. Thunderbird). Please note that this flag will only ever be true
+   * if the load is of TYPE_DOCUMENT.
+   */
+  [infallible] attribute boolean loadTriggeredFromExternal;
+
+  /**
+   * True if the tainting has been set by the service worker.
+   */
+  [noscript, infallible] readonly attribute boolean serviceWorkerTaintingSynthesized;
+
+  /**
+   * Whenever a channel gets redirected, append the redirect history entry of
+   * the channel which contains principal referrer and remote address [before
+   * the channels got redirected] to the loadinfo, so that at every point this
+   * array provides us information about all the redirects this channel went
+   * through.
+   * @param channelToDeriveFrom the channel being redirected
+   * @param aIsInternalRedirect should be true if the channel is going
+   *        through an internal redirect, otherwise false.
+   */
+  void appendRedirectHistoryEntry(in nsIChannel channelToDeriveFrom,
+                                  in boolean isInternalRedirect);
+
+  /**
+   * An array of nsIRedirectHistoryEntry which stores redirects associated
+   * with this channel. This array is filled whether or not the channel has
+   * ever been opened. The last element of the array is associated with the
+   * most recent redirect. Please note, that this array *includes* internal
+   * redirects.
+   */
+  [implicit_jscontext]
+  readonly attribute jsval redirectChainIncludingInternalRedirects;
+
+  /**
+   * A C++-friendly version of redirectChain.
+   * Please note that this array has the same lifetime as the
+   * loadInfo object - use with caution!
+   */
+  [noscript, notxpcom, nostdcall, binaryname(RedirectChainIncludingInternalRedirects)]
+  nsIRedirectHistoryEntryArray binaryRedirectChainIncludingInternalRedirects();
+
+  /**
+   * Same as RedirectChain but does *not* include internal redirects.
+   */
+  [implicit_jscontext]
+  readonly attribute jsval redirectChain;
+
+  /**
+   * A C++-friendly version of redirectChain.
+   * Please note that this array has the same lifetime as the
+   * loadInfo object - use with caution!
+   */
+  [noscript, notxpcom, nostdcall, binaryname(RedirectChain)]
+  nsIRedirectHistoryEntryArray binaryRedirectChain();
+
+  /**
+   * This array is only filled out when we are in the parent process and we are
+   * creating a loadInfo object or deserializing LoadInfoArgs into LoadInfo,
+   * as we ever only need in the parent process.
+   *
+   * The array is meant to be a list of principals of the documents that the
+   * browsing context, corresponding to this loadInfo object, is "nested through" in
+   * the sense of
+   * <https://html.spec.whatwg.org/multipage/browsers.html#browsing-context-nested-through>.
+   * Note that the array does not include the principal corresponding to the frame
+   * loading this request. The closest ancestor is at index zero and the top level
+   * ancestor is at the last index.
+   *
+   * If this is a toplevel content browsing context (i.e. toplevel document in spec
+   * terms), the list is empty.
+   *
+   * Otherwise the array is a list for the document we're nested through (again in
+   * the spec sense), with the principal of that document prepended. The
+   * ancestorPrincipals[0] entry for an iframe load will be the principal of the
+   * iframe element's owner document. The ancestorPrincipals[0] entry for an image
+   * loaded in an iframe will be the principal of the iframe element's owner
+   * document. This matches the ordering specified for Location.ancestorOrigins.
+   *
+   * Please note that this array has the same lifetime as the loadInfo object - use
+   * with caution!
+   */
+  [noscript, notxpcom, nostdcall]
+  PrincipalArrayRef AncestorPrincipals();
+
+  /**
+   * An array of BrowsingContext IDs which correspond to nsILoadInfo::AncestorPrincipals
+   * above.  AncestorBrowsingContextIDs[0] is the BrowsingContext ID of the frame
+   * associated with the principal at ancestorPrincipals[0], and so forth.
+   *
+   * Please note that this array has the same lifetime as the
+   * loadInfo object - use with caution!
+   */
+  [noscript, notxpcom, nostdcall]
+  Uint64ArrayRef AncestorBrowsingContextIDs();
+
+  /**
+   * Sets the list of unsafe headers according to CORS spec, as well as
+   * potentially forces a preflight.
+   * Note that you do not need to set the Content-Type header. That will be
+   * automatically detected as needed.
+   *
+   * Only call this function when using the SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT mode.
+   */
+  [noscript, notxpcom, nostdcall]
+  void setCorsPreflightInfo(in CStringArrayRef unsafeHeaders,
+                            in boolean forcePreflight);
+
+  /**
+   * A C++-friendly getter for the list of cors-unsafe headers.
+   * Please note that this array has the same lifetime as the
+   * loadInfo object - use with caution!
+   */
+  [noscript, notxpcom, nostdcall, binaryname(CorsUnsafeHeaders)]
+  CStringArrayRef corsUnsafeHeaders();
+
+  /**
+   * Returns value set through setCorsPreflightInfo.
+   */
+  [infallible] readonly attribute boolean forcePreflight;
+
+  /**
+   * A C++ friendly getter for the forcePreflight flag.
+   */
+  [infallible] readonly attribute boolean isPreflight;
+
+  /**
+  * Constants reflecting the channel tainting.  These are mainly defined here
+  * for script.  Internal C++ code should use the enum defined in LoadTainting.h.
+  * See LoadTainting.h for documentation.
+  */
+  const unsigned long TAINTING_BASIC = 0;
+  const unsigned long TAINTING_CORS = 1;
+  const unsigned long TAINTING_OPAQUE = 2;
+
+  /**
+   * Determine the associated channel's current tainting.  Note, this can
+   * change due to a service worker intercept, so it should be checked after
+   * OnStartRequest() fires.
+   */
+  readonly attribute unsigned long tainting;
+
+  /**
+   * Note a new tainting level and possibly increase the current tainting
+   * to match.  If the tainting level is already greater than the given
+   * value, then there is no effect.  It is not possible to reduce the tainting
+   * level on an existing channel/loadinfo.
+   */
+  void maybeIncreaseTainting(in unsigned long aTainting);
+
+  /**
+   * Various helper code to provide more convenient C++ access to the tainting
+   * attribute and maybeIncreaseTainting().
+   */
+%{C++
+  static_assert(TAINTING_BASIC == static_cast<uint32_t>(mozilla::LoadTainting::Basic),
+                "basic tainting enums should match");
+  static_assert(TAINTING_CORS == static_cast<uint32_t>(mozilla::LoadTainting::CORS),
+                "cors tainting enums should match");
+  static_assert(TAINTING_OPAQUE == static_cast<uint32_t>(mozilla::LoadTainting::Opaque),
+                "opaque tainting enums should match");
+
+  mozilla::LoadTainting GetTainting()
+  {
+    uint32_t tainting = TAINTING_BASIC;
+    MOZ_ALWAYS_SUCCEEDS(GetTainting(&tainting));
+    return static_cast<mozilla::LoadTainting>(tainting);
+  }
+
+  void MaybeIncreaseTainting(mozilla::LoadTainting aTainting)
+  {
+    uint32_t tainting = static_cast<uint32_t>(aTainting);
+    MOZ_ALWAYS_SUCCEEDS(MaybeIncreaseTainting(tainting));
+  }
+%}
+
+  /**
+   * Returns true if this load is for top level document.
+   * Note that the load for a sub-frame's document will return false here.
+   */
+  [infallible] readonly attribute boolean isTopLevelLoad;
+
+  /**
+   * If this is non-null, this property represents two things: (1) the
+   * URI to be used for the principal if the channel with this loadinfo
+   * gets a principal based on URI and (2) the URI to use for a document
+   * created from the channel with this loadinfo.
+   */
+  attribute nsIURI resultPrincipalURI;
+
+  /**
+   * This is the URI used to create the most recent channel in the load's
+   * redirect chain, if it's different from channel's `originalURI`.
+   * This is always null for loads not handled by DocumentLoadListener. If
+   * non-null, channelCreationOriginalURI will be used instead of channel's
+   * originalURI to re-create the channel in the final content process selected
+   * to perform the load.
+   */
+  attribute nsIURI channelCreationOriginalURI;
+
+  /**
+   * Returns a unique nsID used to construct the null principal for the
+   * resulting resource if the SANDBOXED_ORIGIN flag is set.  This is used by
+   * GetChannelResultPrincipal() to ensure that the same null principal is
+   * returned every time.
+   */
+  [noscript, nostdcall, notxpcom]
+  nsIDRef GetSandboxedNullPrincipalID();
+
+  /**
+   * Generates a new nsID to be returned by a future call to
+   * `GetSandboxedNullPrincipalID()`.
+   */
+  [noscript, nostdcall, notxpcom]
+  void ResetSandboxedNullPrincipalID();
+
+  /**
+   * Return the top-level principal, which is the principal of the top-level
+   * window.
+   */
+  [notxpcom, nostdcall] readonly attribute nsIPrincipal topLevelPrincipal;
+
+  /**
+   * Note which client (i.e. global) initiated this network request.  All
+   * nsGlobalWindow and WorkerPrivate can be converted to a ClientInfo to
+   * be set here.  While this is being added to support service worker
+   * FetchEvent, it can also be used to communicate other information about
+   * the source global context in the future.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SetClientInfo(in const_ClientInfoRef aClientInfo);
+
+  /**
+   * Get the ClientInfo for the global that initiated the network request,
+   * if it has been set.
+   */
+  [noscript, nostdcall, notxpcom]
+  const_MaybeClientInfoRef GetClientInfo();
+
+  /**
+   * Give a pre-allocated ClientSource to the channel LoadInfo.  This is
+   * intended to be used by docshell when loading windows without an
+   * initial about:blank document.  The docshell will allocate the ClientSource
+   * to represent the client that will be created as a result of the navigation
+   * network request.  If the channel succeeds and remains same-origin, then
+   * the result nsGlobalWindow will take ownership of the reserved ClientSource.
+   *
+   * This method is also called when a cross-origin redirect occurs.  A new
+   * ClientSource with a different UUID must be created in this case.
+   *
+   * This method automatically calls SetReservedClientInfo() with the
+   * ClientSource::Info().
+   */
+  [noscript, nostdcall, notxpcom]
+  void GiveReservedClientSource(in UniqueClientSourceMove aClientSource);
+
+  /**
+   * This method takes ownership of the reserved ClientSource previously
+   * provided in GiveReservedClientSource().  It may return nullptr if the
+   * nsILoadInfo does not own a ClientSource object.
+   */
+  [noscript, nostdcall, notxpcom]
+  UniqueClientSource TakeReservedClientSource();
+
+  /**
+   * Note the reserved client that be created if this non-subresource
+   * network request succeeds.  Depending on the type of client this
+   * may be called directly or indirectly via GiveReservedClientSource().
+   * For example, web workers do not call give their ClientSource to
+   * the nsILoadInfo, but must still call this method to indicate the
+   * reserved client for their main script load.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SetReservedClientInfo(in const_ClientInfoRef aClientInfo);
+
+  /**
+   * This will clear any existing reserved or initial client and override
+   * it with the given reserved client.  This is similar to calling
+   * TakeReservedClientSource() and then GiveReservedClientSource() with
+   * a new client as ClientChannelHelper does.  This method is needed,
+   * though, to perform this operation in the parent process where
+   * the LoadInfo does not have direct access to a ClientSource.
+   *
+   * If in doubt, do not call this method.  Its really only needed for
+   * a specific redirect case where the child has created a new client on
+   * redirect and we need to override the parent side's reserved client
+   * to match.
+   */
+  [noscript, nostdcall, notxpcom]
+  void OverrideReservedClientInfoInParent(in const_ClientInfoRef aClientInfo);
+
+  /**
+   * Return the reserved ClientInfo for this load, if one has been set.
+   */
+  [noscript, nostdcall, notxpcom]
+  const_MaybeClientInfoRef GetReservedClientInfo();
+
+  /**
+   * Note that this non-subresource network request will result in
+   * re-using an existing "initial" active client.  This mainly only
+   * happens when an initial about:blank document is replaced with
+   * a real load in a window.  In these cases we need to track this
+   * initial client so that we may report its existence in a FetchEvent.
+   *
+   * Note, an nsILoadInfo may only have a reserved client or an
+   * initial client.  It should never have both.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SetInitialClientInfo(in const_ClientInfoRef aClientInfo);
+
+  /**
+   * Return the initial ClientInfo for this load, if one has been set.
+   */
+  [noscript, nostdcall, notxpcom]
+  const_MaybeClientInfoRef GetInitialClientInfo();
+
+  /**
+   * Note that this network request should be controlled by a service worker.
+   * For non-subresource requests this may be set during the load when
+   * the first service worker interception occurs.  For subresource requests
+   * it may be set by the source client if its already controlled by a
+   * service worker.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SetController(in const_ServiceWorkerDescriptorRef aServiceWorker);
+
+  /**
+   * Clear the service worker controller for this channel.  This should only
+   * be used for window navigation redirects.  By default we want to keep
+   * the controller in all other cases.
+   */
+  [noscript, nostdcall, notxpcom]
+  void ClearController();
+
+  /**
+   * Get the service worker controlling this network request, if one has
+   * been set.
+   */
+  [noscript, nostdcall, notxpcom]
+  const_MaybeServiceWorkerDescriptorRef GetController();
+
+  /**
+   * Set a custom performance storage. This is meant to be executed only for
+   * workers. If a PerformanceStorage is not set, the loadingDocument->Window
+   * Performance object will be returned instead.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SetPerformanceStorage(in PerformanceStoragePtr aPerformanceStorage);
+
+  /**
+   * Get the custom PerformanceStorage if set by SetPerformanceStorage.
+   * Otherwise the loadingDocument->Window Performance object will be returned
+   * instead if all the following conditions are met:
+   * - the triggeringPrincipal is the same as the loadingDocument's principal.
+   * - if the external content policy type is TYPE_SUBDOCUMENT then loading
+   *   wasn't caused by processing the attributes of the browsing context
+   *   container.
+   */
+  [noscript, nostdcall, notxpcom]
+  PerformanceStoragePtr GetPerformanceStorage();
+
+  /**
+   * Returns the CSP (or Preload CSP for preloads) which should be enforced
+   * when fetching the resource this loadinfo belongs to.
+   *
+   * a) Non-navigations:
+   * For non-navigation loads, GetCsp() returns what the spec refers to as the
+   * "request's client's global object's CSP list". In practice, if this is the
+   * loadinfo of a subresource load (e.g an image load), then GetCsp() or
+   * GetPreloadCSP() returns the CSP of the document which embeds the image.
+   * The returned CSP includes any policy delivered through the HTTP header or
+   * also through the meta tag (modulo the difference for preloads, e.g. image
+   * preloads have to query GetPreloadCsp() because at the time of preloading
+   * we are not entirely sure if the Meta CSP will be applied to the document
+   * in the end or not). Please note that GetCSPToInherit() called on a
+   * loadinfo for any non-navigation always returns null.
+   *
+   * b) Navigations:
+   *   * Top-level loads:
+   *     For top-level loads (navigations) GetCsp() will return null, unless
+   *     the navigation is started by a WebExtension, in which case it will
+   *     return the CSP of the webextension, if any.
+   *     If you need to query the CSP that potentially should apply to the
+   *     new top-level load, you have to query GetCspToInherit(), which is
+   *     the CSP of the request's client's global object, just like GetCsp()
+   *     is for non-navigation requests.
+   *
+   *   * Iframe-loads:
+   *     For iframe-loads (navigations) GetCsp() will return the CSP of the
+   *     parent document, unless the navigation is started by a WebExtension,
+   *     in which case it will return the CSP of the webextension, if any.
+   *
+   * If you need to query the CSP that should potentially be inherited
+   * into the new document, you have to query GetCSPToInherit().
+   *
+   * TODO Bug 1557114:
+   * After evaluating what CSP to use for frame navigations we should
+   * update the above documentation to match the outcome of Bug 1557114.
+   */
+  [notxpcom,nostdcall] CSPRef GetCsp();
+  [notxpcom,nostdcall] CSPRef GetPreloadCsp();
+  [notxpcom,nostdcall] CSPRef GetCspToInherit();
+
+  /**
+    * The service worker and fetch specifications require returning the
+    * exact tainting level of the Response passed to FetchEvent.respondWith().
+    * This method allows us to override the tainting level in that case.
+    *
+    * NOTE: This should not be used outside of service worker code! Use
+    *       nsILoadInfo::MaybeIncreaseTainting() instead.
+   */
+  [noscript, nostdcall, notxpcom]
+  void SynthesizeServiceWorkerTainting(in LoadTainting aTainting);
+
+  /**
+    * The top-level document has been user-interacted.
+    */
+  [infallible] attribute boolean documentHasUserInteracted;
+
+  /**
+    * During a top-level document channel redirect from tracking to
+    * non-tracking resources, our anti-tracking heuristic, grants the storage
+    * access permission for a short amount of seconds (See
+    * privacy.restrict3rdpartystorage.expiration_redirect pref).
+    * We use this flag to remember this decision even if this channel is part
+    * of a chain of redirects.
+    */
+  [infallible] attribute boolean allowListFutureDocumentsCreatedFromThisRedirectChain;
+
+  /**
+   * Indicates that we need to check if we should apply the anti-tracking
+   * heuristic after the channel has been classified.
+   */
+  [infallible] attribute boolean needForCheckingAntiTrackingHeuristic;
+
+  /**
+   * A snapshot of the nonce at load start time which is used for CSP
+   * checks and only set for:
+   *  * TYPE_SCRIPT and
+   *  * TYPE_STYLESHEET
+   */
+  attribute AString cspNonce;
+
+  /**
+   * List of possible reasons the request associated with this load info
+   * may have been blocked, set by various content blocking checkers.
+   */
+  const uint32_t BLOCKING_REASON_NONE = 0;
+  const uint32_t BLOCKING_REASON_CORSDISABLED = 1001;
+  const uint32_t BLOCKING_REASON_CORSDIDNOTSUCCEED = 1002;
+  const uint32_t BLOCKING_REASON_CORSREQUESTNOTHTTP = 1003;
+  const uint32_t BLOCKING_REASON_CORSMULTIPLEALLOWORIGINNOTALLOWED = 1004;
+  const uint32_t BLOCKING_REASON_CORSMISSINGALLOWORIGIN = 1005;
+  const uint32_t BLOCKING_REASON_CORSNOTSUPPORTINGCREDENTIALS = 1006;
+  const uint32_t BLOCKING_REASON_CORSALLOWORIGINNOTMATCHINGORIGIN = 1007;
+  const uint32_t BLOCKING_REASON_CORSMISSINGALLOWCREDENTIALS = 1008;
+  const uint32_t BLOCKING_REASON_CORSORIGINHEADERNOTADDED = 1009;
+  const uint32_t BLOCKING_REASON_CORSEXTERNALREDIRECTNOTALLOWED = 1010;
+  const uint32_t BLOCKING_REASON_CORSPREFLIGHTDIDNOTSUCCEED = 1011;
+  const uint32_t BLOCKING_REASON_CORSINVALIDALLOWMETHOD = 1012;
+  const uint32_t BLOCKING_REASON_CORSMETHODNOTFOUND = 1013;
+  const uint32_t BLOCKING_REASON_CORSINVALIDALLOWHEADER = 1014;
+  const uint32_t BLOCKING_REASON_CORSMISSINGALLOWHEADERFROMPREFLIGHT = 1015;
+  const uint32_t BLOCKING_REASON_CLASSIFY_MALWARE_URI = 2001;
+  const uint32_t BLOCKING_REASON_CLASSIFY_PHISHING_URI = 2002;
+  const uint32_t BLOCKING_REASON_CLASSIFY_UNWANTED_URI = 2003;
+  const uint32_t BLOCKING_REASON_CLASSIFY_TRACKING_URI = 2004;
+  const uint32_t BLOCKING_REASON_CLASSIFY_BLOCKED_URI = 2005;
+  const uint32_t BLOCKING_REASON_CLASSIFY_HARMFUL_URI = 2006;
+  const uint32_t BLOCKING_REASON_CLASSIFY_CRYPTOMINING_URI = 2007;
+  const uint32_t BLOCKING_REASON_CLASSIFY_FINGERPRINTING_URI = 2008;
+  const uint32_t BLOCKING_REASON_CLASSIFY_SOCIALTRACKING_URI = 2009;
+  const uint32_t BLOCKING_REASON_CLASSIFY_EMAILTRACKING_URI = 2010;
+  const uint32_t BLOCKING_REASON_MIXED_BLOCKED = 3001;
+  // The general reason comes from nsCSPContext::permitsInternal(),
+  // which is way too generic to distinguish an exact reason.
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_GENERAL = 4000;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_NO_DATA_PROTOCOL = 4001;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_WEBEXT = 4002;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_CONTENT_BLOCKED = 4003;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_DATA_DOCUMENT = 4004;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_WEB_BROWSER = 4005;
+  const uint32_t BLOCKING_REASON_CONTENT_POLICY_PRELOAD = 4006;
+  // The reason used when SEC_REQUIRE_SAME_ORIGIN_* is set and not satisifed.
+  const uint32_t BLOCKING_REASON_NOT_SAME_ORIGIN = 5000;
+  // The reason used when an extension cancels the request via the WebRequest api.
+  const uint32_t BLOCKING_REASON_EXTENSION_WEBREQUEST = 6000;
+
+  /**
+   * If the request associated with this load info was blocked by some of
+   * our content or load blockers, the reason can be found here.
+   * Note that setting this attribute has NO EFFECT on blocking the request.
+   * This attribute is only informative!
+   *
+   * By default the value is '0' - NONE.
+   * Each write rewrites the last value.
+   * Can be accessed only on a single thread.
+   */
+  [infallible] attribute unsigned long requestBlockingReason;
+
+  /**
+    * The object in charged to receive CSP violation events. It can be null.
+    * This attribute will be merged into the CSP object eventually.
+    * See bug 1500908.
+    */
+  attribute nsICSPEventListener cspEventListener;
+
+  /**
+   * This attribute will be true if this is a load triggered by
+   * https://html.spec.whatwg.org/multipage/iframe-embed-object.html#process-the-iframe-attributes
+   * or https://html.spec.whatwg.org/multipage/obsolete.html#process-the-frame-attributes
+   */
+  [infallible] readonly attribute boolean isFromProcessingFrameAttributes;
+
+  cenum CrossOriginOpenerPolicy : 8 {
+    OPENER_POLICY_UNSAFE_NONE = 0,
+    OPENER_POLICY_SAME_ORIGIN = 1,
+    OPENER_POLICY_SAME_ORIGIN_ALLOW_POPUPS = 2,
+    OPENER_POLICY_EMBEDDER_POLICY_REQUIRE_CORP_FLAG = 0x10,
+    OPENER_POLICY_SAME_ORIGIN_EMBEDDER_POLICY_REQUIRE_CORP =
+        OPENER_POLICY_SAME_ORIGIN |
+        OPENER_POLICY_EMBEDDER_POLICY_REQUIRE_CORP_FLAG
+  };
+
+  cenum CrossOriginEmbedderPolicy : 8 {
+    EMBEDDER_POLICY_NULL = 0,
+    EMBEDDER_POLICY_REQUIRE_CORP = 1,
+    EMBEDDER_POLICY_CREDENTIALLESS = 2,
+  };
+
+  /**
+   * This attribute is the loading context's cross origin embedder policy.
+   * The value is initialized with corresponding WindowContext which get by
+   * innerWindowIID in the nsILoadInfo.
+   * It also could be set by workers when fetch is called under
+   * the workers' scope.
+   */
+  [infallible] attribute nsILoadInfo_CrossOriginEmbedderPolicy
+        loadingEmbedderPolicy;
+
+  /**
+   * This attribute will be true if the top level document has COEP:
+   * credentialless enabled in Origin Trial.
+   */
+  [infallible] attribute boolean isOriginTrialCoepCredentiallessEnabledForTopLevel;
+  /**
+   * This attribute will be true if this is a load triggered by a media
+   * element.
+   */
+  [infallible] attribute boolean isMediaRequest;
+
+  /**
+   * This attribute will be true if this is a load triggered by a media
+   * element and it's an initial request.
+   */
+  [infallible] attribute boolean isMediaInitialRequest;
+
+  /**
+   * This attribute will be true if the fetch request is from object or embed
+   * elements
+   */
+  [infallible] attribute boolean isFromObjectOrEmbed;
+
+  /**
+   * This attribute will be true if the URL is known to be possibly broken and
+   * CheckForBrokenChromeURL and RecordZeroLengthEvent should be skipped.
+   */
+  [infallible] readonly attribute boolean shouldSkipCheckForBrokenURLOrZeroSized;
+
+  /**
+   * If this is non-null, this property holds the URI as it was before query
+   * stripping was performed.
+   */
+  attribute nsIURI unstrippedURI;
+
+  /**
+   * Propagated information from InterceptedHttpChannel
+   * It should be null when the channel is not created from FetchEvent.request
+   * or ServiceWorker NavigationPreload.
+   * nsIFetchEventInfo is C++ only, so it is not an attribute.
+   */
+  [noscript, notxpcom, nostdcall, binaryname(InterceptionInfo)]
+  nsIInterceptionInfo binaryInterceptionInfo();
+
+  [noscript, notxpcom, nostdcall, binaryname(SetInterceptionInfo)]
+  void binarySetInterceptionInfo(in nsIInterceptionInfo info);
+
+  /**
+   * Whether nsICookieInjector has injected a cookie for this request to
+   * handle a cookie banner. This is only done for top-level requests.
+   */
+  [infallible] attribute boolean hasInjectedCookieForCookieBannerHandling;
+};
diff --git a/netwerk/base/nsIMIMEInputStream.idl b/netwerk/base/nsIMIMEInputStream.idl
new file mode 100644
index 0000000000..1842cdb40c
--- /dev/null
+++ b/netwerk/base/nsIMIMEInputStream.idl
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIHttpHeaderVisitor.idl"
+#include "nsIInputStream.idl"
+
+/**
+ * The MIME stream separates headers and a datastream. It also allows
+ * automatic creation of the content-length header.
+ */
+
+[scriptable, builtinclass, uuid(dcbce63c-1dd1-11b2-b94d-91f6d49a3161)]
+interface nsIMIMEInputStream : nsIInputStream
+{
+    /**
+     * Adds an additional header to the stream on the form "name: value". May
+     * not be called once the stream has been started to be read.
+     * @param name   name of the header
+     * @param value  value of the header
+     */
+    void addHeader(in string name, in string value);
+
+    /**
+     * Visits all headers which have been added via addHeader.  Calling
+     * addHeader while visiting request headers has undefined behavior.
+     *
+     * @param aVisitor
+     *        The header visitor instance.
+     */
+    void visitHeaders(in nsIHttpHeaderVisitor visitor);
+
+    /**
+     * Sets data-stream. May not be called once the stream has been started
+     * to be read.
+     * The cursor of the new stream should be located at the beginning of the
+     * stream if the implementation of the nsIMIMEInputStream also is used as
+     * an nsISeekableStream.
+     * @param stream  stream containing the data for the stream
+     */
+    void setData(in nsIInputStream stream);
+
+    /**
+     * Get the wrapped data stream
+     */
+    readonly attribute nsIInputStream data;
+};
diff --git a/netwerk/base/nsIMultiPartChannel.idl b/netwerk/base/nsIMultiPartChannel.idl
new file mode 100644
index 0000000000..3e4bf58812
--- /dev/null
+++ b/netwerk/base/nsIMultiPartChannel.idl
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+
+/**
+ * An interface to access the the base channel
+ * associated with a MultiPartChannel.
+ */
+
+[scriptable, builtinclass, uuid(4fefb490-5567-11e5-a837-0800200c9a66)]
+interface nsIMultiPartChannel : nsISupports
+{
+    /**
+     * readonly attribute to access the underlying channel
+     */
+    readonly attribute nsIChannel baseChannel;
+
+    /**
+     * Attribute guaranteed to be different for different parts of
+     * the same multipart document.
+     */
+    readonly attribute uint32_t partID;
+
+    [noscript] readonly attribute boolean isFirstPart;
+
+    /**
+     * Set to true when onStopRequest is received from the base channel.
+     * The listener can check this from its onStopRequest to determine
+     * whether more data can be expected.
+     */
+    readonly attribute boolean isLastPart;
+};
+
+/**
+ * An interface that listeners can implement to receive a notification
+ * when the last part of the multi-part channel has finished, and the
+ * final OnStopRequest has been sent.
+  */
+[scriptable, uuid(b084959a-4fb9-41a5-88a0-d0f045ce75cf)]
+interface nsIMultiPartChannelListener : nsISupports
+{
+    /**
+     * Sent when all parts have finished and sent OnStopRequest.
+     */
+    void onAfterLastPart(in nsresult status);
+};
diff --git a/netwerk/base/nsINestedURI.idl b/netwerk/base/nsINestedURI.idl
new file mode 100644
index 0000000000..df124348af
--- /dev/null
+++ b/netwerk/base/nsINestedURI.idl
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+
+/**
+ * nsINestedURI is an interface that must be implemented by any nsIURI
+ * implementation which has an "inner" URI that it actually gets data
+ * from.
+ *
+ * For example, if URIs for the scheme "sanitize" have the structure:
+ *
+ *   sanitize:http://example.com
+ *
+ * and opening a channel on such a sanitize: URI gets the data from
+ * http://example.com, sanitizes it, and returns it, then the sanitize: URI
+ * should implement nsINestedURI and return the http://example.com URI as its
+ * inner URI.
+ */
+[scriptable, builtinclass, uuid(6de2c874-796c-46bf-b57f-0d7bd7d6cab0)]
+interface nsINestedURI : nsISupports
+{
+  /**
+   * The inner URI for this nested URI.  This must not return null if the
+   * getter succeeds; URIs that have no inner must not QI to this interface.
+   * Dynamically changing whether there is an inner URI is not allowed.
+   *
+   * Modifying the returned URI must not in any way modify the nested URI; this
+   * means the returned URI must be either immutable or a clone.
+   */
+  readonly attribute nsIURI innerURI;
+
+  /**
+   * The innermost URI for this nested URI.  This must not return null if the
+   * getter succeeds.  This is equivalent to repeatedly calling innerURI while
+   * the returned URI QIs to nsINestedURI.
+   *
+   * Modifying the returned URI must not in any way modify the nested URI; this
+   * means the returned URI must be either immutable or a clone.
+   */
+  readonly attribute nsIURI innermostURI;
+};
+
+[scriptable, builtinclass, uuid(ca3d6c03-4eee-4271-a97a-d16c0a0b2c5c)]
+interface nsINestedURIMutator : nsISupports
+{
+  /*
+   *  - Creates a new URI with the given innerURI.
+   */
+  [must_use, noscript] void init(in nsIURI innerURI);
+};
+
+[scriptable, builtinclass, uuid(c6357a3b-c2bb-4b4b-9278-513377398a38)]
+interface nsINestedAboutURIMutator : nsISupports
+{
+  /*
+   *  - Creates a new URI with the given innerURI and base.
+   */
+  [must_use, noscript] void initWithBase(in nsIURI innerURI, in nsIURI baseURI);
+};
+
+[scriptable, builtinclass, uuid(3bd44535-08ea-478f-99b9-85fa1084e820)]
+interface nsIJSURIMutator : nsISupports
+{
+  /*
+   *  - Inits the URI by setting the base URI
+   *  - It is the caller's responsibility to also call SetSpec afterwards,
+   *    otherwise we will return an incomplete URI (with only a base)
+   */
+  [must_use, noscript] void setBase(in nsIURI aBaseURI);
+};
diff --git a/netwerk/base/nsINetAddr.idl b/netwerk/base/nsINetAddr.idl
new file mode 100644
index 0000000000..bbbcd28c0e
--- /dev/null
+++ b/netwerk/base/nsINetAddr.idl
@@ -0,0 +1,88 @@
+/* vim: et ts=4 sw=4 tw=80
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{ C++
+namespace mozilla {
+namespace net {
+union NetAddr;
+}
+}
+%}
+native NetAddr(mozilla::net::NetAddr);
+
+/**
+ * nsINetAddr
+ *
+ * This interface represents a native NetAddr struct in a readonly
+ * interface.
+ */
+[scriptable, uuid(652B9EC5-D159-45D7-9127-50BB559486CD)]
+interface nsINetAddr : nsISupports
+{
+    /**
+     * @return the address family of the network address, which corresponds to
+     * one of the FAMILY_ constants.
+     */
+    readonly attribute unsigned short family;
+
+    /**
+     * @return Either the IP address (FAMILY_INET, FAMILY_INET6) or the path
+     * (FAMILY_LOCAL) in string form. IP addresses are in the format produced by
+     * mozilla::net::NetAddr::ToStringBuffer.
+     *
+     * Note: Paths for FAMILY_LOCAL may have length limitations which are
+     * implementation dependent and not documented as part of this interface.
+     */
+    readonly attribute AUTF8String address;
+
+    /**
+     * @return the port number for a FAMILY_INET or FAMILY_INET6 address.
+     *
+     * @throws NS_ERROR_NOT_AVAILABLE if the address family is not FAMILY_INET or
+     * FAMILY_INET6.
+     */
+    readonly attribute unsigned short port;
+
+    /**
+     * @return the flow label for a FAMILY_INET6 address.
+     *
+     * @see http://www.ietf.org/rfc/rfc3697.txt
+     *
+     * @throws NS_ERROR_NOT_AVAILABLE if the address family is not FAMILY_INET6
+     */
+    readonly attribute unsigned long flow;
+
+    /**
+     * @return the address scope of a FAMILY_INET6 address.
+     *
+     * @see http://tools.ietf.org/html/rfc4007
+     *
+     * @throws NS_ERROR_NOT_AVAILABLE if the address family is not FAMILY_INET6
+     */
+    readonly attribute unsigned long scope;
+
+    /**
+     * @return whether a FAMILY_INET6 address is mapped from FAMILY_INET.
+     *
+     * @throws NS_ERROR_NOT_AVAILABLE if the address family is not FAMILY_INET6
+     */
+    readonly attribute boolean isV4Mapped;
+
+    /**
+     * Network address families. These correspond to all the network address
+     * families supported by the NetAddr struct.
+     */
+    const unsigned long FAMILY_INET = 1;
+    const unsigned long FAMILY_INET6 = 2;
+    const unsigned long FAMILY_LOCAL = 3;
+
+    /**
+     * @return the underlying NetAddr struct.
+     */
+    [noscript] NetAddr getNetAddr();
+};
diff --git a/netwerk/base/nsINetUtil.idl b/netwerk/base/nsINetUtil.idl
new file mode 100644
index 0000000000..67e6c54f2b
--- /dev/null
+++ b/netwerk/base/nsINetUtil.idl
@@ -0,0 +1,223 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIPrefBranch;
+
+/**
+ * nsINetUtil provides various network-related utility methods.
+ */
+[scriptable, uuid(fe2625ec-b884-4df1-b39c-9e830e47aa94)]
+interface nsINetUtil : nsISupports
+{
+  /**
+   * Parse a Content-Type header value in strict mode.  This is a more
+   * conservative parser that reject things that violate RFC 7231 section
+   * 3.1.1.1.  This is typically useful for parsing Content-Type header values
+   * that are used for HTTP requests, and those that are used to make security
+   * decisions.
+   *
+   * @param aTypeHeader the header string to parse
+   * @param [out] aCharset the charset parameter specified in the
+   *              header, if any.
+   * @param [out] aHadCharset whether a charset was explicitly specified.
+   * @return the MIME type specified in the header, in lower-case.
+   */
+  AUTF8String parseRequestContentType(in AUTF8String aTypeHeader,
+                                      out AUTF8String aCharset,
+                                      out boolean aHadCharset);
+
+  /**
+   * Parse a Content-Type header value in relaxed mode.  This is a more
+   * permissive parser that ignores things that go against RFC 7231 section
+   * 3.1.1.1.  This is typically useful for parsing Content-Type header values
+   * received from web servers where we want to make a best effort attempt
+   * at extracting a useful MIME type and charset.
+   *
+   * NOTE: DO NOT USE THIS if you're going to make security decisions
+   * based on the result.
+   *
+   * @param aTypeHeader the header string to parse
+   * @param [out] aCharset the charset parameter specified in the
+   *              header, if any.
+   * @param [out] aHadCharset whether a charset was explicitly specified.
+   * @return the MIME type specified in the header, in lower-case.
+   */
+  AUTF8String parseResponseContentType(in AUTF8String aTypeHeader,
+                                       out AUTF8String aCharset,
+                                       out boolean aHadCharset);
+
+  /**
+   * Test whether the given URI's handler has the given protocol flags.
+   *
+   * @param aURI the URI in question
+   * @param aFlags the flags we're testing for.
+   *
+   * @return whether the protocol handler for aURI has all the flags
+   *         in aFlags.
+   */
+  boolean protocolHasFlags(in nsIURI aURI, in unsigned long aFlag);
+
+  /**
+   * Test whether the protocol handler for this URI or that for any of
+   * its inner URIs has the given protocol flags.  This will QI aURI to
+   * nsINestedURI and walk the nested URI chain.
+   *
+   * @param aURI the URI in question
+   * @param aFlags the flags we're testing for.
+   *
+   * @return whether any of the protocol handlers involved have all the flags
+   *         in aFlags.
+   */
+  boolean URIChainHasFlags(in nsIURI aURI, in unsigned long aFlags);
+
+  /** Escape every character with its %XX-escaped equivalent */
+  const unsigned long ESCAPE_ALL = 0;
+
+  /** Leave alphanumeric characters intact and %XX-escape all others */
+  const unsigned long ESCAPE_XALPHAS = 1;
+
+  /** Leave alphanumeric characters intact, convert spaces to '+',
+      %XX-escape all others */
+  const unsigned long ESCAPE_XPALPHAS = 2;
+
+  /** Leave alphanumeric characters and forward slashes intact,
+      %XX-escape all others */
+  const unsigned long ESCAPE_URL_PATH = 4;
+
+  /** Additional encoding for Apple's NSURL compatibility.
+      Like XALPHAS, but leave '%' to avoid double encoding, '+', and '/'.
+      %XX-escape all others */
+  const unsigned long ESCAPE_URL_APPLE_EXTRA = 8;
+
+  /**
+   * escape a string with %00-style escaping
+   */
+  ACString escapeString(in ACString aString, in unsigned long aEscapeType);
+
+  /** %XX-escape URL scheme */
+  const unsigned long ESCAPE_URL_SCHEME = 1;
+
+  /** %XX-escape username in the URL */
+  const unsigned long ESCAPE_URL_USERNAME = 1 << 1;
+
+  /** %XX-escape password in the URL */
+  const unsigned long ESCAPE_URL_PASSWORD = 1 << 2;
+
+  /** %XX-escape URL host */
+  const unsigned long ESCAPE_URL_HOST = 1 << 3;
+
+  /** %XX-escape URL directory */
+  const unsigned long ESCAPE_URL_DIRECTORY = 1 << 4;
+
+  /** %XX-escape file basename in the URL */
+  const unsigned long ESCAPE_URL_FILE_BASENAME = 1 << 5;
+
+  /** %XX-escape file extension in the URL */
+  const unsigned long ESCAPE_URL_FILE_EXTENSION = 1 << 6;
+
+  /** %XX-escape URL parameters */
+  const unsigned long ESCAPE_URL_PARAM = 1 << 7;
+
+  /** %XX-escape URL query */
+  const unsigned long ESCAPE_URL_QUERY = 1 << 8;
+
+  /** %XX-escape URL ref */
+  const unsigned long ESCAPE_URL_REF = 1 << 9;
+
+  /** %XX-escape URL path - same as escaping directory, basename and extension */
+  const unsigned long ESCAPE_URL_FILEPATH =
+    ESCAPE_URL_DIRECTORY | ESCAPE_URL_FILE_BASENAME | ESCAPE_URL_FILE_EXTENSION;
+
+  /** %XX-escape scheme, username, password, host, path, params, query and ref */
+  const unsigned long ESCAPE_URL_MINIMAL =
+    ESCAPE_URL_SCHEME | ESCAPE_URL_USERNAME | ESCAPE_URL_PASSWORD |
+    ESCAPE_URL_HOST   | ESCAPE_URL_FILEPATH | ESCAPE_URL_PARAM    |
+    ESCAPE_URL_QUERY  | ESCAPE_URL_REF;
+
+  /** Force %XX-escaping of already escaped sequences */
+  const unsigned long ESCAPE_URL_FORCED = 1 << 10;
+
+  /** Skip non-ascii octets, %XX-escape all others */
+  const unsigned long ESCAPE_URL_ONLY_ASCII = 1 << 11;
+
+  /**
+   * Skip graphic octets (0x20-0x7E) when escaping
+   * Skips all ASCII octets (0x00-0x7F) when unescaping
+   */
+  const unsigned long ESCAPE_URL_ONLY_NONASCII = 1 << 12;
+
+  /** Force %XX-escape of colon */
+  const unsigned long ESCAPE_URL_COLON = 1 << 14;
+
+  /** Skip C0 and DEL from unescaping */
+  const unsigned long ESCAPE_URL_SKIP_CONTROL = 1 << 15;
+
+  /** %XX-escape external protocol handler URL */
+  const unsigned long ESCAPE_URL_EXT_HANDLER = 1 << 17;
+
+  /**
+   * %XX-Escape invalid chars in a URL segment.
+   *
+   * @param aStr the URL to be escaped
+   * @param aFlags the URL segment type flags
+   *
+   * @return the escaped string (the string itself if escaping did not happen)
+   *
+   */
+  ACString escapeURL(in ACString aStr, in unsigned long aFlags);
+
+  /**
+   * Expands URL escape sequences
+   *
+   * @param aStr the URL to be unescaped
+   * @param aFlags only ESCAPE_URL_ONLY_NONASCII and ESCAPE_URL_SKIP_CONTROL
+   *               are recognized.  If |aFlags| is 0 all escape sequences are
+   *               unescaped
+   * @return unescaped string
+   */
+  ACString unescapeString(in AUTF8String aStr, in unsigned long aFlags);
+
+  /**
+   * Extract the charset parameter location and value from a content-type
+   * header.
+   *
+   * @param aTypeHeader the header string to parse
+   * @param [out] aCharset the charset parameter specified in the
+   *              header, if any.
+   * @param [out] aCharsetStart index of the start of the charset parameter
+   *              (the ';' separating it from what came before) in aTypeHeader.
+   *              If this function returns false, this argument will still be
+   *              set, to the index of the location where a new charset should
+   *              be inserted.
+   * @param [out] aCharsetEnd index of the end of the charset parameter (the
+   *              ';' separating it from what comes after, or the end
+   *              of the string) in aTypeHeader.  If this function returns
+   *              false, this argument will still be set, to the index of the
+   *              location where a new charset should be inserted.
+   *
+   * @return whether a charset parameter was found.  This can be false even in
+   * cases when parseContentType would claim to have a charset, if the type
+   * that won out does not have a charset parameter specified.
+   */
+  boolean extractCharsetFromContentType(in AUTF8String aTypeHeader,
+                                        out AUTF8String aCharset,
+                                        out long aCharsetStart,
+                                        out long aCharsetEnd);
+
+  /**
+   * This is test-only. Send an IPC message to let socket process send a
+   * telemetry.
+   */
+  void socketProcessTelemetryPing();
+
+  /**
+   * This is a void method that is C++ implemented and always
+   * returns NS_ERROR_NOT_IMPLEMENTED. To be used for testing.
+   */
+  void notImplemented();
+};
diff --git a/netwerk/base/nsINetworkConnectivityService.idl b/netwerk/base/nsINetworkConnectivityService.idl
new file mode 100644
index 0000000000..482eaf45ee
--- /dev/null
+++ b/netwerk/base/nsINetworkConnectivityService.idl
@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, builtinclass, uuid(2693457e-3ba5-4455-991f-5350946adb12)]
+interface nsINetworkConnectivityService : nsISupports
+{
+  /**
+   * Each tested feature may be in one of 3 states:
+   *   UNKNOWN, if a check hasn't been performed.
+   *   OK, if the feature was successfully tested
+   *   NOT_AVAILABLE, if the feature is blocked by the network.
+   *                  Note that the endpoints are guaranteed to support the features.
+   */
+  cenum ConnectivityState: 32 {
+    UNKNOWN             = 0,
+    OK                  = 1,
+    NOT_AVAILABLE       = 2
+  };
+
+  /* If DNS v4/v6 queries actually work on the current network */
+  [infallible]
+  readonly attribute nsINetworkConnectivityService_ConnectivityState DNSv4;
+  [infallible]
+  readonly attribute nsINetworkConnectivityService_ConnectivityState DNSv6;
+
+  /* If connecting to IPv4/v6 works on the current network */
+  [infallible]
+  readonly attribute nsINetworkConnectivityService_ConnectivityState IPv4;
+  [infallible]
+  readonly attribute nsINetworkConnectivityService_ConnectivityState IPv6;
+
+  /* If a NAT64 gateway was detected on the current network */
+  [infallible]
+  readonly attribute nsINetworkConnectivityService_ConnectivityState NAT64;
+
+  /* Starts the DNS request to check for DNS v4/v6 availability */
+  void recheckDNS();
+
+  /* Starts HTTP requests over IPv4 and IPv6, and checks if they work */
+  void recheckIPConnectivity();
+};
diff --git a/netwerk/base/nsINetworkInfoService.idl b/netwerk/base/nsINetworkInfoService.idl
new file mode 100644
index 0000000000..9349abe13f
--- /dev/null
+++ b/netwerk/base/nsINetworkInfoService.idl
@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * Listener for getting list of addresses.
+ */
+[scriptable, uuid(c4bdaac1-3ab1-4fdb-9a16-17cbed794603)]
+interface nsIListNetworkAddressesListener : nsISupports
+{
+  /**
+   * Callback function that gets called by nsINetworkInfoService.listNetworkAddresses.
+   * Each address in the array is a string IP address in canonical form,
+   * e.g. 192.168.1.10, or an IPV6 address in string form.
+   */
+  void onListedNetworkAddresses(in Array<ACString> aAddressArray);
+  void onListNetworkAddressesFailed();
+};
+
+/**
+ * Listener for getting hostname.
+ */
+[scriptable, uuid(3ebdcb62-2df4-4042-8864-3fa81abd4693)]
+interface nsIGetHostnameListener : nsISupports
+{
+  void onGotHostname(in AUTF8String aHostname);
+  void onGetHostnameFailed();
+};
+
+/**
+ * Service information
+ */
+[scriptable, uuid(55fc8dae-4a58-4e0f-a49b-901cbabae809)]
+interface nsINetworkInfoService : nsISupports
+{
+  /**
+   * Obtain a list of local machine network addresses.  The listener object's
+   * onListedNetworkAddresses will be called with the obtained addresses.
+   * On failure, the listener object's onListNetworkAddressesFailed() will be called.
+   */
+  void listNetworkAddresses(in nsIListNetworkAddressesListener aListener);
+
+  /**
+   * Obtain the hostname of the local machine.  The listener object's
+   * onGotHostname will be called with the obtained hostname.
+   * On failure, the listener object's onGetHostnameFailed() will be called.
+   */
+  void getHostname(in nsIGetHostnameListener aListener);
+};
+
+%{ C++
+#define NETWORKINFOSERVICE_CONTRACT_ID \
+  "@mozilla.org/network-info-service;1"
+%}
diff --git a/netwerk/base/nsINetworkInterceptController.idl b/netwerk/base/nsINetworkInterceptController.idl
new file mode 100644
index 0000000000..d72dc570dc
--- /dev/null
+++ b/netwerk/base/nsINetworkInterceptController.idl
@@ -0,0 +1,245 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsIContentPolicy.idl"
+
+interface nsICacheInfoChannel;
+interface nsIChannel;
+interface nsIConsoleReportCollector;
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsIURI;
+
+%{C++
+#include "nsContentUtils.h"
+#include "nsIChannel.h"
+#include "nsIConsoleReportCollector.h"
+#include "nsILoadInfo.h"
+namespace mozilla {
+class TimeStamp;
+
+namespace dom {
+class ChannelInfo;
+}
+}
+%}
+
+native TimeStamp(mozilla::TimeStamp);
+
+[ptr] native ChannelInfo(mozilla::dom::ChannelInfo);
+
+/**
+ * Interface allowing the nsIInterceptedChannel to callback when it is
+ * done reading from the body stream.
+ */
+[scriptable, uuid(51039eb6-bea0-40c7-b523-ccab56cc4fde)]
+interface nsIInterceptedBodyCallback : nsISupports
+{
+  void bodyComplete(in nsresult aRv);
+};
+
+/**
+ * Interface to allow implementors of nsINetworkInterceptController to control the behaviour
+ * of intercepted channels without tying implementation details of the interception to
+ * the actual channel. nsIInterceptedChannel is expected to be implemented by objects
+ * which do not implement nsIChannel.
+ */
+
+[scriptable, uuid(f4b82975-6a86-4cc4-87fe-9a1fd430c86d)]
+interface nsIInterceptedChannel : nsISupports
+{
+    /**
+     * Instruct a channel that has been intercepted to continue with the original
+     * network request.
+     *
+     * For our mitigations, we support this reset triggering "bypass" mode which
+     * results in the resulting client not being controlled.
+     */
+    void resetInterception(in boolean bypass);
+
+    /**
+     * Set the status and reason for the forthcoming synthesized response.
+     * Multiple calls overwrite existing values.
+     */
+    void synthesizeStatus(in uint16_t status, in ACString reason);
+
+    /**
+     * Attach a header name/value pair to the forthcoming synthesized response.
+     * Overwrites any existing header value.
+     */
+    void synthesizeHeader(in ACString name, in ACString value);
+
+    /**
+     * Instruct a channel that has been intercepted that a response is
+     * starting to be synthesized.  No further header modification is allowed
+     * after this point.  There are a few parameters:
+     * - A body stream may be optionally passed.  If nullptr, then an
+     *   empty body is assumed.
+     * - A callback may be optionally passed.  It will be invoked
+     *   when the body is complete.  For a nullptr body this may be
+     *   synchronously on the current thread.  Otherwise it will be invoked
+     *   asynchronously on the current thread.
+     * - A cacheInfoChannel may be optionally passed. If the body stream is
+     *   from alternative data cache, this cacheInfoChannel provides needed
+     *   cache information.
+     * - The caller may optionally pass a spec for a URL that this response
+     *   originates from; an empty string will cause the original
+     *   intercepted request's URL to be used instead.
+     * - The responseRedirected flag is false will cause the channel do an
+     *   internal redirect when the original intercepted reauest's URL is
+     *   different from the response's URL. The flag is true will cause the
+     *   chaanel do a non-internal redirect when the URLs are different.
+     */
+    void startSynthesizedResponse(in nsIInputStream body,
+                                  in nsIInterceptedBodyCallback callback,
+                                  in nsICacheInfoChannel channel,
+                                  in ACString finalURLSpec,
+                                  in bool responseRedirected);
+
+    /**
+     * Instruct a channel that has been intercepted that response synthesis
+     * has completed and all outstanding resources can be closed.
+     */
+    void finishSynthesizedResponse();
+
+    /**
+     * Cancel the pending intercepted request.
+     * @return NS_ERROR_FAILURE if the response has already been synthesized or
+     *         the original request has been instructed to continue.
+     */
+    void cancelInterception(in nsresult status);
+
+    /**
+     * The underlying channel object that was intercepted.
+     */
+    readonly attribute nsIChannel channel;
+
+    /**
+     * The URL of the underlying channel object, corrected for a potential
+     * secure upgrade.
+     */
+    readonly attribute nsIURI secureUpgradedChannelURI;
+
+    /**
+     * This method allows to override the channel info for the channel.
+     */
+    [noscript]
+    void setChannelInfo(in ChannelInfo channelInfo);
+
+    /**
+     * Get the internal load type from the underlying channel.
+     */
+    [noscript]
+    readonly attribute nsContentPolicyType internalContentPolicyType;
+
+    [noscript]
+    readonly attribute nsIConsoleReportCollector consoleReportCollector;
+
+    [noscript]
+    void SetFetchHandlerStart(in TimeStamp aTimeStamp);
+
+    [noscript]
+    void SetFetchHandlerFinish(in TimeStamp aTimeStamp);
+
+    /**
+     * This method indicates if the ServiceWorker Interception is reset to
+     * network or not.
+     */
+    [noscript]
+    bool GetIsReset();
+
+%{C++
+    already_AddRefed<nsIConsoleReportCollector>
+    GetConsoleReportCollector()
+    {
+      nsCOMPtr<nsIConsoleReportCollector> reporter;
+      GetConsoleReportCollector(getter_AddRefs(reporter));
+      return reporter.forget();
+    }
+
+    void
+    GetSubresourceTimeStampKey(nsIChannel* aChannel, nsACString& aKey)
+    {
+      if (!nsContentUtils::IsNonSubresourceRequest(aChannel)) {
+        nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+        switch(loadInfo->InternalContentPolicyType()) {
+          case nsIContentPolicy::TYPE_SCRIPT:
+          case nsIContentPolicy::TYPE_INTERNAL_SCRIPT:
+          case nsIContentPolicy::TYPE_INTERNAL_SCRIPT_PRELOAD:
+          case nsIContentPolicy::TYPE_INTERNAL_MODULE:
+          case nsIContentPolicy::TYPE_INTERNAL_MODULE_PRELOAD:
+          case nsIContentPolicy::TYPE_INTERNAL_WORKER_IMPORT_SCRIPTS:
+          case nsIContentPolicy::TYPE_INTERNAL_WORKER_STATIC_MODULE: {
+            aKey = "subresource-script"_ns;
+            break;
+          }
+          case nsIContentPolicy::TYPE_IMAGE:
+          case nsIContentPolicy::TYPE_INTERNAL_IMAGE:
+          case nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD:
+          case nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON: {
+            aKey = "subresource-image"_ns;
+            break;
+          }
+          case nsIContentPolicy::TYPE_STYLESHEET:
+          case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET:
+          case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET_PRELOAD: {
+            aKey = "subresource-stylesheet"_ns;
+            break;
+          }
+          default: {
+            aKey = "subresource-other"_ns;
+            break;
+          }
+        }
+      }
+    }
+
+    bool
+    IsReset()
+    {
+      bool result;
+      GetIsReset(&result);
+      return result;
+    }
+%}
+
+    /**
+     * Allow the ServiceWorkerManager to set an RAII-style object on the
+     * intercepted channel that should be released once the channel is
+     * torn down.
+     */
+    [noscript]
+    void setReleaseHandle(in nsISupports aHandle);
+};
+
+/**
+ * Interface to allow consumers to attach themselves to a channel's
+ * notification callbacks/loadgroup and determine if a given channel
+ * request should be intercepted before any network request is initiated.
+ */
+
+[scriptable, uuid(70d2b4fe-a552-48cd-8d93-1d8437a56b53)]
+interface nsINetworkInterceptController : nsISupports
+{
+    /**
+     * Returns true if a channel should avoid initiating any network
+     * requests until specifically instructed to do so.
+     *
+     * @param aURI The URI to be loaded.  Note, this may differ from
+     *             the channel's current URL in some cases.
+     * @param aChannel The channel that may be intercepted.  It will
+     *                 be in the state prior to calling OnStartRequest().
+     */
+    bool shouldPrepareForIntercept(in nsIURI aURI, in nsIChannel aChannel);
+
+    /**
+     * Notification when a given intercepted channel is prepared to accept a synthesized
+     * response via the provided stream.
+     *
+     * @param aChannel the controlling interface for a channel that has been intercepted
+     */
+    void channelIntercepted(in nsIInterceptedChannel aChannel);
+};
diff --git a/netwerk/base/nsINetworkLinkService.idl b/netwerk/base/nsINetworkLinkService.idl
new file mode 100644
index 0000000000..29c7fab836
--- /dev/null
+++ b/netwerk/base/nsINetworkLinkService.idl
@@ -0,0 +1,154 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:expandtab:shiftwidth=4:tabstop=4:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+interface nsINetAddr;
+
+%{ C++
+#include "nsTArrayForwardDeclare.h"
+namespace mozilla {
+namespace net {
+union NetAddr;
+}
+}
+%}
+native NetAddr(mozilla::net::NetAddr);
+
+/**
+ * Network link status monitoring service.
+ */
+[scriptable, uuid(103e5293-77b3-4b70-af59-6e9e4a1f994a)]
+interface nsINetworkLinkService : nsISupports
+{
+  /* Link type constants */
+  const unsigned long LINK_TYPE_UNKNOWN = 0;
+  const unsigned long LINK_TYPE_ETHERNET = 1;
+  const unsigned long LINK_TYPE_USB = 2;
+  const unsigned long LINK_TYPE_WIFI = 3;
+  const unsigned long LINK_TYPE_WIMAX = 4;
+  const unsigned long LINK_TYPE_MOBILE = 9;
+
+  /**
+   * This is set to true when the system is believed to have a usable
+   * network connection.
+   *
+   * The link is only up when network connections can be established. For
+   * example, the link is down during DHCP configuration (unless there
+   * is another usable interface already configured).
+   *
+   * If the link status is not currently known, we generally assume that
+   * it is up.
+   */
+  readonly attribute boolean isLinkUp;
+
+  /**
+   * This is set to true when we believe that isLinkUp is accurate.
+   */
+  readonly attribute boolean linkStatusKnown;
+
+  /**
+   * The type of network connection.
+   */
+  readonly attribute unsigned long linkType;
+
+  /**
+   * A string uniquely identifying the current active network interfaces.
+   * Empty when there are no active network interfaces.
+   */
+  readonly attribute ACString networkID;
+
+  /**
+   * The list of DNS suffixes for the currently active network interfaces.
+   */
+  readonly attribute Array<ACString> dnsSuffixList;
+
+  /**
+   * The IPs of the DNS resolvers currently used by the platform.
+   */
+  [noscript] readonly attribute Array<NetAddr> nativeResolvers;
+
+  /**
+   * Same as previous - returns the IPs of DNS resolvers but this time as
+   * XPCOM objects usable by extensions.
+   */
+  readonly attribute Array<nsINetAddr> resolvers;
+
+  const unsigned long NONE_DETECTED = 0;
+  const unsigned long VPN_DETECTED = 1 << 0;
+  const unsigned long PROXY_DETECTED = 1 << 1;
+  const unsigned long NRPT_DETECTED = 1 << 2;
+
+  /**
+   * A bitfield that encodes the platform attributes we detected which
+   * indicate that we should only use DNS, not TRR.
+   */
+  readonly attribute unsigned long platformDNSIndications;
+};
+
+%{C++
+/**
+ * We send notifications through nsIObserverService with topic
+ * NS_NETWORK_LINK_TOPIC whenever one of isLinkUp or linkStatusKnown
+ * changes. We pass one of the NS_NETWORK_LINK_DATA_ constants below
+ * as the aData parameter of the notification.
+ */
+#define NS_NETWORK_LINK_TOPIC "network:link-status-changed"
+
+/**
+ * isLinkUp is now true, linkStatusKnown is true.
+ */
+#define NS_NETWORK_LINK_DATA_UP      "up"
+/**
+ * isLinkUp is now false, linkStatusKnown is true.
+ */
+#define NS_NETWORK_LINK_DATA_DOWN    "down"
+/**
+ * isLinkUp is still true, but the network setup is modified.
+ * linkStatusKnown is true.
+ */
+#define NS_NETWORK_LINK_DATA_CHANGED "changed"
+/**
+ * linkStatusKnown is now false.
+ */
+#define NS_NETWORK_LINK_DATA_UNKNOWN "unknown"
+
+/**
+ * network ID has changed.
+ */
+#define NS_NETWORK_ID_CHANGED_TOPIC "network:networkid-changed"
+
+/**
+ * DNS suffix list has updated.
+ */
+#define NS_DNS_SUFFIX_LIST_UPDATED_TOPIC "network:dns-suffix-list-updated"
+
+/**
+ * We send notifications through nsIObserverService with topic
+ * NS_NETWORK_LINK_TYPE_TOPIC whenever the network connection type
+ * changes. We pass one of the valid connection type constants
+ * below as the aData parameter of the notification.
+ */
+#define NS_NETWORK_LINK_TYPE_TOPIC "network:link-type-changed"
+
+/** We were unable to determine the network connection type */
+#define NS_NETWORK_LINK_TYPE_UNKNOWN  "unknown"
+
+/** A standard wired ethernet connection */
+#define NS_NETWORK_LINK_TYPE_ETHERNET    "ethernet"
+
+/** A connection via a USB port */
+#define NS_NETWORK_LINK_TYPE_USB    "usb"
+
+/** A connection via a WiFi access point (IEEE802.11) */
+#define NS_NETWORK_LINK_TYPE_WIFI "wifi"
+
+/** A connection via WiMax (IEEE802.16) */
+#define NS_NETWORK_LINK_TYPE_WIMAX "wimax"
+
+/** A mobile connection (e.g. 2G, 3G, etc) */
+#define NS_NETWORK_LINK_TYPE_MOBILE "mobile"
+%}
diff --git a/netwerk/base/nsINetworkPredictor.idl b/netwerk/base/nsINetworkPredictor.idl
new file mode 100644
index 0000000000..07f88cba8d
--- /dev/null
+++ b/netwerk/base/nsINetworkPredictor.idl
@@ -0,0 +1,194 @@
+/* vim: set ts=2 sts=2 et sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsINetworkPredictorVerifier;
+
+webidl Document;
+
+typedef unsigned long PredictorPredictReason;
+typedef unsigned long PredictorLearnReason;
+
+%{C++
+namespace mozilla {
+
+class OriginAttributes;
+
+}
+%}
+
+[ref] native OriginAttributes(const mozilla::OriginAttributes);
+
+/**
+ * nsINetworkPredictor - learn about pages users visit, and allow us to take
+ *                       predictive actions upon future visits.
+ *                       NOTE: nsINetworkPredictor should only
+ *                       be used on the main thread.
+ */
+[scriptable, builtinclass, uuid(acc88e7c-3f39-42c7-ac31-6377c2c3d73e)]
+interface nsINetworkPredictor : nsISupports
+{
+  /**
+   * Prediction reasons
+   *
+   * PREDICT_LINK - we are being asked to take predictive action because
+   * the user is hovering over a link.
+   *
+   * PREDICT_LOAD - we are being asked to take predictive action because
+   * the user has initiated a pageload.
+   *
+   * PREDICT_STARTUP - we are being asked to take predictive action
+   * because the browser is starting up.
+   */
+  const PredictorPredictReason PREDICT_LINK = 0;
+  const PredictorPredictReason PREDICT_LOAD = 1;
+  const PredictorPredictReason PREDICT_STARTUP = 2;
+
+  /**
+   * Start taking predictive actions
+   *
+   * Calling this will cause the predictor to (possibly) start
+   * taking actions such as DNS prefetch and/or TCP preconnect based on
+   * (1) the host name that we are given, and (2) the reason we are being
+   * asked to take actions.
+   *
+   * @param targetURI - The URI we are being asked to take actions based on.
+   * @param sourceURI - The URI that is currently loaded. This is so we can
+   *   avoid doing predictive actions for link hover on an HTTPS page (for
+   *   example).
+   * @param reason - The reason we are being asked to take actions. Can be
+   *   any of the PREDICT_* values above.
+   *   In the case of PREDICT_LINK, targetURI should be the URI of the link
+   *   that is being hovered over, and sourceURI should be the URI of the page
+   *   on which the link appears.
+   *   In the case of PREDICT_LOAD, targetURI should be the URI of the page that
+   *   is being loaded and sourceURI should be null.
+   *   In the case of PREDICT_STARTUP, both targetURI and sourceURI should be
+   *   null.
+   * @param originAttributes - The originAttributes of the page load we are
+   *   predicting about.
+   * @param verifier - An nsINetworkPredictorVerifier used in testing to ensure
+   *   we're predicting the way we expect to. Not necessary (or desired) for
+   *   normal operation.
+   */
+  [implicit_jscontext]
+  void predict(in nsIURI targetURI,
+               in nsIURI sourceURI,
+               in PredictorPredictReason reason,
+               in jsval originAttributes,
+               in nsINetworkPredictorVerifier verifier);
+
+  [notxpcom]
+  nsresult predictNative(in nsIURI targetURI,
+                         in nsIURI sourceURI,
+                         in PredictorPredictReason reason,
+                         in OriginAttributes originAttributes,
+                         in nsINetworkPredictorVerifier verifier);
+
+
+  /*
+   * Reasons we are learning something
+   *
+   * LEARN_LOAD_TOPLEVEL - we are learning about the toplevel resource of a
+   *                       pageload (NOTE: this should ONLY be used by tests)
+   *
+   * LEARN_LOAD_SUBRESOURCE - we are learning a subresource from a pageload
+   *
+   * LEARN_LOAD_REDIRECT - we are learning about the re-direct of a URI
+   *
+   * LEARN_STARTUP - we are learning about a page loaded during startup
+   */
+  const PredictorLearnReason LEARN_LOAD_TOPLEVEL = 0;
+  const PredictorLearnReason LEARN_LOAD_SUBRESOURCE = 1;
+  const PredictorLearnReason LEARN_LOAD_REDIRECT = 2;
+  const PredictorLearnReason LEARN_STARTUP = 3;
+
+  /**
+   * Add to our compendium of knowledge
+   *
+   * This adds to our prediction database to make things (hopefully)
+   * smarter next time we predict something.
+   *
+   * @param targetURI - The URI that was loaded that we are keeping track of.
+   * @param sourceURI - The URI that caused targetURI to be loaded (for page
+   *   loads). This means the DOCUMENT URI.
+   * @param reason - The reason we are learning this bit of knowledge.
+   *   Reason can be any of the LEARN_* values.
+   *   In the case of LEARN_LOAD_SUBRESOURCE, targetURI should be the URI of a
+   *   subresource of a page, and sourceURI should be the top-level URI.
+   *   In the case of LEARN_LOAD_REDIRECT, targetURI is the NEW URI of a
+   *   top-level resource that was redirected to, and sourceURI is the
+   *   ORIGINAL URI of said top-level resource.
+   *   In the case of LEARN_STARTUP, targetURI should be the URI of a page
+   *   that was loaded immediately after browser startup, and sourceURI should
+   *   be null.
+   * @param originAttributes - The originAttributes for the page load that we
+   *   are learning about.
+   */
+  [implicit_jscontext]
+  void learn(in nsIURI targetURI,
+             in nsIURI sourceURI,
+             in PredictorLearnReason reason,
+             in jsval originAttributes);
+
+  [notxpcom]
+  nsresult learnNative(in nsIURI targetURI,
+                       in nsIURI sourceURI,
+                       in PredictorLearnReason reason,
+                       in OriginAttributes originAttributes);
+
+  /**
+   * Clear out all our learned knowledge
+   *
+   * This removes everything from our database so that any predictions begun
+   * after this completes will start from a blank slate.
+   */
+  void reset();
+};
+
+%{C++
+// Wrapper functions to make use of the predictor easier and less invasive
+class nsIChannel;
+
+class nsILoadContext;
+class nsILoadGroup;
+class nsINetworkPredictorVerifier;
+
+namespace mozilla {
+
+class OriginAttributes;
+
+namespace net {
+
+nsresult PredictorPredict(nsIURI *targetURI,
+                          nsIURI *sourceURI,
+                          PredictorPredictReason reason,
+                          const OriginAttributes& originAttributes,
+                          nsINetworkPredictorVerifier *verifier);
+
+nsresult PredictorLearn(nsIURI *targetURI,
+                        nsIURI *sourceURI,
+                        PredictorLearnReason reason,
+                        const OriginAttributes& originAttributes);
+
+nsresult PredictorLearn(nsIURI *targetURI,
+                        nsIURI *sourceURI,
+                        PredictorLearnReason reason,
+                        nsILoadGroup *loadGroup);
+
+nsresult PredictorLearn(nsIURI *targetURI,
+                        nsIURI *sourceURI,
+                        PredictorLearnReason reason,
+                        dom::Document *document);
+
+nsresult PredictorLearnRedirect(nsIURI *targetURI,
+                                nsIChannel *channel,
+                                const OriginAttributes& originAttributes);
+
+} // mozilla::net
+} // mozilla
+%}
diff --git a/netwerk/base/nsINetworkPredictorVerifier.idl b/netwerk/base/nsINetworkPredictorVerifier.idl
new file mode 100644
index 0000000000..b00aecc076
--- /dev/null
+++ b/netwerk/base/nsINetworkPredictorVerifier.idl
@@ -0,0 +1,40 @@
+/* vim: set ts=2 sts=2 et sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * nsINetworkPredictorVerifier - used for testing the network predictor to
+ *                               ensure it does what we expect it to do.
+ */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+
+[scriptable, uuid(2e43bb32-dabf-4494-9f90-2b3195b1c73d)]
+interface nsINetworkPredictorVerifier : nsISupports
+{
+    /**
+     * Callback for when we do a predictive prefetch
+     *
+     * @param uri - The URI that was prefetched
+     * @param status - The request status code returned by the
+     *   prefetch attempt e.g. 200 (OK):w
+     */
+    void onPredictPrefetch(in nsIURI uri, in uint32_t status);
+
+    /**
+     * Callback for when we do a predictive preconnect
+     *
+     * @param uri - The URI that was preconnected to
+     */
+    void onPredictPreconnect(in nsIURI uri);
+
+    /**
+     * Callback for when we do a predictive DNS lookup
+     *
+     * @param uri - The URI that was looked up
+     */
+    void onPredictDNS(in nsIURI uri);
+};
diff --git a/netwerk/base/nsINullChannel.idl b/netwerk/base/nsINullChannel.idl
new file mode 100644
index 0000000000..6c03a2743b
--- /dev/null
+++ b/netwerk/base/nsINullChannel.idl
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface is only used in order to mark the fact that
+ * an object isn't a complete implementation of its interfaces.
+ * For example, a consumer can QI NullHttpChannel to nsINullChannel,
+ * to determine if the object is just a dummy implementation of nsIHttpChannel.
+ */
+[scriptable, builtinclass, uuid(4610b901-df41-4bb4-bd3f-fd4d6b6d8d68)]
+interface nsINullChannel : nsISupports
+{
+};
diff --git a/netwerk/base/nsIOService.cpp b/netwerk/base/nsIOService.cpp
new file mode 100644
index 0000000000..c1a6ba9734
--- /dev/null
+++ b/netwerk/base/nsIOService.cpp
@@ -0,0 +1,2201 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 cindent et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#include "nsIOService.h"
+#include "nsIProtocolHandler.h"
+#include "nsIFileProtocolHandler.h"
+#include "nscore.h"
+#include "nsIURI.h"
+#include "prprf.h"
+#include "netCore.h"
+#include "nsIObserverService.h"
+#include "nsXPCOM.h"
+#include "nsIProxiedProtocolHandler.h"
+#include "nsIProxyInfo.h"
+#include "nsDNSService2.h"
+#include "nsEscape.h"
+#include "nsNetUtil.h"
+#include "nsNetCID.h"
+#include "nsCRT.h"
+#include "nsSimpleNestedURI.h"
+#include "nsSocketTransport2.h"
+#include "nsTArray.h"
+#include "nsIConsoleService.h"
+#include "nsIUploadChannel2.h"
+#include "nsXULAppAPI.h"
+#include "nsIProtocolProxyCallback.h"
+#include "nsICancelable.h"
+#include "nsINetworkLinkService.h"
+#include "nsAsyncRedirectVerifyHelper.h"
+#include "nsURLHelper.h"
+#include "nsIProtocolProxyService2.h"
+#include "MainThreadUtils.h"
+#include "nsINode.h"
+#include "nsIWebTransport.h"
+#include "nsIWidget.h"
+#include "nsThreadUtils.h"
+#include "WebTransportSessionProxy.h"
+#include "mozilla/AppShutdown.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/Services.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/net/NeckoParent.h"
+#include "mozilla/dom/ClientInfo.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/nsHTTPSOnlyUtils.h"
+#include "mozilla/dom/ServiceWorkerDescriptor.h"
+#include "mozilla/net/CaptivePortalService.h"
+#include "mozilla/net/NetworkConnectivityService.h"
+#include "mozilla/net/SocketProcessHost.h"
+#include "mozilla/net/SocketProcessParent.h"
+#include "mozilla/net/SSLTokensCache.h"
+#include "mozilla/Unused.h"
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StaticPrefs_security.h"
+#include "nsNSSComponent.h"
+#include "ssl.h"
+#include "StaticComponents.h"
+
+namespace mozilla {
+namespace net {
+
+using mozilla::Maybe;
+using mozilla::dom::ClientInfo;
+using mozilla::dom::ServiceWorkerDescriptor;
+
+#define PORT_PREF_PREFIX "network.security.ports."
+#define PORT_PREF(x) PORT_PREF_PREFIX x
+#define MANAGE_OFFLINE_STATUS_PREF "network.manage-offline-status"
+
+// Nb: these have been misnomers since bug 715770 removed the buffer cache.
+// "network.segment.count" and "network.segment.size" would be better names,
+// but the old names are still used to preserve backward compatibility.
+#define NECKO_BUFFER_CACHE_COUNT_PREF "network.buffer.cache.count"
+#define NECKO_BUFFER_CACHE_SIZE_PREF "network.buffer.cache.size"
+#define NETWORK_CAPTIVE_PORTAL_PREF "network.captive-portal-service.enabled"
+#define WEBRTC_PREF_PREFIX "media.peerconnection."
+#define NETWORK_DNS_PREF "network.dns."
+#define FORCE_EXTERNAL_PREF_PREFIX "network.protocol-handler.external."
+
+#define MAX_RECURSION_COUNT 50
+
+nsIOService* gIOService;
+static bool gHasWarnedUploadChannel2;
+static bool gCaptivePortalEnabled = false;
+static LazyLogModule gIOServiceLog("nsIOService");
+#undef LOG
+#define LOG(args) MOZ_LOG(gIOServiceLog, LogLevel::Debug, args)
+
+// A general port blacklist.  Connections to these ports will not be allowed
+// unless the protocol overrides.
+//
+// This list is to be kept in sync with "bad ports" as defined in the
+// WHATWG Fetch standard at <https://fetch.spec.whatwg.org/#port-blocking>
+
+int16_t gBadPortList[] = {
+    1,      // tcpmux
+    7,      // echo
+    9,      // discard
+    11,     // systat
+    13,     // daytime
+    15,     // netstat
+    17,     // qotd
+    19,     // chargen
+    20,     // ftp-data
+    21,     // ftp
+    22,     // ssh
+    23,     // telnet
+    25,     // smtp
+    37,     // time
+    42,     // name
+    43,     // nicname
+    53,     // domain
+    69,     // tftp
+    77,     // priv-rjs
+    79,     // finger
+    87,     // ttylink
+    95,     // supdup
+    101,    // hostriame
+    102,    // iso-tsap
+    103,    // gppitnp
+    104,    // acr-nema
+    109,    // pop2
+    110,    // pop3
+    111,    // sunrpc
+    113,    // auth
+    115,    // sftp
+    117,    // uucp-path
+    119,    // nntp
+    123,    // ntp
+    135,    // loc-srv / epmap
+    137,    // netbios
+    139,    // netbios
+    143,    // imap2
+    161,    // snmp
+    179,    // bgp
+    389,    // ldap
+    427,    // afp (alternate)
+    465,    // smtp (alternate)
+    512,    // print / exec
+    513,    // login
+    514,    // shell
+    515,    // printer
+    526,    // tempo
+    530,    // courier
+    531,    // chat
+    532,    // netnews
+    540,    // uucp
+    548,    // afp
+    554,    // rtsp
+    556,    // remotefs
+    563,    // nntp+ssl
+    587,    // smtp (outgoing)
+    601,    // syslog-conn
+    636,    // ldap+ssl
+    989,    // ftps-data
+    990,    // ftps
+    993,    // imap+ssl
+    995,    // pop3+ssl
+    1719,   // h323gatestat
+    1720,   // h323hostcall
+    1723,   // pptp
+    2049,   // nfs
+    3659,   // apple-sasl
+    4045,   // lockd
+    5060,   // sip
+    5061,   // sips
+    6000,   // x11
+    6566,   // sane-port
+    6665,   // irc (alternate)
+    6666,   // irc (alternate)
+    6667,   // irc (default)
+    6668,   // irc (alternate)
+    6669,   // irc (alternate)
+    6697,   // irc+tls
+    10080,  // amanda
+    0,      // Sentinel value: This MUST be zero
+};
+
+static const char kProfileChangeNetTeardownTopic[] =
+    "profile-change-net-teardown";
+static const char kProfileChangeNetRestoreTopic[] =
+    "profile-change-net-restore";
+static const char kProfileDoChange[] = "profile-do-change";
+
+// Necko buffer defaults
+uint32_t nsIOService::gDefaultSegmentSize = 4096;
+uint32_t nsIOService::gDefaultSegmentCount = 24;
+
+uint32_t nsIOService::sSocketProcessCrashedCount = 0;
+
+////////////////////////////////////////////////////////////////////////////////
+
+nsIOService::nsIOService()
+    : mLastOfflineStateChange(PR_IntervalNow()),
+      mLastConnectivityChange(PR_IntervalNow()),
+      mLastNetworkLinkChange(PR_IntervalNow()) {}
+
+static const char* gCallbackPrefs[] = {
+    PORT_PREF_PREFIX,
+    MANAGE_OFFLINE_STATUS_PREF,
+    NECKO_BUFFER_CACHE_COUNT_PREF,
+    NECKO_BUFFER_CACHE_SIZE_PREF,
+    NETWORK_CAPTIVE_PORTAL_PREF,
+    FORCE_EXTERNAL_PREF_PREFIX,
+    nullptr,
+};
+
+static const char* gCallbackPrefsForSocketProcess[] = {
+    WEBRTC_PREF_PREFIX,
+    NETWORK_DNS_PREF,
+    "network.send_ODA_to_content_directly",
+    "network.trr.",
+    "doh-rollout.",
+    "network.dns.disableIPv6",
+    "network.dns.skipTRR-when-parental-control-enabled",
+    "network.offline-mirrors-connectivity",
+    "network.disable-localhost-when-offline",
+    "network.proxy.parse_pac_on_socket_process",
+    "network.proxy.allow_hijacking_localhost",
+    "network.connectivity-service.",
+    "network.captive-portal-service.testMode",
+    nullptr,
+};
+
+static const char* gCallbackSecurityPrefs[] = {
+    // Note the prefs listed below should be in sync with the code in
+    // HandleTLSPrefChange().
+    "security.tls.version.min",
+    "security.tls.version.max",
+    "security.tls.version.enable-deprecated",
+    "security.tls.hello_downgrade_check",
+    "security.ssl.require_safe_negotiation",
+    "security.ssl.enable_false_start",
+    "security.ssl.enable_alpn",
+    "security.tls.enable_0rtt_data",
+    "security.ssl.disable_session_identifiers",
+    "security.tls.enable_post_handshake_auth",
+    "security.tls.enable_delegated_credentials",
+    // Note the prefs listed below should be in sync with the code in
+    // SetValidationOptionsCommon().
+    "security.ssl.enable_ocsp_stapling",
+    "security.ssl.enable_ocsp_must_staple",
+    "security.pki.certificate_transparency.mode",
+    nullptr,
+};
+
+nsresult nsIOService::Init() {
+  SSLTokensCache::Init();
+
+  InitializeCaptivePortalService();
+
+  // setup our bad port list stuff
+  for (int i = 0; gBadPortList[i]; i++) {
+    // We can't be accessed by another thread yet
+    MOZ_PUSH_IGNORE_THREAD_SAFETY
+    mRestrictedPortList.AppendElement(gBadPortList[i]);
+    MOZ_POP_THREAD_SAFETY
+  }
+
+  // Further modifications to the port list come from prefs
+  Preferences::RegisterPrefixCallbacks(nsIOService::PrefsChanged,
+                                       gCallbackPrefs, this);
+  PrefsChanged();
+
+  mSocketProcessTopicBlockedList.Insert(
+      nsLiteralCString(NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID));
+  mSocketProcessTopicBlockedList.Insert(
+      nsLiteralCString(NS_XPCOM_SHUTDOWN_OBSERVER_ID));
+  mSocketProcessTopicBlockedList.Insert("xpcom-shutdown-threads"_ns);
+  mSocketProcessTopicBlockedList.Insert("profile-do-change"_ns);
+  mSocketProcessTopicBlockedList.Insert("network:socket-process-crashed"_ns);
+
+  // Register for profile change notifications
+  mObserverService = services::GetObserverService();
+  AddObserver(this, kProfileChangeNetTeardownTopic, true);
+  AddObserver(this, kProfileChangeNetRestoreTopic, true);
+  AddObserver(this, kProfileDoChange, true);
+  AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
+  AddObserver(this, NS_NETWORK_LINK_TOPIC, true);
+  AddObserver(this, NS_NETWORK_ID_CHANGED_TOPIC, true);
+  AddObserver(this, NS_WIDGET_WAKE_OBSERVER_TOPIC, true);
+
+  // Register observers for sending notifications to nsSocketTransportService
+  if (XRE_IsParentProcess()) {
+    AddObserver(this, "profile-initial-state", true);
+    AddObserver(this, NS_WIDGET_SLEEP_OBSERVER_TOPIC, true);
+  }
+
+  if (IsSocketProcessChild()) {
+    Preferences::RegisterCallbacks(nsIOService::OnTLSPrefChange,
+                                   gCallbackSecurityPrefs, this);
+  }
+
+  gIOService = this;
+
+  InitializeNetworkLinkService();
+  InitializeProtocolProxyService();
+
+  SetOffline(false);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::AddObserver(nsIObserver* aObserver, const char* aTopic,
+                         bool aOwnsWeak) {
+  if (!mObserverService) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Register for the origional observer.
+  nsresult rv = mObserverService->AddObserver(aObserver, aTopic, aOwnsWeak);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (!XRE_IsParentProcess()) {
+    return NS_OK;
+  }
+
+  nsAutoCString topic(aTopic);
+  // This happens when AddObserver() is called by nsIOService::Init(). We don't
+  // want to add nsIOService again.
+  if (SameCOMIdentity(aObserver, static_cast<nsIObserver*>(this))) {
+    mIOServiceTopicList.Insert(topic);
+    return NS_OK;
+  }
+
+  if (!UseSocketProcess()) {
+    return NS_OK;
+  }
+
+  if (mSocketProcessTopicBlockedList.Contains(topic)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Avoid registering  duplicate topics.
+  if (mObserverTopicForSocketProcess.Contains(topic)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mObserverTopicForSocketProcess.Insert(topic);
+
+  // Avoid registering duplicate topics.
+  if (mIOServiceTopicList.Contains(topic)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return mObserverService->AddObserver(this, aTopic, true);
+}
+
+NS_IMETHODIMP
+nsIOService::RemoveObserver(nsIObserver* aObserver, const char* aTopic) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIOService::EnumerateObservers(const char* aTopic,
+                                nsISimpleEnumerator** anEnumerator) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP nsIOService::NotifyObservers(nsISupports* aSubject,
+                                           const char* aTopic,
+                                           const char16_t* aSomeData) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsIOService::~nsIOService() {
+  if (gIOService) {
+    MOZ_ASSERT(gIOService == this);
+    gIOService = nullptr;
+  }
+}
+
+// static
+void nsIOService::OnTLSPrefChange(const char* aPref, void* aSelf) {
+  MOZ_ASSERT(IsSocketProcessChild());
+
+  if (!EnsureNSSInitializedChromeOrContent()) {
+    LOG(("NSS not initialized."));
+    return;
+  }
+
+  nsAutoCString pref(aPref);
+  // The preferences listed in gCallbackSecurityPrefs need to be in sync with
+  // the code in HandleTLSPrefChange() and SetValidationOptionsCommon().
+  if (HandleTLSPrefChange(pref)) {
+    LOG(("HandleTLSPrefChange done"));
+  } else if (pref.EqualsLiteral("security.ssl.enable_ocsp_stapling") ||
+             pref.EqualsLiteral("security.ssl.enable_ocsp_must_staple") ||
+             pref.EqualsLiteral("security.pki.certificate_transparency.mode")) {
+    SetValidationOptionsCommon();
+  }
+}
+
+nsresult nsIOService::InitializeCaptivePortalService() {
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    // We only initalize a captive portal service in the main process
+    return NS_OK;
+  }
+
+  mCaptivePortalService = do_GetService(NS_CAPTIVEPORTAL_CID);
+  if (mCaptivePortalService) {
+    return static_cast<CaptivePortalService*>(mCaptivePortalService.get())
+        ->Initialize();
+  }
+
+  // Instantiate and initialize the service
+  RefPtr<NetworkConnectivityService> ncs =
+      NetworkConnectivityService::GetSingleton();
+
+  return NS_OK;
+}
+
+nsresult nsIOService::InitializeSocketTransportService() {
+  nsresult rv = NS_OK;
+
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    LOG(
+        ("nsIOService aborting InitializeSocketTransportService because of app "
+         "shutdown"));
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  if (!mSocketTransportService) {
+    mSocketTransportService =
+        do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("failed to get socket transport service");
+    }
+  }
+
+  if (mSocketTransportService) {
+    rv = mSocketTransportService->Init();
+    NS_ASSERTION(NS_SUCCEEDED(rv), "socket transport service init failed");
+    mSocketTransportService->SetOffline(false);
+  }
+
+  return rv;
+}
+
+nsresult nsIOService::InitializeNetworkLinkService() {
+  nsresult rv = NS_OK;
+
+  if (mNetworkLinkServiceInitialized) return rv;
+
+  if (!NS_IsMainThread()) {
+    NS_WARNING("Network link service should be created on main thread");
+    return NS_ERROR_FAILURE;
+  }
+
+  // go into managed mode if we can, and chrome process
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  mNetworkLinkService = do_GetService(NS_NETWORK_LINK_SERVICE_CONTRACTID, &rv);
+
+  if (mNetworkLinkService) {
+    mNetworkLinkServiceInitialized = true;
+  }
+
+  // After initializing the networkLinkService, query the connectivity state
+  OnNetworkLinkEvent(NS_NETWORK_LINK_DATA_UNKNOWN);
+
+  return rv;
+}
+
+nsresult nsIOService::InitializeProtocolProxyService() {
+  nsresult rv = NS_OK;
+
+  if (XRE_IsParentProcess()) {
+    // for early-initialization
+    Unused << do_GetService(NS_PROTOCOLPROXYSERVICE_CONTRACTID, &rv);
+  }
+
+  return rv;
+}
+
+already_AddRefed<nsIOService> nsIOService::GetInstance() {
+  if (!gIOService) {
+    RefPtr<nsIOService> ios = new nsIOService();
+    if (NS_SUCCEEDED(ios->Init())) {
+      MOZ_ASSERT(gIOService == ios.get());
+      return ios.forget();
+    }
+  }
+  return do_AddRef(gIOService);
+}
+
+class SocketProcessListenerProxy : public SocketProcessHost::Listener {
+ public:
+  SocketProcessListenerProxy() = default;
+  void OnProcessLaunchComplete(SocketProcessHost* aHost, bool aSucceeded) {
+    if (!gIOService) {
+      return;
+    }
+
+    gIOService->OnProcessLaunchComplete(aHost, aSucceeded);
+  }
+
+  void OnProcessUnexpectedShutdown(SocketProcessHost* aHost) {
+    if (!gIOService) {
+      return;
+    }
+
+    gIOService->OnProcessUnexpectedShutdown(aHost);
+  }
+};
+
+// static
+bool nsIOService::TooManySocketProcessCrash() {
+  return sSocketProcessCrashedCount >=
+         StaticPrefs::network_max_socket_process_failed_count();
+}
+
+// static
+void nsIOService::IncreaseSocketProcessCrashCount() {
+  MOZ_ASSERT(IsNeckoChild());
+  sSocketProcessCrashedCount++;
+}
+
+nsresult nsIOService::LaunchSocketProcess() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (XRE_GetProcessType() != GeckoProcessType_Default) {
+    return NS_OK;
+  }
+
+  // We shouldn't launch socket prcess when shutdown begins.
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    return NS_OK;
+  }
+
+  if (mSocketProcess) {
+    return NS_OK;
+  }
+
+  if (PR_GetEnv("MOZ_DISABLE_SOCKET_PROCESS")) {
+    LOG(("nsIOService skipping LaunchSocketProcess because of the env"));
+    return NS_OK;
+  }
+
+  if (!StaticPrefs::network_process_enabled()) {
+    LOG(("nsIOService skipping LaunchSocketProcess because of the pref"));
+    return NS_OK;
+  }
+
+  Preferences::RegisterPrefixCallbacks(
+      nsIOService::NotifySocketProcessPrefsChanged,
+      gCallbackPrefsForSocketProcess, this);
+
+  // The subprocess is launched asynchronously, so we wait for a callback to
+  // acquire the IPDL actor.
+  mSocketProcess = new SocketProcessHost(new SocketProcessListenerProxy());
+  LOG(("nsIOService::LaunchSocketProcess"));
+  if (!mSocketProcess->Launch()) {
+    NS_WARNING("Failed to launch socket process!!");
+    DestroySocketProcess();
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+void nsIOService::DestroySocketProcess() {
+  LOG(("nsIOService::DestroySocketProcess"));
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (XRE_GetProcessType() != GeckoProcessType_Default || !mSocketProcess) {
+    return;
+  }
+
+  Preferences::UnregisterPrefixCallbacks(
+      nsIOService::NotifySocketProcessPrefsChanged,
+      gCallbackPrefsForSocketProcess, this);
+
+  mSocketProcess->Shutdown();
+  mSocketProcess = nullptr;
+}
+
+bool nsIOService::SocketProcessReady() {
+  return mSocketProcess && mSocketProcess->IsConnected();
+}
+
+static bool sUseSocketProcess = false;
+static bool sUseSocketProcessChecked = false;
+
+// static
+bool nsIOService::UseSocketProcess(bool aCheckAgain) {
+  if (sUseSocketProcessChecked && !aCheckAgain) {
+    return sUseSocketProcess;
+  }
+
+  sUseSocketProcessChecked = true;
+  sUseSocketProcess = false;
+
+  if (PR_GetEnv("MOZ_DISABLE_SOCKET_PROCESS")) {
+    return sUseSocketProcess;
+  }
+
+  if (TooManySocketProcessCrash()) {
+    LOG(("TooManySocketProcessCrash"));
+    return sUseSocketProcess;
+  }
+
+  if (PR_GetEnv("MOZ_FORCE_USE_SOCKET_PROCESS")) {
+    sUseSocketProcess = true;
+    return sUseSocketProcess;
+  }
+
+  if (StaticPrefs::network_process_enabled()) {
+    sUseSocketProcess =
+        StaticPrefs::network_http_network_access_on_socket_process_enabled();
+  }
+  return sUseSocketProcess;
+}
+
+// static
+void nsIOService::NotifySocketProcessPrefsChanged(const char* aName,
+                                                  void* aSelf) {
+  static_cast<nsIOService*>(aSelf)->NotifySocketProcessPrefsChanged(aName);
+}
+
+void nsIOService::NotifySocketProcessPrefsChanged(const char* aName) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
+  if (!StaticPrefs::network_process_enabled()) {
+    return;
+  }
+
+  dom::Pref pref(nsCString(aName), /* isLocked */ false,
+                 /* isSanitized */ false, Nothing(), Nothing());
+
+  Preferences::GetPreference(&pref, GeckoProcessType_Socket,
+                             /* remoteType */ ""_ns);
+  auto sendPrefUpdate = [pref]() {
+    Unused << gIOService->mSocketProcess->GetActor()->SendPreferenceUpdate(
+        pref);
+  };
+  CallOrWaitForSocketProcess(sendPrefUpdate);
+}
+
+void nsIOService::OnProcessLaunchComplete(SocketProcessHost* aHost,
+                                          bool aSucceeded) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  LOG(("nsIOService::OnProcessLaunchComplete aSucceeded=%d\n", aSucceeded));
+
+  mSocketProcessLaunchComplete = aSucceeded;
+
+  if (mShutdown || !SocketProcessReady() || !aSucceeded) {
+    mPendingEvents.Clear();
+    return;
+  }
+
+  if (!mPendingEvents.IsEmpty()) {
+    nsTArray<std::function<void()>> pendingEvents = std::move(mPendingEvents);
+    for (auto& func : pendingEvents) {
+      func();
+    }
+  }
+}
+
+void nsIOService::CallOrWaitForSocketProcess(
+    const std::function<void()>& aFunc) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (IsSocketProcessLaunchComplete() && SocketProcessReady()) {
+    aFunc();
+  } else {
+    mPendingEvents.AppendElement(aFunc);  // infallible
+    LaunchSocketProcess();
+  }
+}
+
+int32_t nsIOService::SocketProcessPid() {
+  if (!mSocketProcess) {
+    return 0;
+  }
+  if (SocketProcessParent* actor = mSocketProcess->GetActor()) {
+    return (int32_t)actor->OtherPid();
+  }
+  return 0;
+}
+
+bool nsIOService::IsSocketProcessLaunchComplete() {
+  MOZ_ASSERT(NS_IsMainThread());
+  return mSocketProcessLaunchComplete;
+}
+
+void nsIOService::OnProcessUnexpectedShutdown(SocketProcessHost* aHost) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  LOG(("nsIOService::OnProcessUnexpectedShutdown\n"));
+  DestroySocketProcess();
+  mPendingEvents.Clear();
+
+  // Nothing to do if socket process was not used before.
+  if (!UseSocketProcess()) {
+    return;
+  }
+
+  sSocketProcessCrashedCount++;
+  if (TooManySocketProcessCrash()) {
+    sUseSocketProcessChecked = false;
+    DNSServiceWrapper::SwitchToBackupDNSService();
+  }
+
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+  if (observerService) {
+    (void)observerService->NotifyObservers(
+        nullptr, "network:socket-process-crashed", nullptr);
+  }
+
+  // UseSocketProcess() could return false if we have too many crashes, so we
+  // should call it again.
+  if (UseSocketProcess()) {
+    MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(
+        NewRunnableMethod("nsIOService::LaunchSocketProcess", this,
+                          &nsIOService::LaunchSocketProcess)));
+  }
+}
+
+RefPtr<MemoryReportingProcess> nsIOService::GetSocketProcessMemoryReporter() {
+  // Check the prefs here again, since we don't want to create
+  // SocketProcessMemoryReporter for some tests.
+  if (!StaticPrefs::network_process_enabled() || !SocketProcessReady()) {
+    return nullptr;
+  }
+
+  return new SocketProcessMemoryReporter();
+}
+
+NS_IMETHODIMP
+nsIOService::SocketProcessTelemetryPing() {
+  CallOrWaitForSocketProcess([]() {
+    Unused << gIOService->mSocketProcess->GetActor()
+                  ->SendSocketProcessTelemetryPing();
+  });
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(nsIOService, nsIIOService, nsINetUtil, nsISpeculativeConnect,
+                  nsIObserver, nsIIOServiceInternal, nsISupportsWeakReference,
+                  nsIObserverService)
+
+////////////////////////////////////////////////////////////////////////////////
+
+nsresult nsIOService::RecheckCaptivePortal() {
+  MOZ_ASSERT(NS_IsMainThread(), "Must be called on the main thread");
+  if (!mCaptivePortalService) {
+    return NS_OK;
+  }
+  nsCOMPtr<nsIRunnable> task = NewRunnableMethod(
+      "nsIOService::RecheckCaptivePortal", mCaptivePortalService,
+      &nsICaptivePortalService::RecheckCaptivePortal);
+  return NS_DispatchToMainThread(task);
+}
+
+nsresult nsIOService::RecheckCaptivePortalIfLocalRedirect(nsIChannel* newChan) {
+  nsresult rv;
+
+  if (!mCaptivePortalService) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  rv = newChan->GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCString host;
+  rv = uri->GetHost(host);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  NetAddr addr;
+  // If the redirect wasn't to an IP literal, so there's probably no need
+  // to trigger the captive portal detection right now. It can wait.
+  if (NS_SUCCEEDED(addr.InitFromString(host)) && addr.IsIPAddrLocal()) {
+    RecheckCaptivePortal();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsIOService::AsyncOnChannelRedirect(
+    nsIChannel* oldChan, nsIChannel* newChan, uint32_t flags,
+    nsAsyncRedirectVerifyHelper* helper) {
+  // If a redirect to a local network address occurs, then chances are we
+  // are in a captive portal, so we trigger a recheck.
+  RecheckCaptivePortalIfLocalRedirect(newChan);
+
+  // This is silly. I wish there was a simpler way to get at the global
+  // reference of the contentSecurityManager. But it lives in the XPCOM
+  // service registry.
+  nsCOMPtr<nsIChannelEventSink> sink =
+      do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
+  if (sink) {
+    nsresult rv =
+        helper->DelegateOnChannelRedirect(sink, oldChan, newChan, flags);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  // Finally, our category
+  nsCOMArray<nsIChannelEventSink> entries;
+  mChannelEventSinks.GetEntries(entries);
+  int32_t len = entries.Count();
+  for (int32_t i = 0; i < len; ++i) {
+    nsresult rv =
+        helper->DelegateOnChannelRedirect(entries[i], oldChan, newChan, flags);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  nsCOMPtr<nsIHttpChannel> httpChan(do_QueryInterface(oldChan));
+
+  // Collect the redirection from HTTP(S) only.
+  if (httpChan) {
+    MOZ_ASSERT(NS_IsMainThread());
+    nsCOMPtr<nsIURI> newURI;
+    newChan->GetURI(getter_AddRefs(newURI));
+    MOZ_ASSERT(newURI);
+
+    nsAutoCString scheme;
+    newURI->GetScheme(scheme);
+    MOZ_ASSERT(!scheme.IsEmpty());
+
+    Telemetry::AccumulateCategoricalKeyed(
+        scheme,
+        oldChan->IsDocument()
+            ? Telemetry::LABELS_NETWORK_HTTP_REDIRECT_TO_SCHEME::topLevel
+            : Telemetry::LABELS_NETWORK_HTTP_REDIRECT_TO_SCHEME::subresource);
+  }
+
+  return NS_OK;
+}
+
+bool nsIOService::UsesExternalProtocolHandler(const nsACString& aScheme) {
+  if (aScheme == "file"_ns || aScheme == "chrome"_ns ||
+      aScheme == "resource"_ns) {
+    // Don't allow file:, chrome: or resource: URIs to be handled with
+    // nsExternalProtocolHandler, since internally we rely on being able to
+    // use and read from these URIs.
+    return false;
+  }
+
+  if (aScheme == "place"_ns || aScheme == "fake-favicon-uri"_ns ||
+      aScheme == "favicon"_ns || aScheme == "moz-nullprincipal"_ns) {
+    // Force place: fake-favicon-uri: favicon: and moz-nullprincipal: URIs to be
+    // handled with nsExternalProtocolHandler, and not with a dynamically
+    // registered handler.
+    return true;
+  }
+
+  // If prefs configure the URI to be handled externally, do so.
+  for (const auto& scheme : mForceExternalSchemes) {
+    if (aScheme == scheme) {
+      return true;
+    }
+  }
+  return false;
+}
+
+ProtocolHandlerInfo nsIOService::LookupProtocolHandler(
+    const nsACString& aScheme) {
+  // Look-ups are ASCII-case-insensitive, so lower-case the string before
+  // continuing.
+  nsAutoCString scheme(aScheme);
+  ToLowerCase(scheme);
+
+  // NOTE: If we could get rid of mForceExternalSchemes (or prevent them from
+  // disabling static protocols), we could avoid locking mLock until we need to
+  // check `mRuntimeProtocolHandlers.
+  AutoReadLock lock(mLock);
+  if (!UsesExternalProtocolHandler(scheme)) {
+    // Try the static protocol handler first - they cannot be overridden by
+    // dynamic protocols.
+    if (const xpcom::StaticProtocolHandler* handler =
+            xpcom::StaticProtocolHandler::Lookup(scheme)) {
+      return ProtocolHandlerInfo(*handler);
+    }
+    if (auto handler = mRuntimeProtocolHandlers.Lookup(scheme)) {
+      return ProtocolHandlerInfo(handler.Data());
+    }
+  }
+  return ProtocolHandlerInfo(xpcom::StaticProtocolHandler::Default());
+}
+
+NS_IMETHODIMP
+nsIOService::GetProtocolHandler(const char* scheme,
+                                nsIProtocolHandler** result) {
+  AssertIsOnMainThread();
+  NS_ENSURE_ARG_POINTER(scheme);
+
+  *result = LookupProtocolHandler(nsDependentCString(scheme)).Handler().take();
+  return *result ? NS_OK : NS_ERROR_UNKNOWN_PROTOCOL;
+}
+
+NS_IMETHODIMP
+nsIOService::ExtractScheme(const nsACString& inURI, nsACString& scheme) {
+  return net_ExtractURLScheme(inURI, scheme);
+}
+
+NS_IMETHODIMP
+nsIOService::HostnameIsLocalIPAddress(nsIURI* aURI, bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aURI);
+
+  nsCOMPtr<nsIURI> innerURI = NS_GetInnermostURI(aURI);
+  NS_ENSURE_ARG_POINTER(innerURI);
+
+  nsAutoCString host;
+  nsresult rv = innerURI->GetAsciiHost(host);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  *aResult = false;
+
+  NetAddr addr;
+  if (NS_SUCCEEDED(addr.InitFromString(host)) && addr.IsIPAddrLocal()) {
+    *aResult = true;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::HostnameIsSharedIPAddress(nsIURI* aURI, bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aURI);
+
+  nsCOMPtr<nsIURI> innerURI = NS_GetInnermostURI(aURI);
+  NS_ENSURE_ARG_POINTER(innerURI);
+
+  nsAutoCString host;
+  nsresult rv = innerURI->GetAsciiHost(host);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  *aResult = false;
+
+  NetAddr addr;
+  if (NS_SUCCEEDED(addr.InitFromString(host)) && addr.IsIPAddrShared()) {
+    *aResult = true;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::GetProtocolFlags(const char* scheme, uint32_t* flags) {
+  NS_ENSURE_ARG_POINTER(scheme);
+
+  *flags =
+      LookupProtocolHandler(nsDependentCString(scheme)).StaticProtocolFlags();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::GetDynamicProtocolFlags(nsIURI* uri, uint32_t* flags) {
+  AssertIsOnMainThread();
+  NS_ENSURE_ARG(uri);
+
+  nsAutoCString scheme;
+  nsresult rv = uri->GetScheme(scheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return LookupProtocolHandler(scheme).DynamicProtocolFlags(uri, flags);
+}
+
+NS_IMETHODIMP
+nsIOService::GetDefaultPort(const char* scheme, int32_t* defaultPort) {
+  NS_ENSURE_ARG_POINTER(scheme);
+
+  *defaultPort =
+      LookupProtocolHandler(nsDependentCString(scheme)).DefaultPort();
+  return NS_OK;
+}
+
+class AutoIncrement {
+ public:
+  explicit AutoIncrement(uint32_t* var) : mVar(var) { ++*var; }
+  ~AutoIncrement() { --*mVar; }
+
+ private:
+  uint32_t* mVar;
+};
+
+nsresult nsIOService::NewURI(const nsACString& aSpec, const char* aCharset,
+                             nsIURI* aBaseURI, nsIURI** result) {
+  return NS_NewURI(result, aSpec, aCharset, aBaseURI);
+}
+
+NS_IMETHODIMP
+nsIOService::NewFileURI(nsIFile* file, nsIURI** result) {
+  nsresult rv;
+  NS_ENSURE_ARG_POINTER(file);
+
+  nsCOMPtr<nsIProtocolHandler> handler;
+
+  rv = GetProtocolHandler("file", getter_AddRefs(handler));
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIFileProtocolHandler> fileHandler(do_QueryInterface(handler, &rv));
+  if (NS_FAILED(rv)) return rv;
+
+  return fileHandler->NewFileURI(file, result);
+}
+
+// static
+already_AddRefed<nsIURI> nsIOService::CreateExposableURI(nsIURI* aURI) {
+  MOZ_ASSERT(aURI, "Must have a URI");
+  nsCOMPtr<nsIURI> uri = aURI;
+
+  nsAutoCString userPass;
+  uri->GetUserPass(userPass);
+  if (!userPass.IsEmpty()) {
+    DebugOnly<nsresult> rv = NS_MutateURI(uri).SetUserPass(""_ns).Finalize(uri);
+    MOZ_ASSERT(NS_SUCCEEDED(rv) && uri, "Mutating URI should never fail");
+  }
+  return uri.forget();
+}
+
+NS_IMETHODIMP
+nsIOService::CreateExposableURI(nsIURI* aURI, nsIURI** _result) {
+  NS_ENSURE_ARG_POINTER(aURI);
+  NS_ENSURE_ARG_POINTER(_result);
+  nsCOMPtr<nsIURI> exposableURI = CreateExposableURI(aURI);
+  exposableURI.forget(_result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::NewChannelFromURI(nsIURI* aURI, nsINode* aLoadingNode,
+                               nsIPrincipal* aLoadingPrincipal,
+                               nsIPrincipal* aTriggeringPrincipal,
+                               uint32_t aSecurityFlags,
+                               nsContentPolicyType aContentPolicyType,
+                               nsIChannel** result) {
+  return NewChannelFromURIWithProxyFlags(aURI,
+                                         nullptr,  // aProxyURI
+                                         0,        // aProxyFlags
+                                         aLoadingNode, aLoadingPrincipal,
+                                         aTriggeringPrincipal, aSecurityFlags,
+                                         aContentPolicyType, result);
+}
+nsresult nsIOService::NewChannelFromURIWithClientAndController(
+    nsIURI* aURI, nsINode* aLoadingNode, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal,
+    const Maybe<ClientInfo>& aLoadingClientInfo,
+    const Maybe<ServiceWorkerDescriptor>& aController, uint32_t aSecurityFlags,
+    nsContentPolicyType aContentPolicyType, uint32_t aSandboxFlags,
+    bool aSkipCheckForBrokenURLOrZeroSized, nsIChannel** aResult) {
+  return NewChannelFromURIWithProxyFlagsInternal(
+      aURI,
+      nullptr,  // aProxyURI
+      0,        // aProxyFlags
+      aLoadingNode, aLoadingPrincipal, aTriggeringPrincipal, aLoadingClientInfo,
+      aController, aSecurityFlags, aContentPolicyType, aSandboxFlags,
+      aSkipCheckForBrokenURLOrZeroSized, aResult);
+}
+
+NS_IMETHODIMP
+nsIOService::NewChannelFromURIWithLoadInfo(nsIURI* aURI, nsILoadInfo* aLoadInfo,
+                                           nsIChannel** result) {
+  return NewChannelFromURIWithProxyFlagsInternal(aURI,
+                                                 nullptr,  // aProxyURI
+                                                 0,        // aProxyFlags
+                                                 aLoadInfo, result);
+}
+
+nsresult nsIOService::NewChannelFromURIWithProxyFlagsInternal(
+    nsIURI* aURI, nsIURI* aProxyURI, uint32_t aProxyFlags,
+    nsINode* aLoadingNode, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal,
+    const Maybe<ClientInfo>& aLoadingClientInfo,
+    const Maybe<ServiceWorkerDescriptor>& aController, uint32_t aSecurityFlags,
+    nsContentPolicyType aContentPolicyType, uint32_t aSandboxFlags,
+    bool aSkipCheckForBrokenURLOrZeroSized, nsIChannel** result) {
+  nsCOMPtr<nsILoadInfo> loadInfo = new LoadInfo(
+      aLoadingPrincipal, aTriggeringPrincipal, aLoadingNode, aSecurityFlags,
+      aContentPolicyType, aLoadingClientInfo, aController, aSandboxFlags,
+      aSkipCheckForBrokenURLOrZeroSized);
+  return NewChannelFromURIWithProxyFlagsInternal(aURI, aProxyURI, aProxyFlags,
+                                                 loadInfo, result);
+}
+
+nsresult nsIOService::NewChannelFromURIWithProxyFlagsInternal(
+    nsIURI* aURI, nsIURI* aProxyURI, uint32_t aProxyFlags,
+    nsILoadInfo* aLoadInfo, nsIChannel** result) {
+  nsresult rv;
+  NS_ENSURE_ARG_POINTER(aURI);
+  // all channel creations must provide a valid loadinfo
+  MOZ_ASSERT(aLoadInfo, "can not create channel without aLoadInfo");
+  NS_ENSURE_ARG_POINTER(aLoadInfo);
+
+  nsAutoCString scheme;
+  rv = aURI->GetScheme(scheme);
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIProtocolHandler> handler;
+  rv = GetProtocolHandler(scheme.get(), getter_AddRefs(handler));
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIChannel> channel;
+  nsCOMPtr<nsIProxiedProtocolHandler> pph = do_QueryInterface(handler);
+  if (pph) {
+    rv = pph->NewProxiedChannel(aURI, nullptr, aProxyFlags, aProxyURI,
+                                aLoadInfo, getter_AddRefs(channel));
+  } else {
+    rv = handler->NewChannel(aURI, aLoadInfo, getter_AddRefs(channel));
+  }
+  if (NS_FAILED(rv)) return rv;
+
+  // Make sure that all the individual protocolhandlers attach a loadInfo.
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  if (aLoadInfo != loadInfo) {
+    MOZ_ASSERT(false, "newly created channel must have a loadinfo attached");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // If we're sandboxed, make sure to clear any owner the channel
+  // might already have.
+  if (loadInfo->GetLoadingSandboxed()) {
+    channel->SetOwner(nullptr);
+  }
+
+  // Some extensions override the http protocol handler and provide their own
+  // implementation. The channels returned from that implementation doesn't
+  // seem to always implement the nsIUploadChannel2 interface, presumably
+  // because it's a new interface.
+  // Eventually we should remove this and simply require that http channels
+  // implement the new interface.
+  // See bug 529041
+  if (!gHasWarnedUploadChannel2 && scheme.EqualsLiteral("http")) {
+    nsCOMPtr<nsIUploadChannel2> uploadChannel2 = do_QueryInterface(channel);
+    if (!uploadChannel2) {
+      nsCOMPtr<nsIConsoleService> consoleService =
+          do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+      if (consoleService) {
+        consoleService->LogStringMessage(
+            u"Http channel implementation "
+            "doesn't support nsIUploadChannel2. An extension has "
+            "supplied a non-functional http protocol handler. This will "
+            "break behavior and in future releases not work at all.");
+      }
+      gHasWarnedUploadChannel2 = true;
+    }
+  }
+
+  channel.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::NewChannelFromURIWithProxyFlags(
+    nsIURI* aURI, nsIURI* aProxyURI, uint32_t aProxyFlags,
+    nsINode* aLoadingNode, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal, uint32_t aSecurityFlags,
+    nsContentPolicyType aContentPolicyType, nsIChannel** result) {
+  return NewChannelFromURIWithProxyFlagsInternal(
+      aURI, aProxyURI, aProxyFlags, aLoadingNode, aLoadingPrincipal,
+      aTriggeringPrincipal, Maybe<ClientInfo>(),
+      Maybe<ServiceWorkerDescriptor>(), aSecurityFlags, aContentPolicyType, 0,
+      /* aSkipCheckForBrokenURLOrZeroSized = */ false, result);
+}
+
+NS_IMETHODIMP
+nsIOService::NewChannel(const nsACString& aSpec, const char* aCharset,
+                        nsIURI* aBaseURI, nsINode* aLoadingNode,
+                        nsIPrincipal* aLoadingPrincipal,
+                        nsIPrincipal* aTriggeringPrincipal,
+                        uint32_t aSecurityFlags,
+                        nsContentPolicyType aContentPolicyType,
+                        nsIChannel** result) {
+  nsresult rv;
+  nsCOMPtr<nsIURI> uri;
+  rv = NewURI(aSpec, aCharset, aBaseURI, getter_AddRefs(uri));
+  if (NS_FAILED(rv)) return rv;
+
+  return NewChannelFromURI(uri, aLoadingNode, aLoadingPrincipal,
+                           aTriggeringPrincipal, aSecurityFlags,
+                           aContentPolicyType, result);
+}
+
+NS_IMETHODIMP
+nsIOService::NewWebTransport(nsIWebTransport** result) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<nsIWebTransport> webTransport = new WebTransportSessionProxy();
+
+  webTransport.forget(result);
+  return NS_OK;
+}
+
+bool nsIOService::IsLinkUp() {
+  InitializeNetworkLinkService();
+
+  if (!mNetworkLinkService) {
+    // We cannot decide, assume the link is up
+    return true;
+  }
+
+  bool isLinkUp;
+  nsresult rv;
+  rv = mNetworkLinkService->GetIsLinkUp(&isLinkUp);
+  if (NS_FAILED(rv)) {
+    return true;
+  }
+
+  return isLinkUp;
+}
+
+NS_IMETHODIMP
+nsIOService::GetOffline(bool* offline) {
+  if (StaticPrefs::network_offline_mirrors_connectivity()) {
+    *offline = mOffline || !mConnectivity;
+  } else {
+    *offline = mOffline;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::SetOffline(bool offline) { return SetOfflineInternal(offline); }
+
+nsresult nsIOService::SetOfflineInternal(bool offline,
+                                         bool notifySocketProcess) {
+  LOG(("nsIOService::SetOffline offline=%d\n", offline));
+  // When someone wants to go online (!offline) after we got XPCOM shutdown
+  // throw ERROR_NOT_AVAILABLE to prevent return to online state.
+  if ((mShutdown || mOfflineForProfileChange) && !offline) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // SetOffline() may re-enter while it's shutting down services.
+  // If that happens, save the most recent value and it will be
+  // processed when the first SetOffline() call is done bringing
+  // down the service.
+  mSetOfflineValue = offline;
+  if (mSettingOffline) {
+    return NS_OK;
+  }
+
+  mSettingOffline = true;
+
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+
+  NS_ASSERTION(observerService, "The observer service should not be null");
+
+  if (XRE_IsParentProcess()) {
+    if (observerService) {
+      (void)observerService->NotifyObservers(nullptr,
+                                             NS_IPC_IOSERVICE_SET_OFFLINE_TOPIC,
+                                             offline ? u"true" : u"false");
+    }
+    if (SocketProcessReady() && notifySocketProcess) {
+      Unused << mSocketProcess->GetActor()->SendSetOffline(offline);
+    }
+  }
+
+  nsIIOService* subject = static_cast<nsIIOService*>(this);
+  while (mSetOfflineValue != mOffline) {
+    offline = mSetOfflineValue;
+
+    if (offline && !mOffline) {
+      mOffline = true;  // indicate we're trying to shutdown
+
+      // don't care if notifications fail
+      if (observerService) {
+        observerService->NotifyObservers(subject,
+                                         NS_IOSERVICE_GOING_OFFLINE_TOPIC,
+                                         u"" NS_IOSERVICE_OFFLINE);
+      }
+
+      if (mSocketTransportService) mSocketTransportService->SetOffline(true);
+
+      mLastOfflineStateChange = PR_IntervalNow();
+      if (observerService) {
+        observerService->NotifyObservers(subject,
+                                         NS_IOSERVICE_OFFLINE_STATUS_TOPIC,
+                                         u"" NS_IOSERVICE_OFFLINE);
+      }
+    } else if (!offline && mOffline) {
+      // go online
+      InitializeSocketTransportService();
+      mOffline = false;  // indicate success only AFTER we've
+                         // brought up the services
+
+      mLastOfflineStateChange = PR_IntervalNow();
+      // don't care if notification fails
+      // Only send the ONLINE notification if there is connectivity
+      if (observerService && mConnectivity) {
+        observerService->NotifyObservers(subject,
+                                         NS_IOSERVICE_OFFLINE_STATUS_TOPIC,
+                                         (u"" NS_IOSERVICE_ONLINE));
+      }
+    }
+  }
+
+  // Don't notify here, as the above notifications (if used) suffice.
+  if ((mShutdown || mOfflineForProfileChange) && mOffline) {
+    if (mSocketTransportService) {
+      DebugOnly<nsresult> rv = mSocketTransportService->Shutdown(mShutdown);
+      NS_ASSERTION(NS_SUCCEEDED(rv),
+                   "socket transport service shutdown failed");
+    }
+  }
+
+  mSettingOffline = false;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::GetConnectivity(bool* aConnectivity) {
+  *aConnectivity = mConnectivity;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::SetConnectivity(bool aConnectivity) {
+  LOG(("nsIOService::SetConnectivity aConnectivity=%d\n", aConnectivity));
+  // This should only be called from ContentChild to pass the connectivity
+  // value from the chrome process to the content process.
+  if (XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  return SetConnectivityInternal(aConnectivity);
+}
+
+nsresult nsIOService::SetConnectivityInternal(bool aConnectivity) {
+  LOG(("nsIOService::SetConnectivityInternal aConnectivity=%d\n",
+       aConnectivity));
+  if (mConnectivity == aConnectivity) {
+    // Nothing to do here.
+    return NS_OK;
+  }
+  mConnectivity = aConnectivity;
+
+  // This is used for PR_Connect PR_Close telemetry so it is important that
+  // we have statistic about network change event even if we are offline.
+  mLastConnectivityChange = PR_IntervalNow();
+
+  if (mCaptivePortalService) {
+    if (aConnectivity && gCaptivePortalEnabled) {
+      // This will also trigger a captive portal check for the new network
+      static_cast<CaptivePortalService*>(mCaptivePortalService.get())->Start();
+    } else {
+      static_cast<CaptivePortalService*>(mCaptivePortalService.get())->Stop();
+    }
+  }
+
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+  if (!observerService) {
+    return NS_OK;
+  }
+  // This notification sends the connectivity to the child processes
+  if (XRE_IsParentProcess()) {
+    observerService->NotifyObservers(nullptr,
+                                     NS_IPC_IOSERVICE_SET_CONNECTIVITY_TOPIC,
+                                     aConnectivity ? u"true" : u"false");
+    if (SocketProcessReady()) {
+      Unused << mSocketProcess->GetActor()->SendSetConnectivity(aConnectivity);
+    }
+  }
+
+  if (mOffline) {
+    // We don't need to send any notifications if we're offline
+    return NS_OK;
+  }
+
+  if (aConnectivity) {
+    // If we were previously offline due to connectivity=false,
+    // send the ONLINE notification
+    observerService->NotifyObservers(static_cast<nsIIOService*>(this),
+                                     NS_IOSERVICE_OFFLINE_STATUS_TOPIC,
+                                     (u"" NS_IOSERVICE_ONLINE));
+  } else {
+    // If we were previously online and lost connectivity
+    // send the OFFLINE notification
+    observerService->NotifyObservers(static_cast<nsIIOService*>(this),
+                                     NS_IOSERVICE_GOING_OFFLINE_TOPIC,
+                                     u"" NS_IOSERVICE_OFFLINE);
+    observerService->NotifyObservers(static_cast<nsIIOService*>(this),
+                                     NS_IOSERVICE_OFFLINE_STATUS_TOPIC,
+                                     u"" NS_IOSERVICE_OFFLINE);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::AllowPort(int32_t inPort, const char* scheme, bool* _retval) {
+  int32_t port = inPort;
+  if (port == -1) {
+    *_retval = true;
+    return NS_OK;
+  }
+
+  if (port <= 0 || port > std::numeric_limits<uint16_t>::max()) {
+    *_retval = false;
+    return NS_OK;
+  }
+
+  nsTArray<int32_t> restrictedPortList;
+  {
+    AutoReadLock lock(mLock);
+    restrictedPortList.Assign(mRestrictedPortList);
+  }
+  // first check to see if the port is in our blacklist:
+  int32_t badPortListCnt = restrictedPortList.Length();
+  for (int i = 0; i < badPortListCnt; i++) {
+    if (port == restrictedPortList[i]) {
+      *_retval = false;
+
+      // check to see if the protocol wants to override
+      if (!scheme) return NS_OK;
+
+      // We don't support get protocol handler off main thread.
+      if (!NS_IsMainThread()) {
+        return NS_OK;
+      }
+      nsCOMPtr<nsIProtocolHandler> handler;
+      nsresult rv = GetProtocolHandler(scheme, getter_AddRefs(handler));
+      if (NS_FAILED(rv)) return rv;
+
+      // let the protocol handler decide
+      return handler->AllowPort(port, scheme, _retval);
+    }
+  }
+
+  *_retval = true;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+// static
+void nsIOService::PrefsChanged(const char* pref, void* self) {
+  static_cast<nsIOService*>(self)->PrefsChanged(pref);
+}
+
+void nsIOService::PrefsChanged(const char* pref) {
+  // Look for extra ports to block
+  if (!pref || strcmp(pref, PORT_PREF("banned")) == 0) {
+    ParsePortList(PORT_PREF("banned"), false);
+  }
+
+  // ...as well as previous blocks to remove.
+  if (!pref || strcmp(pref, PORT_PREF("banned.override")) == 0) {
+    ParsePortList(PORT_PREF("banned.override"), true);
+  }
+
+  if (!pref || strcmp(pref, MANAGE_OFFLINE_STATUS_PREF) == 0) {
+    bool manage;
+    if (mNetworkLinkServiceInitialized &&
+        NS_SUCCEEDED(
+            Preferences::GetBool(MANAGE_OFFLINE_STATUS_PREF, &manage))) {
+      LOG(("nsIOService::PrefsChanged ManageOfflineStatus manage=%d\n",
+           manage));
+      SetManageOfflineStatus(manage);
+    }
+  }
+
+  if (!pref || strcmp(pref, NECKO_BUFFER_CACHE_COUNT_PREF) == 0) {
+    int32_t count;
+    if (NS_SUCCEEDED(
+            Preferences::GetInt(NECKO_BUFFER_CACHE_COUNT_PREF, &count))) {
+      /* check for bogus values and default if we find such a value */
+      if (count > 0) gDefaultSegmentCount = count;
+    }
+  }
+
+  if (!pref || strcmp(pref, NECKO_BUFFER_CACHE_SIZE_PREF) == 0) {
+    int32_t size;
+    if (NS_SUCCEEDED(
+            Preferences::GetInt(NECKO_BUFFER_CACHE_SIZE_PREF, &size))) {
+      /* check for bogus values and default if we find such a value
+       * the upper limit here is arbitrary. having a 1mb segment size
+       * is pretty crazy.  if you remove this, consider adding some
+       * integer rollover test.
+       */
+      if (size > 0 && size < 1024 * 1024) gDefaultSegmentSize = size;
+    }
+    NS_WARNING_ASSERTION(!(size & (size - 1)),
+                         "network segment size is not a power of 2!");
+  }
+
+  if (!pref || strcmp(pref, NETWORK_CAPTIVE_PORTAL_PREF) == 0) {
+    nsresult rv = Preferences::GetBool(NETWORK_CAPTIVE_PORTAL_PREF,
+                                       &gCaptivePortalEnabled);
+    if (NS_SUCCEEDED(rv) && mCaptivePortalService) {
+      if (gCaptivePortalEnabled) {
+        static_cast<CaptivePortalService*>(mCaptivePortalService.get())
+            ->Start();
+      } else {
+        static_cast<CaptivePortalService*>(mCaptivePortalService.get())->Stop();
+      }
+    }
+  }
+
+  if (!pref || strncmp(pref, FORCE_EXTERNAL_PREF_PREFIX,
+                       strlen(FORCE_EXTERNAL_PREF_PREFIX)) == 0) {
+    nsTArray<nsCString> prefs;
+    if (nsIPrefBranch* prefRootBranch = Preferences::GetRootBranch()) {
+      prefRootBranch->GetChildList(FORCE_EXTERNAL_PREF_PREFIX, prefs);
+    }
+    nsTArray<nsCString> forceExternalSchemes;
+    for (const auto& pref : prefs) {
+      if (Preferences::GetBool(pref.get(), false)) {
+        forceExternalSchemes.AppendElement(
+            Substring(pref, strlen(FORCE_EXTERNAL_PREF_PREFIX)));
+      }
+    }
+    AutoWriteLock lock(mLock);
+    mForceExternalSchemes = std::move(forceExternalSchemes);
+  }
+}
+
+void nsIOService::ParsePortList(const char* pref, bool remove) {
+  nsAutoCString portList;
+  nsTArray<int32_t> restrictedPortList;
+  {
+    AutoWriteLock lock(mLock);
+    restrictedPortList.Assign(std::move(mRestrictedPortList));
+  }
+  // Get a pref string and chop it up into a list of ports.
+  Preferences::GetCString(pref, portList);
+  if (!portList.IsVoid()) {
+    nsTArray<nsCString> portListArray;
+    ParseString(portList, ',', portListArray);
+    uint32_t index;
+    for (index = 0; index < portListArray.Length(); index++) {
+      portListArray[index].StripWhitespace();
+      int32_t portBegin, portEnd;
+
+      if (PR_sscanf(portListArray[index].get(), "%d-%d", &portBegin,
+                    &portEnd) == 2) {
+        if ((portBegin < 65536) && (portEnd < 65536)) {
+          int32_t curPort;
+          if (remove) {
+            for (curPort = portBegin; curPort <= portEnd; curPort++) {
+              restrictedPortList.RemoveElement(curPort);
+            }
+          } else {
+            for (curPort = portBegin; curPort <= portEnd; curPort++) {
+              restrictedPortList.AppendElement(curPort);
+            }
+          }
+        }
+      } else {
+        nsresult aErrorCode;
+        int32_t port = portListArray[index].ToInteger(&aErrorCode);
+        if (NS_SUCCEEDED(aErrorCode) && port < 65536) {
+          if (remove) {
+            restrictedPortList.RemoveElement(port);
+          } else {
+            restrictedPortList.AppendElement(port);
+          }
+        }
+      }
+    }
+  }
+
+  AutoWriteLock lock(mLock);
+  mRestrictedPortList.Assign(std::move(restrictedPortList));
+}
+
+class nsWakeupNotifier : public Runnable {
+ public:
+  explicit nsWakeupNotifier(nsIIOServiceInternal* ioService)
+      : Runnable("net::nsWakeupNotifier"), mIOService(ioService) {}
+
+  NS_IMETHOD Run() override { return mIOService->NotifyWakeup(); }
+
+ private:
+  virtual ~nsWakeupNotifier() = default;
+  nsCOMPtr<nsIIOServiceInternal> mIOService;
+};
+
+NS_IMETHODIMP
+nsIOService::NotifyWakeup() {
+  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
+
+  NS_ASSERTION(observerService, "The observer service should not be null");
+
+  if (observerService && StaticPrefs::network_notify_changed()) {
+    (void)observerService->NotifyObservers(nullptr, NS_NETWORK_LINK_TOPIC,
+                                           (u"" NS_NETWORK_LINK_DATA_CHANGED));
+  }
+
+  RecheckCaptivePortal();
+
+  return NS_OK;
+}
+
+void nsIOService::SetHttpHandlerAlreadyShutingDown() {
+  if (!mShutdown && !mOfflineForProfileChange) {
+    mNetTearingDownStarted = PR_IntervalNow();
+    mHttpHandlerAlreadyShutingDown = true;
+  }
+}
+
+// nsIObserver interface
+NS_IMETHODIMP
+nsIOService::Observe(nsISupports* subject, const char* topic,
+                     const char16_t* data) {
+  if (UseSocketProcess() && SocketProcessReady() &&
+      mObserverTopicForSocketProcess.Contains(nsDependentCString(topic))) {
+    nsCString topicStr(topic);
+    nsString dataStr(data);
+    Unused << mSocketProcess->GetActor()->SendNotifyObserver(topicStr, dataStr);
+  }
+
+  if (!strcmp(topic, kProfileChangeNetTeardownTopic)) {
+    if (!mHttpHandlerAlreadyShutingDown) {
+      mNetTearingDownStarted = PR_IntervalNow();
+    }
+    mHttpHandlerAlreadyShutingDown = false;
+    if (!mOffline) {
+      mOfflineForProfileChange = true;
+      SetOfflineInternal(true, false);
+    }
+  } else if (!strcmp(topic, kProfileChangeNetRestoreTopic)) {
+    if (mOfflineForProfileChange) {
+      mOfflineForProfileChange = false;
+      SetOfflineInternal(false, false);
+    }
+  } else if (!strcmp(topic, kProfileDoChange)) {
+    if (data && u"startup"_ns.Equals(data)) {
+      // Lazy initialization of network link service (see bug 620472)
+      InitializeNetworkLinkService();
+      // Set up the initilization flag regardless the actuall result.
+      // If we fail here, we will fail always on.
+      mNetworkLinkServiceInitialized = true;
+
+      // And now reflect the preference setting
+      PrefsChanged(MANAGE_OFFLINE_STATUS_PREF);
+
+      // Bug 870460 - Read cookie database at an early-as-possible time
+      // off main thread. Hence, we have more chance to finish db query
+      // before something calls into the cookie service.
+      nsCOMPtr<nsISupports> cookieServ =
+          do_GetService(NS_COOKIESERVICE_CONTRACTID);
+    }
+  } else if (!strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+    // Remember we passed XPCOM shutdown notification to prevent any
+    // changes of the offline status from now. We must not allow going
+    // online after this point.
+    mShutdown = true;
+
+    if (!mHttpHandlerAlreadyShutingDown && !mOfflineForProfileChange) {
+      mNetTearingDownStarted = PR_IntervalNow();
+    }
+    mHttpHandlerAlreadyShutingDown = false;
+
+    SetOfflineInternal(true, false);
+
+    if (mCaptivePortalService) {
+      static_cast<CaptivePortalService*>(mCaptivePortalService.get())->Stop();
+      mCaptivePortalService = nullptr;
+    }
+
+    SSLTokensCache::Shutdown();
+
+    DestroySocketProcess();
+
+    if (IsSocketProcessChild()) {
+      Preferences::UnregisterCallbacks(nsIOService::OnTLSPrefChange,
+                                       gCallbackSecurityPrefs, this);
+      PrepareForShutdownInSocketProcess();
+    }
+
+    // We're in XPCOM shutdown now. Unregister any dynamic protocol handlers
+    // after this point to avoid leaks.
+    {
+      AutoWriteLock lock(mLock);
+      mRuntimeProtocolHandlers.Clear();
+    }
+  } else if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
+    OnNetworkLinkEvent(NS_ConvertUTF16toUTF8(data).get());
+  } else if (!strcmp(topic, NS_NETWORK_ID_CHANGED_TOPIC)) {
+    LOG(("nsIOService::OnNetworkLinkEvent Network id changed"));
+  } else if (!strcmp(topic, NS_WIDGET_WAKE_OBSERVER_TOPIC)) {
+    // coming back alive from sleep
+    // this indirection brought to you by:
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1152048#c19
+    nsCOMPtr<nsIRunnable> wakeupNotifier = new nsWakeupNotifier(this);
+    NS_DispatchToMainThread(wakeupNotifier);
+  }
+
+  return NS_OK;
+}
+
+// nsINetUtil interface
+NS_IMETHODIMP
+nsIOService::ParseRequestContentType(const nsACString& aTypeHeader,
+                                     nsACString& aCharset, bool* aHadCharset,
+                                     nsACString& aContentType) {
+  net_ParseRequestContentType(aTypeHeader, aContentType, aCharset, aHadCharset);
+  return NS_OK;
+}
+
+// nsINetUtil interface
+NS_IMETHODIMP
+nsIOService::ParseResponseContentType(const nsACString& aTypeHeader,
+                                      nsACString& aCharset, bool* aHadCharset,
+                                      nsACString& aContentType) {
+  net_ParseContentType(aTypeHeader, aContentType, aCharset, aHadCharset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::ProtocolHasFlags(nsIURI* uri, uint32_t flags, bool* result) {
+  NS_ENSURE_ARG(uri);
+
+  *result = false;
+  nsAutoCString scheme;
+  nsresult rv = uri->GetScheme(scheme);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  auto handler = LookupProtocolHandler(scheme);
+
+  uint32_t protocolFlags;
+  if (flags & nsIProtocolHandler::DYNAMIC_URI_FLAGS) {
+    AssertIsOnMainThread();
+    rv = handler.DynamicProtocolFlags(uri, &protocolFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    protocolFlags = handler.StaticProtocolFlags();
+  }
+
+  *result = (protocolFlags & flags) == flags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::URIChainHasFlags(nsIURI* uri, uint32_t flags, bool* result) {
+  nsresult rv = ProtocolHasFlags(uri, flags, result);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (*result) {
+    return rv;
+  }
+
+  // Dig deeper into the chain.  Note that this is not a do/while loop to
+  // avoid the extra addref/release on |uri| in the common (non-nested) case.
+  nsCOMPtr<nsINestedURI> nestedURI = do_QueryInterface(uri);
+  while (nestedURI) {
+    nsCOMPtr<nsIURI> innerURI;
+    rv = nestedURI->GetInnerURI(getter_AddRefs(innerURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = ProtocolHasFlags(innerURI, flags, result);
+
+    if (*result) {
+      return rv;
+    }
+
+    nestedURI = do_QueryInterface(innerURI);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIOService::SetManageOfflineStatus(bool aManage) {
+  LOG(("nsIOService::SetManageOfflineStatus aManage=%d\n", aManage));
+  mManageLinkStatus = aManage;
+
+  // When detection is not activated, the default connectivity state is true.
+  if (!mManageLinkStatus) {
+    SetConnectivityInternal(true);
+    return NS_OK;
+  }
+
+  InitializeNetworkLinkService();
+  // If the NetworkLinkService is already initialized, it does not call
+  // OnNetworkLinkEvent. This is needed, when mManageLinkStatus goes from
+  // false to true.
+  OnNetworkLinkEvent(NS_NETWORK_LINK_DATA_UNKNOWN);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::GetManageOfflineStatus(bool* aManage) {
+  *aManage = mManageLinkStatus;
+  return NS_OK;
+}
+
+// input argument 'data' is already UTF8'ed
+nsresult nsIOService::OnNetworkLinkEvent(const char* data) {
+  if (IsNeckoChild() || IsSocketProcessChild()) {
+    // There is nothing IO service could do on the child process
+    // with this at the moment.  Feel free to add functionality
+    // here at will, though.
+    return NS_OK;
+  }
+
+  if (mShutdown) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCString dataAsString(data);
+  for (auto* cp : mozilla::dom::ContentParent::AllProcesses(
+           mozilla::dom::ContentParent::eLive)) {
+    PNeckoParent* neckoParent = SingleManagedOrNull(cp->ManagedPNeckoParent());
+    if (!neckoParent) {
+      continue;
+    }
+    Unused << neckoParent->SendNetworkChangeNotification(dataAsString);
+  }
+
+  LOG(("nsIOService::OnNetworkLinkEvent data:%s\n", data));
+  if (!mNetworkLinkService) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (!mManageLinkStatus) {
+    LOG(("nsIOService::OnNetworkLinkEvent mManageLinkStatus=false\n"));
+    return NS_OK;
+  }
+
+  bool isUp = true;
+  if (!strcmp(data, NS_NETWORK_LINK_DATA_CHANGED)) {
+    mLastNetworkLinkChange = PR_IntervalNow();
+    // CHANGED means UP/DOWN didn't change
+    // but the status of the captive portal may have changed.
+    RecheckCaptivePortal();
+    return NS_OK;
+  }
+  if (!strcmp(data, NS_NETWORK_LINK_DATA_DOWN)) {
+    isUp = false;
+  } else if (!strcmp(data, NS_NETWORK_LINK_DATA_UP)) {
+    isUp = true;
+  } else if (!strcmp(data, NS_NETWORK_LINK_DATA_UNKNOWN)) {
+    nsresult rv = mNetworkLinkService->GetIsLinkUp(&isUp);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NS_WARNING("Unhandled network event!");
+    return NS_OK;
+  }
+
+  return SetConnectivityInternal(isUp);
+}
+
+NS_IMETHODIMP
+nsIOService::EscapeString(const nsACString& aString, uint32_t aEscapeType,
+                          nsACString& aResult) {
+  NS_ENSURE_ARG_MAX(aEscapeType, 4);
+
+  nsAutoCString stringCopy(aString);
+  nsCString result;
+
+  if (!NS_Escape(stringCopy, result, (nsEscapeMask)aEscapeType)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  aResult.Assign(result);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::EscapeURL(const nsACString& aStr, uint32_t aFlags,
+                       nsACString& aResult) {
+  aResult.Truncate();
+  NS_EscapeURL(aStr.BeginReading(), aStr.Length(), aFlags | esc_AlwaysCopy,
+               aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::UnescapeString(const nsACString& aStr, uint32_t aFlags,
+                            nsACString& aResult) {
+  aResult.Truncate();
+  NS_UnescapeURL(aStr.BeginReading(), aStr.Length(), aFlags | esc_AlwaysCopy,
+                 aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::ExtractCharsetFromContentType(const nsACString& aTypeHeader,
+                                           nsACString& aCharset,
+                                           int32_t* aCharsetStart,
+                                           int32_t* aCharsetEnd,
+                                           bool* aHadCharset) {
+  nsAutoCString ignored;
+  net_ParseContentType(aTypeHeader, ignored, aCharset, aHadCharset,
+                       aCharsetStart, aCharsetEnd);
+  if (*aHadCharset && *aCharsetStart == *aCharsetEnd) {
+    *aHadCharset = false;
+  }
+  return NS_OK;
+}
+
+// nsISpeculativeConnect
+class IOServiceProxyCallback final : public nsIProtocolProxyCallback {
+  ~IOServiceProxyCallback() = default;
+
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIPROTOCOLPROXYCALLBACK
+
+  IOServiceProxyCallback(nsIInterfaceRequestor* aCallbacks,
+                         nsIOService* aIOService,
+                         Maybe<OriginAttributes>&& aOriginAttributes)
+      : mCallbacks(aCallbacks),
+        mIOService(aIOService),
+        mOriginAttributes(std::move(aOriginAttributes)) {}
+
+ private:
+  RefPtr<nsIInterfaceRequestor> mCallbacks;
+  RefPtr<nsIOService> mIOService;
+  Maybe<OriginAttributes> mOriginAttributes;
+};
+
+NS_IMPL_ISUPPORTS(IOServiceProxyCallback, nsIProtocolProxyCallback)
+
+NS_IMETHODIMP
+IOServiceProxyCallback::OnProxyAvailable(nsICancelable* request,
+                                         nsIChannel* channel, nsIProxyInfo* pi,
+                                         nsresult status) {
+  // Checking proxy status for speculative connect
+  nsAutoCString type;
+  if (NS_SUCCEEDED(status) && pi && NS_SUCCEEDED(pi->GetType(type)) &&
+      !type.EqualsLiteral("direct")) {
+    // proxies dont do speculative connect
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = channel->GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return NS_OK;
+  }
+
+  nsAutoCString scheme;
+  rv = uri->GetScheme(scheme);
+  if (NS_FAILED(rv)) return NS_OK;
+
+  nsCOMPtr<nsIProtocolHandler> handler;
+  rv = mIOService->GetProtocolHandler(scheme.get(), getter_AddRefs(handler));
+  if (NS_FAILED(rv)) return NS_OK;
+
+  nsCOMPtr<nsISpeculativeConnect> speculativeHandler =
+      do_QueryInterface(handler);
+  if (!speculativeHandler) return NS_OK;
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  nsCOMPtr<nsIPrincipal> principal = loadInfo->GetLoadingPrincipal();
+
+  nsLoadFlags loadFlags = 0;
+  channel->GetLoadFlags(&loadFlags);
+  bool anonymous = !!(loadFlags & nsIRequest::LOAD_ANONYMOUS);
+  if (mOriginAttributes) {
+    speculativeHandler->SpeculativeConnectWithOriginAttributesNative(
+        uri, std::move(mOriginAttributes.ref()), mCallbacks, anonymous);
+  } else {
+    speculativeHandler->SpeculativeConnect(uri, principal, mCallbacks,
+                                           anonymous);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsIOService::SpeculativeConnectInternal(
+    nsIURI* aURI, nsIPrincipal* aPrincipal,
+    Maybe<OriginAttributes>&& aOriginAttributes,
+    nsIInterfaceRequestor* aCallbacks, bool aAnonymous) {
+  NS_ENSURE_ARG(aURI);
+
+  if (!aURI->SchemeIs("http") && !aURI->SchemeIs("https")) {
+    // We don't speculatively connect to non-HTTP[S] URIs.
+    return NS_OK;
+  }
+
+  if (IsNeckoChild()) {
+    gNeckoChild->SendSpeculativeConnect(
+        aURI, aPrincipal, std::move(aOriginAttributes), aAnonymous);
+    return NS_OK;
+  }
+
+  // Check for proxy information. If there is a proxy configured then a
+  // speculative connect should not be performed because the potential
+  // reward is slim with tcp peers closely located to the browser.
+  nsresult rv;
+  nsCOMPtr<nsIProtocolProxyService> pps =
+      do_GetService(NS_PROTOCOLPROXYSERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIPrincipal> loadingPrincipal = aPrincipal;
+
+  MOZ_ASSERT(aPrincipal || aOriginAttributes,
+             "We expect passing a principal or OriginAttributes here.");
+
+  if (!aPrincipal && !aOriginAttributes) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (aOriginAttributes) {
+    loadingPrincipal =
+        BasePrincipal::CreateContentPrincipal(aURI, aOriginAttributes.ref());
+  }
+
+  // XXX Bug 1724080: Avoid TCP connections on port 80 when https-only
+  // or https-first is enabled. Let's create a dummy loadinfo which we
+  // only use to determine whether we need ot upgrade the speculative
+  // connection from http to https.
+  nsCOMPtr<nsIURI> httpsURI;
+  if (aURI->SchemeIs("http")) {
+    nsCOMPtr<nsILoadInfo> httpsOnlyCheckLoadInfo =
+        new LoadInfo(loadingPrincipal, loadingPrincipal, nullptr,
+                     nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK,
+                     nsIContentPolicy::TYPE_SPECULATIVE);
+
+    // Check if https-only, or https-first would upgrade the request
+    if (nsHTTPSOnlyUtils::ShouldUpgradeRequest(aURI, httpsOnlyCheckLoadInfo) ||
+        nsHTTPSOnlyUtils::ShouldUpgradeHttpsFirstRequest(
+            aURI, httpsOnlyCheckLoadInfo)) {
+      rv = NS_GetSecureUpgradedURI(aURI, getter_AddRefs(httpsURI));
+      NS_ENSURE_SUCCESS(rv, rv);
+      aURI = httpsURI.get();
+    }
+  }
+
+  // dummy channel used to create a TCP connection.
+  // we perform security checks on the *real* channel, responsible
+  // for any network loads. this real channel just checks the TCP
+  // pool if there is an available connection created by the
+  // channel we create underneath - hence it's safe to use
+  // the systemPrincipal as the loadingPrincipal for this channel.
+  nsCOMPtr<nsIChannel> channel;
+  rv = NewChannelFromURI(
+      aURI,
+      nullptr,  // aLoadingNode,
+      loadingPrincipal,
+      nullptr,  // aTriggeringPrincipal,
+      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+      nsIContentPolicy::TYPE_SPECULATIVE, getter_AddRefs(channel));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aAnonymous) {
+    nsLoadFlags loadFlags = 0;
+    channel->GetLoadFlags(&loadFlags);
+    loadFlags |= nsIRequest::LOAD_ANONYMOUS;
+    channel->SetLoadFlags(loadFlags);
+  }
+
+  nsCOMPtr<nsICancelable> cancelable;
+  RefPtr<IOServiceProxyCallback> callback = new IOServiceProxyCallback(
+      aCallbacks, this, std::move(aOriginAttributes));
+  nsCOMPtr<nsIProtocolProxyService2> pps2 = do_QueryInterface(pps);
+  if (pps2) {
+    return pps2->AsyncResolve2(channel, 0, callback, nullptr,
+                               getter_AddRefs(cancelable));
+  }
+  return pps->AsyncResolve(channel, 0, callback, nullptr,
+                           getter_AddRefs(cancelable));
+}
+
+NS_IMETHODIMP
+nsIOService::SpeculativeConnect(nsIURI* aURI, nsIPrincipal* aPrincipal,
+                                nsIInterfaceRequestor* aCallbacks,
+                                bool aAnonymous) {
+  return SpeculativeConnectInternal(aURI, aPrincipal, Nothing(), aCallbacks,
+                                    aAnonymous);
+}
+
+NS_IMETHODIMP nsIOService::SpeculativeConnectWithOriginAttributes(
+    nsIURI* aURI, JS::Handle<JS::Value> aOriginAttributes,
+    nsIInterfaceRequestor* aCallbacks, bool aAnonymous, JSContext* aCx) {
+  OriginAttributes attrs;
+  if (!aOriginAttributes.isObject() || !attrs.Init(aCx, aOriginAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  SpeculativeConnectWithOriginAttributesNative(aURI, std::move(attrs),
+                                               aCallbacks, aAnonymous);
+  return NS_OK;
+}
+
+NS_IMETHODIMP_(void)
+nsIOService::SpeculativeConnectWithOriginAttributesNative(
+    nsIURI* aURI, OriginAttributes&& aOriginAttributes,
+    nsIInterfaceRequestor* aCallbacks, bool aAnonymous) {
+  Maybe<OriginAttributes> originAttributes;
+  originAttributes.emplace(aOriginAttributes);
+  Unused << SpeculativeConnectInternal(
+      aURI, nullptr, std::move(originAttributes), aCallbacks, aAnonymous);
+}
+
+NS_IMETHODIMP
+nsIOService::NotImplemented() { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsIOService::GetSocketProcessLaunched(bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+
+  *aResult = SocketProcessReady();
+  return NS_OK;
+}
+
+bool nsIOService::HasObservers(const char* aTopic) {
+  MOZ_ASSERT(false, "Calling this method is unexpected");
+  return false;
+}
+
+NS_IMETHODIMP
+nsIOService::GetSocketProcessId(uint64_t* aPid) {
+  NS_ENSURE_ARG_POINTER(aPid);
+
+  *aPid = 0;
+  if (!mSocketProcess) {
+    return NS_OK;
+  }
+
+  if (SocketProcessParent* actor = mSocketProcess->GetActor()) {
+    *aPid = (uint64_t)actor->OtherPid();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIOService::RegisterProtocolHandler(const nsACString& aScheme,
+                                     nsIProtocolHandler* aHandler,
+                                     uint32_t aProtocolFlags,
+                                     int32_t aDefaultPort) {
+  if (mShutdown) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  if (aScheme.IsEmpty()) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsAutoCString scheme(aScheme);
+  ToLowerCase(scheme);
+
+  AutoWriteLock lock(mLock);
+  return mRuntimeProtocolHandlers.WithEntryHandle(scheme, [&](auto&& entry) {
+    if (entry) {
+      NS_WARNING("Cannot override an existing dynamic protocol handler");
+      return NS_ERROR_FACTORY_EXISTS;
+    }
+    if (xpcom::StaticProtocolHandler::Lookup(scheme)) {
+      NS_WARNING("Cannot override an existing static protocol handler");
+      return NS_ERROR_FACTORY_EXISTS;
+    }
+    nsMainThreadPtrHandle<nsIProtocolHandler> handler(
+        new nsMainThreadPtrHolder<nsIProtocolHandler>("RuntimeProtocolHandler",
+                                                      aHandler));
+    entry.Insert(RuntimeProtocolHandler{
+        .mHandler = std::move(handler),
+        .mProtocolFlags = aProtocolFlags,
+        .mDefaultPort = aDefaultPort,
+    });
+    return NS_OK;
+  });
+}
+
+NS_IMETHODIMP
+nsIOService::UnregisterProtocolHandler(const nsACString& aScheme) {
+  if (mShutdown) {
+    return NS_OK;
+  }
+  if (aScheme.IsEmpty()) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsAutoCString scheme(aScheme);
+  ToLowerCase(scheme);
+
+  AutoWriteLock lock(mLock);
+  return mRuntimeProtocolHandlers.Remove(scheme)
+             ? NS_OK
+             : NS_ERROR_FACTORY_NOT_REGISTERED;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsIOService.h b/netwerk/base/nsIOService.h
new file mode 100644
index 0000000000..55dbea6c55
--- /dev/null
+++ b/netwerk/base/nsIOService.h
@@ -0,0 +1,281 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsIOService_h__
+#define nsIOService_h__
+
+#include "nsStringFwd.h"
+#include "nsIIOService.h"
+#include "nsTArray.h"
+#include "nsCOMPtr.h"
+#include "nsIObserver.h"
+#include "nsIWeakReferenceUtils.h"
+#include "nsINetUtil.h"
+#include "nsIChannelEventSink.h"
+#include "nsCategoryCache.h"
+#include "nsISpeculativeConnect.h"
+#include "nsWeakReference.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/RWLock.h"
+#include "mozilla/net/ProtocolHandlerInfo.h"
+#include "prtime.h"
+#include "nsICaptivePortalService.h"
+#include "nsIObserverService.h"
+#include "nsTHashSet.h"
+#include "nsWeakReference.h"
+#include "nsNetCID.h"
+
+#define NS_N(x) (sizeof(x) / sizeof(*(x)))
+
+// We don't want to expose this observer topic.
+// Intended internal use only for remoting offline/inline events.
+// See Bug 552829
+#define NS_IPC_IOSERVICE_SET_OFFLINE_TOPIC "ipc:network:set-offline"
+#define NS_IPC_IOSERVICE_SET_CONNECTIVITY_TOPIC "ipc:network:set-connectivity"
+
+class nsINetworkLinkService;
+class nsIPrefBranch;
+class nsIProtocolProxyService2;
+class nsIProxyInfo;
+class nsPISocketTransportService;
+
+namespace mozilla {
+class MemoryReportingProcess;
+namespace net {
+class NeckoChild;
+class nsAsyncRedirectVerifyHelper;
+class SocketProcessHost;
+class SocketProcessMemoryReporter;
+
+class nsIOService final : public nsIIOService,
+                          public nsIObserver,
+                          public nsINetUtil,
+                          public nsISpeculativeConnect,
+                          public nsSupportsWeakReference,
+                          public nsIIOServiceInternal,
+                          public nsIObserverService {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIIOSERVICE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSINETUTIL
+  NS_DECL_NSISPECULATIVECONNECT
+  NS_DECL_NSIIOSERVICEINTERNAL
+  NS_DECL_NSIOBSERVERSERVICE
+
+  // Gets the singleton instance of the IO Service, creating it as needed
+  // Returns nullptr on out of memory or failure to initialize.
+  static already_AddRefed<nsIOService> GetInstance();
+
+  nsresult Init();
+  nsresult NewURI(const char* aSpec, nsIURI* aBaseURI, nsIURI** result,
+                  nsIProtocolHandler** hdlrResult);
+
+  // Called by channels before a redirect happens. This notifies the global
+  // redirect observers.
+  nsresult AsyncOnChannelRedirect(nsIChannel* oldChan, nsIChannel* newChan,
+                                  uint32_t flags,
+                                  nsAsyncRedirectVerifyHelper* helper);
+
+  bool IsOffline() { return mOffline; }
+  PRIntervalTime LastOfflineStateChange() { return mLastOfflineStateChange; }
+  PRIntervalTime LastConnectivityChange() { return mLastConnectivityChange; }
+  PRIntervalTime LastNetworkLinkChange() { return mLastNetworkLinkChange; }
+  bool IsNetTearingDown() {
+    return mShutdown || mOfflineForProfileChange ||
+           mHttpHandlerAlreadyShutingDown;
+  }
+  PRIntervalTime NetTearingDownStarted() { return mNetTearingDownStarted; }
+
+  // nsHttpHandler is going to call this function to inform nsIOService that
+  // network is in process of tearing down. Moving nsHttpConnectionMgr::Shutdown
+  // to nsIOService caused problems (bug 1242755) so we doing it in this way. As
+  // soon as nsIOService gets notification that it is shutdown it is going to
+  // reset mHttpHandlerAlreadyShutingDown.
+  void SetHttpHandlerAlreadyShutingDown();
+
+  bool IsLinkUp();
+
+  // Converts an internal URI (e.g. one that has a username and password in
+  // it) into one which we can expose to the user, for example on the URL bar.
+  static already_AddRefed<nsIURI> CreateExposableURI(nsIURI*);
+
+  // Used to count the total number of HTTP requests made
+  void IncrementRequestNumber() { mTotalRequests++; }
+  uint32_t GetTotalRequestNumber() { return mTotalRequests; }
+  // Used to keep "race cache with network" stats
+  void IncrementCacheWonRequestNumber() { mCacheWon++; }
+  uint32_t GetCacheWonRequestNumber() { return mCacheWon; }
+  void IncrementNetWonRequestNumber() { mNetWon++; }
+  uint32_t GetNetWonRequestNumber() { return mNetWon; }
+
+  // Used to trigger a recheck of the captive portal status
+  nsresult RecheckCaptivePortal();
+
+  void OnProcessLaunchComplete(SocketProcessHost* aHost, bool aSucceeded);
+  void OnProcessUnexpectedShutdown(SocketProcessHost* aHost);
+  bool SocketProcessReady();
+  static void NotifySocketProcessPrefsChanged(const char* aName, void* aSelf);
+  void NotifySocketProcessPrefsChanged(const char* aName);
+  static bool UseSocketProcess(bool aCheckAgain = false);
+
+  bool IsSocketProcessLaunchComplete();
+
+  // Call func immediately if socket process is launched completely. Otherwise,
+  // |func| will be queued and then executed in the *main thread* once socket
+  // process is launced.
+  void CallOrWaitForSocketProcess(const std::function<void()>& aFunc);
+
+  int32_t SocketProcessPid();
+  SocketProcessHost* SocketProcess() { return mSocketProcess; }
+
+  friend SocketProcessMemoryReporter;
+  RefPtr<MemoryReportingProcess> GetSocketProcessMemoryReporter();
+
+  // Lookup the ProtocolHandlerInfo based on a given scheme.
+  // Safe to call from any thread.
+  ProtocolHandlerInfo LookupProtocolHandler(const nsACString& aScheme);
+
+  static void OnTLSPrefChange(const char* aPref, void* aSelf);
+
+  nsresult LaunchSocketProcess();
+
+  static bool TooManySocketProcessCrash();
+  static void IncreaseSocketProcessCrashCount();
+
+ private:
+  // These shouldn't be called directly:
+  // - construct using GetInstance
+  // - destroy using Release
+  nsIOService();
+  ~nsIOService();
+  nsresult SetConnectivityInternal(bool aConnectivity);
+
+  nsresult OnNetworkLinkEvent(const char* data);
+
+  nsresult InitializeCaptivePortalService();
+  nsresult RecheckCaptivePortalIfLocalRedirect(nsIChannel* newChan);
+
+  // Prefs wrangling
+  static void PrefsChanged(const char* pref, void* self);
+  void PrefsChanged(const char* pref = nullptr);
+  void ParsePortList(const char* pref, bool remove);
+
+  nsresult InitializeSocketTransportService();
+  nsresult InitializeNetworkLinkService();
+  nsresult InitializeProtocolProxyService();
+
+  // consolidated helper function
+  void LookupProxyInfo(nsIURI* aURI, nsIURI* aProxyURI, uint32_t aProxyFlags,
+                       nsCString* aScheme, nsIProxyInfo** outPI);
+
+  nsresult NewChannelFromURIWithProxyFlagsInternal(
+      nsIURI* aURI, nsIURI* aProxyURI, uint32_t aProxyFlags,
+      nsINode* aLoadingNode, nsIPrincipal* aLoadingPrincipal,
+      nsIPrincipal* aTriggeringPrincipal,
+      const mozilla::Maybe<mozilla::dom::ClientInfo>& aLoadingClientInfo,
+      const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+      uint32_t aSecurityFlags, nsContentPolicyType aContentPolicyType,
+      uint32_t aSandboxFlags, bool aSkipCheckForBrokenURLOrZeroSized,
+      nsIChannel** result);
+
+  nsresult NewChannelFromURIWithProxyFlagsInternal(nsIURI* aURI,
+                                                   nsIURI* aProxyURI,
+                                                   uint32_t aProxyFlags,
+                                                   nsILoadInfo* aLoadInfo,
+                                                   nsIChannel** result);
+
+  nsresult SpeculativeConnectInternal(
+      nsIURI* aURI, nsIPrincipal* aPrincipal,
+      Maybe<OriginAttributes>&& aOriginAttributes,
+      nsIInterfaceRequestor* aCallbacks, bool aAnonymous);
+
+  void DestroySocketProcess();
+
+  nsresult SetOfflineInternal(bool offline, bool notifySocketProcess = true);
+
+  bool UsesExternalProtocolHandler(const nsACString& aScheme)
+      MOZ_REQUIRES_SHARED(mLock);
+
+ private:
+  mozilla::Atomic<bool, mozilla::Relaxed> mOffline{true};
+  mozilla::Atomic<bool, mozilla::Relaxed> mOfflineForProfileChange{false};
+  bool mManageLinkStatus{false};
+  mozilla::Atomic<bool, mozilla::Relaxed> mConnectivity{true};
+
+  // Used to handle SetOffline() reentrancy.  See the comment in
+  // SetOffline() for more details.
+  bool mSettingOffline{false};
+  bool mSetOfflineValue{false};
+
+  bool mSocketProcessLaunchComplete{false};
+
+  mozilla::Atomic<bool, mozilla::Relaxed> mShutdown{false};
+  mozilla::Atomic<bool, mozilla::Relaxed> mHttpHandlerAlreadyShutingDown{false};
+
+  nsCOMPtr<nsPISocketTransportService> mSocketTransportService;
+  nsCOMPtr<nsICaptivePortalService> mCaptivePortalService;
+  nsCOMPtr<nsINetworkLinkService> mNetworkLinkService;
+  bool mNetworkLinkServiceInitialized{false};
+
+  // cached categories
+  nsCategoryCache<nsIChannelEventSink> mChannelEventSinks{
+      NS_CHANNEL_EVENT_SINK_CATEGORY};
+
+  RWLock mLock{"nsIOService::mLock"};
+  nsTArray<int32_t> mRestrictedPortList MOZ_GUARDED_BY(mLock);
+  nsTArray<nsCString> mForceExternalSchemes MOZ_GUARDED_BY(mLock);
+  nsTHashMap<nsCString, RuntimeProtocolHandler> mRuntimeProtocolHandlers
+      MOZ_GUARDED_BY(mLock);
+
+  uint32_t mTotalRequests{0};
+  uint32_t mCacheWon{0};
+  uint32_t mNetWon{0};
+  static uint32_t sSocketProcessCrashedCount;
+
+  // These timestamps are needed for collecting telemetry on PR_Connect,
+  // PR_ConnectContinue and PR_Close blocking time.  If we spend very long
+  // time in any of these functions we want to know if and what network
+  // change has happened shortly before.
+  mozilla::Atomic<PRIntervalTime> mLastOfflineStateChange;
+  mozilla::Atomic<PRIntervalTime> mLastConnectivityChange;
+  mozilla::Atomic<PRIntervalTime> mLastNetworkLinkChange;
+
+  // Time a network tearing down started.
+  mozilla::Atomic<PRIntervalTime> mNetTearingDownStarted{0};
+
+  SocketProcessHost* mSocketProcess{nullptr};
+
+  // Events should be executed after the socket process is launched. Will
+  // dispatch these events while socket process fires OnProcessLaunchComplete.
+  // Note: this array is accessed only on the main thread.
+  nsTArray<std::function<void()>> mPendingEvents;
+
+  // The observer notifications need to be forwarded to socket process.
+  nsTHashSet<nsCString> mObserverTopicForSocketProcess;
+  // Some noticications (e.g., NS_XPCOM_SHUTDOWN_OBSERVER_ID) are triggered in
+  // socket process, so we should not send the notifications again.
+  nsTHashSet<nsCString> mSocketProcessTopicBlockedList;
+  // Used to store the topics that are already observed by IOService.
+  nsTHashSet<nsCString> mIOServiceTopicList;
+
+  nsCOMPtr<nsIObserverService> mObserverService;
+
+ public:
+  // Used for all default buffer sizes that necko allocates.
+  static uint32_t gDefaultSegmentSize;
+  static uint32_t gDefaultSegmentCount;
+};
+
+/**
+ * Reference to the IO service singleton. May be null.
+ */
+extern nsIOService* gIOService;
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsIOService_h__
diff --git a/netwerk/base/nsIParentChannel.idl b/netwerk/base/nsIParentChannel.idl
new file mode 100644
index 0000000000..a351019d7d
--- /dev/null
+++ b/netwerk/base/nsIParentChannel.idl
@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+#include "nsIHttpChannel.idl"
+
+interface nsIRemoteTab;
+
+%{C++
+namespace mozilla {
+namespace net {
+class ParentChannelListener;
+}
+}
+%}
+
+[ptr] native ParentChannelListener(mozilla::net::ParentChannelListener);
+
+/**
+ * Implemented by chrome side of IPC protocols.
+ */
+
+[scriptable, uuid(e0fc4801-6030-4653-a59f-1fb282bd1a04)]
+interface nsIParentChannel : nsIStreamListener
+{
+  /**
+   * Called to set the ParentChannelListener object (optional).
+   */
+  [noscript] void setParentListener(in ParentChannelListener listener);
+
+   /**
+   * Called to set matched information when URL matches SafeBrowsing list.
+   * @param aList
+   *        Name of the list that matched
+   * @param aProvider
+   *        Name of provider that matched
+   * @param aFullHash
+   *        String represents full hash that matched
+   */
+  [noscript] void setClassifierMatchedInfo(in ACString aList,
+                                           in ACString aProvider,
+                                           in ACString aFullHash);
+
+   /**
+   * Called to set matched tracking information when URL matches tracking annotation list.
+   * @param aList
+   *        Comma-separated list of tables that matched
+   * @param aFullHashes
+   *        Comma-separated list of base64 encoded full hashes that matched
+   */
+  [noscript] void setClassifierMatchedTrackingInfo(in ACString aLists,
+                                                   in ACString aFullHashes);
+
+  /**
+   * Called to notify the HttpChannelChild that the resource being loaded
+   * has been classified.
+   * @param aClassificationFlags
+   *        What classifier identifies this channel.
+   * @param aIsThirdParty
+   *        Whether or not the resourced is considered first-party
+   *        with the URI of the window.
+   */
+  [noscript] void notifyClassificationFlags(in uint32_t aClassificationFlags,
+                                            in bool aIsThirdParty);
+
+  /**
+   * Called to invoke deletion of the IPC protocol.
+   */
+  void delete();
+
+  /**
+   * The remote type of the target process for this load.
+   */
+  readonly attribute AUTF8String remoteType;
+};
diff --git a/netwerk/base/nsIParentRedirectingChannel.idl b/netwerk/base/nsIParentRedirectingChannel.idl
new file mode 100644
index 0000000000..6302775c51
--- /dev/null
+++ b/netwerk/base/nsIParentRedirectingChannel.idl
@@ -0,0 +1,68 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIParentChannel.idl"
+
+interface nsIRemoteTab;
+interface nsIChannel;
+interface nsIAsyncVerifyRedirectCallback;
+
+[uuid(01987690-48cf-45de-bae3-e143c2adc2a8)]
+interface nsIAsyncVerifyRedirectReadyCallback : nsISupports
+{
+  /**
+   * Asynchronous callback when redirected channel finishes the preparation for
+   * completing the verification procedure.
+   *
+   * @param result
+   *    SUCCEEDED if preparation for redirection verification succceed.
+   *    If FAILED the redirection must be aborted.
+   */
+  void readyToVerify(in nsresult result);
+};
+
+/**
+ * Implemented by chrome side of IPC protocols that support redirect responses.
+ */
+
+[scriptable, uuid(3ed1d288-5324-46ee-8a98-33ac37d1080b)]
+interface nsIParentRedirectingChannel : nsIParentChannel
+{
+  /**
+   * Called when the channel got a response that redirects it to a different
+   * URI.  The implementation is responsible for calling the redirect observers
+   * on the child process and provide the decision result to the callback.
+   *
+   * @param newURI
+   *    the URI we redirect to
+   * @param callback
+   *    redirect result callback, usage is compatible with how
+   *    nsIChannelEventSink defines it
+   */
+  void startRedirect(in nsIChannel newChannel,
+                     in uint32_t redirectFlags,
+                     in nsIAsyncVerifyRedirectCallback callback);
+
+  /**
+   * Called to new channel when the original channel got Redirect2Verify
+   * response from child. Callback will be invoked when the new channel
+   * finishes the preparation for Redirect2Verify and can be called immediately.
+   *
+   * @param callback
+   *    redirect ready callback, will be called when redirect verification
+   *    procedure can proceed.
+   */
+  void continueVerification(in nsIAsyncVerifyRedirectReadyCallback callback);
+
+  /**
+   * Called after we are done with redirecting process and we know if to
+   * redirect or not.  Forward the redirect result to the child process.  From
+   * that moment the nsIParentChannel implementation expects it will be
+   * forwarded all notifications from the 'real' channel.
+   *
+   * Primarilly used by HttpChannelParent::OnRedirectResult and kept as
+   * mActiveChannel and mRedirectChannel in that class.
+   */
+  void completeRedirect(in nsresult succeeded);
+};
diff --git a/netwerk/base/nsIPermission.idl b/netwerk/base/nsIPermission.idl
new file mode 100644
index 0000000000..029f0d8395
--- /dev/null
+++ b/netwerk/base/nsIPermission.idl
@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIPrincipal;
+interface nsIURI;
+
+/**
+ * This interface defines a "permission" object,
+ * used to specify allowed/blocked objects from
+ * user-specified sites (cookies, images etc).
+ */
+[scriptable, uuid(bb409a51-2371-4fea-9dc9-b7286a458b8c)]
+interface nsIPermission : nsISupports
+{
+    /**
+     * The principal for which this permission applies.
+     */
+    readonly attribute nsIPrincipal principal;
+
+    /**
+     * a case-sensitive ASCII string, indicating the type of permission
+     * (e.g., "cookie", "image", etc).
+     * This string is specified by the consumer when adding a permission
+     * via nsIPermissionManager.
+     * @see nsIPermissionManager
+     */
+    readonly attribute ACString type;
+
+    /**
+     * The permission (see nsIPermissionManager.idl for allowed values)
+     */
+    readonly attribute uint32_t capability;
+
+    /**
+     * The expiration type of the permission (session, time-based or none).
+     * Constants are EXPIRE_*, defined in nsIPermissionManager.
+     * @see nsIPermissionManager
+     */
+    readonly attribute uint32_t expireType;
+
+    /**
+     * The expiration time of the permission (milliseconds since Jan 1 1970
+     * 0:00:00).
+     */
+    readonly attribute int64_t expireTime;
+
+    /**
+     * The last modification time of the permission (milliseconds since Jan 1 1970
+     * 0:00:00).
+     */
+    readonly attribute int64_t modificationTime;
+
+    /**
+     * Test whether a principal would be affected by this permission.
+     *
+     * @param principal  the principal to test
+     * @param exactHost  If true, only the specific host will be matched,
+     *                   @see nsIPermissionManager::testExactPermission.
+     *                   If false, subdomains will also be searched,
+     *                   @see nsIPermissionManager::testPermission.
+     */
+    boolean matches(in nsIPrincipal principal,
+                    in boolean exactHost);
+
+    /**
+     * Test whether a URI would be affected by this permission.
+     * NOTE: This performs matches with default origin attribute values.
+     *
+     * @param uri        the uri to test
+     * @param exactHost  If true, only the specific host will be matched,
+     *                   @see nsIPermissionManager::testExactPermission.
+     *                   If false, subdomains will also be searched,
+     *                   @see nsIPermissionManager::testPermission.
+     */
+    boolean matchesURI(in nsIURI uri,
+                       in boolean exactHost);
+};
diff --git a/netwerk/base/nsIPermissionManager.idl b/netwerk/base/nsIPermissionManager.idl
new file mode 100644
index 0000000000..f234958010
--- /dev/null
+++ b/netwerk/base/nsIPermissionManager.idl
@@ -0,0 +1,242 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This file contains an interface to the Permission Manager,
+ * used to persistenly store permissions for different object types (cookies,
+ * images etc) on a site-by-site basis.
+ *
+ * This service broadcasts the following notification when the permission list
+ * is changed:
+ *
+ * topic  : "perm-changed" (PERM_CHANGE_NOTIFICATION)
+ *          broadcast whenever the permission list changes in some way. there
+ *          are four possible data strings for this notification; one
+ *          notification will be broadcast for each change, and will involve
+ *          a single permission.
+ * subject: an nsIPermission interface pointer representing the permission object
+ *          that changed.
+ * data   : "deleted"
+ *          a permission was deleted. the subject is the deleted permission.
+ *          "added"
+ *          a permission was added. the subject is the added permission.
+ *          "changed"
+ *          a permission was changed. the subject is the new permission.
+ *          "cleared"
+ *          the entire permission list was cleared. the subject is null.
+ */
+
+#include "nsISupports.idl"
+
+interface nsIPrincipal;
+interface nsIPermission;
+
+[scriptable, builtinclass, uuid(4dcb3851-eba2-4e42-b236-82d2596fca22)]
+interface nsIPermissionManager : nsISupports
+{
+  /**
+   * Predefined return values for the testPermission method and for
+   * the permission param of the add method
+   * NOTE: UNKNOWN_ACTION (0) is reserved to represent the
+   * default permission when no entry is found for a host, and
+   * should not be used by consumers to indicate otherwise.
+   */
+  const uint32_t UNKNOWN_ACTION = 0;
+  const uint32_t ALLOW_ACTION = 1;
+  const uint32_t DENY_ACTION = 2;
+  const uint32_t PROMPT_ACTION = 3;
+
+  /**
+   * Predefined expiration types for permissions.  Permissions can be permanent
+   * (never expire), expire at the end of the session, or expire at a specified
+   * time. Permissions that expire at the end of a session may also have a
+   * specified expiration time.
+   *
+   * EXPIRE_POLICY is a special expiration status. It is set when the permission
+   * is set by reading an enterprise policy. These permissions cannot be overridden.
+   */
+  const uint32_t EXPIRE_NEVER = 0;
+  const uint32_t EXPIRE_SESSION = 1;
+  const uint32_t EXPIRE_TIME = 2;
+  const uint32_t EXPIRE_POLICY = 3;
+
+
+  /**
+   * Get all custom permissions for a given nsIPrincipal. This will return an
+   * enumerator of all permissions which are not set to default and which
+   * belong to the matching principal of the given nsIPrincipal.
+   *
+   * @param principal  the URI to get all permissions for
+   */
+  Array<nsIPermission> getAllForPrincipal(in nsIPrincipal principal);
+
+  /**
+   * Get all custom permissions of a specific type, specified with a prefix
+   * string.  This will return an array of all permissions which are not set to
+   * default.  Also the passed type argument is either equal to or a prefix of
+   * the type of the returned permissions.
+   *
+   * @param prefix  the type prefix string
+   */
+  Array<nsIPermission> getAllWithTypePrefix(in ACString prefix);
+
+
+  /**
+   * Get all custom permissions whose type exactly match one of the types defined
+   * in the passed array argument.
+   * This will return an array of all permissions which are not set to default.
+   *
+   * @param types  an array of case-sensitive ASCII strings, identifying the
+   *               permissions to be matched.
+   */
+  Array<nsIPermission> getAllByTypes(in Array<ACString> types);
+
+  /**
+   * Get all custom permissions of a specific type and that were modified after
+   * the specified date. This will return an array of all permissions which are
+   * not set to default.
+   *
+   * @param type    a case-sensitive ASCII string, identifying the permission.
+   * @param since   a unix timestamp representing the number of milliseconds from
+   *                Jan 1, 1970 00:00:00 UTC.
+   */
+  Array<nsIPermission> getAllByTypeSince(in ACString type, in int64_t since);
+
+  /**
+   * Add permission information for a given principal.
+   * It is internally calling the other add() method using the nsIURI from the
+   * principal.
+   * Passing a system principal will be a no-op because they will always be
+   * granted permissions.
+   */
+  void addFromPrincipal(in nsIPrincipal principal, in ACString type,
+                        in uint32_t permission,
+                        [optional] in uint32_t expireType,
+                        [optional] in int64_t expireTime);
+
+  /**
+   * Add permanent permission information for a given principal in private
+   * browsing.
+   *
+   * Normally permissions in private browsing are cleared at the end of the
+   * session, this method allows you to override this behavior and set
+   * permanent permissions.
+   *
+   * WARNING: setting permanent permissions _will_ leak data in private
+   * browsing. Only use if you understand the consequences and trade-offs. If
+   * you are unsure, |addFromPrincipal| is very likely what you want to use
+   * instead.
+   */
+  void addFromPrincipalAndPersistInPrivateBrowsing(in nsIPrincipal principal,
+                                                   in ACString type,
+                                                   in uint32_t permission);
+
+  /**
+   * Remove permission information for a given principal.
+   * This is internally calling remove() with the host from the principal's URI.
+   * Passing system principal will be a no-op because we never add them to the
+   * database.
+   */
+  void removeFromPrincipal(in nsIPrincipal principal, in ACString type);
+
+  /**
+   * Remove the given permission from the permission manager.
+   *
+   * @param perm   a permission obtained from the permission manager.
+   */
+  void removePermission(in nsIPermission perm);
+
+  /**
+   * Clear permission information for all websites.
+   */
+  void removeAll();
+
+  /**
+   * Clear all permission information added since the specified time.
+   */
+  void removeAllSince(in int64_t since);
+
+  /**
+   * Clear all permissions of the passed type.
+   */
+  void removeByType(in ACString type);
+
+  /**
+   * Clear all permissions of the passed type added since the specified time.
+   * @param type    a case-sensitive ASCII string, identifying the permission.
+   * @param since   a unix timestamp representing the number of milliseconds from
+   *                Jan 1, 1970 00:00:00 UTC.
+   */
+  void removeByTypeSince(in ACString type, in int64_t since);
+
+  /**
+   * Test whether the principal has the permission to perform a given action.
+   * System principals will always have permissions granted.
+   * This function will perform a pref lookup to permissions.default.<type>
+   * if the specific permission type is part of the whitelist for that functionality.
+   */
+  uint32_t testPermissionFromPrincipal(in nsIPrincipal principal,
+                                       in ACString type);
+
+  /**
+   * Test whether the principal has the permission to perform a given action.
+   * This requires an exact hostname match. Subdomain principals do not match
+   * permissions of base domains.
+   * System principals will always have permissions granted.
+   * This function will perform a pref lookup to permissions.default.<type>
+   * if the specific permission type is part of the whitelist for that functionality.
+   */
+  uint32_t testExactPermissionFromPrincipal(in nsIPrincipal principal,
+                                            in ACString type);
+
+  /**
+   * Test whether a website has permission to perform the given action
+   * ignoring active sessions.
+   * System principals will always have permissions granted.
+   * This function will perform a pref lookup to permissions.default.<type>
+   * if the specific permission type is part of the whitelist for that functionality.
+   *
+   * @param principal the principal
+   * @param type      a case-sensitive ASCII string, identifying the consumer
+   * @param return    see add(), param permission. returns UNKNOWN_ACTION when
+   *                  there is no stored permission for this uri and / or type.
+   */
+  uint32_t testExactPermanentPermission(in nsIPrincipal principal,
+                                        in ACString type);
+
+  /**
+   * Get the permission object associated with the given principal and action.
+   * @param principal The principal
+   * @param type      A case-sensitive ASCII string identifying the consumer
+   * @param exactHost If true, only the specific host will be matched.
+   *                  If false, base domains of the principal will also
+   *                  be searched.
+   * @returns The matching permission object, or null if no matching object
+   *          was found. No matching object is equivalent to UNKNOWN_ACTION.
+   * @note Clients in general should prefer the test* methods unless they
+   *       need to know the specific stored details.
+   * @note This method will always return null for the system principal.
+   */
+  nsIPermission getPermissionObject(in nsIPrincipal principal,
+                                    in ACString type,
+                                    in boolean exactHost);
+
+  /**
+   * Returns all stored permissions.
+   * @return an array of nsIPermission objects
+   */
+  readonly attribute Array<nsIPermission> all;
+
+  /**
+   * Remove all permissions that will match the origin pattern.
+   */
+  void removePermissionsWithAttributes(in AString patternAsJSON);
+};
+
+%{ C++
+#define NS_PERMISSIONMANAGER_CONTRACTID "@mozilla.org/permissionmanager;1"
+
+#define PERM_CHANGE_NOTIFICATION "perm-changed"
+%}
diff --git a/netwerk/base/nsIPrivateBrowsingChannel.idl b/netwerk/base/nsIPrivateBrowsingChannel.idl
new file mode 100644
index 0000000000..3bc822f018
--- /dev/null
+++ b/netwerk/base/nsIPrivateBrowsingChannel.idl
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface is implemented by channels which support overriding the
+ * privacy state of the channel.
+ *
+ * This interface must be used only from the XPCOM main thread.
+ */
+[scriptable, uuid(df702bb0-55b8-11e2-bcfd-0800200c9a66)]
+interface nsIPrivateBrowsingChannel : nsISupports
+{
+    /**
+     * Determine whether the channel is tied to a private browsing window.
+     *
+     * This value can be set only before the channel is opened.  Setting it
+     * after that does not have any effect.  This value overrides the privacy
+     * state of the channel, which means that if you call this method, then
+     * the loadGroup and load context will no longer be consulted when we
+     * need to know the private mode status for a channel.
+     *
+     * Note that this value is only meant to be used when the channel's privacy
+     * status cannot be obtained from the loadGroup or load context (for
+     * example, when the channel is not associated with any loadGroup or load
+     * context.)  Setting this value directly should be avoided if possible.
+     *
+     * Implementations must enforce the ordering semantics of this function by
+     * raising errors if setPrivate is called on a channel which has a loadGroup
+     * and/or callbacks that implement nsILoadContext, or if the loadGroup
+     * or notificationCallbacks are set after setPrivate has been called.
+     *
+     * @param aPrivate whether the channel should be opened in private mode.
+     */
+    void setPrivate(in boolean aPrivate);
+
+    /**
+     * States whether the channel is in private browsing mode. This may either
+     * happen because the channel is opened from a private mode context or
+     * when the mode is explicitly set with ::setPrivate().
+     *
+     * This attribute is equivalent to NS_UsePrivateBrowsing(), but scriptable.
+     */
+    readonly attribute boolean isChannelPrivate;
+
+    /*
+     * This function is used to determine whether the channel's private mode
+     * has been overridden by a call to setPrivate.  It is intended to be used
+     * by NS_UsePrivateBrowsing(), and you should not call it directly.
+     *
+     * @param aValue the overridden value.  This will only be set if the function
+     *               returns true.
+     */
+    [noscript] boolean isPrivateModeOverriden(out boolean aValue);
+};
diff --git a/netwerk/base/nsIProgressEventSink.idl b/netwerk/base/nsIProgressEventSink.idl
new file mode 100644
index 0000000000..5420239e4c
--- /dev/null
+++ b/netwerk/base/nsIProgressEventSink.idl
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIRequest;
+
+/**
+ * nsIProgressEventSink
+ *
+ * This interface is used to asynchronously convey channel status and progress
+ * information that is generally not critical to the processing of the channel.
+ * The information is intended to be displayed to the user in some meaningful
+ * way.
+ *
+ * An implementation of this interface can be passed to a channel via the
+ * channel's notificationCallbacks attribute.  See nsIChannel for more info.
+ *
+ * The channel will begin passing notifications to the progress event sink
+ * after its asyncOpen method has been called.  Notifications will cease once
+ * the channel calls its listener's onStopRequest method or once the channel
+ * is canceled (via nsIRequest::cancel).
+ *
+ * NOTE: This interface is actually not specific to channels and may be used
+ * with other implementations of nsIRequest.
+ */
+[scriptable, uuid(87d55fba-cb7e-4f38-84c1-5c6c2b2a55e9)]
+interface nsIProgressEventSink : nsISupports
+{
+    /**
+     * Called to notify the event sink that progress has occurred for the
+     * given request.
+     *
+     * @param aRequest
+     *        the request being observed (may QI to nsIChannel).
+     * @param aProgress
+     *        numeric value in the range 0 to aProgressMax indicating the
+     *        number of bytes transfered thus far.
+     * @param aProgressMax
+     *        numeric value indicating maximum number of bytes that will be
+     *        transfered (or -1 if total is unknown).
+     */
+    void onProgress(in nsIRequest aRequest,
+                    in long long aProgress,
+                    in long long aProgressMax);
+
+    /**
+     * Called to notify the event sink with a status message for the given
+     * request.
+     *
+     * @param aRequest
+     *        the request being observed (may QI to nsIChannel).
+     * @param aStatus
+     *        status code (not necessarily an error code) indicating the
+     *        state of the channel (usually the state of the underlying
+     *        transport).  see nsISocketTransport for socket specific status
+     *        codes.
+     * @param aStatusArg
+     *        status code argument to be used with the string bundle service
+     *        to convert the status message into localized, human readable
+     *        text.  the meaning of this parameter is specific to the value
+     *        of the status code.  for socket status codes, this parameter
+     *        indicates the host:port associated with the status code.
+     */
+    void onStatus(in nsIRequest aRequest,
+                  in nsresult aStatus,
+                  in wstring aStatusArg);
+
+};
diff --git a/netwerk/base/nsIPrompt.idl b/netwerk/base/nsIPrompt.idl
new file mode 100644
index 0000000000..9ceaa6b892
--- /dev/null
+++ b/netwerk/base/nsIPrompt.idl
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This is the prompt interface which can be used without knowlege of a
+ * parent window. The parentage is hidden by the GetInterface though
+ * which it is gotten. This interface is identical to nsIPromptService
+ * but without the parent nsIDOMWindow parameter. See nsIPromptService
+ * for all documentation.
+ *
+ * Accesskeys can be attached to buttons and checkboxes by inserting
+ * an & before the accesskey character. For a real &, use && instead.
+ */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(a63f70c0-148b-11d3-9333-00104ba0fd40)]
+interface nsIPrompt : nsISupports
+{
+    void alert(in wstring dialogTitle,
+               in wstring text);
+
+    void alertCheck(in wstring dialogTitle,
+                    in wstring text,
+                    in wstring checkMsg,
+                    inout boolean checkValue);
+
+    boolean confirm(in wstring dialogTitle,
+                    in wstring text);
+
+    boolean confirmCheck(in wstring dialogTitle,
+                         in wstring text,
+                         in wstring checkMsg,
+                         inout boolean checkValue);
+
+    const unsigned long BUTTON_POS_0              = 1;
+    const unsigned long BUTTON_POS_1              = 1 << 8;
+    const unsigned long BUTTON_POS_2              = 1 << 16;
+
+    const unsigned long BUTTON_TITLE_OK            = 1;
+    const unsigned long BUTTON_TITLE_CANCEL        = 2;
+    const unsigned long BUTTON_TITLE_YES           = 3;
+    const unsigned long BUTTON_TITLE_NO            = 4;
+    const unsigned long BUTTON_TITLE_SAVE          = 5;
+    const unsigned long BUTTON_TITLE_DONT_SAVE     = 6;
+    const unsigned long BUTTON_TITLE_REVERT        = 7;
+
+    const unsigned long BUTTON_TITLE_IS_STRING     = 127;
+
+    const unsigned long BUTTON_POS_0_DEFAULT       = 0 << 24;
+    const unsigned long BUTTON_POS_1_DEFAULT       = 1 << 24;
+    const unsigned long BUTTON_POS_2_DEFAULT       = 2 << 24;
+
+    /* used for security dialogs, buttons are initially disabled */
+    const unsigned long BUTTON_DELAY_ENABLE        = 1 << 26;
+
+    const unsigned long STD_OK_CANCEL_BUTTONS      = (BUTTON_TITLE_OK * BUTTON_POS_0) +
+                                                    (BUTTON_TITLE_CANCEL * BUTTON_POS_1);
+    const unsigned long STD_YES_NO_BUTTONS         = (BUTTON_TITLE_YES * BUTTON_POS_0) +
+                                                    (BUTTON_TITLE_NO * BUTTON_POS_1);
+
+
+    // Indicates whether a prompt should be shown in-content, on tab level or as a separate window
+    const unsigned long MODAL_TYPE_CONTENT = 1;
+    const unsigned long MODAL_TYPE_TAB = 2;
+    const unsigned long MODAL_TYPE_WINDOW = 3;
+    // Like MODAL_TYPE_WINDOW, but shown inside a parent window (with similar
+    // styles as _TAB and _CONTENT types) rather than as a new window:
+    const unsigned long MODAL_TYPE_INTERNAL_WINDOW = 4;
+
+    int32_t confirmEx(in wstring dialogTitle,
+                   in wstring text,
+                   in unsigned long buttonFlags,
+                   in wstring button0Title,
+                   in wstring button1Title,
+                   in wstring button2Title,
+                   in wstring checkMsg,
+                   inout boolean checkValue);
+
+     boolean prompt(in wstring dialogTitle,
+                    in wstring text,
+                    inout wstring value,
+                    in wstring checkMsg,
+                    inout boolean checkValue);
+
+     boolean promptPassword(in wstring dialogTitle,
+                            in wstring text,
+                            inout wstring password);
+
+     boolean promptUsernameAndPassword(in wstring dialogTitle,
+                                       in wstring text,
+                                       inout wstring username,
+                                       inout wstring password);
+
+    boolean select(in wstring dialogTitle,
+                   in wstring text,
+                   in Array<AString> selectList,
+                   out long outSelection);
+};
diff --git a/netwerk/base/nsIProtocolHandler.idl b/netwerk/base/nsIProtocolHandler.idl
new file mode 100644
index 0000000000..ac92af1264
--- /dev/null
+++ b/netwerk/base/nsIProtocolHandler.idl
@@ -0,0 +1,311 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{C++
+#include "nsCOMPtr.h"
+
+/**
+ * Protocol handlers are registered with XPCOM under the following CONTRACTID prefix:
+ */
+#define NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "@mozilla.org/network/protocol;1?name="
+/**
+ * For example, "@mozilla.org/network/protocol;1?name=http"
+ */
+
+#if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
+#define IS_ORIGIN_IS_FULL_SPEC_DEFINED 1
+#endif
+%}
+
+interface nsIURI;
+interface nsIChannel;
+interface nsILoadInfo;
+
+/**
+ * nsIProtocolHandlerWithDynamicFlags
+ *
+ * Protocols that wish to return different flags depending on the URI should
+ * implement this interface.
+ */
+[scriptable, builtinclass, uuid(65a8e823-0591-4fc0-a56a-03265e0a4ce8)]
+interface nsIProtocolHandlerWithDynamicFlags : nsISupports
+{
+    /*
+     * Returns protocol flags for the given URI, which may be different from the
+     * flags for another URI of the same scheme.
+     *
+     * Only DYNAMIC_URI_FLAGS may be different from the registered flags for the
+     * protocol handler.
+     */
+    unsigned long getFlagsForURI(in nsIURI aURI);
+};
+
+/**
+ * nsIProtocolHandler
+ */
+[scriptable, uuid(a87210e6-7c8c-41f7-864d-df809015193e)]
+interface nsIProtocolHandler : nsISupports
+{
+    /**
+     * The scheme of this protocol (e.g., "file").
+     */
+    readonly attribute ACString scheme;
+
+    /**
+     * Constructs a new channel from the given URI for this protocol handler and
+     * sets the loadInfo for the constructed channel.
+     */
+    nsIChannel newChannel(in nsIURI aURI, in nsILoadInfo aLoadinfo);
+
+    /**
+     * Allows a protocol to override blacklisted ports.
+     *
+     * This method will be called when there is an attempt to connect to a port
+     * that is blacklisted.  For example, for most protocols, port 25 (Simple Mail
+     * Transfer) is banned.  When a URI containing this "known-to-do-bad-things"
+     * port number is encountered, this function will be called to ask if the
+     * protocol handler wants to override the ban.
+     */
+    boolean allowPort(in long port, in string scheme);
+
+
+    /**************************************************************************
+     * Constants for the protocol flags (the first is the default mask, the
+     * others are deviations):
+     *
+     * NOTE: Protocol flags are provided when the protocol handler is
+     * registered, either through a static component or dynamically with
+     * `nsIIOService.registerProtocolHandler`.
+     *
+     * NOTE: Implementation must ignore any flags they do not understand.
+     */
+
+    /**
+     * standard full URI with authority component and concept of relative
+     * URIs (http, ...)
+     */
+    const unsigned long URI_STD = 0;
+
+    /**
+     * no concept of relative URIs (about, javascript, finger, ...)
+     */
+    const unsigned long URI_NORELATIVE = (1<<0);
+
+    /**
+     * no authority component (file, ...)
+     */
+    const unsigned long URI_NOAUTH = (1<<1);
+
+    /**
+     * This protocol handler can be proxied via a proxy (socks or http)
+     * (e.g., irc, smtp, http, etc.).  If the protocol supports transparent
+     * proxying, the handler should implement nsIProxiedProtocolHandler.
+     *
+     * If it supports only HTTP proxying, then it need not support
+     * nsIProxiedProtocolHandler, but should instead set the ALLOWS_PROXY_HTTP
+     * flag (see below).
+     *
+     * @see nsIProxiedProtocolHandler
+     */
+    const unsigned long ALLOWS_PROXY = (1<<2);
+
+    /**
+     * This protocol handler can be proxied using a http proxy (e.g., http,
+     * etc.).  nsIIOService::newChannelFromURI will feed URIs from this
+     * protocol handler to the HTTP protocol handler instead.  This flag is
+     * ignored if ALLOWS_PROXY is not set.
+     */
+    const unsigned long ALLOWS_PROXY_HTTP = (1<<3);
+
+    /**
+     * The URIs for this protocol have no inherent security context, so
+     * documents loaded via this protocol should inherit the security context
+     * from the document that loads them.
+     */
+    const unsigned long URI_INHERITS_SECURITY_CONTEXT = (1<<4);
+
+    /**
+     * "Automatic" loads that would replace the document (e.g. <meta> refresh,
+     * certain types of XLinks, possibly other loads that the application
+     * decides are not user triggered) are not allowed if the originating (NOT
+     * the target) URI has this protocol flag.  Note that the decision as to
+     * what constitutes an "automatic" load is made externally, by the caller
+     * of nsIScriptSecurityManager::CheckLoadURI.  See documentation for that
+     * method for more information.
+     *
+     * A typical protocol that might want to set this flag is a protocol that
+     * shows highly untrusted content in a viewing area that the user expects
+     * to have a lot of control over, such as an e-mail reader.
+     */
+    const unsigned long URI_FORBIDS_AUTOMATIC_DOCUMENT_REPLACEMENT = (1<<5);
+
+    /**
+     * +-------------------------------------------------------------------+
+     * |                                                                   |
+     * |  ALL PROTOCOL HANDLERS MUST SET ONE OF THE FOLLOWING FIVE FLAGS.  |
+     * |                                                                   |
+     * +-------------------------------------------------------------------+
+     *
+     *    * URI_LOADABLE_BY_ANYONE
+     *    * URI_DANGEROUS_TO_LOAD
+     *    * URI_IS_UI_RESOURCE
+     *    * URI_IS_LOCAL_FILE
+     *    * URI_LOADABLE_BY_SUBSUMERS
+     *
+     * These flags are used to determine who is allowed to load URIs for this
+     * protocol.  Note that if a URI is nested, only the flags for the
+     * innermost URI matter.  See nsINestedURI.
+     *
+     * If none of these five flags are set, the ContentSecurityManager will
+     * deny the load.
+     */
+
+    /**
+     * The URIs for this protocol can be loaded by anyone.  For example, any
+     * website should be allowed to trigger a load of a URI for this protocol.
+     * Web-safe protocols like "http" should set this flag.
+     */
+    const unsigned long URI_LOADABLE_BY_ANYONE = (1<<6);
+
+    /**
+     * The URIs for this protocol are UNSAFE if loaded by untrusted (web)
+     * content and may only be loaded by privileged code (for example, code
+     * which has the system principal).  Various internal protocols should set
+     * this flag.
+     */
+    const unsigned long URI_DANGEROUS_TO_LOAD = (1<<7);
+
+    /**
+     * The URIs for this protocol point to resources that are part of the
+     * application's user interface.  There are cases when such resources may
+     * be made accessible to untrusted content such as web pages, so this is
+     * less restrictive than URI_DANGEROUS_TO_LOAD but more restrictive than
+     * URI_LOADABLE_BY_ANYONE.  See the documentation for
+     * nsIScriptSecurityManager::CheckLoadURI.
+     */
+    const unsigned long URI_IS_UI_RESOURCE = (1<<8);
+
+    /**
+     * Loading of URIs for this protocol from other origins should only be
+     * allowed if those origins should have access to the local filesystem.
+     * It's up to the application to decide what origins should have such
+     * access.  Protocols like "file" that point to local data should set this
+     * flag.
+     */
+    const unsigned long URI_IS_LOCAL_FILE = (1<<9);
+
+    /**
+     * The URIs for this protocol can be loaded only by callers with a
+     * principal that subsumes this uri. For example, privileged code and
+     * websites that are same origin as this uri.
+     */
+    const unsigned long URI_LOADABLE_BY_SUBSUMERS = (1<<10);
+
+    /**
+     * Channels using this protocol never call OnDataAvailable
+     * on the listener passed to AsyncOpen and they therefore
+     * do not return any data that we can use.
+     */
+    const unsigned long URI_DOES_NOT_RETURN_DATA = (1<<11);
+
+    /**
+     * URIs for this protocol are considered to be local resources.  This could
+     * be a local file (URI_IS_LOCAL_FILE), a UI resource (URI_IS_UI_RESOURCE),
+     * or something else that would not hit the network.
+     */
+    const unsigned long URI_IS_LOCAL_RESOURCE = (1<<12);
+
+    /**
+     * URIs for this protocol execute script when they are opened.
+     */
+    const unsigned long URI_OPENING_EXECUTES_SCRIPT = (1<<13);
+
+    /**
+     * Loading channels from this protocol has side-effects that make
+     * it unsuitable for saving to a local file.
+     */
+    const unsigned long URI_NON_PERSISTABLE = (1<<14);
+
+    /**
+     * URIs for this protocol require the webapps permission on the principal
+     * when opening URIs for a different domain. See bug#773886
+     */
+    const unsigned long URI_CROSS_ORIGIN_NEEDS_WEBAPPS_PERM = (1<<15);
+
+    /**
+     * Channels for this protocol don't need to spin the event loop to handle
+     * Open() and reads on the resulting stream.
+     */
+    const unsigned long URI_SYNC_LOAD_IS_OK = (1<<16);
+
+    /**
+     * All the origins whose URI has this scheme are considered potentially
+     * trustworthy.
+     * Per the SecureContext spec, https: and wss: should be considered
+     * a priori secure, and implementations may consider other,
+     * implementation-specific URI schemes as secure.
+     */
+    const unsigned long URI_IS_POTENTIALLY_TRUSTWORTHY = (1<<17);
+
+    /**
+     * This URI may be fetched and the contents are visible to anyone. This is
+     * semantically equivalent to the resource being served with all-access CORS
+     * headers.  This is only used in MV2 Extensions and should not otherwise
+     * be used.
+     */
+    const unsigned long URI_FETCHABLE_BY_ANYONE = (1 << 18);
+
+    /**
+     * If this flag is set, then the origin for this protocol is the full URI
+     * spec, not just the scheme + host + port.
+     *
+     * Note: this is not supported in Firefox.  It is currently only available
+     * in Thunderbird and SeaMonkey.
+     */
+    const unsigned long ORIGIN_IS_FULL_SPEC = (1 << 19);
+
+    /**
+     * If this flag is set, the URI does not always allow content using the same
+     * protocol to link to it.
+     */
+    const unsigned long URI_SCHEME_NOT_SELF_LINKABLE = (1 << 20);
+
+    /**
+     * The URIs for this protocol can be loaded by extensions.
+     */
+    const unsigned long URI_LOADABLE_BY_EXTENSIONS = (1 << 21);
+
+    /**
+     * The URIs for this protocol can not be loaded into private contexts.
+     */
+    const unsigned long URI_DISALLOW_IN_PRIVATE_CONTEXT = (1 << 22);
+
+    /**
+     * This protocol handler forbids accessing cookies e.g. for mail related
+     * protocols. Only used in Mailnews (comm-central).
+     */
+    const unsigned long URI_FORBIDS_COOKIE_ACCESS = (1 << 23);
+
+    /**
+     * This is an extension web accessible uri that is loadable if checked
+     * against an allowlist using ExtensionPolicyService::SourceMayLoadExtensionURI.
+     */
+    const unsigned long WEBEXT_URI_WEB_ACCESSIBLE = (1 << 24);
+
+    /**
+     * Flags which are allowed to be different from the static flags when
+     * returned from `nsIProtocolHandlerWithDynamicFlags::getFlagsForURI`.
+     *
+     * All other flags must match the flags provided when the protocol handler
+     * was registered.
+     */
+    const unsigned long DYNAMIC_URI_FLAGS =
+        URI_LOADABLE_BY_ANYONE | URI_DANGEROUS_TO_LOAD |
+        URI_IS_POTENTIALLY_TRUSTWORTHY | URI_FETCHABLE_BY_ANYONE |
+        URI_LOADABLE_BY_EXTENSIONS | URI_DISALLOW_IN_PRIVATE_CONTEXT |
+        WEBEXT_URI_WEB_ACCESSIBLE;
+};
diff --git a/netwerk/base/nsIProtocolProxyCallback.idl b/netwerk/base/nsIProtocolProxyCallback.idl
new file mode 100644
index 0000000000..96c2181eca
--- /dev/null
+++ b/netwerk/base/nsIProtocolProxyCallback.idl
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+interface nsIProxyInfo;
+interface nsICancelable;
+
+/**
+ * This interface serves as a closure for nsIProtocolProxyService's
+ * asyncResolve method.
+ */
+[scriptable, uuid(fbb6eff6-0cc2-4d99-8d6f-0a12b462bdeb)]
+interface nsIProtocolProxyCallback : nsISupports
+{
+  /**
+   * This method is called when proxy info is available or when an error
+   * in the proxy resolution occurs.
+   *
+   * @param aRequest
+   *        The value returned from asyncResolve.
+   * @param aChannel
+   *        The channel passed to asyncResolve.
+   * @param aProxyInfo
+   *        The resulting proxy info or null if there is no associated proxy
+   *        info for aURI.  As with the result of nsIProtocolProxyService's
+   *        resolve method, a null result implies that a direct connection
+   *        should be used.
+   * @param aStatus
+   *        The status of the callback.  This is a failure code if the request
+   *        could not be satisfied, in which case the value of aStatus
+   *        indicates the reason for the failure and aProxyInfo will be null.
+   */
+  void onProxyAvailable(in nsICancelable aRequest,
+                        in nsIChannel aChannel,
+                        in nsIProxyInfo aProxyInfo,
+                        in nsresult aStatus);
+};
diff --git a/netwerk/base/nsIProtocolProxyFilter.idl b/netwerk/base/nsIProtocolProxyFilter.idl
new file mode 100644
index 0000000000..a771af5f43
--- /dev/null
+++ b/netwerk/base/nsIProtocolProxyFilter.idl
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+interface nsIProtocolProxyService;
+interface nsIProxyInfo;
+interface nsIURI;
+
+/**
+ * Recipient of the result of implementers of nsIProtocolProxy(Channel)Filter
+ * allowing the proxyinfo be provided asynchronously.
+ */
+[scriptable, uuid(009E6C3F-FB64-40C5-8093-F1495C64773E)]
+interface nsIProxyProtocolFilterResult : nsISupports
+{
+  /**
+   * It's mandatory to call this method exactly once when the applyFilter()
+   * implementation doesn't throw and to not call it when applyFilter() does
+   * throw.
+   *
+   * It's mandatory to call this method on the same thread as the call to
+   * applyFilter() has been made on.
+   *
+   * Following the above conditions, can be called either from within
+   * applyFilter() or asynchronouly any time later.
+   */
+  void onProxyFilterResult(in nsIProxyInfo aProxy);
+};
+
+/**
+ * This interface is used to apply filters to the proxies selected for a given
+ * URI.  Use nsIProtocolProxyService::registerFilter to hook up instances of
+ * this interface. See also nsIProtocolProxyChannelFilter.
+ */
+[scriptable, uuid(f424abd3-32b4-456c-9f45-b7e3376cb0d1)]
+interface nsIProtocolProxyFilter : nsISupports
+{
+  /**
+   * This method is called to apply proxy filter rules for the given URI
+   * and proxy object (or list of proxy objects).
+   *
+   * @param aURI
+   *        The URI for which these proxy settings apply.
+   * @param aProxy
+   *        The proxy (or list of proxies) that would be used by default for
+   *        the given URI.  This may be null.
+   *
+   * @param aCallback
+   *        An object that the implementer is obligated to call on with
+   *        the result (from within applyFilter() or asynchronously) when
+   *        applyFilter didn't throw.  The argument passed to onProxyFilterResult
+   *        is the proxy (or list of proxies) that should be used in place of
+   *        aProxy.  This can be just be aProxy if the filter chooses not to
+   *        modify the proxy.  It can also be null to indicate that a direct
+   *        connection should be used.  Use nsIProtocolProxyService.newProxyInfo
+   *        to construct nsIProxyInfo objects.
+   */
+  void applyFilter(in nsIURI aURI, in nsIProxyInfo aProxy,
+                   in nsIProxyProtocolFilterResult aCallback);
+};
+
+/**
+ * This interface is used to apply filters to the proxies selected for a given
+ * channel.  Use nsIProtocolProxyService::registerChannelFilter to hook up instances of
+ * this interface. See also nsIProtocolProxyFilter.
+ */
+[scriptable, uuid(245b0880-82c5-4e6e-be6d-bc586aa55a90)]
+interface nsIProtocolProxyChannelFilter : nsISupports
+{
+  /**
+   * This method is called to apply proxy filter rules for the given channel
+   * and proxy object (or list of proxy objects).
+   *
+   * @param aChannel
+   *        The channel for which these proxy settings apply.
+   * @param aProxy
+   *        The proxy (or list of proxies) that would be used by default for
+   *        the given channel. This may be null.
+   *
+   * @param aCallback
+   *        An object that the implementer is obligated to call on with
+   *        the result (from within applyFilter() or asynchronously) when
+   *        applyFilter didn't throw.  The argument passed to onProxyFilterResult
+   *        is the proxy (or list of proxies) that should be used in place of
+   *        aProxy.  This can be just be aProxy if the filter chooses not to
+   *        modify the proxy.  It can also be null to indicate that a direct
+   *        connection should be used.  Use nsIProtocolProxyService.newProxyInfo
+   *        to construct nsIProxyInfo objects.
+   */
+  void applyFilter(in nsIChannel aChannel, in nsIProxyInfo aProxy,
+                   in nsIProxyProtocolFilterResult aCallback);
+};
diff --git a/netwerk/base/nsIProtocolProxyService.idl b/netwerk/base/nsIProtocolProxyService.idl
new file mode 100644
index 0000000000..8463f7acd0
--- /dev/null
+++ b/netwerk/base/nsIProtocolProxyService.idl
@@ -0,0 +1,330 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim:set ts=4 sw=4 sts=4 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsICancelable;
+interface nsIProtocolProxyCallback;
+interface nsIProtocolProxyFilter;
+interface nsIProtocolProxyChannelFilter;
+interface nsIProxyInfo;
+interface nsIChannel;
+interface nsIURI;
+interface nsISerialEventTarget;
+
+[scriptable, uuid(77984234-aad5-47fc-a412-03398c2134a5)]
+interface nsIProxyConfigChangedCallback : nsISupports
+{
+   /**
+     * Called when one of the following conditions are changed.
+     * 1. System proxy settings changed.
+     * 2. A proxy filter is registered or unregistered.
+     * 3. Proxy related prefs changed.
+     */
+  void onProxyConfigChanged();
+};
+
+/**
+ * nsIProtocolProxyService provides methods to access information about
+ * various network proxies.
+ */
+[scriptable, builtinclass, uuid(ef57c8b6-e09d-4cd4-9222-2a5d2402e15d)]
+interface nsIProtocolProxyService : nsISupports
+{
+    /** Flag 1 << 0 is unused **/
+
+    /**
+     * When the proxy configuration is manual this flag may be passed to the
+     * resolve and asyncResolve methods to request to prefer the SOCKS proxy
+     * to HTTP ones.
+     */
+    const unsigned long RESOLVE_PREFER_SOCKS_PROXY = 1 << 1;
+
+    /**
+     * When the proxy configuration is manual this flag may be passed to the
+     * resolve and asyncResolve methods to request to not analyze the uri's
+     * scheme specific proxy. When this flag is set the main HTTP proxy is the
+     * preferred one.
+     *
+     * NOTE: if RESOLVE_PREFER_SOCKS_PROXY is set then the SOCKS proxy is
+     *       the preferred one.
+     *
+     * NOTE: if RESOLVE_PREFER_HTTPS_PROXY is set then the HTTPS proxy
+     *       is the preferred one.
+     */
+    const unsigned long RESOLVE_IGNORE_URI_SCHEME = 1 << 2;
+
+    /**
+     * When the proxy configuration is manual this flag may be passed to the
+     * resolve and asyncResolve methods to request to prefer the HTTPS proxy
+     * to the others HTTP ones.
+     *
+     * NOTE: RESOLVE_PREFER_SOCKS_PROXY takes precedence over this flag.
+     *
+     * NOTE: This flag implies RESOLVE_IGNORE_URI_SCHEME.
+     */
+    const unsigned long RESOLVE_PREFER_HTTPS_PROXY =
+        (1 << 3) | RESOLVE_IGNORE_URI_SCHEME;
+
+    /**
+     * When the proxy configuration is manual this flag may be passed to the
+     * resolve and asyncResolve methods to that all methods will be tunneled via
+     * CONNECT through the http proxy.
+     */
+    const unsigned long RESOLVE_ALWAYS_TUNNEL = (1 << 4);
+
+    /**
+     * This method returns via callback a nsIProxyInfo instance that identifies
+     * a proxy to be used for the given channel.  Otherwise, this method returns
+     * null indicating that a direct connection should be used.
+     *
+     * @param aChannelOrURI
+     *        The channel for which a proxy is to be found, or, if no channel is
+     *        available, a URI indicating the same. This method will return
+     *        NS_ERROR_NOINTERFACE if this argument isn't either an nsIURI or an
+     *        nsIChannel.
+     * @param aFlags
+     *        A bit-wise combination of the RESOLVE_ flags defined above.  Pass
+     *        0 to specify the default behavior.  Any additional bits that do
+     *        not correspond to a RESOLVE_ flag are reserved for future use.
+     * @param aCallback
+     *        The object to be notified when the result is available.
+     * @param aMainThreadTarget
+     *        A labelled event target for dispatching runnables to main thread.
+     *
+     * @return An object that can be used to cancel the asychronous operation.
+     *         If canceled, the cancelation status (aReason) will be forwarded
+     *         to the callback's onProxyAvailable method via the aStatus param.
+     *
+     * NOTE: If this proxy is unavailable, getFailoverForProxy may be called
+     * to determine the correct secondary proxy to be used.
+     *
+     * NOTE: If the protocol handler for the given URI supports
+     * nsIProxiedProtocolHandler, then the nsIProxyInfo instance returned from
+     * resolve may be passed to the newProxiedChannel method to create a
+     * nsIChannel to the given URI that uses the specified proxy.
+     *
+     * NOTE: However, if the nsIProxyInfo type is "http", then it means that
+     * the given URI should be loaded using the HTTP protocol handler, which
+     * also supports nsIProxiedProtocolHandler.
+     *
+     * @see nsIProxiedProtocolHandler::newProxiedChannel
+     */
+    nsICancelable asyncResolve(
+        in nsISupports aChannelOrURI, in unsigned long aFlags,
+        in nsIProtocolProxyCallback aCallback,
+        [optional] in nsISerialEventTarget aMainThreadTarget);
+
+    /**
+     * This method may be called to construct a nsIProxyInfo instance from
+     * the given parameters.  This method may be useful in conjunction with
+     * nsISocketTransportService::createTransport for creating, for example,
+     * a SOCKS connection.
+     *
+     * @param aType
+     *        The proxy type.  This is a string value that identifies the proxy
+     *        type.  Standard values include:
+     *          "http"    - specifies a HTTP proxy
+     *          "https"   - specifies HTTP proxying over TLS connection to proxy
+     *          "socks"   - specifies a SOCKS version 5 proxy
+     *          "socks4"  - specifies a SOCKS version 4 proxy
+     *          "direct"  - specifies a direct connection (useful for failover)
+     *        The type name is case-insensitive.  Other string values may be
+     *        possible, and new types may be defined by a future version of
+     *        this interface.
+     * @param aHost
+     *        The proxy hostname or IP address.
+     * @param aPort
+     *        The proxy port.
+     * @param aFlags
+     *        Flags associated with this connection.  See nsIProxyInfo.idl
+     *        for currently defined flags.
+     * @param aFailoverTimeout
+     *        Specifies the length of time (in seconds) to ignore this proxy if
+     *        this proxy fails.  Pass UINT32_MAX to specify the default
+     *        timeout value, causing nsIProxyInfo::failoverTimeout to be
+     *        assigned the default value.
+     * @param aFailoverProxy
+     *        Specifies the next proxy to try if this proxy fails.  This
+     *        parameter may be null.
+     */
+    nsIProxyInfo newProxyInfo(in ACString aType, in AUTF8String aHost,
+                              in long aPort,
+                              in ACString aProxyAuthorizationHeader,
+                              in ACString aConnectionIsolationKey,
+                              in unsigned long aFlags,
+                              in unsigned long aFailoverTimeout,
+                              in nsIProxyInfo aFailoverProxy);
+
+    /**
+     * This method may be called to construct a nsIProxyInfo instance for
+     * with the specified username and password.
+     * Currently implemented for SOCKS proxies only.
+     * @param aType
+     *        The proxy type.  This is a string value that identifies the proxy
+     *        type.  Standard values include:
+     *          "socks"   - specifies a SOCKS version 5 proxy
+     *          "socks4"  - specifies a SOCKS version 4 proxy
+     *        The type name is case-insensitive.  Other string values may be
+     *        possible, and new types may be defined by a future version of
+     *        this interface.
+     * @param aHost
+     *        The proxy hostname or IP address.
+     * @param aPort
+     *        The proxy port.
+     * @param aUsername
+     *        The proxy username
+     * @param aPassword
+     *        The proxy password
+     * @param aFlags
+     *        Flags associated with this connection.  See nsIProxyInfo.idl
+     *        for currently defined flags.
+     * @param aFailoverTimeout
+     *        Specifies the length of time (in seconds) to ignore this proxy if
+     *        this proxy fails.  Pass UINT32_MAX to specify the default
+     *        timeout value, causing nsIProxyInfo::failoverTimeout to be
+     *        assigned the default value.
+     * @param aFailoverProxy
+     *        Specifies the next proxy to try if this proxy fails.  This
+     *        parameter may be null.
+     */
+    nsIProxyInfo newProxyInfoWithAuth(in ACString aType, in AUTF8String aHost,
+                                      in long aPort,
+                                      in ACString aUsername, in ACString aPassword,
+                                      in ACString aProxyAuthorizationHeader,
+                                      in ACString aConnectionIsolationKey,
+                                      in unsigned long aFlags,
+                                      in unsigned long aFailoverTimeout,
+                                      in nsIProxyInfo aFailoverProxy);
+
+    /**
+     * If the proxy identified by aProxyInfo is unavailable for some reason,
+     * this method may be called to access an alternate proxy that may be used
+     * instead.  As a side-effect, this method may affect future result values
+     * from resolve/asyncResolve as well as from getFailoverForProxy.
+     *
+     * @param aProxyInfo
+     *        The proxy that was unavailable.
+     * @param aURI
+     *        The URI that was originally passed to resolve/asyncResolve.
+     * @param aReason
+     *        The error code corresponding to the proxy failure.  This value
+     *        may be used to tune the delay before this proxy is used again.
+     *
+     * @throw NS_ERROR_NOT_AVAILABLE if there is no alternate proxy available.
+     */
+    nsIProxyInfo getFailoverForProxy(in nsIProxyInfo aProxyInfo,
+                                     in nsIURI       aURI,
+                                     in nsresult     aReason);
+
+    /**
+     * This method may be used to register a proxy filter instance.  Each proxy
+     * filter is registered with an associated position that determines the
+     * order in which the filters are applied (starting from position 0).  When
+     * resolve/asyncResolve is called, it generates a list of proxies for the
+     * given URI, and then it applies the proxy filters.  The filters have the
+     * opportunity to modify the list of proxies.
+     *
+     * If two filters register for the same position, then the filters will be
+     * visited in the order in which they were registered.
+     *
+     * If the filter is already registered, then its position will be updated.
+     *
+     * After filters have been run, any disabled or disallowed proxies will be
+     * removed from the list.  A proxy is disabled if it had previously failed-
+     * over to another proxy (see getFailoverForProxy).  A proxy is disallowed,
+     * for example, if it is a HTTP proxy and the nsIProtocolHandler for the
+     * queried URI does not permit proxying via HTTP.
+     *
+     * If a nsIProtocolHandler disallows all proxying, then filters will never
+     * have a chance to intercept proxy requests for such URLs.
+     *
+     * @param aFilter
+     *        The nsIProtocolProxyFilter instance to be registered.
+     * @param aPosition
+     *        The position of the filter.
+     *
+     * NOTE: It is possible to construct filters that compete with one another
+     * in undesirable ways.  This API does not attempt to protect against such
+     * problems.  It is recommended that any extensions that choose to call
+     * this method make their position value configurable at runtime (perhaps
+     * via the preferences service).
+     */
+    void registerFilter(in nsIProtocolProxyFilter aFilter,
+                        in unsigned long aPosition);
+
+    /**
+     * Similar to registerFilter, but accepts an nsIProtocolProxyChannelFilter,
+     * which selects proxies according to channel rather than URI.
+     *
+     * @param aFilter
+     *        The nsIProtocolProxyChannelFilter instance to be registered.
+     * @param aPosition
+     *        The position of the filter.
+     */
+    void registerChannelFilter(in nsIProtocolProxyChannelFilter aFilter,
+                               in unsigned long aPosition);
+
+    /**
+     * This method may be used to unregister a proxy filter instance.  All
+     * filters will be automatically unregistered at XPCOM shutdown.
+     *
+     * @param aFilter
+     *        The nsIProtocolProxyFilter instance to be unregistered.
+     */
+    void unregisterFilter(in nsIProtocolProxyFilter aFilter);
+
+    /**
+     * This method may be used to unregister a proxy channel filter instance.  All
+     * filters will be automatically unregistered at XPCOM shutdown.
+     *
+     * @param aFilter
+     *        The nsIProtocolProxyChannelFilter instance to be unregistered.
+     */
+    void unregisterChannelFilter(in nsIProtocolProxyChannelFilter aFilter);
+
+    /**
+     * This method is used to register a nsIProxyConfigChangedCallback.
+     *
+     * @param aCallback
+     *        The aCallback instance to be registered.
+     */
+    void addProxyConfigCallback(in nsIProxyConfigChangedCallback aCallback);
+
+    /**
+     * This method is used to unregister a nsIProxyConfigChangedCallback.
+     *
+     * @param aCallback
+     *        The aCallback instance to be unregistered.
+     */
+    void removeProxyConfigCallback(in nsIProxyConfigChangedCallback aCallback);
+
+
+    /**
+     * This method is used internal only. Called when proxy config is changed.
+     */
+    void notifyProxyConfigChangedInternal();
+
+     /**
+      * These values correspond to the possible integer values for the
+      * network.proxy.type preference.
+      */
+     const unsigned long PROXYCONFIG_DIRECT   = 0;
+     const unsigned long PROXYCONFIG_MANUAL   = 1;
+     const unsigned long PROXYCONFIG_PAC      = 2;
+     const unsigned long PROXYCONFIG_WPAD     = 4;
+     const unsigned long PROXYCONFIG_SYSTEM   = 5;
+
+     /**
+      * This attribute specifies the current type of proxy configuration.
+      */
+     readonly attribute unsigned long proxyConfigType;
+
+     /**
+      * True if there is a PAC download in progress.
+      */
+    [notxpcom, nostdcall] readonly attribute boolean isPACLoading;
+};
diff --git a/netwerk/base/nsIProtocolProxyService2.idl b/netwerk/base/nsIProtocolProxyService2.idl
new file mode 100644
index 0000000000..fe031bac40
--- /dev/null
+++ b/netwerk/base/nsIProtocolProxyService2.idl
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIProtocolProxyService.idl"
+
+/**
+ * An extension of nsIProtocolProxyService
+ */
+[scriptable, builtinclass, uuid(b2e5b2c0-e21e-4845-b336-be6d60a38951)]
+interface nsIProtocolProxyService2 : nsIProtocolProxyService
+{
+  /**
+   * Call this method to cause the PAC file (if any is configured) to be
+   * reloaded.  The PAC file is loaded asynchronously.
+   */
+  void reloadPAC();
+
+    /**
+     * This method is identical to asyncResolve() except:
+     *  - it only accepts an nsIChannel, not an nsIURI;
+     *  - it may execute the callback function immediately (i.e from the stack
+     *    of asyncResolve2()) if it is immediately ready to run.
+     *    The nsICancelable return value will be null in that case.
+     */
+  nsICancelable asyncResolve2(
+      in nsIChannel aChannel, in unsigned long aFlags,
+      in nsIProtocolProxyCallback aCallback,
+      [optional] in nsISerialEventTarget aMainThreadTarget);
+};
diff --git a/netwerk/base/nsIProxiedChannel.idl b/netwerk/base/nsIProxiedChannel.idl
new file mode 100644
index 0000000000..c6796b9f9d
--- /dev/null
+++ b/netwerk/base/nsIProxiedChannel.idl
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIProxyInfo;
+
+/**
+ * An interface for accessing the proxy info that a channel was
+ * constructed with.
+ *
+ * @see nsIProxiedProtocolHandler
+ */
+[scriptable, uuid(6238f134-8c3f-4354-958f-dfd9d54a4446)]
+interface nsIProxiedChannel : nsISupports
+{
+  /**
+   * Gets the proxy info the channel was constructed with. null or a
+   * proxyInfo with type "direct" mean no proxy.
+   *
+   * The returned proxy info must not be modified.
+   */
+  readonly attribute nsIProxyInfo proxyInfo;
+
+  /**
+   * The HTTP response code returned from the proxy to the CONNECT method.
+   * The response code is only available when we get the response from
+   * the proxy server, so this value is known in and after OnStartRequest.
+   *
+   * If CONNECT method is not used, httpProxyConnectResponseCode is always -1.
+   * After OnStartRequest, httpProxyConnectResponseCode is the real HTTP
+   * response code or 0 if we can't reach to the proxy.
+   */
+  readonly attribute int32_t httpProxyConnectResponseCode;
+};
diff --git a/netwerk/base/nsIProxiedProtocolHandler.idl b/netwerk/base/nsIProxiedProtocolHandler.idl
new file mode 100644
index 0000000000..d9436e94a7
--- /dev/null
+++ b/netwerk/base/nsIProxiedProtocolHandler.idl
@@ -0,0 +1,36 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIProtocolHandler.idl"
+
+interface nsIChannel;
+interface nsIURI;
+interface nsIProxyInfo;
+interface nsILoadInfo;
+
+[scriptable, builtinclass, uuid(3756047a-fa2b-4b45-9948-3b5f8fc375e7)]
+interface nsIProxiedProtocolHandler : nsIProtocolHandler
+{
+    /** Create a new channel with the given proxyInfo
+     *
+     * @param uri the channel uri
+     * @param proxyInfo any proxy information that has already been determined,
+     *        or null if channel should later determine the proxy on its own using
+     *        proxyResolveFlags/proxyURI
+     * @param proxyResolveFlags used if the proxy is later determined
+     *        from nsIProtocolProxyService::asyncResolve
+     * @param proxyURI used if the proxy is later determined from
+     *        nsIProtocolProxyService::asyncResolve with this as the proxyURI name.
+     *        Generally this is the same as uri (or null which has the same
+     *        effect), except in the case of websockets which wants to bootstrap
+     *        to an http:// channel but make its proxy determination based on
+     *        a ws:// uri.
+     * @param aLoadInfo used to evaluate who initated the resource request.
+     */
+    nsIChannel newProxiedChannel(in nsIURI uri, in nsIProxyInfo proxyInfo,
+                                 in unsigned long proxyResolveFlags,
+                                 in nsIURI proxyURI,
+                                 in nsILoadInfo aLoadInfo);
+};
diff --git a/netwerk/base/nsIProxyInfo.idl b/netwerk/base/nsIProxyInfo.idl
new file mode 100644
index 0000000000..dc762fbd2d
--- /dev/null
+++ b/netwerk/base/nsIProxyInfo.idl
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface identifies a proxy server.
+ */
+[scriptable, uuid(63fff172-2564-4138-96c6-3ae7d245fbed)]
+interface nsIProxyInfo : nsISupports
+{
+  /**
+   * This attribute specifies the hostname of the proxy server.
+   */
+  readonly attribute AUTF8String host;
+
+  /**
+   * This attribute specifies the port number of the proxy server.
+   */
+  readonly attribute long port;
+
+  /**
+   * This attribute specifies the type of the proxy server as an ASCII string.
+   *
+   * Some special values for this attribute include (but are not limited to)
+   * the following:
+   *   "http"     HTTP proxy (or SSL CONNECT for HTTPS)
+   *   "https"    HTTP proxying over TLS connection to proxy
+   *   "socks"    SOCKS v5 proxy
+   *   "socks4"   SOCKS v4 proxy
+   *   "direct"   no proxy
+   *   "unknown"  unknown proxy (see nsIProtocolProxyService::resolve)
+   *
+   * A future version of this interface may define additional types.
+   */
+  readonly attribute ACString type;
+
+  /**
+   * This attribute specifies flags that modify the proxy type.  The value of
+   * this attribute is the bit-wise combination of the Proxy Flags defined
+   * below.  Any undefined bits are reserved for future use.
+   */
+  readonly attribute unsigned long flags;
+
+  /**
+   * This attribute specifies flags that were used by nsIProxyProtocolService when
+   * creating this ProxyInfo element.
+   */
+  readonly attribute unsigned long resolveFlags;
+
+  /**
+   * Specifies a proxy username.
+   */
+  readonly attribute ACString username;
+
+  /**
+   * Specifies a proxy password.
+   */
+  readonly attribute ACString password;
+
+  /**
+   * This attribute specifies the failover timeout in seconds for this proxy.
+   * If a nsIProxyInfo is reported as failed via nsIProtocolProxyService::
+   * getFailoverForProxy, then the failed proxy will not be used again for this
+   * many seconds.
+   */
+  readonly attribute unsigned long failoverTimeout;
+
+  /**
+   * This attribute specifies the proxy to failover to when this proxy fails.
+   */
+  attribute nsIProxyInfo failoverProxy;
+
+  /**
+   * Specifies an ID related to the source of this proxy configuration.  If
+   * it is created in response to an extension API, it will be the extension ID.
+   */
+  attribute ACString sourceId;
+
+  /**
+   * Any non-empty value will be passed directly as Proxy-Authorization header
+   * value for the CONNECT request attempt.  However, this header set on the
+   * resource request itself takes precedence.
+   */
+  readonly attribute ACString proxyAuthorizationHeader;
+
+  /**
+   * An optional key used for additional isolation of this proxy connection.
+   */
+  readonly attribute ACString connectionIsolationKey;
+
+  /****************************************************************************
+   * The following "Proxy Flags" may be bit-wise combined to construct the
+   * flags attribute defined on this interface.  All unspecified bits are
+   * reserved for future use.
+   */
+
+  /**
+   * This flag is set if the proxy is to perform name resolution itself.  If
+   * this is the case, the hostname is used in some fashion, and we shouldn't
+   * do any form of DNS lookup ourselves.
+   */
+  const unsigned short TRANSPARENT_PROXY_RESOLVES_HOST = 1 << 0;
+};
diff --git a/netwerk/base/nsIRandomGenerator.idl b/netwerk/base/nsIRandomGenerator.idl
new file mode 100644
index 0000000000..29ee25bbe1
--- /dev/null
+++ b/netwerk/base/nsIRandomGenerator.idl
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * Interface used to generate random data.
+ *
+ * @threadsafe
+ */
+[scriptable, uuid(2362d97a-747a-4576-8863-697667309209)]
+interface nsIRandomGenerator : nsISupports {
+  /**
+   * Generates the specified amount of random bytes.
+   *
+   * @param aLength
+   *        The length of the data to generate.
+   * @param aBuffer
+   *        A buffer that contains random bytes of size aLength.
+   */
+  void generateRandomBytes(in unsigned long aLength,
+                           [retval, array, size_is(aLength)] out octet aBuffer);
+};
diff --git a/netwerk/base/nsIRedirectChannelRegistrar.idl b/netwerk/base/nsIRedirectChannelRegistrar.idl
new file mode 100644
index 0000000000..26dfdf3c6f
--- /dev/null
+++ b/netwerk/base/nsIRedirectChannelRegistrar.idl
@@ -0,0 +1,71 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+interface nsIParentChannel;
+
+/**
+ * Used on the chrome process as a service to join channel implementation
+ * and parent IPC protocol side under a unique id.  Provides this way a generic
+ * communication while redirecting to various protocols.
+ *
+ * See also nsIChildChannel and nsIParentChannel.
+ */
+
+[scriptable, uuid (efa36ea2-5b07-46fc-9534-a5acb8b77b72)]
+interface nsIRedirectChannelRegistrar : nsISupports
+{
+  /**
+   * Register the redirect target channel. The passed id needs to be a
+   * unique ID for that channel (see `nsContentUtils::GenerateLoadIdentifier`).
+   *
+   * Primarily used in ParentChannelListener::AsyncOnChannelRedirect to get
+   * a channel id sent to the HttpChannelChild being redirected.
+   */
+  void registerChannel(in nsIChannel channel, in uint64_t id);
+
+  /**
+   * First, search for the channel registered under the id.  If found return
+   * it.  Then, register under the same id the parent side of IPC protocol
+   * to let it be later grabbed back by the originator of the redirect and
+   * notifications from the real channel could be forwarded to this parent
+   * channel.
+   *
+   * Primarily used in parent side of an IPC protocol implementation
+   * in reaction to nsIChildChannel.connectParent(id) called from the child
+   * process.
+   */
+  nsIChannel linkChannels(in uint64_t id, in nsIParentChannel channel);
+
+  /**
+   * Returns back the channel previously registered under the ID with
+   * registerChannel method.
+   *
+   * Primarilly used in chrome IPC side of protocols when attaching a redirect
+   * target channel to an existing 'real' channel implementation.
+   */
+  nsIChannel getRegisteredChannel(in uint64_t id);
+
+  /**
+   * Returns the stream listener that shall be attached to the redirect target
+   * channel, all notification from the redirect target channel will be
+   * forwarded to this stream listener.
+   *
+   * Primarilly used in HttpChannelParent::OnRedirectResult callback to grab
+   * the created parent side of the channel and forward notifications to it.
+   */
+  nsIParentChannel getParentChannel(in uint64_t id);
+
+  /**
+   * To not force all channel implementations to support weak reference
+   * consumers of this service must ensure release of registered channels them
+   * self.  This releases both the real and parent channel registered under
+   * the id.
+   *
+   * Primarilly used in HttpChannelParent::OnRedirectResult callback.
+   */
+  void deregisterChannels(in uint64_t id);
+};
diff --git a/netwerk/base/nsIRedirectHistoryEntry.idl b/netwerk/base/nsIRedirectHistoryEntry.idl
new file mode 100644
index 0000000000..50086574f8
--- /dev/null
+++ b/netwerk/base/nsIRedirectHistoryEntry.idl
@@ -0,0 +1,34 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIPrincipal;
+interface nsIURI;
+
+/**
+ * This nsIRedirectHistoryEntry defines an interface for specifying channel
+ * redirect information
+ */
+
+[scriptable, uuid(133b2905-0eba-411c-a8bb-f59787142aa2)]
+interface nsIRedirectHistoryEntry : nsISupports
+{
+  /**
+   * The principal of this redirect entry
+   */
+  readonly attribute nsIPrincipal principal;
+
+  /**
+   * The referring URI of this redirect entry.  This may be null.
+   */
+  readonly attribute nsIURI referrerURI;
+
+  /**
+   * The remote address of this redirect entry.
+   */
+  readonly attribute ACString remoteAddress;
+
+};
diff --git a/netwerk/base/nsIRedirectResultListener.idl b/netwerk/base/nsIRedirectResultListener.idl
new file mode 100644
index 0000000000..57241350a4
--- /dev/null
+++ b/netwerk/base/nsIRedirectResultListener.idl
@@ -0,0 +1,22 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(85cd2640-e91e-41ac-bdca-1dbf10dc131e)]
+interface nsIRedirectResultListener : nsISupports
+{
+  /**
+   *  When an HTTP redirect has been processed (either successfully or not)
+   *  nsIHttpChannel will call this function if its callbacks implement this
+   *  interface.
+   *
+   *  @param proceeding
+   *         Indicated whether the redirect will be proceeding, or not (i.e.
+   *         has been canceled, or failed).
+   */
+  void onRedirectResult(in nsresult status);
+};
diff --git a/netwerk/base/nsIRequest.idl b/netwerk/base/nsIRequest.idl
new file mode 100644
index 0000000000..84b168dc60
--- /dev/null
+++ b/netwerk/base/nsIRequest.idl
@@ -0,0 +1,341 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{ C++
+#include "nsString.h"
+%}
+
+interface nsILoadGroup;
+
+typedef unsigned long nsLoadFlags;
+
+/**
+ * nsIRequest
+ */
+[scriptable, uuid(ef6bfbd2-fd46-48d8-96b7-9f8f0fd387fe)]
+interface nsIRequest : nsISupports
+{
+    /**
+     * The name of the request.  Often this is the URI of the request.
+     */
+    readonly attribute AUTF8String name;
+
+    /**
+     * Indicates whether the request is pending. nsIRequest::isPending is
+     * true when there is an outstanding asynchronous event that will make
+     * the request no longer be pending.  Requests do not necessarily start
+     * out pending; in some cases, requests have to be explicitly initiated
+     * (e.g. nsIChannel implementations are only pending once asyncOpen
+     * returns successfully).
+     *
+     * Requests can become pending multiple times during their lifetime.
+     *
+     * @return TRUE if the request has yet to reach completion.
+     * @return FALSE if the request has reached completion (e.g., after
+     *   OnStopRequest has fired).
+     * @note Suspended requests are still considered pending.
+     */
+    boolean isPending();
+
+    /**
+     * The error status associated with the request.
+     */
+    readonly attribute nsresult status;
+
+    /**
+     * Cancels the current request.  This will close any open input or
+     * output streams and terminate any async requests.  Users should
+     * normally pass NS_BINDING_ABORTED, although other errors may also
+     * be passed.  The error passed in will become the value of the
+     * status attribute.
+     *
+     * Implementations must not send any notifications (e.g. via
+     * nsIRequestObserver) synchronously from this function. Similarly,
+     * removal from the load group (if any) must also happen asynchronously.
+     *
+     * Requests that use nsIStreamListener must not call onDataAvailable
+     * anymore after cancel has been called.
+     *
+     * @param aStatus the reason for canceling this request.
+     *
+     * NOTE: most nsIRequest implementations expect aStatus to be a
+     * failure code; however, some implementations may allow aStatus to
+     * be a success code such as NS_OK.  In general, aStatus should be
+     * a failure code.
+     */
+    void cancel(in nsresult aStatus);
+
+    /**
+     * Suspends the current request.  This may have the effect of closing
+     * any underlying transport (in order to free up resources), although
+     * any open streams remain logically opened and will continue delivering
+     * data when the transport is resumed.
+     *
+     * Calling cancel() on a suspended request must not send any
+     * notifications (such as onstopRequest) until the request is resumed.
+     *
+     * NOTE: some implementations are unable to immediately suspend, and
+     * may continue to deliver events already posted to an event queue. In
+     * general, callers should be capable of handling events even after
+     * suspending a request.
+     */
+    void suspend();
+
+    /**
+     * Resumes the current request.  This may have the effect of re-opening
+     * any underlying transport and will resume the delivery of data to
+     * any open streams.
+     */
+    void resume();
+
+    /**
+     * The load group of this request.  While pending, the request is a
+     * member of the load group.  It is the responsibility of the request
+     * to implement this policy.
+     */
+    attribute nsILoadGroup loadGroup;
+
+    /**
+     * The load flags of this request.  Bits 0-15 are reserved.
+     *
+     * When added to a load group, this request's load flags are merged with
+     * the load flags of the load group.
+     */
+    attribute nsLoadFlags loadFlags;
+
+    /**
+     * Mask defining the bits reserved for nsIRequest LoadFlags
+     */
+    const unsigned long LOAD_REQUESTMASK = 0xFFFF;
+
+    /**************************************************************************
+     * Listed below are the various load flags which may be or'd together.
+     */
+
+    /**
+     * No special load flags:
+     */
+    const unsigned long LOAD_NORMAL = 0;
+
+    /**
+     * Do not deliver status notifications to the nsIProgressEventSink and
+     * do not block the loadgroup from completing (should this load belong to one).
+     * Note: Progress notifications will still be delivered.
+     */
+    const unsigned long LOAD_BACKGROUND = 1 << 0;
+
+    /**
+     * This flag marks the request as being made to load the data for an html
+     * <object> tag. This means that the LOAD_DOCUMENT_URI flag may be set after
+     * the channel has been provided with the MIME type.
+     */
+    const unsigned long LOAD_HTML_OBJECT_DATA = 1 << 1;
+
+    /**
+     * This flag marks the request as belonging to a document that requires access
+     * to the document.cookies API.
+     */
+    const unsigned long LOAD_DOCUMENT_NEEDS_COOKIE = 1 << 2;
+
+    cenum TRRMode : 32 {
+        TRR_DEFAULT_MODE = 0,
+        TRR_DISABLED_MODE = 1,
+        TRR_FIRST_MODE = 2,
+        TRR_ONLY_MODE = 3
+    };
+
+    /**
+     * These methods encode/decode the TRR mode to/from the loadFlags.
+     * Helper methods Get/SetTRRModeImpl are provided so implementations don't
+     * need to duplicate code.
+     *
+     * Requests with TRR_DEFAULT_MODE will use the mode indicated by the pref
+     *   - see network.trr.mode in all.js
+     * Requests with TRR_DISABLED_MODE will always use native DNS, even if the
+     *   pref is set to mode3 (TRR-only).
+     * Requests with TRR_FIRST_MODE will first use TRR then fallback to regular
+     *   DNS, unless TRR is disabled by setting the pref to mode5, parental
+     *   control being enabled, or the domain being in the exclusion list.
+     * Requests with TRR_ONLY_MODE will only use TRR, unless not allowed by
+     *   the same conditions mentioned above.
+     */
+    nsIRequest_TRRMode getTRRMode();
+    void setTRRMode(in nsIRequest_TRRMode mode);
+
+    %{C++
+        inline TRRMode GetTRRMode() {
+            TRRMode mode = TRR_DEFAULT_MODE;
+            GetTRRMode(&mode);
+            return mode;
+        }
+
+        inline nsresult GetTRRModeImpl(nsIRequest::TRRMode* aTRRMode) {
+          NS_ENSURE_ARG_POINTER(aTRRMode);
+          nsLoadFlags flags = nsIRequest::LOAD_NORMAL;
+          nsresult rv = GetLoadFlags(&flags);
+          if (NS_FAILED(rv)) {
+            return rv;
+          }
+          *aTRRMode = static_cast<nsIRequest::TRRMode>(
+              (flags & nsIRequest::LOAD_TRR_MASK) >> 3);
+          return NS_OK;
+        }
+
+        inline nsresult SetTRRModeImpl(nsIRequest::TRRMode aTRRMode) {
+          MOZ_ASSERT(aTRRMode <= 3, "invalid value");
+          nsLoadFlags flags = nsIRequest::LOAD_NORMAL;
+          nsresult rv = GetLoadFlags(&flags);
+          if (NS_FAILED(rv)) {
+            return rv;
+          }
+          flags = (flags & ~nsIRequest::LOAD_TRR_MASK) | (aTRRMode << 3);
+          return SetLoadFlags(flags);
+        }
+    %}
+
+    /**
+     * These two bits encode the TRR mode.
+     * Do not get/set manually, rather use the getTRRMode/setTRRMode methods.
+     */
+    const unsigned long LOAD_TRR_MASK = (1 << 3) | (1 << 4);
+    const unsigned long LOAD_TRR_DISABLED_MODE = 1 << 3;
+    const unsigned long LOAD_TRR_FIRST_MODE = 1 << 4;
+    const unsigned long LOAD_TRR_ONLY_MODE = (1 << 3) | (1 << 4);
+
+    void cancelWithReason(in nsresult aStatus, in ACString aReason);
+    attribute ACString canceledReason;
+
+    %{C++
+      protected:
+        nsCString mCanceledReason;
+
+      public:
+        inline nsresult SetCanceledReasonImpl(const nsACString& aReason) {
+          if (mCanceledReason.IsEmpty()) {
+            mCanceledReason.Assign(aReason);
+          }
+
+          return NS_OK;
+        }
+
+        inline nsresult CancelWithReasonImpl(nsresult aStatus,
+                                             const nsACString& aReason) {
+          SetCanceledReasonImpl(aReason);
+          return Cancel(aStatus);
+        }
+
+        inline nsresult GetCanceledReasonImpl(nsACString& aReason) {
+          aReason.Assign(mCanceledReason);
+          return NS_OK;
+        }
+    %}
+
+    /**
+     * This is used for a temporary workaround for a web-compat issue. The flag is
+     * only set on CORS preflight request to allowed sending client certificates
+     * on a connection for an anonymous request.
+     */
+    const long LOAD_ANONYMOUS_ALLOW_CLIENT_CERT = 1 << 5;
+
+    /**
+     * Record HTTP_PRELOAD_IMAGE_STARTREQUEST_DELAY telemetry for the delay between
+     * sending OnStartRequest from the socket thread to it being processed by the
+     * main thread.
+     * This is temporary while we collect telemetry around the value of
+     * handling OnStartRequest off the main thread.
+     */
+    const long LOAD_RECORD_START_REQUEST_DELAY = 1 << 6;
+
+    /**************************************************************************
+     * The following flags control the flow of data into the cache.
+     */
+
+    /**
+     * This flag prevents caching of any kind.  It does not, however, prevent
+     * cached content from being used to satisfy this request.
+     */
+    const unsigned long INHIBIT_CACHING = 1 << 7;
+
+    /**
+     * This flag prevents caching on disk (or other persistent media), which
+     * may be needed to preserve privacy.
+     */
+    const unsigned long INHIBIT_PERSISTENT_CACHING = 1 << 8;
+
+    /**************************************************************************
+     * The following flags control what happens when the cache contains data
+     * that could perhaps satisfy this request.  They are listed in descending
+     * order of precidence.
+     */
+
+    /**
+     * Force an end-to-end download of content data from the origin server.
+     * This flag is used for a shift-reload.
+     */
+    const unsigned long LOAD_BYPASS_CACHE = 1 << 9;
+
+    /**
+     * Attempt to force a load from the cache, bypassing ALL validation logic
+     * (note: this is stronger than VALIDATE_NEVER, which still validates for
+     * certain conditions).
+     *
+     * If the resource is not present in cache, it will be loaded from the
+     * network.  Combine this flag with LOAD_ONLY_FROM_CACHE if you wish to
+     * perform cache-only loads without validation checks.
+     *
+     * This flag is used when browsing via history.  It is not recommended for
+     * normal browsing as it may likely violate reasonable assumptions made by
+     * the server and confuse users.
+     */
+    const unsigned long LOAD_FROM_CACHE   = 1 << 10;
+
+    /**
+     * The following flags control the frequency of cached content validation
+     * when neither LOAD_BYPASS_CACHE or LOAD_FROM_CACHE are set.  By default,
+     * cached content is automatically validated if necessary before reuse.
+     *
+     * VALIDATE_ALWAYS forces validation of any cached content independent of
+     * its expiration time (unless it is https with Cache-Control: immutable)
+     *
+     * VALIDATE_NEVER disables validation of cached content, unless it arrived
+     * with the "Cache: no-store" header, or arrived via HTTPS with the
+     * "Cache: no-cache" header.
+     *
+     * VALIDATE_ONCE_PER_SESSION disables validation of expired content,
+     * provided it has already been validated (at least once) since the start
+     * of this session.
+     *
+     * NOTE TO IMPLEMENTORS:
+     *   These flags are intended for normal browsing, and they should therefore
+     *   not apply to content that must be validated before each use.  Consider,
+     *   for example, a HTTP response with a "Cache-control: no-cache" header.
+     *   According to RFC2616, this response must be validated before it can
+     *   be taken from a cache.  Breaking this requirement could result in
+     *   incorrect and potentially undesirable side-effects.
+     */
+    const unsigned long VALIDATE_ALWAYS           = 1 << 11;
+    const unsigned long VALIDATE_NEVER            = 1 << 12;
+    const unsigned long VALIDATE_ONCE_PER_SESSION = 1 << 13;
+
+    /**
+     * When set, this flag indicates that no user-specific data should be added
+     * to the request when opened. This means that things like authorization
+     * tokens or cookie headers should not be added.
+     */
+    const unsigned long LOAD_ANONYMOUS = 1 << 14;
+
+    /**
+     * When set, this flag indicates that caches of network connections,
+     * particularly HTTP persistent connections, should not be used.
+     * Use this together with LOAD_INITIAL_DOCUMENT_URI as otherwise it has no
+     * effect.
+     */
+    const unsigned long LOAD_FRESH_CONNECTION = 1 << 15;
+
+    // Note that all flags are taken, the rest of the flags
+    // are located in nsIChannel and nsICachingChannel
+};
diff --git a/netwerk/base/nsIRequestContext.idl b/netwerk/base/nsIRequestContext.idl
new file mode 100644
index 0000000000..6c9f265af2
--- /dev/null
+++ b/netwerk/base/nsIRequestContext.idl
@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{C++
+// Forward-declare mozilla::net::SpdyPushCache
+namespace mozilla {
+namespace net {
+class SpdyPushCache;
+}
+}
+%}
+
+interface nsILoadGroup;
+interface nsIChannel;
+interface nsIStreamListener;
+
+[ptr] native SpdyPushCachePtr(mozilla::net::SpdyPushCache);
+
+/**
+ * Requests capable of tail-blocking must implement this
+ * interfaces (typically channels).
+ * If the request is tail-blocked, it will be held in its request
+ * context queue until unblocked.
+ */
+[uuid(7EB361D4-37A5-42C9-AFAE-F6C88FE7C394)]
+interface nsIRequestTailUnblockCallback : nsISupports
+{
+  /**
+   * Called when the requests is unblocked and proceed.
+   * @param result
+   *    NS_OK - the request is OK to go, unblocking is not
+   *            caused by cancelation of the request.
+   *    any error - the request must behave as it were canceled
+   *                with the result as status.
+   */
+  void onTailUnblock(in nsresult aResult);
+};
+
+/**
+ * The nsIRequestContext is used to maintain state about connections
+ * that are in some way associated with each other (often by being part
+ * of the same load group) and how they interact with blocking items like
+ * HEAD css/js loads.
+ *
+ * This used to be known as nsILoadGroupConnectionInfo and nsISchedulingContext.
+ */
+[uuid(658e3e6e-8633-4b1a-8d66-fa9f72293e63)]
+interface nsIRequestContext : nsISupports
+{
+  /**
+   * A unique identifier for this request context
+   */
+  [notxpcom, nostdcall] readonly attribute unsigned long long ID;
+
+  /**
+   * Called by the associated document when its load starts.  This resets
+   * context's internal states.
+   */
+  void beginLoad();
+
+  /**
+  * Called when the associated document notified the DOMContentLoaded event.
+  */
+  void DOMContentLoaded();
+
+  /**
+   * Number of active blocking transactions associated with this context
+   */
+  readonly attribute unsigned long blockingTransactionCount;
+
+  /**
+   * Increase the number of active blocking transactions associated
+   * with this context by one.
+   */
+  void addBlockingTransaction();
+
+  /**
+   * Decrease the number of active blocking transactions associated
+   * with this context by one. The return value is the number of remaining
+   * blockers.
+   */
+  unsigned long removeBlockingTransaction();
+
+  /**
+   * This gives out a weak pointer to the push cache.
+   * The nsIRequestContext implementation owns the cache
+   * and will destroy it when overwritten or when the context
+   * ends.
+   */
+  [notxpcom,nostdcall] attribute SpdyPushCachePtr spdyPushCache;
+
+  /**
+   * Increases/decrease the number of non-tailed requests in this context.
+   * If the count drops to zero, all tail-blocked callbacks are notified
+   * shortly after that to be unblocked.
+   */
+  void addNonTailRequest();
+  void removeNonTailRequest();
+
+  /**
+   * If the request context is in tail-blocked state, the callback
+   * is queued and result is true.  The callback will be notified
+   * about tail-unblocking or when the request context is canceled.
+   */
+  [must_use] boolean isContextTailBlocked(in nsIRequestTailUnblockCallback callback);
+
+  /**
+   * Called when the request is sitting in the tail queue but has been
+   * canceled before untailing.  This just removes the request from the
+   * queue so that it is not notified on untail and not referenced.
+   */
+  void cancelTailedRequest(in nsIRequestTailUnblockCallback request);
+
+  /**
+   * This notifies all queued tail-blocked requests, they will be notified
+   * aResult and released afterwards.  Called by the load group when
+   * it's canceled.
+   */
+  void cancelTailPendingRequests(in nsresult aResult);
+};
+
+/**
+ * The nsIRequestContextService is how anyone gets access to a request
+ * context when they haven't been explicitly given a strong reference to an
+ * existing one. It is responsible for creating and handing out strong
+ * references to nsIRequestContexts, but only keeps weak references itself.
+ * The shared request context will go away once no one else is keeping a
+ * reference to it. If you ask for a request context that has no one else
+ * holding a reference to it, you'll get a brand new request context. Anyone
+ * who asks for the same request context while you're holding a reference
+ * will get a reference to the same request context you have.
+ */
+[uuid(7fcbf4da-d828-4acc-b144-e5435198f727)]
+interface nsIRequestContextService : nsISupports
+{
+  /**
+   * Get an existing request context from its ID
+   */
+  nsIRequestContext getRequestContext(in unsigned long long id);
+  /**
+   * Shorthand to get request context from a load group
+   */
+  nsIRequestContext getRequestContextFromLoadGroup(in nsILoadGroup lg);
+
+  /**
+   * Create a new request context
+   */
+  nsIRequestContext newRequestContext();
+
+  /**
+   * Remove an existing request context from its ID
+   */
+  void removeRequestContext(in unsigned long long id);
+};
diff --git a/netwerk/base/nsIRequestObserver.idl b/netwerk/base/nsIRequestObserver.idl
new file mode 100644
index 0000000000..772de50d32
--- /dev/null
+++ b/netwerk/base/nsIRequestObserver.idl
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIRequest;
+
+/**
+ * nsIRequestObserver
+ */
+[scriptable, uuid(fd91e2e0-1481-11d3-9333-00104ba0fd40)]
+interface nsIRequestObserver : nsISupports
+{
+    /**
+     * Called to signify the beginning of an asynchronous request.
+     *
+     * @param aRequest request being observed
+     *
+     * An exception thrown from onStartRequest has the side-effect of
+     * causing the request to be canceled.
+     */
+    void onStartRequest(in nsIRequest aRequest);
+
+    /**
+     * Called to signify the end of an asynchronous request.  This
+     * call is always preceded by a call to onStartRequest.
+     *
+     * @param aRequest request being observed
+     * @param aStatusCode reason for stopping (NS_OK if completed successfully)
+     *
+     * An exception thrown from onStopRequest is generally ignored.
+     */
+    void onStopRequest(in nsIRequest aRequest,
+                       in nsresult aStatusCode);
+};
diff --git a/netwerk/base/nsIRequestObserverProxy.idl b/netwerk/base/nsIRequestObserverProxy.idl
new file mode 100644
index 0000000000..7b79f53427
--- /dev/null
+++ b/netwerk/base/nsIRequestObserverProxy.idl
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequestObserver.idl"
+
+interface nsIEventTarget;
+
+/**
+ * A request observer proxy is used to ship data over to another thread
+ * specified by the thread's dispatch target. The "true" request observer's
+ * methods are invoked on the other thread.
+ *
+ * This interface only provides the initialization needed after construction.
+ * Otherwise, these objects are used simply as nsIRequestObserver's.
+ */
+[scriptable, uuid(c2b06151-1bf8-4eef-aea9-1532f12f5a10)]
+interface nsIRequestObserverProxy : nsIRequestObserver
+{
+    /**
+     * Initializes an nsIRequestObserverProxy.
+     *
+     * @param observer - receives observer notifications on the main thread
+     * @param context  - the context argument that will be passed to OnStopRequest
+     *                   and OnStartRequest. This has to be stored permanently on
+     *                   initialization because it sometimes can't be
+     *                   AddRef/Release'd off-main-thread.
+     */
+    void init(in nsIRequestObserver observer, in nsISupports context);
+};
diff --git a/netwerk/base/nsIResumableChannel.idl b/netwerk/base/nsIResumableChannel.idl
new file mode 100644
index 0000000000..6737e8bf9d
--- /dev/null
+++ b/netwerk/base/nsIResumableChannel.idl
@@ -0,0 +1,39 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIStreamListener;
+
+[scriptable, uuid(4ad136fa-83af-4a22-a76e-503642c0f4a8)]
+interface nsIResumableChannel : nsISupports {
+    /**
+     * Prepare this channel for resuming. The request will not start until
+     * asyncOpen or open is called. Calling resumeAt after open or asyncOpen
+     * has been called has undefined behaviour.
+     *
+     * @param startPos the starting offset, in bytes, to use to download
+     * @param entityID information about the file, to match before obtaining
+     *  the file. Pass an empty string to use anything.
+     *
+     * During OnStartRequest, this channel will have a status of
+     *  NS_ERROR_NOT_RESUMABLE if the file cannot be resumed, eg because the
+     *  server doesn't support this. This error may occur even if startPos
+     *  is 0, so that the front end can warn the user.
+     * Similarly, the status of this channel during OnStartRequest may be
+     *  NS_ERROR_ENTITY_CHANGED, which indicates that the entity has changed,
+     *  as indicated by a changed entityID.
+     * In both of these cases, no OnDataAvailable will be called, and
+     *  OnStopRequest will immediately follow with the same status code.
+     */
+    void resumeAt(in unsigned long long startPos,
+                  in ACString entityID);
+
+    /**
+     * The entity id for this URI. Available after OnStartRequest.
+     * @throw NS_ERROR_NOT_RESUMABLE if this load is not resumable.
+     */
+    readonly attribute ACString entityID;
+};
diff --git a/netwerk/base/nsISecCheckWrapChannel.idl b/netwerk/base/nsISecCheckWrapChannel.idl
new file mode 100644
index 0000000000..21f4d0c290
--- /dev/null
+++ b/netwerk/base/nsISecCheckWrapChannel.idl
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIChannel;
+
+/**
+ * nsISecCheckWrapChannel
+ * Describes an XPCOM component used to wrap channels for performing
+ * security checks. Channels wrapped inside this class can use
+ * this interface to query the wrapped inner channel.
+ */
+
+[scriptable, uuid(9446c5d5-c9fb-4a6e-acf9-ca4fc666efe0)]
+interface nsISecCheckWrapChannel : nsISupports
+{
+  /**
+   * Returns the wrapped channel inside this class.
+   */
+  readonly attribute nsIChannel innerChannel;
+
+};
diff --git a/netwerk/base/nsISecureBrowserUI.idl b/netwerk/base/nsISecureBrowserUI.idl
new file mode 100644
index 0000000000..3984310d93
--- /dev/null
+++ b/netwerk/base/nsISecureBrowserUI.idl
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsITransportSecurityInfo;
+
+[scriptable, builtinclass, uuid(718c662a-f810-4a80-a6c9-0b1810ecade2)]
+interface nsISecureBrowserUI : nsISupports
+{
+    readonly attribute unsigned long state;
+    readonly attribute bool isSecureContext;
+    readonly attribute nsITransportSecurityInfo secInfo;
+};
+
+%{C++
+#define NS_SECURE_BROWSER_UI_CONTRACTID "@mozilla.org/secure_browser_ui;1"
+%}
diff --git a/netwerk/base/nsISensitiveInfoHiddenURI.idl b/netwerk/base/nsISensitiveInfoHiddenURI.idl
new file mode 100644
index 0000000000..abb3f082b9
--- /dev/null
+++ b/netwerk/base/nsISensitiveInfoHiddenURI.idl
@@ -0,0 +1,17 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(a5761968-6e1a-4f2d-8191-ec749602b178)]
+interface nsISensitiveInfoHiddenURI : nsISupports
+{
+  /**
+   * Returns the spec attribute with sensitive information hidden. This will
+   * only affect uri with password. The password part of uri will be
+   * transformed into "****".
+   */
+   AUTF8String getSensitiveInfoHiddenSpec();
+};
diff --git a/netwerk/base/nsISerializationHelper.idl b/netwerk/base/nsISerializationHelper.idl
new file mode 100644
index 0000000000..740927f407
--- /dev/null
+++ b/netwerk/base/nsISerializationHelper.idl
@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * Simple scriptable serialization helper. Can be used as a service.
+ */
+
+interface nsISerializable;
+
+[scriptable, uuid(31654c0f-35f3-44c6-b31e-37a11516e6bc)]
+interface nsISerializationHelper : nsISupports
+{
+  /**
+   * Serialize the object to a base64 string. This string can be later passed
+   * as an input to deserializeObject method.
+   */
+  ACString serializeToString(in nsISerializable serializable);
+
+  /**
+   * Takes base64 encoded string that cointains serialization of a single
+   * object. Most commonly, input is result of previous call to
+   * serializeToString.
+   */
+  nsISupports deserializeObject(in ACString input);
+};
diff --git a/netwerk/base/nsIServerSocket.idl b/netwerk/base/nsIServerSocket.idl
new file mode 100644
index 0000000000..d6fd348778
--- /dev/null
+++ b/netwerk/base/nsIServerSocket.idl
@@ -0,0 +1,269 @@
+/* vim:set ts=4 sw=4 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIFile;
+interface nsIServerSocketListener;
+interface nsISocketTransport;
+
+native PRNetAddr(union PRNetAddr);
+[ptr] native PRNetAddrPtr(union PRNetAddr);
+
+typedef unsigned long nsServerSocketFlag;
+
+/**
+ * nsIServerSocket
+ *
+ * An interface to a server socket that can accept incoming connections.
+ */
+[scriptable, uuid(7a9c39cb-a13f-4eef-9bdf-a74301628742)]
+interface nsIServerSocket : nsISupports
+{
+    /**
+     * @name Server Socket Flags
+     * These flags define various socket options.
+     * @{
+     */
+    /// The server socket will only respond to connections on the
+    /// local loopback interface.  Otherwise, it will accept connections
+    /// from any interface.  To specify a particular network interface,
+    /// use initWithAddress.
+    const nsServerSocketFlag LoopbackOnly = 0x00000001;
+    /// The server socket will not be closed when Gecko is set
+    /// offline.
+    const nsServerSocketFlag KeepWhenOffline = 0x00000002;
+    /** @} */
+
+    /**
+     * init
+     *
+     * This method initializes a server socket.
+     *
+     * @param aPort
+     *        The port of the server socket.  Pass -1 to indicate no preference,
+     *        and a port will be selected automatically.
+     * @param aLoopbackOnly
+     *        If true, the server socket will only respond to connections on the
+     *        local loopback interface.  Otherwise, it will accept connections
+     *        from any interface.  To specify a particular network interface,
+     *        use initWithAddress.
+     * @param aBackLog
+     *        The maximum length the queue of pending connections may grow to.
+     *        This parameter may be silently limited by the operating system.
+     *        Pass -1 to use the default value.
+     */
+    void init(in long aPort,
+              in boolean aLoopbackOnly,
+              in long aBackLog);
+
+    /**
+     * the same as init(), but initializes an IPv6 server socket
+     */
+    void initIPv6(in long aPort,
+                  in boolean aLoopbackOnly,
+                  in long aBackLog);
+
+    /**
+     * Similar to init(), but initializes a server socket that supports
+     * both IPv4 and IPv6.
+     */
+    void initDualStack(in long aPort,
+                       in long aBackLog);
+
+    /**
+     * initSpecialConnection
+     *
+     * This method initializes a server socket and offers the ability to have
+     * that socket not get terminated if Gecko is set offline.
+     *
+     * @param aPort
+     *        The port of the server socket.  Pass -1 to indicate no preference,
+     *        and a port will be selected automatically.
+     * @param aFlags
+     *        Flags for the socket.
+     * @param aBackLog
+     *        The maximum length the queue of pending connections may grow to.
+     *        This parameter may be silently limited by the operating system.
+     *        Pass -1 to use the default value.
+     */
+    void initSpecialConnection(in long aPort,
+                               in nsServerSocketFlag aFlags,
+                               in long aBackLog);
+
+
+    /**
+     * initWithAddress
+     *
+     * This method initializes a server socket, and binds it to a particular
+     * local address (and hence a particular local network interface).
+     *
+     * @param aAddr
+     *        The address to which this server socket should be bound.
+     * @param aBackLog
+     *        The maximum length the queue of pending connections may grow to.
+     *        This parameter may be silently limited by the operating system.
+     *        Pass -1 to use the default value.
+     */
+    [noscript] void initWithAddress([const] in PRNetAddrPtr aAddr, in long aBackLog);
+
+    /**
+     * initWithFilename
+     *
+     * This method initializes a Unix domain or "local" server socket. Such
+     * a socket has a name in the filesystem, like an ordinary file. To
+     * connect, a client supplies the socket's filename, and the usual
+     * permission checks on socket apply.
+     *
+     * This makes Unix domain sockets useful for communication between the
+     * programs being run by a specific user on a single machine: the
+     * operating system takes care of authentication, and the user's home
+     * directory or profile directory provide natural per-user rendezvous
+     * points.
+     *
+     * Since Unix domain sockets are always local to the machine, they are
+     * not affected by the nsIIOService's 'offline' flag.
+     *
+     * The system-level socket API may impose restrictions on the length of
+     * the filename that are stricter than those of the underlying
+     * filesystem. If the file name is too long, this returns
+     * NS_ERROR_FILE_NAME_TOO_LONG.
+     *
+     * All components of the path prefix of |aPath| must name directories;
+     * otherwise, this returns NS_ERROR_FILE_NOT_DIRECTORY.
+     *
+     * This call requires execute permission on all directories containing
+     * the one in which the socket is to be created, and write and execute
+     * permission on the directory itself. Otherwise, this returns
+     * NS_ERROR_CONNECTION_REFUSED.
+     *
+     * This call creates the socket's directory entry. There must not be
+     * any existing entry with the given name. If there is, this returns
+     * NS_ERROR_SOCKET_ADDRESS_IN_USE.
+     *
+     * On systems that don't support Unix domain sockets at all, this
+     * returns NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED.
+     *
+     * @param aPath nsIFile
+     *        The file name at which the socket should be created.
+     *
+     * @param aPermissions unsigned long
+     *        Unix-style permission bits to be applied to the new socket.
+     *
+     * Note about permissions: Linux's unix(7) man page claims that some
+     * BSD-derived systems ignore permissions on UNIX-domain sockets;
+     * NetBSD's bind(2) man page agrees, but says it does check now (dated
+     * 2005). POSIX has required 'connect' to fail if write permission on
+     * the socket itself is not granted since 2003 (Issue 6). NetBSD says
+     * that the permissions on the containing directory (execute) have
+     * always applied, so creating sockets in appropriately protected
+     * directories should be secure on both old and new systems.
+     */
+    void initWithFilename(in nsIFile aPath, in unsigned long aPermissions,
+                          in long aBacklog);
+
+    /**
+     * initWithAbstractAddress
+     *
+     * This mehtod is a flavor of initWithFilename method. This initializes
+     * a UNIX domain socket that uses abstract socket address.
+     * This socket type is only supported on Linux and Android.
+     *
+     * On systems that don't support this type's UNIX domain sockets at all,
+     * this returns NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED.
+     *
+     * @param aName
+     *        The abstract socket address which the socket should be created.
+     * @param aBacklog
+     *        The maximum length the queue of pending connections may grow to.
+     */
+    void initWithAbstractAddress(in AUTF8String aName,
+                                 in long aBacklog);
+
+    /**
+     * close
+     *
+     * This method closes a server socket.  This does not affect already
+     * connected client sockets (i.e., the nsISocketTransport instances
+     * created from this server socket).  This will cause the onStopListening
+     * event to asynchronously fire with a status of NS_BINDING_ABORTED.
+     */
+    void close();
+
+    /**
+     * asyncListen
+     *
+     * This method puts the server socket in the listening state.  It will
+     * asynchronously listen for and accept client connections.  The listener
+     * will be notified once for each client connection that is accepted.  The
+     * listener's onSocketAccepted method will be called on the same thread
+     * that called asyncListen (the calling thread must have a nsIEventTarget).
+     *
+     * The listener will be passed a reference to an already connected socket
+     * transport (nsISocketTransport).  See below for more details.
+     *
+     * @param aListener
+     *        The listener to be notified when client connections are accepted.
+     */
+    void asyncListen(in nsIServerSocketListener aListener);
+
+    /**
+     * Returns the port of this server socket.
+     */
+    readonly attribute long port;
+
+    /**
+     * Returns the address to which this server socket is bound.  Since a
+     * server socket may be bound to multiple network devices, this address
+     * may not necessarily be specific to a single network device.  In the
+     * case of an IP socket, the IP address field would be zerod out to
+     * indicate a server socket bound to all network devices.  Therefore,
+     * this method cannot be used to determine the IP address of the local
+     * system.  See nsIDNSService::myHostName if this is what you need.
+     */
+    [noscript] PRNetAddr getAddress();
+};
+
+/**
+ * nsIServerSocketListener
+ *
+ * This interface is notified whenever a server socket accepts a new connection.
+ * The transport is in the connected state, and read/write streams can be opened
+ * using the normal nsITransport API.  The address of the client can be found by
+ * calling the nsISocketTransport::GetAddress method or by inspecting
+ * nsISocketTransport::GetHost, which returns a string representation of the
+ * client's IP address (NOTE: this may be an IPv4 or IPv6 string literal).
+ */
+[scriptable, uuid(836d98ec-fee2-4bde-b609-abd5e966eabd)]
+interface nsIServerSocketListener : nsISupports
+{
+    /**
+     * onSocketAccepted
+     *
+     * This method is called when a client connection is accepted.
+     *
+     * @param aServ
+     *        The server socket.
+     * @param aTransport
+     *        The connected socket transport.
+     */
+    void onSocketAccepted(in nsIServerSocket aServ,
+                          in nsISocketTransport aTransport);
+
+    /**
+     * onStopListening
+     *
+     * This method is called when the listening socket stops for some reason.
+     * The server socket is effectively dead after this notification.
+     *
+     * @param aServ
+     *        The server socket.
+     * @param aStatus
+     *        The reason why the server socket stopped listening.  If the
+     *        server socket was manually closed, then this value will be
+     *        NS_BINDING_ABORTED.
+     */
+    void onStopListening(in nsIServerSocket aServ, in nsresult aStatus);
+};
diff --git a/netwerk/base/nsISimpleStreamListener.idl b/netwerk/base/nsISimpleStreamListener.idl
new file mode 100644
index 0000000000..99169481f5
--- /dev/null
+++ b/netwerk/base/nsISimpleStreamListener.idl
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+interface nsIOutputStream;
+
+/**
+ * A simple stream listener can be used with AsyncRead to supply data to
+ * a output stream.
+ */
+[scriptable, uuid(a9b84f6a-0824-4278-bae6-bfca0570a26e)]
+interface nsISimpleStreamListener : nsIStreamListener
+{
+    /**
+     * Initialize the simple stream listener.
+     *
+     * @param aSink data will be read from the channel to this output stream.
+     *              Must implement writeFrom.
+     * @param aObserver optional stream observer (can be NULL)
+     */
+    void init(in nsIOutputStream aSink,
+              in nsIRequestObserver aObserver);
+};
diff --git a/netwerk/base/nsISimpleURIMutator.idl b/netwerk/base/nsISimpleURIMutator.idl
new file mode 100644
index 0000000000..786c8701d2
--- /dev/null
+++ b/netwerk/base/nsISimpleURIMutator.idl
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+interface nsIURIMutator;
+
+[scriptable, builtinclass, uuid(e055bddd-f3c2-404b-adec-db9304e93be2)]
+interface nsISimpleURIMutator : nsISupports
+{
+    /**
+     * Same behaviour as nsIURISetSpec.setSpec() but filters whitespace.
+     */
+    nsIURIMutator setSpecAndFilterWhitespace(in AUTF8String aSpec);
+};
diff --git a/netwerk/base/nsISocketFilter.idl b/netwerk/base/nsISocketFilter.idl
new file mode 100644
index 0000000000..0846fa2eda
--- /dev/null
+++ b/netwerk/base/nsISocketFilter.idl
@@ -0,0 +1,53 @@
+/* -*- Mode: IDL; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+#include "nsINetAddr.idl"
+
+native NetAddr(mozilla::net::NetAddr);
+[ptr] native NetAddrPtr(mozilla::net::NetAddr);
+
+
+/**
+ * Filters are created and run on the parent, and filter all packets, both
+ * ingoing and outgoing. The child must specify the name of a recognized filter
+ * in order to create a socket.
+ */
+[uuid(afe2c40c-b9b9-4207-b898-e5cde18c6139)]
+interface nsISocketFilter : nsISupports
+{
+  const long SF_INCOMING = 0;
+  const long SF_OUTGOING = 1;
+
+  bool filterPacket([const]in NetAddrPtr remote_addr,
+                    [const, array, size_is(len)]in uint8_t data,
+                    in unsigned long len,
+                    in long direction);
+};
+
+/**
+ * Factory of a specified filter.
+ */
+[uuid(81ee76c6-4753-4125-9c8c-290ed9ba62fb)]
+interface nsISocketFilterHandler : nsISupports
+{
+   nsISocketFilter newFilter();
+};
+
+%{C++
+/**
+ * Filter handlers are registered with XPCOM under the following CONTRACTID prefix:
+ */
+#define NS_NETWORK_UDP_SOCKET_FILTER_HANDLER_PREFIX "@mozilla.org/network/udp-filter-handler;1?name="
+#define NS_NETWORK_TCP_SOCKET_FILTER_HANDLER_PREFIX "@mozilla.org/network/tcp-filter-handler;1?name="
+
+#define NS_NETWORK_SOCKET_FILTER_HANDLER_STUN_SUFFIX "stun"
+
+#define NS_STUN_UDP_SOCKET_FILTER_HANDLER_CONTRACTID NS_NETWORK_UDP_SOCKET_FILTER_HANDLER_PREFIX NS_NETWORK_SOCKET_FILTER_HANDLER_STUN_SUFFIX
+
+
+#define NS_STUN_TCP_SOCKET_FILTER_HANDLER_CONTRACTID NS_NETWORK_TCP_SOCKET_FILTER_HANDLER_PREFIX NS_NETWORK_SOCKET_FILTER_HANDLER_STUN_SUFFIX
+%}
diff --git a/netwerk/base/nsISocketTransport.idl b/netwerk/base/nsISocketTransport.idl
new file mode 100644
index 0000000000..58b869203e
--- /dev/null
+++ b/netwerk/base/nsISocketTransport.idl
@@ -0,0 +1,382 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsITransport.idl"
+#include "nsIRequest.idl"
+#include "nsITRRSkipReason.idl"
+
+interface nsIInterfaceRequestor;
+interface nsINetAddr;
+interface nsITLSSocketControl;
+
+%{ C++
+#include "mozilla/BasePrincipal.h"
+namespace mozilla {
+namespace net {
+union NetAddr;
+}
+}
+%}
+native NetAddr(mozilla::net::NetAddr);
+[ptr] native NetAddrPtr(mozilla::net::NetAddr);
+native OriginAttributes(mozilla::OriginAttributes);
+[ref] native const_OriginAttributesRef(const mozilla::OriginAttributes);
+
+/**
+ * nsISocketTransport
+ *
+ * NOTE: Connection setup is triggered by opening an input or output stream,
+ * it does not start on its own. Completion of the connection setup is
+ * indicated by a STATUS_CONNECTED_TO notification to the event sink (if set).
+ *
+ * NOTE: This is a free-threaded interface, meaning that the methods on
+ * this interface may be called from any thread.
+ */
+[scriptable, builtinclass, uuid(79221831-85e2-43a8-8152-05d77d6fde31)]
+interface nsISocketTransport : nsITransport
+{
+    /**
+     * Get the peer's host for the underlying socket connection.
+     * For Unix domain sockets, this is a pathname, or the empty string for
+     * unnamed and abstract socket addresses.
+     */
+    readonly attribute AUTF8String host;
+
+    /**
+     * Get the port for the underlying socket connection.
+     * For Unix domain sockets, this is zero.
+     */
+    readonly attribute long port;
+
+    /**
+     * The origin attributes are used to create sockets.  The first party domain
+     * will eventually be used to isolate OCSP cache and is only non-empty when
+     * "privacy.firstparty.isolate" is enabled.  Setting this is the only way to
+     * carry origin attributes down to NSPR layers which are final consumers.
+     * It must be set before the socket transport is built.
+     */
+    [implicit_jscontext, binaryname(ScriptableOriginAttributes)]
+    attribute jsval originAttributes;
+
+    [noscript, nostdcall, binaryname(GetOriginAttributes)]
+    OriginAttributes binaryGetOriginAttributes();
+
+    [noscript, nostdcall, binaryname(SetOriginAttributes)]
+    void binarySetOriginAttributes(in const_OriginAttributesRef aOriginAttrs);
+
+    /**
+     * Returns the IP address of the socket connection peer. This
+     * attribute is defined only once a connection has been established.
+     */
+    [noscript] NetAddr getPeerAddr();
+
+    /**
+     * Returns the IP address of the initiating end. This attribute
+     * is defined only once a connection has been established.
+     */
+    [noscript] NetAddr getSelfAddr();
+
+    /**
+     * Bind to a specific local address.
+     */
+    [noscript] void bind(in NetAddrPtr aLocalAddr);
+
+    /**
+     * Returns a scriptable version of getPeerAddr. This attribute is defined
+     * only once a connection has been established.
+     */
+    nsINetAddr getScriptablePeerAddr();
+
+    /**
+     * Returns a scriptable version of getSelfAddr. This attribute is defined
+     * only once a connection has been established.
+     */
+    nsINetAddr getScriptableSelfAddr();
+
+    /**
+     * TLS socket control object. This attribute is only available once the
+     * socket is connected.
+     */
+    readonly attribute nsITLSSocketControl tlsSocketControl;
+
+    /**
+     * Security notification callbacks passed to the secure socket provider
+     * via nsITLSSocketControl at socket creation time.
+     *
+     * NOTE: this attribute cannot be changed once a stream has been opened.
+     */
+    attribute nsIInterfaceRequestor securityCallbacks;
+
+    /**
+     * Test if this socket transport is (still) connected.
+     */
+    boolean isAlive();
+
+    /**
+     * Socket timeouts in seconds.  To specify no timeout, pass UINT32_MAX
+     * as aValue to setTimeout.  The implementation may truncate timeout values
+     * to a smaller range of values (e.g., 0 to 0xFFFF).
+     */
+    unsigned long getTimeout(in unsigned long aType);
+    void          setTimeout(in unsigned long aType, in unsigned long aValue);
+
+    /**
+     * Sets the SO_LINGER option with the specified values for the l_onoff and
+     * l_linger parameters. This applies PR_SockOpt_Linger before PR_Close and
+     * can be used with a timeout of zero to send an RST packet when closing.
+     */
+    void setLinger(in boolean aPolarity, in short aTimeout);
+
+    /**
+     * True to set addr and port reuse socket options.
+     */
+    void setReuseAddrPort(in bool reuseAddrPort);
+
+    /**
+     * Values for the aType parameter passed to get/setTimeout.
+     */
+    const unsigned long TIMEOUT_CONNECT    = 0;
+    const unsigned long TIMEOUT_READ_WRITE = 1;
+
+    /**
+     * nsITransportEventSink status codes.
+     *
+     * Although these look like XPCOM error codes and are passed in an nsresult
+     * variable, they are *not* error codes.  Note that while they *do* overlap
+     * with existing error codes in Necko, these status codes are confined
+     * within a very limited context where no error codes may appear, so there
+     * is no ambiguity.
+     *
+     * The values of these status codes must never change.
+     *
+     * The status codes appear in near-chronological order (not in numeric
+     * order).  STATUS_RESOLVING may be skipped if the host does not need to be
+     * resolved.  STATUS_WAITING_FOR is an optional status code, which the impl
+     * of this interface may choose not to generate.
+     *
+     * In C++, these constants have a type of uint32_t, so C++ callers must use
+     * the NS_NET_STATUS_* constants defined below, which have a type of
+     * nsresult.
+     */
+    const unsigned long STATUS_RESOLVING      = 0x4b0003;
+    const unsigned long STATUS_RESOLVED       = 0x4b000b;
+    const unsigned long STATUS_CONNECTING_TO  = 0x4b0007;
+    const unsigned long STATUS_CONNECTED_TO   = 0x4b0004;
+    const unsigned long STATUS_SENDING_TO     = 0x4b0005;
+    const unsigned long STATUS_WAITING_FOR    = 0x4b000a;
+    const unsigned long STATUS_RECEIVING_FROM = 0x4b0006;
+    const unsigned long STATUS_TLS_HANDSHAKE_STARTING = 0x4b000c;
+    const unsigned long STATUS_TLS_HANDSHAKE_ENDED    = 0x4b000d;
+
+    /**
+     * connectionFlags is a bitmask that can be used to modify underlying
+     * behavior of the socket connection. See the flags below.
+     */
+    attribute unsigned long connectionFlags;
+
+    /**
+     * Values for the connectionFlags
+     *
+     * When making a new connection BYPASS_CACHE will force the Necko DNS
+     * cache entry to be refreshed with a new call to NSPR if it is set before
+     * opening the new stream.
+     */
+    const unsigned long BYPASS_CACHE = (1 << 0);
+
+    /**
+     * When setting this flag, the socket will not apply any
+     * credentials when establishing a connection. For example,
+     * an SSL connection would not send any client-certificates
+     * if this flag is set.
+     */
+    const unsigned long ANONYMOUS_CONNECT = (1 << 1);
+
+    /**
+     * If set, we will skip all IPv6 addresses the host may have and only
+     * connect to IPv4 ones.
+     */
+    const unsigned long DISABLE_IPV6 = (1 << 2);
+
+    /**
+     * If set, indicates that the connection was initiated from a source
+     * defined as being private in the sense of Private Browsing. Generally,
+     * there should be no state shared between connections that are private
+     * and those that are not; it is OK for multiple private connections
+     * to share state with each other, and it is OK for multiple non-private
+     * connections to share state with each other.
+     */
+    const unsigned long NO_PERMANENT_STORAGE = (1 << 3);
+
+    /**
+     * If set, we will skip all IPv4 addresses the host may have and only
+     * connect to IPv6 ones.
+     */
+    const unsigned long DISABLE_IPV4 = (1 << 4);
+
+    /**
+     * If set, indicates that the socket should not connect if the hostname
+     * resolves to an RFC1918 address or IPv6 equivalent.
+     */
+    const unsigned long DISABLE_RFC1918 = (1 << 5);
+
+    /**
+     * If set, do not use newer protocol features that might have interop problems
+     * on the Internet. Intended only for use with critical infra like the updater.
+     * default is false.
+     */
+    const unsigned long BE_CONSERVATIVE = (1 << 6);
+
+    /**
+     * If set, do not use TRR for resolving the host name. Intended only for
+     * retries or other scenarios when TRR is deemed likely to have returned a
+     * wrong adddress.
+     */
+    const unsigned long DISABLE_TRR = (1 << 7);
+
+    /**
+     * Values for the connectionFlags
+     *
+     * When using BYPASS_CACHE, setting this bit will invalidate the existing
+     * cached entry immediately while the new resolve is being done to avoid
+     * other users from using stale content in the mean time.
+     */
+    const unsigned long REFRESH_CACHE = (1 << 8);
+
+    /**
+     * If this flag is set then it means that if connecting the preferred ip
+     * family has failed, retry with the oppsite one once more.
+     */
+    const unsigned long RETRY_WITH_DIFFERENT_IP_FAMILY = (1 << 9);
+
+    /**
+     * If we know that a server speaks only tls <1.3 there is no need to try
+     * to use ech.
+     */
+    const unsigned long DONT_TRY_ECH = (1 << 10);
+
+    /**
+     * These two bits encode the TRR mode of the request.
+     * Use the static helper methods convert between the TRR mode and flags.
+     */
+    const unsigned long TRR_MODE_FLAGS = (1 << 11) | (1 << 12);
+
+%{C++
+
+    static uint32_t GetFlagsFromTRRMode(nsIRequest::TRRMode aMode) {
+        return static_cast<uint32_t>(aMode) << 11;
+    }
+
+    static nsIRequest::TRRMode GetTRRModeFromFlags(uint32_t aFlags) {
+        return static_cast<nsIRequest::TRRMode>((aFlags & TRR_MODE_FLAGS) >> 11);
+    }
+%}
+
+    /**
+     * If set, we will use IP hint addresses to connect to the host.
+     */
+    const unsigned long USE_IP_HINT_ADDRESS = (1 << 13);
+
+    /**
+     * This is used for a temporary workaround for a web-compat issue. The flag is
+     * only set on CORS preflight request to allowed sending client certificates
+     * on a connection for an anonymous request.
+     */
+    const unsigned long ANONYMOUS_CONNECT_ALLOW_CLIENT_CERT = (1 << 14);
+
+    /**
+     * If set, we've retrying after a failed connection attempt.
+     */
+    const unsigned long IS_RETRY = (1 << 15);
+
+    /**
+     * If set, this is a speculative connection.
+     */
+    const unsigned long IS_SPECULATIVE_CONNECTION = (1 << 16);
+
+    /**
+     * An opaque flags for non-standard behavior of the TLS system.
+     * It is unlikely this will need to be set outside of telemetry studies
+     * relating to the TLS implementation.
+     */
+    attribute unsigned long tlsFlags;
+
+    /**
+     * Socket QoS/ToS markings. Valid values are IPTOS_DSCP_AFxx or
+     * IPTOS_CLASS_CSx (or IPTOS_DSCP_EF, but currently no supported
+     * services require expedited-forwarding).
+     * Not setting this value will leave the socket with the default
+     * ToS value, which on most systems if IPTOS_CLASS_CS0 (formerly
+     * IPTOS_PREC_ROUTINE).
+     */
+    attribute octet QoSBits;
+
+    /**
+     * TCP send and receive buffer sizes. A value of 0 means OS level
+     * auto-tuning is in effect.
+     */
+    attribute unsigned long recvBufferSize;
+    attribute unsigned long sendBufferSize;
+
+    /**
+     * TCP keepalive configuration (support varies by platform).
+     * Note that the attribute as well as the setter can only accessed
+     * in the socket thread.
+     */
+    attribute boolean keepaliveEnabled;
+    void setKeepaliveVals(in long keepaliveIdleTime,
+                          in long keepaliveRetryInterval);
+
+    /**
+     * If true, this socket transport has found out the prefered family
+     * according it's connection flags could not be used to establish
+     * connections any more.  Hence, the preference should be reset.
+     */
+    readonly attribute boolean resetIPFamilyPreference;
+
+    /**
+     * This attribute holds information whether echConfig has been used.
+     * The value is set after PR_Connect is called.
+     */
+   readonly attribute boolean echConfigUsed;
+
+    /**
+     * Called to set the echConfig to the securityInfo object.
+     */
+    void setEchConfig(in ACString echConfig);
+
+    /**
+     * IP address resolved using TRR.
+     */
+    bool resolvedByTRR();
+
+    /**
+     * Returns the effectiveTRRMode used for the DNS resolution.
+     */
+    readonly attribute nsIRequest_TRRMode effectiveTRRMode;
+
+    /**
+     * Returns the TRR skip reason used for the DNS resolution.
+     */
+    readonly attribute nsITRRSkipReason_value trrSkipReason;
+
+    /**
+     * Indicate whether this socket is created from a private window. If yes,
+     * this socket will be closed when the last private window is closed.
+     */
+    [noscript] void setIsPrivate(in boolean isPrivate);
+
+    /**
+     * If DNS is performed externally, this flag informs the caller that it may
+     * retry connecting with a different DNS configuration (e.g. different IP
+     * family preference). The flag is set only if a network error is encounder,
+     * e.g. NS_ERROR_CONNECTION_REFUSED, NS_ERROR_RESET, etc.
+     */
+    readonly attribute boolean retryDnsIfPossible;
+
+    /**
+     * Return the current status of the socket.
+     */
+    [noscript] readonly attribute nsresult status;
+};
diff --git a/netwerk/base/nsISocketTransportService.idl b/netwerk/base/nsISocketTransportService.idl
new file mode 100644
index 0000000000..64891fcfa0
--- /dev/null
+++ b/netwerk/base/nsISocketTransportService.idl
@@ -0,0 +1,162 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIDNSRecord;
+interface nsIFile;
+interface nsISocketTransport;
+interface nsIProxyInfo;
+interface nsIRunnable;
+
+%{C++
+class nsASocketHandler;
+struct PRFileDesc;
+%}
+
+[ptr] native PRFileDescPtr(PRFileDesc);
+[ptr] native nsASocketHandlerPtr(nsASocketHandler);
+
+[scriptable, function, uuid(338947df-2f3b-4d24-9ce4-ecf161c1b7df)]
+interface nsISTSShutdownObserver : nsISupports {
+
+   /**
+    * Observe will be called when the SocketTransportService is shutting down,
+    * before threads are stopped.
+    */
+    void observe();
+};
+
+[builtinclass, scriptable, uuid(ad56b25f-e6bb-4db3-9f7b-5b7db33fd2b1)]
+interface nsISocketTransportService : nsISupports
+{
+    /**
+     * Creates a transport for a specified host and port.
+     *
+     * @param aSocketTypes
+     *        array of socket type strings.  Empty array if using default
+     *        socket type.
+     * @param aHost
+     *        specifies the target hostname or IP address literal of the peer
+     *        for this socket.
+     * @param aPort
+     *        specifies the target port of the peer for this socket.
+     * @param aProxyInfo
+     *        specifies the transport-layer proxy type to use.  null if no
+     *        proxy.  used for communicating information about proxies like
+     *        SOCKS (which are transparent to upper protocols).
+     * @param aDnsRecord
+     *        the dns record to be used for the connection
+     *
+     * @see nsIProxiedProtocolHandler
+     * @see nsIProtocolProxyService::GetProxyInfo
+     *
+     * NOTE: this function can be called from any thread
+     */
+    nsISocketTransport createTransport(in Array<ACString> aSocketTypes,
+                                       in AUTF8String aHost,
+                                       in long aPort,
+                                       in nsIProxyInfo aProxyInfo,
+                                       in nsIDNSRecord dnsRecord);
+
+    /**
+     * Create a transport built on a Unix domain socket, connecting to the
+     * given filename.
+     *
+     * Since Unix domain sockets are always local to the machine, they are
+     * not affected by the nsIIOService's 'offline' flag.
+     *
+     * On systems that don't support Unix domain sockets at all, this
+     * returns NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED.
+     *
+     * The system-level socket API may impose restrictions on the length of
+     * the filename that are stricter than those of the underlying
+     * filesystem. If the file name is too long, this returns
+     * NS_ERROR_FILE_NAME_TOO_LONG.
+     *
+     * The |aPath| parameter must specify an existing directory entry.
+     * Otherwise, this returns NS_ERROR_FILE_NOT_FOUND.
+     *
+     * The program must have search permission on all components of the
+     * path prefix of |aPath|, and read and write permission on |aPath|
+     * itself. Without such permission, this returns
+     * NS_ERROR_CONNECTION_REFUSED.
+     *
+     * The |aPath| parameter must refer to a unix-domain socket. Otherwise,
+     * this returns NS_ERROR_CONNECTION_REFUSED. (POSIX specifies
+     * ECONNREFUSED when "the target address was not listening for
+     * connections", and this is what Linux returns.)
+     *
+     * @param aPath
+     *        The file name of the Unix domain socket to which we should
+     *        connect.
+     */
+    nsISocketTransport createUnixDomainTransport(in nsIFile aPath);
+
+    /**
+     * Create a transport built on a Unix domain socket that uses abstract
+     * address name.
+     *
+     * If abstract socket address isn't supported on System, this returns
+     * NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED.
+     *
+     * @param aName
+     *        The name of abstract socket adress of the Unix domain socket to
+     *        which we should connect.
+     */
+    nsISocketTransport
+    createUnixDomainAbstractAddressTransport(in ACString aName);
+
+    /**
+     * Adds a new socket to the list of controlled sockets.
+     *
+     * This will fail with the error code NS_ERROR_NOT_AVAILABLE if the maximum
+     * number of sockets is already reached.
+     * In this case, the notifyWhenCanAttachSocket method should be used.
+     *
+     * @param aFd
+     *        Open file descriptor of the socket to control.
+     * @param aHandler
+     *        Socket handler that will receive notifications when the socket is
+     *        ready or detached.
+     *
+     * NOTE: this function may only be called from an event dispatch on the
+     *       socket thread.
+     */
+    [noscript] void attachSocket(in PRFileDescPtr aFd,
+                                 in nsASocketHandlerPtr aHandler);
+
+    /**
+     * if the number of sockets reaches the limit, then consumers can be
+     * notified when the number of sockets becomes less than the limit.  the
+     * notification is asynchronous, delivered via the given nsIRunnable
+     * instance on the socket transport thread.
+     *
+     * @param aEvent
+     *        Event that will receive the notification when a new socket can
+     *        be attached
+     *
+     * NOTE: this function may only be called from an event dispatch on the
+     *       socket thread.
+     */
+    [noscript] void notifyWhenCanAttachSocket(in nsIRunnable aEvent);
+
+    [noscript] void addShutdownObserver(in nsISTSShutdownObserver aObserver);
+    [noscript] void removeShutdownObserver(in nsISTSShutdownObserver aObserver);
+};
+
+[builtinclass, scriptable, uuid(c5204623-5b58-4a16-8b2e-67c34dd02e3f)]
+interface nsIRoutedSocketTransportService : nsISocketTransportService
+{
+    // use this instead of createTransport when you have a transport
+    // that distinguishes between origin and route (aka connection)
+    nsISocketTransport createRoutedTransport(in Array<ACString> aSocketTypes,
+                                             in AUTF8String aHost, // origin
+                                             in long aPort, // origin
+                                             in AUTF8String aHostRoute,
+                                             in long aPortRoute,
+                                             in nsIProxyInfo aProxyInfo,
+                                             in nsIDNSRecord aDnsRecord);
+};
diff --git a/netwerk/base/nsISpeculativeConnect.idl b/netwerk/base/nsISpeculativeConnect.idl
new file mode 100644
index 0000000000..e1f890a04b
--- /dev/null
+++ b/netwerk/base/nsISpeculativeConnect.idl
@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIPrincipal;
+interface nsIURI;
+interface nsIInterfaceRequestor;
+
+%{C++
+namespace mozilla {
+
+class OriginAttributes;
+
+}
+%}
+
+native OriginAttributes(mozilla::OriginAttributes&&);
+
+[scriptable, builtinclass, uuid(d74a17ac-5b8a-4824-a309-b1f04a3c4aed)]
+interface nsISpeculativeConnect : nsISupports
+{
+    /**
+     * Called as a hint to indicate a new transaction for the URI is likely coming
+     * soon. The implementer may use this information to start a TCP
+     * and/or SSL level handshake for that resource immediately so that it is
+     * ready and/or progressed when the transaction is actually submitted.
+     *
+     * No obligation is taken on by the implementer, nor is the submitter obligated
+     * to actually open the new channel.
+     *
+     * @param aURI the URI of the hinted transaction
+     * @param aPrincipal the principal that will be used for opening the
+     *        channel of the hinted transaction.
+     * @param aCallbacks any security callbacks for use with SSL for interfaces.
+     *        May be null.
+     * @param aAnonymous indicates if this is an anonymous connection.
+     *
+     */
+    void speculativeConnect(in nsIURI aURI,
+                            in nsIPrincipal aPrincipal,
+                            in nsIInterfaceRequestor aCallbacks,
+                            in boolean aAnonymous);
+
+    /**
+     * This method is similar to speculativeConnect, but it use
+     * the partition key of the originAttributes directly to create the
+     * connection.
+     */
+    [implicit_jscontext]
+    void speculativeConnectWithOriginAttributes(
+        in nsIURI aURI,
+        in jsval originAttributes,
+        in nsIInterfaceRequestor aCallbacks,
+        in boolean aAnonymous);
+
+    [notxpcom]
+    void speculativeConnectWithOriginAttributesNative(
+        in nsIURI aURI,
+        in OriginAttributes originAttributes,
+        in nsIInterfaceRequestor aCallbacks,
+        in boolean aAnonymous);
+};
+
+/**
+ * This is used to override the default values for various values (documented
+ * inline) to determine whether or not to actually make a speculative
+ * connection.
+ */
+[uuid(1040ebe3-6ed1-45a6-8587-995e082518d7)]
+interface nsISpeculativeConnectionOverrider : nsISupports
+{
+    /**
+     * Used to determine the maximum number of unused speculative connections
+     * we will have open for a host at any one time
+     */
+    [infallible] readonly attribute unsigned long parallelSpeculativeConnectLimit;
+
+    /**
+     * Used to determine if we will ignore the existence of any currently idle
+     * connections when we decide whether or not to make a speculative
+     * connection.
+     */
+    [infallible] readonly attribute boolean ignoreIdle;
+
+    /*
+     * Used by the Predictor to gather telemetry data on speculative connection
+     * usage.
+     */
+    [infallible] readonly attribute boolean isFromPredictor;
+
+    /**
+     * by default speculative connections are not made to RFC 1918 addresses
+     */
+    [infallible] readonly attribute boolean allow1918;
+};
diff --git a/netwerk/base/nsIStandardURL.idl b/netwerk/base/nsIStandardURL.idl
new file mode 100644
index 0000000000..dae8ecc13c
--- /dev/null
+++ b/netwerk/base/nsIStandardURL.idl
@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIURIMutator;
+
+/**
+ * nsIStandardURL defines the interface to an URL with the standard
+ * file path format common to protocols like http, ftp, and file.
+ * It supports initialization from a relative path and provides
+ * some customization on how URLs are normalized.
+ */
+[scriptable, builtinclass, uuid(babd6cca-ebe7-4329-967c-d6b9e33caa81)]
+interface nsIStandardURL : nsISupports
+{
+    /**
+     * blah:foo/bar    => blah://foo/bar
+     * blah:/foo/bar   => blah:///foo/bar
+     * blah://foo/bar  => blah://foo/bar
+     * blah:///foo/bar => blah:///foo/bar
+     */
+    const unsigned long URLTYPE_STANDARD        = 1;
+
+    /**
+     * blah:foo/bar    => blah://foo/bar
+     * blah:/foo/bar   => blah://foo/bar
+     * blah://foo/bar  => blah://foo/bar
+     * blah:///foo/bar => blah://foo/bar
+     */
+    const unsigned long URLTYPE_AUTHORITY       = 2;
+
+    /**
+     * blah:foo/bar    => blah:///foo/bar
+     * blah:/foo/bar   => blah:///foo/bar
+     * blah://foo/bar  => blah://foo/bar
+     * blah:///foo/bar => blah:///foo/bar
+     */
+    const unsigned long URLTYPE_NO_AUTHORITY    = 3;
+};
+
+[scriptable, builtinclass, uuid(fc894e98-23a1-43cd-a7fe-72876f8ea2ee)]
+interface nsIStandardURLMutator : nsISupports
+{
+    /**
+     * Initialize a standard URL.
+     *
+     * @param aUrlType       - one of the URLTYPE_ flags listed above.
+     * @param aDefaultPort   - if the port parsed from the URL string matches
+     *                         this port, then the port will be removed from the
+     *                         canonical form of the URL.
+     * @param aSpec          - URL string.
+     * @param aOriginCharset - the charset from which this URI string
+     *                         originated.  this corresponds to the charset
+     *                         that should be used when communicating this
+     *                         URI to an origin server, for example.  if
+     *                         null, then provide aBaseURI implements this
+     *                         interface, the origin charset of aBaseURI will
+     *                         be assumed, otherwise defaulting to UTF-8 (i.e.,
+     *                         no charset transformation from aSpec).
+     * @param aBaseURI       - if null, aSpec must specify an absolute URI.
+     *                         otherwise, aSpec will be resolved relative
+     *                         to aBaseURI.
+     */
+    nsIURIMutator init(in unsigned long aUrlType,
+                       in long aDefaultPort,
+                       in AUTF8String aSpec,
+                       in string aOriginCharset,
+                       in nsIURI aBaseURI);
+
+    /**
+     * Set the default port.
+     *
+     * Note: If this object is already using its default port (i.e. if it has
+     * mPort == -1), then it will now implicitly be using the new default port.
+     *
+     * @param aNewDefaultPort - if the URI has (or is later given) a port that
+     *                          matches this default, then we won't include a
+     *                          port number in the canonical form of the URL.
+     */
+    nsIURIMutator setDefaultPort(in long aNewDefaultPort);
+};
diff --git a/netwerk/base/nsIStreamListener.idl b/netwerk/base/nsIStreamListener.idl
new file mode 100644
index 0000000000..68ade60cd1
--- /dev/null
+++ b/netwerk/base/nsIStreamListener.idl
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIRequestObserver.idl"
+
+interface nsIInputStream;
+
+/**
+ * nsIStreamListener
+ */
+[scriptable, uuid(3b4c8a77-76ba-4610-b316-678c73a3b88c)]
+interface nsIStreamListener : nsIRequestObserver
+{
+    /**
+     * Called when the next chunk of data (corresponding to the request) may
+     * be read without blocking the calling thread.  The onDataAvailable impl
+     * must read exactly |aCount| bytes of data before returning.
+     *
+     * @param aRequest request corresponding to the source of the data
+     * @param aInputStream input stream containing the data chunk
+     * @param aOffset
+     *        Number of bytes that were sent in previous onDataAvailable calls
+     *        for this request. In other words, the sum of all previous count
+     *        parameters.
+     * @param aCount number of bytes available in the stream
+     *
+     * NOTE: The aInputStream parameter must implement readSegments.
+     *
+     * An exception thrown from onDataAvailable has the side-effect of
+     * causing the request to be canceled.
+     */
+    void onDataAvailable(in nsIRequest aRequest,
+                         in nsIInputStream aInputStream,
+                         in unsigned long long aOffset,
+                         in unsigned long aCount);
+};
diff --git a/netwerk/base/nsIStreamListenerTee.idl b/netwerk/base/nsIStreamListenerTee.idl
new file mode 100644
index 0000000000..d51bdf3c46
--- /dev/null
+++ b/netwerk/base/nsIStreamListenerTee.idl
@@ -0,0 +1,50 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+interface nsIOutputStream;
+interface nsIRequestObserver;
+interface nsIEventTarget;
+
+/**
+ * As data "flows" into a stream listener tee, it is copied to the output stream
+ * and then forwarded to the real listener.
+ */
+[scriptable, uuid(62b27fc1-6e8c-4225-8ad0-b9d44252973a)]
+interface nsIStreamListenerTee : nsIStreamListener
+{
+    /**
+     * Initalize the tee.
+     *
+     * @param listener
+     *    the original listener the tee will propagate onStartRequest,
+     *    onDataAvailable and onStopRequest notifications to, exceptions from
+     *    the listener will be propagated back to the channel
+     * @param sink
+     *    the stream the data coming from the channel will be written to,
+     *    should be blocking
+     * @param requestObserver
+     *    optional parameter, listener that gets only onStartRequest and
+     *    onStopRequest notifications; exceptions threw within this optional
+     *    observer are also propagated to the channel, but exceptions from
+     *    the original listener (listener parameter) are privileged
+     */
+    void init(in nsIStreamListener listener,
+              in nsIOutputStream sink,
+              [optional] in nsIRequestObserver requestObserver);
+
+    /**
+     * Initalize the tee like above, but with the extra parameter to make it
+     * possible to copy the output asynchronously
+     * @param anEventTarget
+     *    if set, this event-target is used to copy data to the output stream,
+     *    giving an asynchronous tee
+    */
+    void initAsync(in nsIStreamListener listener,
+                   in nsIEventTarget eventTarget,
+                   in nsIOutputStream sink,
+                   [optional] in nsIRequestObserver requestObserver);
+
+};
diff --git a/netwerk/base/nsIStreamLoader.idl b/netwerk/base/nsIStreamLoader.idl
new file mode 100644
index 0000000000..274a07e9d0
--- /dev/null
+++ b/netwerk/base/nsIStreamLoader.idl
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+interface nsIRequest;
+interface nsIStreamLoader;
+
+[scriptable, uuid(359F7990-D4E9-11d3-A1A5-0050041CAF44)]
+interface nsIStreamLoaderObserver : nsISupports
+{
+    /**
+     * Called when the entire stream has been loaded.
+     *
+     * @param loader the stream loader that loaded the stream.
+     * @param ctxt the context parameter of the underlying channel
+     * @param status the status of the underlying channel
+     * @param resultLength the length of the data loaded
+     * @param result the data
+     *
+     * This method will always be called asynchronously by the
+     * nsIStreamLoader involved, on the thread that called the
+     * loader's init() method.
+     *
+     * If the observer wants to take over responsibility for the
+     * data buffer (result), it returns NS_SUCCESS_ADOPTED_DATA
+     * in place of NS_OK as its success code. The loader will then
+     * "forget" about the data and not free() it after
+     * onStreamComplete() returns; observer must call free()
+     * when the data is no longer required.
+     */
+    void onStreamComplete(in nsIStreamLoader loader,
+                          in nsISupports ctxt,
+                          in nsresult status,
+                          in unsigned long resultLength,
+                          [const,array,size_is(resultLength)] in octet result);
+};
+
+/**
+ * Asynchronously loads a channel into a memory buffer.
+ *
+ * To use this interface, first call init() with a nsIStreamLoaderObserver
+ * that will be notified when the data has been loaded. Then call asyncOpen()
+ * on the channel with the nsIStreamLoader as the listener. The context
+ * argument in the asyncOpen() call will be passed to the onStreamComplete()
+ * callback.
+ *
+ * XXX define behaviour for sizes >4 GB
+ */
+[scriptable, uuid(323bcff1-7513-4e1f-a541-1c9213c2ed1b)]
+interface nsIStreamLoader : nsIStreamListener
+{
+    /**
+     * Initialize this stream loader, and start loading the data.
+     *
+     * @param aStreamObserver
+     *        An observer that will be notified when the data is complete.
+     * @param aRequestObserver
+     *        An optional observer that will be notified when the request
+     *        has started or stopped.
+     */
+    void init(in nsIStreamLoaderObserver aStreamObserver,
+              [optional] in nsIRequestObserver aRequestObserver);
+
+    /**
+     * Gets the number of bytes read so far.
+     */
+    readonly attribute unsigned long numBytesRead;
+
+    /**
+     * Gets the request that loaded this file.
+     * null after the request has finished loading.
+     */
+    readonly attribute nsIRequest request;
+};
diff --git a/netwerk/base/nsIStreamTransportService.idl b/netwerk/base/nsIStreamTransportService.idl
new file mode 100644
index 0000000000..3a1c5a4239
--- /dev/null
+++ b/netwerk/base/nsIStreamTransportService.idl
@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsITransport;
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsIInputAvailableCallback;
+
+/**
+ * This service read/writes a stream on a background thread.
+ *
+ * Note: instead of using this interface, probably you want to use
+ * NS_MakeAsyncNonBlockingInputStream.
+ *
+ * Use this service to transform any blocking stream (e.g., file stream)
+ * into a fully asynchronous stream that can be read/written without
+ * blocking the main thread.
+ */
+[builtinclass, scriptable, uuid(5e0adf7d-9785-45c3-a193-04f25a75da8f)]
+interface nsIStreamTransportService : nsISupports
+{
+    /**
+     * CreateInputTransport
+     *
+     * @param aStream
+     *        The input stream that will be read on a background thread.
+     *        This stream must implement "blocking" stream semantics.
+     * @param aCloseWhenDone
+     *        Specify this flag to have the input stream closed once its
+     *        contents have been completely read.
+     *
+     * @return nsITransport instance.
+     */
+    nsITransport createInputTransport(in nsIInputStream aStream,
+                                      in boolean aCloseWhenDone);
+
+    void InputAvailable(in nsIInputStream aStream,
+                        in nsIInputAvailableCallback aCallback);
+};
+
+[uuid(ff2da731-44d0-4dd9-8236-c99387fec721)]
+interface nsIInputAvailableCallback : nsISupports
+{
+  void onInputAvailableComplete(in unsigned long long available,
+                                in nsresult available_return_code);
+};
diff --git a/netwerk/base/nsISyncStreamListener.idl b/netwerk/base/nsISyncStreamListener.idl
new file mode 100644
index 0000000000..9a46dda787
--- /dev/null
+++ b/netwerk/base/nsISyncStreamListener.idl
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIStreamListener.idl"
+
+[scriptable, uuid(7e1aa658-6e3f-4521-9946-9685a169f764)]
+interface nsISyncStreamListener : nsIStreamListener
+{
+    /**
+     * Returns an input stream that when read will fetch data delivered to the
+     * sync stream listener.  The nsIInputStream implementation will wait for
+     * OnDataAvailable events before returning from Read.
+     *
+     * NOTE: Reading from the returned nsIInputStream may spin the current
+     * thread's event queue, which could result in any event being processed.
+     */
+    readonly attribute nsIInputStream inputStream;
+};
diff --git a/netwerk/base/nsISystemProxySettings.idl b/netwerk/base/nsISystemProxySettings.idl
new file mode 100644
index 0000000000..9cd561fb64
--- /dev/null
+++ b/netwerk/base/nsISystemProxySettings.idl
@@ -0,0 +1,42 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface allows the proxy code to use platform-specific proxy
+ * settings when the proxy preference is set to "automatic discovery". This service
+ * acts like a PAC parser to netwerk, but it will actually read the system settings and
+ * either return the proper proxy data from the autoconfig URL specified in the system proxy,
+ * or generate proxy data based on the system's manual proxy settings.
+ */
+[scriptable, uuid(971591cd-277e-409a-bbf6-0a79879cd307)]
+interface nsISystemProxySettings : nsISupports
+{
+    /**
+     * Whether or not it is appropriate to execute getProxyForURI off the main thread.
+     * If that method can block (e.g. for WPAD as windows does) then it must be
+     * not mainThreadOnly to avoid creating main thread jank. The main thread only option is
+     * provided for implementations that do not block but use other main thread only
+     * functions such as dbus.
+     */
+    readonly attribute bool mainThreadOnly;
+
+    /**
+     * If non-empty, use this PAC file. If empty, call getProxyForURI instead.
+     */
+    readonly attribute AUTF8String PACURI;
+
+    /**
+     * See ProxyAutoConfig::getProxyForURI; this function behaves similarly except
+     * a more relaxed return string is allowed that includes full urls instead of just
+     * host:port syntax. e.g. "PROXY http://www.foo.com:8080" instead of
+     * "PROXY www.foo.com:8080"
+     */
+    AUTF8String getProxyForURI(in AUTF8String testSpec,
+                               in AUTF8String testScheme,
+                               in AUTF8String testHost,
+                               in int32_t     testPort);
+};
diff --git a/netwerk/base/nsITLSServerSocket.idl b/netwerk/base/nsITLSServerSocket.idl
new file mode 100644
index 0000000000..e944f23af7
--- /dev/null
+++ b/netwerk/base/nsITLSServerSocket.idl
@@ -0,0 +1,183 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIServerSocket.idl"
+
+interface nsIX509Cert;
+interface nsITLSServerSecurityObserver;
+interface nsISocketTransport;
+
+[scriptable, uuid(cc2c30f9-cfaa-4b8a-bd44-c24881981b74)]
+interface nsITLSServerSocket : nsIServerSocket
+{
+  /**
+   * serverCert
+   *
+   * The server's certificate that is presented to the client during the TLS
+   * handshake.  This is required to be set before calling |asyncListen|.
+   */
+  attribute nsIX509Cert serverCert;
+
+  /**
+   * setSessionTickets
+   *
+   * Whether the server should support session tickets.  Defaults to true.  This
+   * should be set before calling |asyncListen| if you wish to change the
+   * default.
+   */
+  void setSessionTickets(in boolean aSessionTickets);
+
+  /**
+   * Values for setRequestClientCertificate
+   */
+  // Never request
+  const unsigned long REQUEST_NEVER           = 0;
+  // Request (but do not require) during the first handshake only
+  const unsigned long REQUEST_FIRST_HANDSHAKE = 1;
+  // Request (but do not require) during each handshake
+  const unsigned long REQUEST_ALWAYS          = 2;
+  // Require during the first handshake only
+  const unsigned long REQUIRE_FIRST_HANDSHAKE = 3;
+  // Require during each handshake
+  const unsigned long REQUIRE_ALWAYS          = 4;
+
+  /**
+   * setRequestClientCertificate
+   *
+   * Whether the server should request and/or require a client auth certificate
+   * from the client.  Defaults to REQUEST_NEVER.  See the possible options
+   * above.  This should be set before calling |asyncListen| if you wish to
+   * change the default.
+   */
+  void setRequestClientCertificate(in unsigned long aRequestClientCert);
+
+  /**
+   * setVersionRange
+   *
+   * The server's TLS versions that is used by the TLS handshake.
+   * This is required to be set before calling |asyncListen|.
+   *
+   * aMinVersion and aMaxVersion is a TLS version value from
+   * |nsITLSClientStatus| constants.
+   */
+  void setVersionRange(in unsigned short aMinVersion,
+                       in unsigned short aMaxVersion);
+};
+
+/**
+ * Security summary for a given TLS client connection being handled by a
+ * |nsITLSServerSocket| server.
+ *
+ * This is accessible through the security info object on the transport, which
+ * will be an instance of |nsITLSServerConnectionInfo| (see below).
+ *
+ * The values of these attributes are available once the |onHandshakeDone|
+ * method of the security observer has been called (see
+ * |nsITLSServerSecurityObserver| below).
+ */
+[scriptable, uuid(19668ea4-e5ad-4182-9698-7e890d48f327)]
+interface nsITLSClientStatus : nsISupports
+{
+  /**
+   * peerCert
+   *
+   * The client's certificate, if one was requested via |requestCertificate|
+   * above and supplied by the client.
+   */
+  readonly attribute nsIX509Cert peerCert;
+
+  /**
+   * Values for tlsVersionUsed, as defined by TLS
+   */
+  const short SSL_VERSION_3   = 0x0300;
+  const short TLS_VERSION_1   = 0x0301;
+  const short TLS_VERSION_1_1 = 0x0302;
+  const short TLS_VERSION_1_2 = 0x0303;
+  const short TLS_VERSION_1_3 = 0x0304;
+  const short TLS_VERSION_UNKNOWN = -1;
+
+  /**
+   * tlsVersionUsed
+   *
+   * The version of TLS used by the connection.  See values above.
+   */
+  readonly attribute short tlsVersionUsed;
+
+  /**
+   * cipherName
+   *
+   * Name of the cipher suite used, such as
+   * "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256".
+   * See security/nss/lib/ssl/sslinfo.c for the possible values.
+   */
+  readonly attribute ACString cipherName;
+
+  /**
+   * keyLength
+   *
+   * The "effective" key size of the symmetric key in bits.
+   */
+  readonly attribute unsigned long keyLength;
+
+  /**
+   * macLength
+   *
+   * The size of the MAC in bits.
+   */
+  readonly attribute unsigned long macLength;
+};
+
+/**
+ * Connection info for a given TLS client connection being handled by a
+ * |nsITLSServerSocket| server.  This object is thread-safe.
+ *
+ * This is exposed as the security info object on the transport, so it can be
+ * accessed via |transport.securityInfo|.
+ *
+ * This interface is available by the time the |onSocketAttached| is called,
+ * which is the first time the TLS server consumer is notified of a new client.
+ */
+[scriptable, uuid(8a93f5d5-eddd-4c62-a4bd-bfd297653184)]
+interface nsITLSServerConnectionInfo : nsISupports
+{
+  /**
+   * setSecurityObserver
+   *
+   * Set the security observer to be notified when the TLS handshake has
+   * completed.
+   */
+  void setSecurityObserver(in nsITLSServerSecurityObserver observer);
+
+  /**
+   * serverSocket
+   *
+   * The nsITLSServerSocket instance that accepted this client connection.
+   */
+  readonly attribute nsITLSServerSocket serverSocket;
+
+  /**
+   * status
+   *
+   * Security summary for this TLS client connection.  Note that the values of
+   * this interface are not available until the TLS handshake has completed.
+   * See |nsITLSClientStatus| above for more details.
+   */
+  readonly attribute nsITLSClientStatus status;
+};
+
+[scriptable, uuid(1f62e1ae-e546-4a38-8917-d428472ed736)]
+interface nsITLSServerSecurityObserver : nsISupports
+{
+  /**
+   * onHandsakeDone
+   *
+   * This method is called once the TLS handshake is completed.  This takes
+   * place after |onSocketAccepted| has been called, which typically opens the
+   * streams to keep things moving along. It's important to be aware that the
+   * handshake has not completed at the point that |onSocketAccepted| is called,
+   * so no security verification can be done until this method is called.
+   */
+  void onHandshakeDone(in nsITLSServerSocket aServer,
+                       in nsITLSClientStatus aStatus);
+};
diff --git a/netwerk/base/nsIThreadRetargetableRequest.idl b/netwerk/base/nsIThreadRetargetableRequest.idl
new file mode 100644
index 0000000000..5087987567
--- /dev/null
+++ b/netwerk/base/nsIThreadRetargetableRequest.idl
@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsISerialEventTarget;
+
+/**
+ * nsIThreadRetargetableRequest
+ *
+ * Should be implemented by requests that support retargeting delivery of
+ * data off the main thread.
+ */
+[uuid(27b84c48-5a73-4ba4-a8a4-8b5e649a145e)]
+interface nsIThreadRetargetableRequest : nsISupports
+{
+  /**
+   * Called to retarget delivery of OnDataAvailable to another thread. Should
+   * only be called before AsyncOpen for nsIWebsocketChannels, or during
+   * OnStartRequest for nsIChannels.
+   * Note: For nsIChannels, OnStartRequest and OnStopRequest will still be
+   * delivered on the main thread.
+   *
+   * @param aNewTarget New event target, e.g. thread or threadpool.
+   *
+   * Note: no return value is given. If the retargeting cannot be handled,
+   * normal delivery to the main thread will continue. As such, listeners
+   * should be ready to deal with OnDataAvailable on either the main thread or
+   * the new target thread.
+   */
+  void retargetDeliveryTo(in nsISerialEventTarget aNewTarget);
+
+  /**
+   * Returns the event target where OnDataAvailable events will be dispatched.
+   *
+   * This is only valid after OnStartRequest has been called. Any time before
+   * that point, the value may be changed by `retargetDeliveryTo` calls.
+   */
+  readonly attribute nsISerialEventTarget deliveryTarget;
+};
diff --git a/netwerk/base/nsIThreadRetargetableStreamListener.idl b/netwerk/base/nsIThreadRetargetableStreamListener.idl
new file mode 100644
index 0000000000..f02ae35d34
--- /dev/null
+++ b/netwerk/base/nsIThreadRetargetableStreamListener.idl
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsIThreadRetargetableStreamListener
+ *
+ * To be used by classes which implement nsIStreamListener and whose
+ * OnDataAvailable callback may be retargeted for delivery off the main thread.
+ */
+[uuid(fb2304b8-f82f-4433-af68-d874a2ebbdc1)]
+interface nsIThreadRetargetableStreamListener : nsISupports
+{
+  /**
+   * Checks this listener and any next listeners it may have to verify that
+   * they can receive OnDataAvailable off the main thread. It is the
+   * responsibility of the implementing class to decide on the criteria to
+   * determine if retargeted delivery of these methods is possible, but it must
+   * check any and all nsIStreamListener objects that might be called in the
+   * listener chain.
+   *
+   * An exception should be thrown if a listener in the chain does not
+   * support retargeted delivery, i.e. if the next listener does not implement
+   * nsIThreadRetargetableStreamListener, or a call to its checkListenerChain()
+   * fails.
+   */
+  void checkListenerChain();
+};
diff --git a/netwerk/base/nsIThrottledInputChannel.idl b/netwerk/base/nsIThrottledInputChannel.idl
new file mode 100644
index 0000000000..ae8d7321db
--- /dev/null
+++ b/netwerk/base/nsIThrottledInputChannel.idl
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIInputStream;
+interface nsIAsyncInputStream;
+
+/**
+ * An instance of this interface can be used to throttle the uploads
+ * of a group of associated channels.
+ */
+[scriptable, uuid(6b4b96fe-3c67-4587-af7b-58b6b17da411)]
+interface nsIInputChannelThrottleQueue : nsISupports
+{
+    /**
+     * Initialize this object with the mean and maximum bytes per
+     * second that will be allowed.  Neither value may be zero, and
+     * the maximum must not be less than the mean.
+     *
+     * @param aMeanBytesPerSecond
+     *        Mean number of bytes per second.
+     * @param aMaxBytesPerSecond
+     *        Maximum number of bytes per second.
+     */
+    void init(in unsigned long aMeanBytesPerSecond, in unsigned long aMaxBytesPerSecond);
+
+    /**
+     * Internal use only. Get the values set by init method.
+     */
+    [noscript] readonly attribute unsigned long meanBytesPerSecond;
+    [noscript] readonly attribute unsigned long maxBytesPerSecond;
+
+
+    /**
+     * Return the number of bytes that are available to the caller in
+     * this time slice.
+     *
+     * @param aRemaining
+     *        The number of bytes available to be processed
+     * @return the number of bytes allowed to be processed during this
+     *        time slice; this will never be greater than aRemaining.
+     */
+    unsigned long available(in unsigned long aRemaining);
+
+    /**
+     * Record a successful read.
+     *
+     * @param aBytesRead
+     *        The number of bytes actually read.
+     */
+    void recordRead(in unsigned long aBytesRead);
+
+    /**
+     * Return the number of bytes allowed through this queue.  This is
+     * the sum of all the values passed to recordRead.  This method is
+     * primarily useful for testing.
+     */
+    unsigned long long bytesProcessed();
+
+    /**
+     * Wrap the given input stream in a new input stream which
+     * throttles the incoming data.
+     *
+     * @param aInputStream the input stream to wrap
+     * @return a new input stream that throttles the data.
+     */
+    nsIAsyncInputStream wrapStream(in nsIInputStream aInputStream);
+};
+
+/**
+ * A throttled input channel can be managed by an
+ * nsIInputChannelThrottleQueue to limit how much data is sent during
+ * a given time slice.
+ */
+[scriptable, uuid(0a32a100-c031-45b6-9e8b-0444c7d4a143)]
+interface nsIThrottledInputChannel : nsISupports
+{
+    /**
+     * The queue that manages this channel.  Multiple channels can
+     * share a single queue.  A null value means that no throttling
+     * will be done.
+     */
+    attribute nsIInputChannelThrottleQueue throttleQueue;
+};
diff --git a/netwerk/base/nsITimedChannel.idl b/netwerk/base/nsITimedChannel.idl
new file mode 100644
index 0000000000..4707bf1b7a
--- /dev/null
+++ b/netwerk/base/nsITimedChannel.idl
@@ -0,0 +1,128 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+interface nsIArray;
+interface nsIPrincipal;
+%{C++
+namespace mozilla {
+class TimeStamp;
+}
+#include "nsTArrayForwardDeclare.h"
+#include "nsCOMPtr.h"
+%}
+
+native TimeStamp(mozilla::TimeStamp);
+
+[scriptable, uuid(c2d9e95b-9cc9-4f47-9ef6-1de0cf7ebc75)]
+interface nsIServerTiming : nsISupports {
+  [must_use] readonly attribute ACString name;
+  [must_use] readonly attribute double duration;
+  [must_use] readonly attribute ACString description;
+};
+
+[ref] native nsServerTimingArrayRef(nsTArray<nsCOMPtr<nsIServerTiming>>);
+
+// All properties return zero if the value is not available
+[scriptable, uuid(ca63784d-959c-4c3a-9a59-234a2a520de0)]
+interface nsITimedChannel : nsISupports {
+  // Set this attribute to true to enable collection of timing data.
+  // channelCreationTime will be available even with this attribute set to
+  // false.
+  attribute boolean timingEnabled;
+
+  // The number of redirects
+  attribute uint8_t redirectCount;
+  attribute uint8_t internalRedirectCount;
+
+  // These properties should only be written externally when they must be
+  // propagated across an internal redirect.  For example, when a service
+  // worker interception falls back to network we need to copy the original
+  // timing values to the new nsHttpChannel.
+  [noscript] attribute TimeStamp channelCreation;
+  [noscript] attribute TimeStamp asyncOpen;
+
+  // The following are only set when the request is intercepted by a service
+  // worker no matter the response is synthesized.
+  [noscript] attribute TimeStamp launchServiceWorkerStart;
+  [noscript] attribute TimeStamp launchServiceWorkerEnd;
+  [noscript] attribute TimeStamp dispatchFetchEventStart;
+  [noscript] attribute TimeStamp dispatchFetchEventEnd;
+  [noscript] attribute TimeStamp handleFetchEventStart;
+  [noscript] attribute TimeStamp handleFetchEventEnd;
+
+  // The following are only set when the document is not (only) read from the
+  // cache
+  [noscript] readonly attribute TimeStamp domainLookupStart;
+  [noscript] readonly attribute TimeStamp domainLookupEnd;
+  [noscript] readonly attribute TimeStamp connectStart;
+  [noscript] readonly attribute TimeStamp tcpConnectEnd;
+  [noscript] readonly attribute TimeStamp secureConnectionStart;
+  [noscript] readonly attribute TimeStamp connectEnd;
+  [noscript] readonly attribute TimeStamp requestStart;
+  [noscript] readonly attribute TimeStamp responseStart;
+  [noscript] readonly attribute TimeStamp responseEnd;
+
+  // The redirect attributes timings must be writeble, se we can transfer
+  // the data from one channel to the redirected channel.
+  [noscript] attribute TimeStamp redirectStart;
+  [noscript] attribute TimeStamp redirectEnd;
+
+  // The initiator type
+  [noscript] attribute AString initiatorType;
+
+  // This flag should be set to false only if a cross-domain redirect occurred
+  [noscript] attribute boolean allRedirectsSameOrigin;
+  // This flag is set to false if the timing allow check fails
+  [noscript] attribute boolean allRedirectsPassTimingAllowCheck;
+  // Implements the timing-allow-check to determine if we should report
+  // timing info for the resourceTiming object.
+  [noscript] boolean timingAllowCheck(in nsIPrincipal origin);
+  %{C++
+  inline bool TimingAllowCheck(nsIPrincipal* aOrigin) {
+    bool allowed = false;
+    return NS_SUCCEEDED(TimingAllowCheck(aOrigin, &allowed)) && allowed;
+  }
+  %}
+
+  // The following are only set if the document is (partially) read from the
+  // cache
+  [noscript] readonly attribute TimeStamp cacheReadStart;
+  [noscript] readonly attribute TimeStamp cacheReadEnd;
+
+  // The time when the transaction was submitted to the Connection Manager.
+  // Not reported to resource/navigation timing, only for performance telemetry.
+  [noscript] readonly attribute TimeStamp transactionPending;
+
+  // All following are PRTime versions of the above.
+  readonly attribute PRTime channelCreationTime;
+  readonly attribute PRTime asyncOpenTime;
+  readonly attribute PRTime launchServiceWorkerStartTime;
+  readonly attribute PRTime launchServiceWorkerEndTime;
+  readonly attribute PRTime dispatchFetchEventStartTime;
+  readonly attribute PRTime dispatchFetchEventEndTime;
+  readonly attribute PRTime handleFetchEventStartTime;
+  readonly attribute PRTime handleFetchEventEndTime;
+  readonly attribute PRTime domainLookupStartTime;
+  readonly attribute PRTime domainLookupEndTime;
+  readonly attribute PRTime connectStartTime;
+  readonly attribute PRTime tcpConnectEndTime;
+  readonly attribute PRTime secureConnectionStartTime;
+  readonly attribute PRTime connectEndTime;
+  readonly attribute PRTime requestStartTime;
+  readonly attribute PRTime responseStartTime;
+  readonly attribute PRTime responseEndTime;
+  readonly attribute PRTime cacheReadStartTime;
+  readonly attribute PRTime cacheReadEndTime;
+  readonly attribute PRTime redirectStartTime;
+  readonly attribute PRTime redirectEndTime;
+  // Not reported to resource/navigation timing, only for performance telemetry.
+  readonly attribute PRTime transactionPendingTime;
+
+  // If this attribute is false, this resource MUST NOT be reported in resource timing.
+  [noscript] attribute boolean reportResourceTiming;
+
+  readonly attribute nsIArray serverTiming;
+  nsServerTimingArrayRef getNativeServerTiming();
+};
diff --git a/netwerk/base/nsITraceableChannel.idl b/netwerk/base/nsITraceableChannel.idl
new file mode 100644
index 0000000000..4d325d4fcb
--- /dev/null
+++ b/netwerk/base/nsITraceableChannel.idl
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIStreamListener;
+
+/**
+ * A channel implementing this interface allows one to intercept its data by
+ * inserting intermediate stream listeners.
+ */
+[scriptable, uuid(68167b0b-ef34-4d79-a09a-8045f7c5140e)]
+interface nsITraceableChannel : nsISupports
+{
+    /*
+     * Replace the channel's listener with a new one, and return the listener
+     * the channel used to have. The new listener intercepts OnStartRequest,
+     * OnDataAvailable and OnStopRequest calls and must pass them to
+     * the original listener after examination. If multiple callers replace
+     * the channel's listener, a chain of listeners is created.
+     * The caller of setNewListener has no way to control at which place
+     * in the chain its listener is placed.
+     *
+     * @param aMustApplyContentConversion Pass true if the new listener requires
+     * content conversion to already be applied by the channel.
+     *
+     * Note: The caller of setNewListener must not delay passing
+     * OnStartRequest to the original listener.
+     *
+     * Note2: A channel may restrict when the listener can be replaced.
+     * It is not recommended to allow listener replacement after OnStartRequest
+     * has been called.
+     */
+    nsIStreamListener setNewListener(in nsIStreamListener aListener, [optional] in boolean aMustApplyContentConversion);
+};
diff --git a/netwerk/base/nsITransport.idl b/netwerk/base/nsITransport.idl
new file mode 100644
index 0000000000..856c4e2000
--- /dev/null
+++ b/netwerk/base/nsITransport.idl
@@ -0,0 +1,162 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIInputStream;
+interface nsIOutputStream;
+interface nsITransportEventSink;
+interface nsIEventTarget;
+
+/**
+ * nsITransport
+ *
+ * This interface provides a common way of accessing i/o streams connected
+ * to some resource.  This interface does not in any way specify the resource.
+ * It provides methods to open blocking or non-blocking, buffered or unbuffered
+ * streams to the resource.  The name "transport" is meant to connote the
+ * inherent data transfer implied by this interface (i.e., data is being
+ * transfered in some fashion via the streams exposed by this interface).
+ *
+ * A transport can have an event sink associated with it.  The event sink
+ * receives transport-specific events as the transfer is occuring.  For a
+ * socket transport, these events can include status about the connection.
+ * See nsISocketTransport for more info about socket transport specifics.
+ */
+[scriptable, uuid(2a8c6334-a5e6-4ec3-9865-1256541446fb)]
+interface nsITransport : nsISupports
+{
+    /**
+     * Open flags.
+     */
+    const unsigned long OPEN_BLOCKING   = 1<<0;
+    const unsigned long OPEN_UNBUFFERED = 1<<1;
+
+    /**
+     * Open an input stream on this transport.
+     *
+     * Flags have the following meaning:
+     *
+     * OPEN_BLOCKING
+     *   If specified, then the resulting stream will have blocking stream
+     *   semantics.  This means that if the stream has no data and is not
+     *   closed, then reading from it will block the calling thread until
+     *   at least one byte is available or until the stream is closed.
+     *   If this flag is NOT specified, then the stream has non-blocking
+     *   stream semantics.  This means that if the stream has no data and is
+     *   not closed, then reading from it returns NS_BASE_STREAM_WOULD_BLOCK.
+     *   In addition, in non-blocking mode, the stream is guaranteed to
+     *   support nsIAsyncInputStream.  This interface allows the consumer of
+     *   the stream to be notified when the stream can again be read.
+     *
+     * OPEN_UNBUFFERED
+     *   If specified, the resulting stream may not support ReadSegments.
+     *   ReadSegments is only gauranteed to be implemented when this flag is
+     *   NOT specified.
+     *
+     * @param aFlags
+     *        optional transport specific flags.
+     * @param aSegmentSize
+     *        if OPEN_UNBUFFERED is not set, then this parameter specifies the
+     *        size of each buffer segment (pass 0 to use default value).
+     * @param aSegmentCount
+     *        if OPEN_UNBUFFERED is not set, then this parameter specifies the
+     *        maximum number of buffer segments (pass 0 to use default value).
+     */
+    nsIInputStream openInputStream(in unsigned long aFlags,
+                                   in unsigned long aSegmentSize,
+                                   in unsigned long aSegmentCount);
+
+    /**
+     * Open an output stream on this transport.
+     *
+     * Flags have the following meaning:
+     *
+     * OPEN_BLOCKING
+     *   If specified, then the resulting stream will have blocking stream
+     *   semantics.  This means that if the stream is full and is not closed,
+     *   then writing to it will block the calling thread until ALL of the
+     *   data can be written or until the stream is closed.  If this flag is
+     *   NOT specified, then the stream has non-blocking stream semantics.
+     *   This means that if the stream is full and is not closed, then writing
+     *   to it returns NS_BASE_STREAM_WOULD_BLOCK.  In addition, in non-
+     *   blocking mode, the stream is guaranteed to support
+     *   nsIAsyncOutputStream.  This interface allows the consumer of the
+     *   stream to be notified when the stream can again accept more data.
+     *
+     * OPEN_UNBUFFERED
+     *   If specified, the resulting stream may not support WriteSegments and
+     *   WriteFrom.  WriteSegments and WriteFrom are only guaranteed to be
+     *   implemented when this flag is NOT specified.
+     *
+     * @param aFlags
+     *        optional transport specific flags.
+     * @param aSegmentSize
+     *        if OPEN_UNBUFFERED is not set, then this parameter specifies the
+     *        size of each buffer segment (pass 0 to use default value).
+     * @param aSegmentCount
+     *        if OPEN_UNBUFFERED is not set, then this parameter specifies the
+     *        maximum number of buffer segments (pass 0 to use default value).
+     */
+    nsIOutputStream openOutputStream(in unsigned long aFlags,
+                                     in unsigned long aSegmentSize,
+                                     in unsigned long aSegmentCount);
+
+    /**
+     * Close the transport and any open streams.
+     *
+     * @param aReason
+     *        the reason for closing the stream.
+     */
+    void close(in nsresult aReason);
+
+    /**
+     * Set the transport event sink.
+     *
+     * @param aSink
+     *        receives transport layer notifications
+     * @param aEventTarget
+     *        indicates the event target to which the notifications should
+     *        be delivered.  if NULL, then the notifications may occur on
+     *        any thread.
+     */
+    void setEventSink(in nsITransportEventSink aSink,
+                      in nsIEventTarget aEventTarget);
+
+    /**
+     * Generic nsITransportEventSink status codes.  nsITransport
+     * implementations may override these status codes with their own more
+     * specific status codes (e.g., see nsISocketTransport).
+     *
+     * In C++, these constants have a type of uint32_t, so C++ callers must use
+     * the NS_NET_STATUS_* constants defined below, which have a type of
+     * nsresult.
+     */
+    const unsigned long STATUS_READING = 0x4b0008;
+    const unsigned long STATUS_WRITING = 0x4b0009;
+};
+
+[scriptable, uuid(EDA4F520-67F7-484b-A691-8C3226A5B0A6)]
+interface nsITransportEventSink : nsISupports
+{
+    /**
+     * Transport status notification.
+     *
+     * @param aTransport
+     *        the transport sending this status notification.
+     * @param aStatus
+     *        the transport status. See nsISocketTransport for socket specific
+     *        status codes and more comments.
+     * @param aProgress
+     *        the amount of data either read or written depending on the value
+     *        of the status code.  this value is relative to aProgressMax.
+     * @param aProgressMax
+     *        the maximum amount of data that will be read or written.  if
+     *        unknown, -1 will be passed.
+     */
+    void onTransportStatus(in nsITransport aTransport,
+                           in nsresult aStatus,
+                           in long long aProgress,
+                           in long long aProgressMax);
+};
diff --git a/netwerk/base/nsIUDPSocket.idl b/netwerk/base/nsIUDPSocket.idl
new file mode 100644
index 0000000000..957df57c2c
--- /dev/null
+++ b/netwerk/base/nsIUDPSocket.idl
@@ -0,0 +1,406 @@
+/* vim:set ts=4 sw=4 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsINetAddr;
+interface nsIUDPSocketListener;
+interface nsIUDPSocketSyncListener;
+interface nsIUDPMessage;
+interface nsISocketTransport;
+interface nsIOutputStream;
+interface nsIInputStream;
+interface nsIPrincipal;
+
+%{ C++
+#include "nsTArrayForwardDeclare.h"
+namespace mozilla {
+namespace net {
+union NetAddr;
+}
+}
+%}
+native NetAddr(mozilla::net::NetAddr);
+[ptr] native NetAddrPtr(mozilla::net::NetAddr);
+[ref] native Uint8TArrayRef(FallibleTArray<uint8_t>);
+
+/**
+ * nsIUDPSocket
+ *
+ * An interface to a UDP socket that can accept incoming connections.
+ */
+[scriptable, uuid(d423bf4e-4499-40cf-bc03-153e2bf206d1)]
+interface nsIUDPSocket : nsISupports
+{
+    /**
+     * init
+     *
+     * This method initializes a UDP socket.
+     *
+     * @param aPort
+     *        The port of the UDP socket.  Pass -1 to indicate no preference,
+     *        and a port will be selected automatically.
+     * @param aLoopbackOnly
+     *        If true, the UDP socket will only respond to connections on the
+     *        local loopback interface.  Otherwise, it will accept connections
+     *        from any interface.  To specify a particular network interface,
+     *        use initWithAddress.
+     * @param aPrincipal
+     *        The principal connected to this socket.
+     * @param aAddressReuse
+     *        If true, the socket is allowed to be bound to an address that is
+     *        already in use. Default is true.
+     */
+    [optional_argc] void init(in long aPort,
+                              in boolean aLoopbackOnly,
+                              in nsIPrincipal aPrincipal,
+                              [optional] in boolean aAddressReuse);
+
+    [optional_argc] void init2(in AUTF8String aAddr,
+                               in long aPort,
+                               in nsIPrincipal aPrincipal,
+                               [optional] in boolean aAddressReuse);
+
+    /**
+     * initWithAddress
+     *
+     * This method initializes a UDP socket, and binds it to a particular
+     * local address (and hence a particular local network interface).
+     *
+     * @param aAddr
+     *        The address to which this UDP socket should be bound.
+     * @param aPrincipal
+     *        The principal connected to this socket.
+     * @param aAddressReuse
+     *        If true, the socket is allowed to be bound to an address that is
+     *        already in use. Default is true.
+     */
+    [noscript, optional_argc] void initWithAddress([const] in NetAddrPtr aAddr,
+                                                   in nsIPrincipal aPrincipal,
+                                                   [optional] in boolean aAddressReuse);
+
+    /**
+     * close
+     *
+     * This method closes a UDP socket.  This does not affect already
+     * connected client sockets (i.e., the nsISocketTransport instances
+     * created from this UDP socket).  This will cause the onStopListening
+     * event to asynchronously fire with a status of NS_BINDING_ABORTED.
+     */
+    void close();
+
+    /**
+     * asyncListen
+     *
+     * This method puts the UDP socket in the listening state.  It will
+     * asynchronously listen for and accept client connections.  The listener
+     * will be notified once for each client connection that is accepted.  The
+     * listener's onSocketAccepted method will be called on the same thread
+     * that called asyncListen (the calling thread must have a nsIEventTarget).
+     *
+     * The listener will be passed a reference to an already connected socket
+     * transport (nsISocketTransport).  See below for more details.
+     *
+     * @param aListener
+     *        The listener to be notified when client connections are accepted.
+     */
+    void asyncListen(in nsIUDPSocketListener aListener);
+
+    /**
+     * This adds a nsIUDPSocketSyncListener listener (defined below).
+     * When data is available onPacketReceived is called and the lisener uses
+     * recvWithAddr to actually retrive data from the socket.
+     * The listener can be use only if it runs on the socket thread.
+     * If it is used off the socket thread there is a risk of triggering a bug
+     * in OS thatcan cause a crash.
+     */
+    void syncListen(in nsIUDPSocketSyncListener aListener);
+
+    /**
+     * connect
+     *
+     * This method connects the UDP socket to a remote UDP address.
+     *
+     * @param aRemoteAddr
+     *        The remote address to connect to
+     */
+     void connect([const] in NetAddrPtr aAddr);
+
+    /**
+     * Returns the local address of this UDP socket
+     */
+    readonly attribute nsINetAddr localAddr;
+
+    /**
+     * Returns the port of this UDP socket.
+     */
+    readonly attribute long port;
+
+    /**
+     * Returns the address to which this UDP socket is bound.  Since a
+     * UDP socket may be bound to multiple network devices, this address
+     * may not necessarily be specific to a single network device.  In the
+     * case of an IP socket, the IP address field would be zerod out to
+     * indicate a UDP socket bound to all network devices.  Therefore,
+     * this method cannot be used to determine the IP address of the local
+     * system.  See nsIDNSService::myHostName if this is what you need.
+     */
+    [noscript] NetAddr getAddress();
+
+    /**
+     * send
+     *
+     * Send out the datagram to specified remote host and port.
+     * DNS lookup will be triggered.
+     *
+     * @param host The remote host name.
+     * @param port The remote port.
+     * @param data The buffer containing the data to be written.
+     * @return number of bytes written. (0 or length of data)
+     */
+    unsigned long send(in AUTF8String host, in unsigned short port,
+                       in Array<uint8_t> data);
+
+    /**
+     * sendWithAddr
+     *
+     * Send out the datagram to specified remote host and port.
+     *
+     * @param addr The remote host address.
+     * @param data The buffer containing the data to be written.
+     * @return number of bytes written. (0 or length of data)
+     */
+    unsigned long sendWithAddr(in nsINetAddr addr,
+                               in Array<uint8_t> data);
+
+
+    /**
+     * Receive a datagram.
+     * @param addr The remote host address.
+     * @param data The buffer to store received datagram.
+     */
+    [noscript] void recvWithAddr(out NetAddr addr,
+                                 out Array<uint8_t> data);
+
+    /**
+     * sendWithAddress
+     *
+     * Send out the datagram to specified remote address and port.
+     *
+     * @param addr The remote host address.
+     * @param data The buffer containing the data to be written.
+     * @return number of bytes written. (0 or length of data)
+     */
+    [noscript] unsigned long sendWithAddress([const] in NetAddrPtr addr,
+                                             in Array<uint8_t> data);
+
+    /**
+     * sendBinaryStream
+     *
+     * Send out the datagram to specified remote address and port.
+     *
+     * @param host The remote host name.
+     * @param port The remote port.
+     * @param stream The input stream to be sent. This must be a buffered stream implementation.
+     */
+    void sendBinaryStream(in AUTF8String host, in unsigned short port,
+                          in nsIInputStream stream);
+
+    /**
+     * sendBinaryStreamWithAddress
+     *
+     * Send out the datagram to specified remote address and port.
+     *
+     * @param addr The remote host address.
+     * @param stream The input stream to be sent. This must be a buffered stream implementation.
+     */
+    void sendBinaryStreamWithAddress([const] in NetAddrPtr addr,
+                                     in nsIInputStream stream);
+
+    /**
+     * joinMulticast
+     *
+     * Join the multicast group specified by |addr|.  You are then able to
+     * receive future datagrams addressed to the group.
+     *
+     * @param addr
+     *        The multicast group address.
+     * @param iface
+     *        The local address of the interface on which to join the group.  If
+     *        this is not specified, the OS may join the group on all interfaces
+     *        or only the primary interface.
+     */
+    void joinMulticast(in AUTF8String addr, [optional] in AUTF8String iface);
+    [noscript] void joinMulticastAddr([const] in NetAddr addr,
+                                      [const, optional] in NetAddrPtr iface);
+
+    /**
+     * leaveMulticast
+     *
+     * Leave the multicast group specified by |addr|.  You will no longer
+     * receive future datagrams addressed to the group.
+     *
+     * @param addr
+     *        The multicast group address.
+     * @param iface
+     *        The local address of the interface on which to leave the group.
+     *        If this is not specified, the OS may leave the group on all
+     *        interfaces or only the primary interface.
+     */
+    void leaveMulticast(in AUTF8String addr, [optional] in AUTF8String iface);
+    [noscript] void leaveMulticastAddr([const] in NetAddr addr,
+                                       [const, optional] in NetAddrPtr iface);
+
+    /**
+     * multicastLoopback
+     *
+     * Whether multicast datagrams sent via this socket should be looped back to
+     * this host (assuming this host has joined the relevant group).  Defaults
+     * to true.
+     * Note: This is currently write-only.
+     */
+    attribute boolean multicastLoopback;
+
+    /**
+     * multicastInterface
+     *
+     * The interface that should be used for sending future multicast datagrams.
+     * Note: This is currently write-only.
+     */
+    attribute AUTF8String multicastInterface;
+
+    /**
+     * multicastInterfaceAddr
+     *
+     * The interface that should be used for sending future multicast datagrams.
+     * Note: This is currently write-only.
+     */
+    [noscript] attribute NetAddr multicastInterfaceAddr;
+
+    /**
+     * recvBufferSize
+     *
+     * The size of the receive buffer. Default depends on the OS.
+     */
+    [noscript] attribute long recvBufferSize;
+
+    /**
+     * sendBufferSize
+     *
+     * The size of the send buffer. Default depends on the OS.
+     */
+    [noscript] attribute long sendBufferSize;
+
+    /**
+     * dontFragment
+     *
+     * The don't fragment flag.
+     * The socket must be initialized before calling this function.
+     */
+    [noscript] attribute boolean dontFragment;
+};
+
+/**
+ * nsIUDPSocketListener
+ *
+ * This interface is notified whenever a UDP socket accepts a new connection.
+ * The transport is in the connected state, and read/write streams can be opened
+ * using the normal nsITransport API.  The address of the client can be found by
+ * calling the nsISocketTransport::GetAddress method or by inspecting
+ * nsISocketTransport::GetHost, which returns a string representation of the
+ * client's IP address (NOTE: this may be an IPv4 or IPv6 string literal).
+ */
+[scriptable, uuid(2E4B5DD3-7358-4281-B81F-10C62EF39CB5)]
+interface nsIUDPSocketListener : nsISupports
+{
+    /**
+     * onPacketReceived
+     *
+     * This method is called when a client sends an UDP packet.
+     *
+     * @param aSocket
+     *        The UDP socket.
+     * @param aMessage
+     *        The message.
+     */
+    void onPacketReceived(in nsIUDPSocket aSocket,
+                          in nsIUDPMessage aMessage);
+
+    /**
+     * onStopListening
+     *
+     * This method is called when the listening socket stops for some reason.
+     * The UDP socket is effectively dead after this notification.
+     *
+     * @param aSocket
+     *        The UDP socket.
+     * @param aStatus
+     *        The reason why the UDP socket stopped listening.  If the
+     *        UDP socket was manually closed, then this value will be
+     *        NS_BINDING_ABORTED.
+     */
+    void onStopListening(in nsIUDPSocket aSocket, in nsresult aStatus);
+};
+
+/**
+ * nsIUDPMessage
+ *
+ * This interface is used to encapsulate an incomming UDP message
+ */
+[scriptable, builtinclass, uuid(afdc743f-9cc0-40d8-b442-695dc54bbb74)]
+interface nsIUDPMessage : nsISupports
+{
+    /**
+     * Address of the source of the message
+     */
+    readonly attribute nsINetAddr fromAddr;
+
+    /**
+     * Data of the message
+     */
+    readonly attribute ACString data;
+
+    /**
+     * Stream to send a response
+     */
+    readonly attribute nsIOutputStream outputStream;
+
+    /**
+     * Raw Data of the message
+     */
+    [implicit_jscontext] readonly attribute jsval rawData;
+    [noscript, notxpcom, nostdcall] Uint8TArrayRef getDataAsTArray();
+};
+
+[uuid(99f3d085-3d69-45da-a2c2-a6176af617cb)]
+interface nsIUDPSocketSyncListener : nsISupports
+{
+    /**
+     * onPacketReceived
+     *
+     * This method is called when a client sends an UDP packet.
+     *
+     * @param aSocket
+     *        The UDP socket.
+     * @param aMessage
+     *        The message.
+     */
+    void onPacketReceived(in nsIUDPSocket aSocket);
+
+    /**
+     * onStopListening
+     *
+     * This method is called when the listening socket stops for some reason.
+     * The UDP socket is effectively dead after this notification.
+     *
+     * @param aSocket
+     *        The UDP socket.
+     * @param aStatus
+     *        The reason why the UDP socket stopped listening.  If the
+     *        UDP socket was manually closed, then this value will be
+     *        NS_BINDING_ABORTED.
+     */
+    void onStopListening(in nsIUDPSocket aSocket, in nsresult aStatus);
+};
diff --git a/netwerk/base/nsIURI.idl b/netwerk/base/nsIURI.idl
new file mode 100644
index 0000000000..df1a98e873
--- /dev/null
+++ b/netwerk/base/nsIURI.idl
@@ -0,0 +1,322 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * URIs are essentially structured names for things -- anything. This interface
+ * provides accessors to get the most basic components of an URI.
+ * If you need to change some parts of the URI use nsIURIMutator.
+ * Subclasses, including nsIURL, impose greater structure on the URI.
+ *
+ * This interface follows Tim Berners-Lee's URI spec (RFC3986) [1], where the
+ * basic URI components are defined as such:
+ * <pre>
+ *      ftp://username:password@hostname:portnumber/pathname?query#ref
+ *      \ /   \               / \      / \        /\       / \   / \ /
+ *       -     ---------------   ------   --------  -------   ---   -
+ *       |            |             |        |         |       |    |
+ *       |            |             |        |      FilePath Query Ref
+ *       |            |             |       Port       \            /
+ *       |            |            Host      /          ------------
+ *       |         UserPass                 /                |
+ *     Scheme                              /                Path
+ *       \                                /
+ *        --------------------------------
+ *                       |
+ *                    PrePath
+ * </pre>
+ * The definition of the URI components has been extended to allow for
+ * internationalized domain names [2] and the more generic IRI structure [3].
+ *
+ * [1] https://tools.ietf.org/html/rfc3986
+ * [2] https://tools.ietf.org/html/rfc5890
+ * [3] https://tools.ietf.org/html/rfc3987
+ */
+
+%{C++
+#include "nsString.h"
+
+#undef GetPort  // XXX Windows!
+#undef SetPort  // XXX Windows!
+
+namespace mozilla {
+class Encoding;
+namespace ipc {
+class URIParams;
+}  // namespace ipc
+}  // namespace mozilla
+%}
+
+[ptr] native Encoding(const mozilla::Encoding);
+[ref] native URIParams(mozilla::ipc::URIParams);
+interface nsIURIMutator;
+
+/**
+ * nsIURI - interface for an uniform resource identifier w/ i18n support.
+ *
+ * AUTF8String attributes may contain unescaped UTF-8 characters.
+ * Consumers should be careful to escape the UTF-8 strings as necessary, but
+ * should always try to "display" the UTF-8 version as provided by this
+ * interface.
+ *
+ * AUTF8String attributes may also contain escaped characters.
+ *
+ * Unescaping URI segments is unadvised unless there is intimate
+ * knowledge of the underlying charset or there is no plan to display (or
+ * otherwise enforce a charset on) the resulting URI substring.
+ *
+ * The correct way to create an nsIURI from a string is via
+ * nsIIOService.newURI.
+ *
+ * NOTE: nsBinaryInputStream::ReadObject contains a hackaround to intercept the
+ * old (pre-gecko6) nsIURI IID and swap in the current IID instead, in order
+ * for sessionstore to work after an upgrade.  If this IID is revved further,
+ * we will need to add additional checks there for all intermediate IIDs, until
+ * ContentPrincipal is fixed to serialize its URIs as nsISupports (bug 662693).
+ */
+[scriptable, builtinclass, uuid(92073a54-6d78-4f30-913a-b871813208c6)]
+interface nsIURI : nsISupports
+{
+    /************************************************************************
+     * The URI is broken down into the following principal components:
+     */
+
+    /**
+     * Returns a string representation of the URI.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String spec;
+
+%{ C++
+    // An infallible wrapper for GetSpec() that returns a failure indication
+    // string if GetSpec() fails. It is most useful for creating
+    // logging/warning/error messages produced for human consumption, and when
+    // matching a URI spec against a fixed spec such as about:blank.
+    nsCString GetSpecOrDefault()
+    {
+        nsCString spec;
+        nsresult rv = GetSpec(spec);
+        if (NS_FAILED(rv)) {
+            spec.AssignLiteral("[nsIURI::GetSpec failed]");
+        }
+        return spec;
+    }
+%}
+
+    /**
+     * The prePath (eg. scheme://user:password@host:port) returns the string
+     * before the path.  This is useful for authentication or managing sessions.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String prePath;
+
+    /**
+     * The Scheme is the protocol to which this URI refers.  The scheme is
+     * restricted to the US-ASCII charset per RFC3986.
+     */
+    readonly attribute ACString scheme;
+
+    /**
+     * The username:password (or username only if value doesn't contain a ':')
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String userPass;
+
+    /**
+     * The optional username and password, assuming the preHost consists of
+     * username:password.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String username;
+    readonly attribute AUTF8String password;
+
+    /**
+     * The host:port (or simply the host, if port == -1).
+     */
+    readonly attribute AUTF8String hostPort;
+
+    /**
+     * The host is the internet domain name to which this URI refers.  It could
+     * be an IPv4 (or IPv6) address literal. Otherwise it is an ASCII or punycode
+     * encoded string.
+     */
+    readonly attribute AUTF8String host;
+
+    /**
+     * A port value of -1 corresponds to the protocol's default port (eg. -1
+     * implies port 80 for http URIs).
+     */
+    readonly attribute long port;
+
+    /**
+     * The path, typically including at least a leading '/' (but may also be
+     * empty, depending on the protocol).
+     *
+     * Some characters may be escaped.
+     *
+     * This attribute contains query and ref parts for historical reasons.
+     * Use the 'filePath' attribute if you do not want those parts included.
+     */
+    readonly attribute AUTF8String pathQueryRef;
+
+
+    /************************************************************************
+     * An URI supports the following methods:
+     */
+
+    /**
+     * URI equivalence test (not a strict string comparison).
+     *
+     * eg. http://foo.com:80/ == http://foo.com/
+     */
+    boolean equals(in nsIURI other);
+
+    /**
+     * An optimization to do scheme checks without requiring the users of nsIURI
+     * to GetScheme, thereby saving extra allocating and freeing. Returns true if
+     * the schemes match (case ignored).
+     */
+    [infallible] boolean schemeIs(in string scheme);
+
+    /**
+     * This method resolves a relative string into an absolute URI string,
+     * using this URI as the base.
+     *
+     * NOTE: some implementations may have no concept of a relative URI.
+     */
+    AUTF8String resolve(in AUTF8String relativePath);
+
+
+    /************************************************************************
+     * Additional attributes:
+     */
+
+    /**
+     * The URI spec with an ASCII compatible encoding.  Host portion follows
+     * the IDNA draft spec.  Other parts are URL-escaped per the rules of
+     * RFC2396.  The result is strictly ASCII.
+     */
+    readonly attribute ACString asciiSpec;
+
+    /**
+     * The host:port (or simply the host, if port == -1), with an ASCII compatible
+     * encoding.  Host portion follows the IDNA draft spec.  The result is strictly
+     * ASCII.
+     */
+    readonly attribute ACString asciiHostPort;
+
+    /**
+     * The URI host with an ASCII compatible encoding.  Follows the IDNA
+     * draft spec for converting internationalized domain names (UTF-8) to
+     * ASCII for compatibility with existing internet infrasture.
+     */
+    readonly attribute ACString asciiHost;
+
+    /************************************************************************
+     * Additional attribute & methods added for .ref support:
+     */
+
+    /**
+     * Returns the reference portion (the part after the "#") of the URI.
+     * If there isn't one, an empty string is returned.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String ref;
+
+    /**
+     * URI equivalence test (not a strict string comparison), ignoring
+     * the value of the .ref member.
+     *
+     * eg. http://foo.com/# == http://foo.com/
+     *     http://foo.com/#aaa == http://foo.com/#bbb
+     */
+    boolean equalsExceptRef(in nsIURI other);
+
+    /**
+     * returns a string for the current URI with the ref element cleared.
+     */
+    readonly attribute AUTF8String specIgnoringRef;
+
+    /**
+     * Returns if there is a reference portion (the part after the "#") of the URI.
+     */
+    readonly attribute boolean hasRef;
+
+    /************************************************************************
+     * Additional attributes added for .query support:
+     */
+
+    /**
+     * Returns a path including the directory and file portions of a
+     * URL.  For example, the filePath of "http://host/foo/bar.html#baz"
+     * is "/foo/bar.html".
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String filePath;
+
+    /**
+     * Returns the query portion (the part after the "?") of the URL.
+     * If there isn't one, an empty string is returned.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String query;
+
+    /**
+     * If the URI has a punycode encoded hostname, this will hold the UTF8
+     * representation of that hostname (if that representation doesn't contain
+     * blacklisted characters, and the network.IDN_show_punycode pref is false)
+     * Otherwise, if the hostname is ASCII, it will return the same as .asciiHost
+     */
+    readonly attribute AUTF8String displayHost;
+
+    /**
+     * The displayHost:port (or simply the displayHost, if port == -1).
+     */
+    readonly attribute AUTF8String displayHostPort;
+
+    /**
+     * Returns the same as calling .spec, only with a UTF8 encoded hostname
+     * (if that hostname doesn't contain blacklisted characters, and
+     * the network.IDN_show_punycode pref is false)
+     */
+    readonly attribute AUTF8String displaySpec;
+
+    /**
+     * Returns the same as calling .prePath, only with a UTF8 encoded hostname
+     * (if that hostname doesn't contain blacklisted characters, and
+     * the network.IDN_show_punycode pref is false)
+     */
+    readonly attribute AUTF8String displayPrePath;
+
+    /**
+     * Returns an nsIURIMutator that can be used to make changes to the URI.
+     * After performing the setter operations on the mutator, one may call
+     * mutator.finalize() to get a new immutable URI with the desired
+     * properties.
+     */
+    nsIURIMutator mutate();
+
+    /**
+     * Serializes a URI object to a URIParams data structure in order for being
+     * passed over IPC.  For deserialization, see nsIURIMutator.
+     */
+    [noscript, notxpcom] void serialize(in URIParams aParams);
+
+    %{C++
+    // MOZ_DBG support
+    friend std::ostream& operator<<(std::ostream& aOut, const nsIURI& aURI) {
+      nsIURI* uri = const_cast<nsIURI*>(&aURI);
+      return aOut << "nsIURI { " << uri->GetSpecOrDefault() << " }";
+    }
+    %}
+};
diff --git a/netwerk/base/nsIURIMutator.idl b/netwerk/base/nsIURIMutator.idl
new file mode 100644
index 0000000000..c4d9293313
--- /dev/null
+++ b/netwerk/base/nsIURIMutator.idl
@@ -0,0 +1,540 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+interface nsIURI;
+interface nsIObjectInputStream;
+interface nsIURIMutator;
+
+%{C++
+#include "nsString.h"
+#include "nsCOMPtr.h"
+#include <utility>
+
+#undef SetPort  // XXX Windows!
+
+namespace mozilla {
+class Encoding;
+}
+
+namespace mozilla {
+namespace ipc {
+class URIParams;
+} // namespace ipc
+} // namespace mozilla
+
+template <class T>
+class BaseURIMutator
+{
+// This is the base class that can be extended by implementors of nsIURIMutator
+// in order to avoid code duplication
+// Class type T should be the type of the class that implements nsIURI
+protected:
+  virtual T* Create()
+  {
+    return new T();
+  }
+
+  [[nodiscard]] nsresult InitFromURI(T* aURI)
+  {
+    nsCOMPtr<nsIURI> clone;
+    nsresult rv = aURI->Clone(getter_AddRefs(clone));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    mURI = static_cast<T*>(clone.get());
+    return NS_OK;
+  }
+
+  [[nodiscard]] nsresult InitFromInputStream(nsIObjectInputStream* aStream)
+  {
+    RefPtr<T> uri = Create();
+    nsresult rv = uri->ReadPrivate(aStream);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    mURI = std::move(uri);
+    return NS_OK;
+  }
+
+  [[nodiscard]] nsresult InitFromIPCParams(const mozilla::ipc::URIParams& aParams)
+  {
+    RefPtr<T> uri = Create();
+    bool ret = uri->Deserialize(aParams);
+    if (!ret) {
+      return NS_ERROR_FAILURE;
+    }
+    mURI = std::move(uri);
+    return NS_OK;
+  }
+
+  [[nodiscard]] nsresult InitFromSpec(const nsACString& aSpec)
+  {
+    nsresult rv = NS_OK;
+    RefPtr<T> uri;
+    if (mURI) {
+      // This only works because all other Init methods create a new object
+      mURI.swap(uri);
+    } else {
+      uri = Create();
+    }
+
+    rv = uri->SetSpecInternal(aSpec);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    mURI = std::move(uri);
+    return NS_OK;
+  }
+
+  RefPtr<T> mURI;
+};
+
+// Since most implementations of nsIURIMutator would extend BaseURIMutator,
+// some methods would have the same implementation. We provide a useful macro
+// to avoid code duplication.
+#define NS_DEFINE_NSIMUTATOR_COMMON                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  Deserialize(const mozilla::ipc::URIParams& aParams) override                \
+  {                                                                           \
+    return InitFromIPCParams(aParams);                                        \
+  }                                                                           \
+                                                                              \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  Finalize(nsIURI** aURI) override                                            \
+  {                                                                           \
+    mURI.forget(aURI); return NS_OK;                                          \
+  }                                                                           \
+                                                                              \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetSpec(const nsACString& aSpec, nsIURIMutator** aMutator) override         \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return InitFromSpec(aSpec);                                               \
+  }                                                                           \
+
+// Implements AddRef, Release and QueryInterface for the mutator
+#define NS_IMPL_NSIURIMUTATOR_ISUPPORTS(aClass, ...)                          \
+  NS_IMPL_ADDREF(aClass)                                                      \
+  NS_IMPL_RELEASE(aClass)                                                     \
+  NS_IMPL_NSIURIMUTATOR_QUERY_INTERFACE(aClass, __VA_ARGS__)                  \
+
+// The list of interfaces is queried and an AddRef-ed pointer is returned if
+// there is a match. Otherwise, we call QueryInterface on mURI and return.
+// The reason for this specialized QueryInterface implementation is that we
+// we want to be able to instantiate the mutator for a given CID of a
+// nsIURI implementation, call nsISerializable.Read() on the mutator to
+// deserialize the URI then QueryInterface the mutator to an nsIURI interface.
+// See bug 1442239.
+// If you QueryInterface a mutator to an interface of the URI
+// implementation this is similar to calling Finalize.
+#define NS_IMPL_NSIURIMUTATOR_QUERY_INTERFACE(aClass, ...)                    \
+  static_assert(MOZ_ARG_COUNT(__VA_ARGS__) > 0,                               \
+                "Need more arguments");                                       \
+  NS_INTERFACE_MAP_BEGIN(aClass)                                              \
+    nsCOMPtr<nsIURI> uri;                                                     \
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIURIMutator)              \
+    MOZ_FOR_EACH(NS_INTERFACE_MAP_ENTRY, (), (__VA_ARGS__))                   \
+    if (aIID.Equals(NS_GET_IID(nsIClassInfo))) {                              \
+      foundInterface = nullptr;                                               \
+    } else                                                                    \
+    if (mURI &&                                                               \
+        NS_SUCCEEDED(mURI->QueryInterface(aIID, getter_AddRefs(uri)))) {      \
+        mURI = nullptr;                                                       \
+        foundInterface = uri.get();                                           \
+    } else                                                                    \
+  NS_INTERFACE_MAP_END                                                        \
+
+%}
+
+[ptr] native Encoding(const mozilla::Encoding);
+[ref] native const_URIParams_ref(const mozilla::ipc::URIParams);
+
+[scriptable, builtinclass, uuid(1fc53257-898b-4c5e-b69c-05bc84b4cd8f)]
+interface nsIURISetSpec : nsISupports
+{
+  /**
+   * This setter is different from all other setters because it may be used to
+   * initialize the object. We define it separately allowing mutator implementors
+   * to define it separately, while the rest of the setters may be simply
+   * forwarded to the mutable URI.
+   */
+  [must_use] nsIURIMutator setSpec(in AUTF8String aSpec);
+};
+
+/**
+ * These methods allow the mutator to change various parts of the URI.
+ * They return the same nsIURIMutator so that we may chain setter operations:
+ * Example:
+ * let newURI = uri.mutate()
+ *                 .setSpec("http://example.com")
+ *                 .setQuery("hello")
+ *                 .finalize();
+ */
+[scriptable, builtinclass, uuid(5403a6ec-99d7-405e-8b45-9f805bbdfcef)]
+interface nsIURISetters : nsIURISetSpec
+{
+  /**
+   * Setting the scheme outside of a protocol handler implementation is highly
+   * discouraged since that will generally lead to incorrect results.
+   */
+  [must_use] nsIURIMutator setScheme(in AUTF8String aScheme);
+  [must_use] nsIURIMutator setUserPass(in AUTF8String aUserPass);
+  [must_use] nsIURIMutator setUsername(in AUTF8String aUsername);
+  [must_use] nsIURIMutator setPassword(in AUTF8String aPassword);
+
+  /**
+   * If you setHostPort to a value that only has a host part, the port
+   * will not be reset. To reset the port set it to -1 beforehand.
+   * If setting the host succeeds, this method will return NS_OK, even if
+   * setting the port fails (error in parsing the port, or value out of range)
+   */
+  [must_use] nsIURIMutator setHostPort(in AUTF8String aHostPort);
+  [must_use] nsIURIMutator setHost(in AUTF8String aHost);
+  [must_use] nsIURIMutator setPort(in long aPort);
+  [must_use] nsIURIMutator setPathQueryRef(in AUTF8String aPathQueryRef);
+  [must_use] nsIURIMutator setRef(in AUTF8String aRef);
+  [must_use] nsIURIMutator setFilePath(in AUTF8String aFilePath);
+  [must_use] nsIURIMutator setQuery(in AUTF8String aQuery);
+  [must_use, noscript] nsIURIMutator setQueryWithEncoding(in AUTF8String query, in Encoding encoding);
+};
+
+%{C++
+
+// Using this macro instead of NS_FORWARD_SAFE_NSIURISETTERS makes chaining
+// setter operations possible.
+#define NS_FORWARD_SAFE_NSIURISETTERS_RET(_to)                                \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetScheme(const nsACString& aScheme, nsIURIMutator** aMutator) override     \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetScheme(aScheme);            \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetUserPass(const nsACString& aUserPass, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetUserPass(aUserPass);        \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetUsername(const nsACString& aUsername, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetUsername(aUsername);        \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetPassword(const nsACString& aPassword, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetPassword(aPassword);        \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetHostPort(const nsACString& aHostPort, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetHostPort(aHostPort);        \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetHost(const nsACString& aHost, nsIURIMutator** aMutator) override         \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetHost(aHost);                \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetPort(int32_t aPort, nsIURIMutator** aMutator) override                   \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetPort(aPort);                \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetPathQueryRef(const nsACString& aPathQueryRef, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetPathQueryRef(aPathQueryRef); \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetRef(const nsACString& aRef, nsIURIMutator** aMutator) override           \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetRef(aRef);                  \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetFilePath(const nsACString& aFilePath, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetFilePath(aFilePath);        \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetQuery(const nsACString& aQuery, nsIURIMutator** aMutator) override       \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetQuery(aQuery);              \
+  }                                                                           \
+  [[nodiscard]] NS_IMETHOD                                                    \
+  SetQueryWithEncoding(const nsACString& query, const mozilla::Encoding *encoding, nsIURIMutator** aMutator) override \
+  {                                                                           \
+    if (aMutator) NS_ADDREF(*aMutator = this);                                \
+    return !_to ? NS_ERROR_NULL_POINTER : _to->SetQueryWithEncoding(query, encoding); \
+  }                                                                           \
+
+%}
+
+[scriptable, builtinclass, uuid(4d1f3103-1c44-4dcd-b717-5d22a697a7d9)]
+interface nsIURIMutator : nsIURISetters
+{
+  /**
+   * Initalizes the URI by reading IPC URIParams.
+   * See nsIURI.
+   */
+  [noscript, notxpcom, must_use]
+  nsresult deserialize(in const_URIParams_ref aParams);
+
+  /**
+   * Finishes changing or constructing the URI and returns an immutable URI.
+   */
+  [must_use]
+  nsIURI finalize();
+};
+
+%{C++
+
+// This templated struct is used to extract the class type of the method
+template <typename Method>
+struct nsMethodTypeTraits;
+
+template <class C, typename R, typename... As>
+struct nsMethodTypeTraits<R(C::*)(As...)>
+{
+  typedef C class_type;
+};
+
+#ifdef NS_HAVE_STDCALL
+template <class C, typename R, typename... As>
+struct nsMethodTypeTraits<R(__stdcall C::*)(As...)>
+{
+  typedef C class_type;
+};
+#endif
+
+
+// This class provides a useful helper that allows chaining of setter operations
+class MOZ_STACK_CLASS NS_MutateURI
+{
+public:
+  explicit NS_MutateURI(nsIURI* aURI);
+  explicit NS_MutateURI(const char * aContractID);
+
+  explicit NS_MutateURI(nsIURIMutator* m)
+  {
+    mStatus = m ? NS_OK : NS_ERROR_NULL_POINTER;
+    mMutator = m;
+    NS_ENSURE_SUCCESS_VOID(mStatus);
+  }
+
+  NS_MutateURI& SetSpec(const nsACString& aSpec)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetSpec(aSpec, nullptr);
+    return *this;
+  }
+  NS_MutateURI& SetScheme(const nsACString& aScheme)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetScheme(aScheme, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetUserPass(const nsACString& aUserPass)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetUserPass(aUserPass, nullptr);
+    return *this;
+  }
+  NS_MutateURI& SetUsername(const nsACString& aUsername)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetUsername(aUsername, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetPassword(const nsACString& aPassword)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetPassword(aPassword, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetHostPort(const nsACString& aHostPort)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetHostPort(aHostPort, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetHost(const nsACString& aHost)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetHost(aHost, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetPort(int32_t aPort)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetPort(aPort, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetPathQueryRef(const nsACString& aPathQueryRef)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetPathQueryRef(aPathQueryRef, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetRef(const nsACString& aRef)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetRef(aRef, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetFilePath(const nsACString& aFilePath)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetFilePath(aFilePath, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetQuery(const nsACString& aQuery)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetQuery(aQuery, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+  NS_MutateURI& SetQueryWithEncoding(const nsACString& query, const mozilla::Encoding *encoding)
+  {
+    if (NS_FAILED(mStatus)) {
+      return *this;
+    }
+    mStatus = mMutator->SetQueryWithEncoding(query, encoding, nullptr);
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    return *this;
+  }
+
+  /**
+   * This method allows consumers to call the methods declared in other
+   * interfaces implemented by the mutator object.
+   *
+   * Example:
+   * nsCOMPtr<nsIURI> uri;
+   * nsresult rv = NS_MutateURI(new URIClass::Mutator())
+   *                 .SetSpec(aSpec)
+   *                 .Apply(&SomeInterface::Method, arg1, arg2)
+   *                 .Finalize(uri);
+   *
+   * If mMutator does not implement SomeInterface, do_QueryInterface will fail
+   * and the method will not be called.
+   * If aMethod does not exist, or if there is a mismatch between argument
+   * types, or the number of arguments, then there will be a compile error.
+   */
+  template <typename Method, typename... Args>
+  NS_MutateURI& Apply(Method aMethod, Args&&... aArgs)
+  {
+    typedef typename nsMethodTypeTraits<Method>::class_type Interface;
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    nsCOMPtr<Interface> target = do_QueryInterface(mMutator, &mStatus);
+    MOZ_ASSERT(NS_SUCCEEDED(mStatus), "URL object must implement interface");
+    NS_ENSURE_SUCCESS(mStatus, *this);
+    mStatus = (target->*aMethod)(std::forward<Args>(aArgs)...);
+    return *this;
+  }
+
+  template <class C>
+  [[nodiscard]] nsresult Finalize(nsCOMPtr<C>& aURI)
+  {
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    nsCOMPtr<nsIURI> uri;
+    mStatus = mMutator->Finalize(getter_AddRefs(uri));
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    aURI = do_QueryInterface(uri, &mStatus);
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    mStatus = NS_ERROR_NOT_AVAILABLE; // Second call to Finalize should fail.
+    return NS_OK;
+  }
+
+  // Overload for nsIURI to avoid query interface.
+  [[nodiscard]] nsresult Finalize(nsCOMPtr<nsIURI>& aURI)
+  {
+    if (NS_FAILED(mStatus)) return mStatus;
+    mStatus = mMutator->Finalize(getter_AddRefs(aURI));
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    mStatus = NS_ERROR_NOT_AVAILABLE; // Second call to Finalize should fail.
+    return NS_OK;
+  }
+
+  template <class C>
+  [[nodiscard]] nsresult Finalize(C** aURI)
+  {
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    nsCOMPtr<nsIURI> uri;
+    mStatus = mMutator->Finalize(getter_AddRefs(uri));
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    nsCOMPtr<C> result = do_QueryInterface(uri, &mStatus);
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    result.forget(aURI);
+    mStatus = NS_ERROR_NOT_AVAILABLE; // Second call to Finalize should fail.
+    return NS_OK;
+  }
+
+  [[nodiscard]] nsresult Finalize(nsIURI** aURI)
+  {
+    if (NS_FAILED(mStatus)) return mStatus;
+    mStatus = mMutator->Finalize(aURI);
+    NS_ENSURE_SUCCESS(mStatus, mStatus);
+
+    mStatus = NS_ERROR_NOT_AVAILABLE; // Second call to Finalize should fail.
+    return NS_OK;
+  }
+
+  nsresult GetStatus() { return mStatus; }
+private:
+  nsresult mStatus;
+  nsCOMPtr<nsIURIMutator> mMutator;
+};
+
+%}
diff --git a/netwerk/base/nsIURIMutatorUtils.cpp b/netwerk/base/nsIURIMutatorUtils.cpp
new file mode 100644
index 0000000000..6c7fd7c92b
--- /dev/null
+++ b/netwerk/base/nsIURIMutatorUtils.cpp
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIURIMutator.h"
+#include "nsIURI.h"
+#include "nsComponentManagerUtils.h"
+
+static nsresult GetURIMutator(nsIURI* aURI, nsIURIMutator** aMutator) {
+  if (NS_WARN_IF(!aURI)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  return aURI->Mutate(aMutator);
+}
+
+NS_MutateURI::NS_MutateURI(nsIURI* aURI) {
+  mStatus = GetURIMutator(aURI, getter_AddRefs(mMutator));
+  NS_ENSURE_SUCCESS_VOID(mStatus);
+}
+
+NS_MutateURI::NS_MutateURI(const char* aContractID)
+    : mStatus(NS_ERROR_NOT_INITIALIZED) {
+  mMutator = do_CreateInstance(aContractID, &mStatus);
+  MOZ_ASSERT(NS_SUCCEEDED(mStatus), "Called with wrong aContractID");
+}
diff --git a/netwerk/base/nsIURIWithSpecialOrigin.idl b/netwerk/base/nsIURIWithSpecialOrigin.idl
new file mode 100644
index 0000000000..3b8e2e0c97
--- /dev/null
+++ b/netwerk/base/nsIURIWithSpecialOrigin.idl
@@ -0,0 +1,20 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+
+/**
+ * nsIURIWithSpecialOrigin is implemented by URIs need to supply an origin that
+ * does not match the spec. This is exclusively used in comm-central's Mailnews module.
+ */
+[scriptable, builtinclass, uuid(4f65569b-d6fc-4580-94d9-21e775658a2a)]
+interface nsIURIWithSpecialOrigin : nsISupports
+{
+    /**
+     * Special origin.
+     */
+    readonly attribute nsIURI origin;
+};
diff --git a/netwerk/base/nsIURL.idl b/netwerk/base/nsIURL.idl
new file mode 100644
index 0000000000..11a9fa0f47
--- /dev/null
+++ b/netwerk/base/nsIURL.idl
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIURI.idl"
+interface nsIURIMutator;
+
+/**
+ * The nsIURL interface provides convenience methods that further
+ * break down the path portion of nsIURI:
+ *
+ * http://host/directory/fileBaseName.fileExtension?query
+ * http://host/directory/fileBaseName.fileExtension#ref
+ *            \          \                       /
+ *             \          -----------------------
+ *              \                   |          /
+ *               \               fileName     /
+ *                ----------------------------
+ *                            |
+ *                        filePath
+ */
+[scriptable, builtinclass, uuid(86adcd89-0b70-47a2-b0fe-5bb2c5f37e31)]
+interface nsIURL : nsIURI
+{
+    /*************************************************************************
+     * The URL path is broken down into the following principal components:
+     *
+     * attribute AUTF8String filePath;
+     * attribute AUTF8String query;
+     *
+     * These are inherited from nsIURI.
+     */
+
+    /*************************************************************************
+     * The URL filepath is broken down into the following sub-components:
+     */
+
+    /**
+     * Returns the directory portion of a URL.  If the URL denotes a path to a
+     * directory and not a file, e.g. http://host/foo/bar/, then the Directory
+     * attribute accesses the complete /foo/bar/ portion, and the FileName is
+     * the empty string. If the trailing slash is omitted, then the Directory
+     * is /foo/ and the file is bar (i.e. this is a syntactic, not a semantic
+     * breakdown of the Path).  And hence don't rely on this for something to
+     * be a definitely be a file. But you can get just the leading directory
+     * portion for sure.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String directory;
+
+    /**
+     * Returns the file name portion of a URL.  If the URL denotes a path to a
+     * directory and not a file, e.g. http://host/foo/bar/, then the Directory
+     * attribute accesses the complete /foo/bar/ portion, and the FileName is
+     * the empty string. Note that this is purely based on searching for the
+     * last trailing slash. And hence don't rely on this to be a definite file.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String fileName;
+
+    /*************************************************************************
+     * The URL filename is broken down even further:
+     */
+
+    /**
+     * Returns the file basename portion of a filename in a url.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String fileBaseName;
+
+    /**
+     * Returns the file extension portion of a filename in a url.  If a file
+     * extension does not exist, the empty string is returned.
+     *
+     * Some characters may be escaped.
+     */
+    readonly attribute AUTF8String fileExtension;
+
+    /**
+     * This method takes a uri and compares the two.  The common uri portion
+     * is returned as a string.  The minimum common uri portion is the
+     * protocol, and any of these if present:  login, password, host and port
+     * If no commonality is found, "" is returned.  If they are identical, the
+     * whole path with file/ref/etc. is returned.  For file uris, it is
+     * expected that the common spec would be at least "file:///" since '/' is
+     * a shared common root.
+     *
+     * Examples:
+     *    this.spec               aURIToCompare.spec        result
+     * 1) http://mozilla.org/     http://www.mozilla.org/   ""
+     * 2) http://foo.com/bar/     ftp://foo.com/bar/        ""
+     * 3) http://foo.com:8080/    http://foo.com/bar/       ""
+     * 4) ftp://user@foo.com/     ftp://user:pw@foo.com/    ""
+     * 5) ftp://foo.com/bar/      ftp://foo.com/bar         ftp://foo.com/
+     * 6) ftp://foo.com/bar/      ftp://foo.com/bar/b.html  ftp://foo.com/bar/
+     * 7) http://foo.com/a.htm#i  http://foo.com/b.htm      http://foo.com/
+     * 8) ftp://foo.com/c.htm#i   ftp://foo.com/c.htm       ftp://foo.com/c.htm
+     * 9) file:///a/b/c.html      file:///d/e/c.html        file:///
+     */
+    AUTF8String getCommonBaseSpec(in nsIURI aURIToCompare);
+
+    /**
+     * This method tries to create a string which specifies the location of the
+     * argument relative to |this|.  If the argument and |this| are equal, the
+     * method returns "".  If any of the URIs' scheme, host, userpass, or port
+     * don't match, the method returns the full spec of the argument.
+     *
+     * Examples:
+     *    this.spec               aURIToCompare.spec        result
+     * 1) http://mozilla.org/     http://www.mozilla.org/   http://www.mozilla.org/
+     * 2) http://mozilla.org/     http://www.mozilla.org    http://www.mozilla.org/
+     * 3) http://foo.com/bar/     http://foo.com:80/bar/    ""
+     * 4) http://foo.com/         http://foo.com/a.htm#b    a.html#b
+     * 5) http://foo.com/a/b/     http://foo.com/c          ../../c
+     */
+    AUTF8String getRelativeSpec(in nsIURI aURIToCompare);
+
+};
+
+[scriptable, builtinclass, uuid(25072eb8-f1e6-482f-9ca9-eddd3d65169a)]
+interface nsIURLMutator : nsISupports
+{
+    [must_use] nsIURIMutator setFileName(in AUTF8String aFileName);
+    [must_use] nsIURIMutator setFileBaseName(in AUTF8String aFileBaseName);
+    [must_use] nsIURIMutator setFileExtension(in AUTF8String aFileExtension);
+};
diff --git a/netwerk/base/nsIURLParser.idl b/netwerk/base/nsIURLParser.idl
new file mode 100644
index 0000000000..3d6ac19b8c
--- /dev/null
+++ b/netwerk/base/nsIURLParser.idl
@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * nsIURLParser specifies the interface to an URL parser that attempts to
+ * follow the definitions of RFC 2396.
+ */
+[scriptable, uuid(78c5d19f-f5d2-4732-8d3d-d5a7d7133bc0)]
+interface nsIURLParser : nsISupports
+{
+    /**
+     * The string to parse in the following methods may be given as a null
+     * terminated string, in which case the length argument should be -1.
+     *
+     * Out parameters of the following methods are all optional (ie. the caller
+     * may pass-in a NULL value if the corresponding results are not needed).
+     * Signed out parameters may hold a value of -1 if the corresponding result
+     * is not part of the string being parsed.
+     *
+     * The parsing routines attempt to be as forgiving as possible.
+     */
+
+    /**
+     * ParseSpec breaks the URL string up into its 3 major components: a scheme,
+     * an authority section (hostname, etc.), and a path.
+     *
+     * spec = <scheme>://<authority><path>
+     */
+    void parseURL        (in string spec,                  in long specLen,
+                          out unsigned long schemePos,    out long schemeLen,
+                          out unsigned long authorityPos, out long authorityLen,
+                          out unsigned long pathPos,      out long pathLen);
+
+    /**
+     * ParseAuthority breaks the authority string up into its 4 components:
+     * username, password, hostname, and hostport.
+     *
+     * auth = <username>:<password>@<hostname>:<port>
+     */
+    void parseAuthority  (in string authority,             in long authorityLen,
+                          out unsigned long usernamePos,  out long usernameLen,
+                          out unsigned long passwordPos,  out long passwordLen,
+                          out unsigned long hostnamePos,  out long hostnameLen,
+                          out long port);
+
+    /**
+     * userinfo = <username>:<password>
+     */
+    void parseUserInfo   (in string userinfo,              in long userinfoLen,
+                          out unsigned long usernamePos,  out long usernameLen,
+                          out unsigned long passwordPos,  out long passwordLen);
+
+    /**
+     * serverinfo = <hostname>:<port>
+     */
+    void parseServerInfo (in string serverinfo,            in long serverinfoLen,
+                          out unsigned long hostnamePos,  out long hostnameLen,
+                          out long port);
+
+    /**
+     * ParsePath breaks the path string up into its 3 major components: a file path,
+     * a query string, and a reference string.
+     *
+     * path = <filepath>?<query>#<ref>
+     */
+    void parsePath       (in string path,                  in long pathLen,
+                          out unsigned long filepathPos,  out long filepathLen,
+                          out unsigned long queryPos,     out long queryLen,
+                          out unsigned long refPos,       out long refLen);
+
+    /**
+     * ParseFilePath breaks the file path string up into: the directory portion,
+     * file base name, and file extension.
+     *
+     * filepath = <directory><basename>.<extension>
+     */
+    void parseFilePath   (in string filepath,              in long filepathLen,
+                          out unsigned long directoryPos, out long directoryLen,
+                          out unsigned long basenamePos,  out long basenameLen,
+                          out unsigned long extensionPos, out long extensionLen);
+
+    /**
+     * filename = <basename>.<extension>
+     */
+    void parseFileName   (in string filename,              in long filenameLen,
+                          out unsigned long basenamePos,  out long basenameLen,
+                          out unsigned long extensionPos, out long extensionLen);
+};
+
+%{C++
+// url parser key for use with the category manager
+// mapping from scheme to url parser.
+#define NS_IURLPARSER_KEY "@mozilla.org/urlparser;1"
+%}
diff --git a/netwerk/base/nsIUploadChannel.idl b/netwerk/base/nsIUploadChannel.idl
new file mode 100644
index 0000000000..1c059e8869
--- /dev/null
+++ b/netwerk/base/nsIUploadChannel.idl
@@ -0,0 +1,56 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIInputStream;
+
+/**
+ * nsIUploadChannel
+ *
+ * A channel may optionally implement this interface if it supports the
+ * notion of uploading a data stream.  The upload stream may only be set
+ * prior to the invocation of asyncOpen on the channel.
+ */
+[scriptable, uuid(5cfe15bd-5adb-4a7f-9e55-4f5a67d15794)]
+interface nsIUploadChannel : nsISupports
+{
+    /**
+     * Sets a stream to be uploaded by this channel.
+     *
+     * Most implementations of this interface require that the stream:
+     *   (1) implement threadsafe addRef and release
+     *   (2) implement nsIInputStream::readSegments
+     *   (3) implement nsISeekableStream::seek
+     *
+     * History here is that we need to support both streams that already have
+     * headers (e.g., Content-Type and Content-Length) information prepended to
+     * the stream (by plugins) as well as clients (composer, uploading
+     * application) that want to upload data streams without any knowledge of
+     * protocol specifications.  For this reason, we have a special meaning
+     * for the aContentType parameter (see below).
+     *
+     * @param aStream
+     *        The stream to be uploaded by this channel.
+     * @param aContentType
+     *        If aContentType is empty, the protocol will assume that no
+     *        content headers are to be added to the uploaded stream and that
+     *        any required headers are already encoded in the stream.  In the
+     *        case of HTTP, if this parameter is non-empty, then its value will
+     *        replace any existing Content-Type header on the HTTP request.
+     *        In the case of FTP and FILE, this parameter is ignored.
+     * @param aContentLength
+     *        A value of -1 indicates that the length of the stream should be
+     *        determined by calling the stream's |available| method.
+     */
+    void setUploadStream(in nsIInputStream aStream,
+                         in ACString aContentType,
+                         in long long aContentLength);
+
+    /**
+     * Get the stream (to be) uploaded by this channel.
+     */
+    readonly attribute nsIInputStream uploadStream;
+};
diff --git a/netwerk/base/nsIUploadChannel2.idl b/netwerk/base/nsIUploadChannel2.idl
new file mode 100644
index 0000000000..45f1d76682
--- /dev/null
+++ b/netwerk/base/nsIUploadChannel2.idl
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface nsIInputStream;
+interface nsIRunnable;
+
+[scriptable, uuid(2f712b52-19c5-4e0c-9e8f-b5c7c3b67049)]
+interface nsIUploadChannel2 : nsISupports
+{
+    /**
+     * Sets a stream to be uploaded by this channel with the specified
+     * Content-Type and Content-Length header values.
+     *
+     * Most implementations of this interface require that the stream:
+     *   (1) implement threadsafe addRef and release
+     *   (2) implement nsIInputStream::readSegments
+     *   (3) implement nsISeekableStream::seek
+     *
+     * @param aStream
+     *        The stream to be uploaded by this channel.
+     * @param aContentType
+     *        This value will replace any existing Content-Type
+     *        header on the HTTP request, regardless of whether
+     *        or not its empty.
+     * @param aContentLength
+     *        A value of -1 indicates that the length of the stream should be
+     *        determined by calling the stream's |available| method.
+     * @param aMethod
+     *        The HTTP request method to set on the stream.
+     * @param aStreamHasHeaders
+     *        True if the stream already contains headers for the HTTP request.
+     */
+    void explicitSetUploadStream(in nsIInputStream aStream,
+                                 in ACString aContentType,
+                                 in long long aContentLength,
+                                 in ACString aMethod,
+                                 in boolean aStreamHasHeaders);
+
+    /**
+     * Value of aStreamHasHeaders from the last successful call to
+     * explicitSetUploadStream.  TRUE indicates the attached upload stream
+     * contains request headers.
+     */
+    readonly attribute boolean uploadStreamHasHeaders;
+
+    /**
+     * Clones the upload stream.  May only be called in the parent process.
+     * aContentLength could be -1 in case the size of the stream is unknown,
+     * otherwise it will contain the known size of the stream.
+     */
+    [noscript]
+    nsIInputStream cloneUploadStream(out long long aContentLength);
+};
diff --git a/netwerk/base/nsIncrementalDownload.cpp b/netwerk/base/nsIncrementalDownload.cpp
new file mode 100644
index 0000000000..d7cb658092
--- /dev/null
+++ b/netwerk/base/nsIncrementalDownload.cpp
@@ -0,0 +1,878 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Attributes.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/UniquePtr.h"
+
+#include "nsIIncrementalDownload.h"
+#include "nsIRequestObserver.h"
+#include "nsIProgressEventSink.h"
+#include "nsIChannelEventSink.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIObserverService.h"
+#include "nsIObserver.h"
+#include "nsIStreamListener.h"
+#include "nsIFile.h"
+#include "nsIHttpChannel.h"
+#include "nsITimer.h"
+#include "nsIURI.h"
+#include "nsIInputStream.h"
+#include "nsNetUtil.h"
+#include "nsWeakReference.h"
+#include "prio.h"
+#include "prprf.h"
+#include <algorithm>
+#include "nsIContentPolicy.h"
+#include "nsContentUtils.h"
+#include "mozilla/Logging.h"
+#include "mozilla/UniquePtr.h"
+
+// Default values used to initialize a nsIncrementalDownload object.
+#define DEFAULT_CHUNK_SIZE (4096 * 16)  // bytes
+#define DEFAULT_INTERVAL 60             // seconds
+
+#define UPDATE_PROGRESS_INTERVAL PRTime(100 * PR_USEC_PER_MSEC)  // 100ms
+
+// Number of times to retry a failed byte-range request.
+#define MAX_RETRY_COUNT 20
+
+using namespace mozilla;
+using namespace mozilla::net;
+
+static LazyLogModule gIDLog("IncrementalDownload");
+#undef LOG
+#define LOG(args) MOZ_LOG(gIDLog, mozilla::LogLevel::Debug, args)
+
+//-----------------------------------------------------------------------------
+
+static nsresult WriteToFile(nsIFile* lf, const char* data, uint32_t len,
+                            int32_t flags) {
+  PRFileDesc* fd;
+  int32_t mode = 0600;
+  nsresult rv;
+  rv = lf->OpenNSPRFileDesc(flags, mode, &fd);
+  if (NS_FAILED(rv)) return rv;
+
+  if (len) {
+    rv = PR_Write(fd, data, len) == int32_t(len) ? NS_OK : NS_ERROR_FAILURE;
+  }
+
+  PR_Close(fd);
+  return rv;
+}
+
+static nsresult AppendToFile(nsIFile* lf, const char* data, uint32_t len) {
+  int32_t flags = PR_WRONLY | PR_CREATE_FILE | PR_APPEND;
+  return WriteToFile(lf, data, len, flags);
+}
+
+// maxSize may be -1 if unknown
+static void MakeRangeSpec(const int64_t& size, const int64_t& maxSize,
+                          int32_t chunkSize, bool fetchRemaining,
+                          nsCString& rangeSpec) {
+  rangeSpec.AssignLiteral("bytes=");
+  rangeSpec.AppendInt(int64_t(size));
+  rangeSpec.Append('-');
+
+  if (fetchRemaining) return;
+
+  int64_t end = size + int64_t(chunkSize);
+  if (maxSize != int64_t(-1) && end > maxSize) end = maxSize;
+  end -= 1;
+
+  rangeSpec.AppendInt(int64_t(end));
+}
+
+//-----------------------------------------------------------------------------
+
+class nsIncrementalDownload final : public nsIIncrementalDownload,
+                                    public nsIStreamListener,
+                                    public nsIObserver,
+                                    public nsIInterfaceRequestor,
+                                    public nsIChannelEventSink,
+                                    public nsSupportsWeakReference,
+                                    public nsIAsyncVerifyRedirectCallback {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSIINCREMENTALDOWNLOAD
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIINTERFACEREQUESTOR
+  NS_DECL_NSICHANNELEVENTSINK
+  NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
+
+  nsIncrementalDownload() = default;
+
+ private:
+  ~nsIncrementalDownload() = default;
+  nsresult FlushChunk();
+  void UpdateProgress();
+  nsresult CallOnStartRequest();
+  void CallOnStopRequest();
+  nsresult StartTimer(int32_t interval);
+  nsresult ProcessTimeout();
+  nsresult ReadCurrentSize();
+  nsresult ClearRequestHeader(nsIHttpChannel* channel);
+
+  nsCOMPtr<nsIRequestObserver> mObserver;
+  nsCOMPtr<nsIProgressEventSink> mProgressSink;
+  nsCOMPtr<nsIURI> mURI;
+  nsCOMPtr<nsIURI> mFinalURI;
+  nsCOMPtr<nsIFile> mDest;
+  nsCOMPtr<nsIChannel> mChannel;
+  nsCOMPtr<nsITimer> mTimer;
+  mozilla::UniquePtr<char[]> mChunk;
+  int32_t mChunkLen{0};
+  int32_t mChunkSize{DEFAULT_CHUNK_SIZE};
+  int32_t mInterval{DEFAULT_INTERVAL};
+  int64_t mTotalSize{-1};
+  int64_t mCurrentSize{-1};
+  uint32_t mLoadFlags{LOAD_NORMAL};
+  int32_t mNonPartialCount{0};
+  nsresult mStatus{NS_OK};
+  bool mIsPending{false};
+  bool mDidOnStartRequest{false};
+  PRTime mLastProgressUpdate{0};
+  nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
+  nsCOMPtr<nsIChannel> mNewRedirectChannel;
+  nsCString mPartialValidator;
+  bool mCacheBust{false};
+
+  // nsITimerCallback is implemented on a subclass so that the name attribute
+  // doesn't conflict with the name attribute of the nsIRequest interface.
+  class TimerCallback final : public nsITimerCallback, public nsINamed {
+   public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSITIMERCALLBACK
+    NS_DECL_NSINAMED
+
+    explicit TimerCallback(nsIncrementalDownload* aIncrementalDownload);
+
+   private:
+    ~TimerCallback() = default;
+
+    RefPtr<nsIncrementalDownload> mIncrementalDownload;
+  };
+};
+
+nsresult nsIncrementalDownload::FlushChunk() {
+  NS_ASSERTION(mTotalSize != int64_t(-1), "total size should be known");
+
+  if (mChunkLen == 0) return NS_OK;
+
+  nsresult rv = AppendToFile(mDest, mChunk.get(), mChunkLen);
+  if (NS_FAILED(rv)) return rv;
+
+  mCurrentSize += int64_t(mChunkLen);
+  mChunkLen = 0;
+
+  return NS_OK;
+}
+
+void nsIncrementalDownload::UpdateProgress() {
+  mLastProgressUpdate = PR_Now();
+
+  if (mProgressSink) {
+    mProgressSink->OnProgress(this, mCurrentSize + mChunkLen, mTotalSize);
+  }
+}
+
+nsresult nsIncrementalDownload::CallOnStartRequest() {
+  if (!mObserver || mDidOnStartRequest) return NS_OK;
+
+  mDidOnStartRequest = true;
+  return mObserver->OnStartRequest(this);
+}
+
+void nsIncrementalDownload::CallOnStopRequest() {
+  if (!mObserver) return;
+
+  // Ensure that OnStartRequest is always called once before OnStopRequest.
+  nsresult rv = CallOnStartRequest();
+  if (NS_SUCCEEDED(mStatus)) mStatus = rv;
+
+  mIsPending = false;
+
+  mObserver->OnStopRequest(this, mStatus);
+  mObserver = nullptr;
+}
+
+nsresult nsIncrementalDownload::StartTimer(int32_t interval) {
+  auto callback = MakeRefPtr<TimerCallback>(this);
+  return NS_NewTimerWithCallback(getter_AddRefs(mTimer), callback,
+                                 interval * 1000, nsITimer::TYPE_ONE_SHOT);
+}
+
+nsresult nsIncrementalDownload::ProcessTimeout() {
+  NS_ASSERTION(!mChannel, "how can we have a channel?");
+
+  // Handle existing error conditions
+  if (NS_FAILED(mStatus)) {
+    CallOnStopRequest();
+    return NS_OK;
+  }
+
+  // Fetch next chunk
+
+  nsCOMPtr<nsIChannel> channel;
+  nsresult rv = NS_NewChannel(
+      getter_AddRefs(channel), mFinalURI, nsContentUtils::GetSystemPrincipal(),
+      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+      nsIContentPolicy::TYPE_OTHER,
+      nullptr,  // nsICookieJarSettings
+      nullptr,  // PerformanceStorage
+      nullptr,  // loadGroup
+      this,     // aCallbacks
+      mLoadFlags);
+
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(channel, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  NS_ASSERTION(mCurrentSize != int64_t(-1),
+               "we should know the current file size by now");
+
+  rv = ClearRequestHeader(http);
+  if (NS_FAILED(rv)) return rv;
+
+  // Don't bother making a range request if we are just going to fetch the
+  // entire document.
+  if (mInterval || mCurrentSize != int64_t(0)) {
+    nsAutoCString range;
+    MakeRangeSpec(mCurrentSize, mTotalSize, mChunkSize, mInterval == 0, range);
+
+    rv = http->SetRequestHeader("Range"_ns, range, false);
+    if (NS_FAILED(rv)) return rv;
+
+    if (!mPartialValidator.IsEmpty()) {
+      rv = http->SetRequestHeader("If-Range"_ns, mPartialValidator, false);
+      if (NS_FAILED(rv)) {
+        LOG(
+            ("nsIncrementalDownload::ProcessTimeout\n"
+             "    failed to set request header: If-Range\n"));
+      }
+    }
+
+    if (mCacheBust) {
+      rv = http->SetRequestHeader("Cache-Control"_ns, "no-cache"_ns, false);
+      if (NS_FAILED(rv)) {
+        LOG(
+            ("nsIncrementalDownload::ProcessTimeout\n"
+             "    failed to set request header: If-Range\n"));
+      }
+      rv = http->SetRequestHeader("Pragma"_ns, "no-cache"_ns, false);
+      if (NS_FAILED(rv)) {
+        LOG(
+            ("nsIncrementalDownload::ProcessTimeout\n"
+             "    failed to set request header: If-Range\n"));
+      }
+    }
+  }
+
+  rv = channel->AsyncOpen(this);
+  if (NS_FAILED(rv)) return rv;
+
+  // Wait to assign mChannel when we know we are going to succeed.  This is
+  // important because we don't want to introduce a reference cycle between
+  // mChannel and this until we know for a fact that AsyncOpen has succeeded,
+  // thus ensuring that our stream listener methods will be invoked.
+  mChannel = channel;
+  return NS_OK;
+}
+
+// Reads the current file size and validates it.
+nsresult nsIncrementalDownload::ReadCurrentSize() {
+  int64_t size;
+  nsresult rv = mDest->GetFileSize((int64_t*)&size);
+  if (rv == NS_ERROR_FILE_NOT_FOUND) {
+    mCurrentSize = 0;
+    return NS_OK;
+  }
+  if (NS_FAILED(rv)) return rv;
+
+  mCurrentSize = size;
+  return NS_OK;
+}
+
+// nsISupports
+
+NS_IMPL_ISUPPORTS(nsIncrementalDownload, nsIIncrementalDownload, nsIRequest,
+                  nsIStreamListener, nsIRequestObserver, nsIObserver,
+                  nsIInterfaceRequestor, nsIChannelEventSink,
+                  nsISupportsWeakReference, nsIAsyncVerifyRedirectCallback)
+
+// nsIRequest
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetName(nsACString& name) {
+  NS_ENSURE_TRUE(mURI, NS_ERROR_NOT_INITIALIZED);
+
+  return mURI->GetSpec(name);
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::IsPending(bool* isPending) {
+  *isPending = mIsPending;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetStatus(nsresult* status) {
+  *status = mStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsIncrementalDownload::SetCanceledReason(
+    const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIncrementalDownload::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIncrementalDownload::CancelWithReason(
+    nsresult aStatus, const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::Cancel(nsresult status) {
+  NS_ENSURE_ARG(NS_FAILED(status));
+
+  // Ignore this cancelation if we're already canceled.
+  if (NS_FAILED(mStatus)) return NS_OK;
+
+  mStatus = status;
+
+  // Nothing more to do if callbacks aren't pending.
+  if (!mIsPending) return NS_OK;
+
+  if (mChannel) {
+    mChannel->Cancel(mStatus);
+    NS_ASSERTION(!mTimer, "what is this timer object doing here?");
+  } else {
+    // dispatch a timer callback event to drive invoking our listener's
+    // OnStopRequest.
+    if (mTimer) mTimer->Cancel();
+    StartTimer(0);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::Suspend() { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsIncrementalDownload::Resume() { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetLoadFlags(nsLoadFlags* loadFlags) {
+  *loadFlags = mLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::SetLoadFlags(nsLoadFlags loadFlags) {
+  mLoadFlags = loadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetLoadGroup(nsILoadGroup** loadGroup) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::SetLoadGroup(nsILoadGroup* loadGroup) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// nsIIncrementalDownload
+
+NS_IMETHODIMP
+nsIncrementalDownload::Init(nsIURI* uri, nsIFile* dest, int32_t chunkSize,
+                            int32_t interval) {
+  // Keep it simple: only allow initialization once
+  NS_ENSURE_FALSE(mURI, NS_ERROR_ALREADY_INITIALIZED);
+
+  mDest = dest;
+  NS_ENSURE_ARG(mDest);
+
+  mURI = uri;
+  mFinalURI = uri;
+
+  if (chunkSize > 0) mChunkSize = chunkSize;
+  if (interval >= 0) mInterval = interval;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetURI(nsIURI** result) {
+  nsCOMPtr<nsIURI> uri = mURI;
+  uri.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetFinalURI(nsIURI** result) {
+  nsCOMPtr<nsIURI> uri = mFinalURI;
+  uri.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetDestination(nsIFile** result) {
+  if (!mDest) {
+    *result = nullptr;
+    return NS_OK;
+  }
+  // Return a clone of mDest so that callers may modify the resulting nsIFile
+  // without corrupting our internal object.  This also works around the fact
+  // that some nsIFile impls may cache the result of stat'ing the filesystem.
+  return mDest->Clone(result);
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetTotalSize(int64_t* result) {
+  *result = mTotalSize;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetCurrentSize(int64_t* result) {
+  *result = mCurrentSize;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::Start(nsIRequestObserver* observer,
+                             nsISupports* context) {
+  NS_ENSURE_ARG(observer);
+  NS_ENSURE_FALSE(mIsPending, NS_ERROR_IN_PROGRESS);
+
+  // Observe system shutdown so we can be sure to release any reference held
+  // between ourselves and the timer.  We have the observer service hold a weak
+  // reference to us, so that we don't have to worry about calling
+  // RemoveObserver.  XXX(darin): The timer code should do this for us.
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (obs) obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
+
+  nsresult rv = ReadCurrentSize();
+  if (NS_FAILED(rv)) return rv;
+
+  rv = StartTimer(0);
+  if (NS_FAILED(rv)) return rv;
+
+  mObserver = observer;
+  mProgressSink = do_QueryInterface(observer);  // ok if null
+
+  mIsPending = true;
+  return NS_OK;
+}
+
+// nsIRequestObserver
+
+NS_IMETHODIMP
+nsIncrementalDownload::OnStartRequest(nsIRequest* request) {
+  nsresult rv;
+
+  nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(request, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  // Ensure that we are receiving a 206 response.
+  uint32_t code;
+  rv = http->GetResponseStatus(&code);
+  if (NS_FAILED(rv)) return rv;
+  if (code != 206) {
+    // We may already have the entire file downloaded, in which case
+    // our request for a range beyond the end of the file would have
+    // been met with an error response code.
+    if (code == 416 && mTotalSize == int64_t(-1)) {
+      mTotalSize = mCurrentSize;
+      // Return an error code here to suppress OnDataAvailable.
+      return NS_ERROR_DOWNLOAD_COMPLETE;
+    }
+    // The server may have decided to give us all of the data in one chunk.  If
+    // we requested a partial range, then we don't want to download all of the
+    // data at once.  So, we'll just try again, but if this keeps happening then
+    // we'll eventually give up.
+    if (code == 200) {
+      if (mInterval) {
+        mChannel = nullptr;
+        if (++mNonPartialCount > MAX_RETRY_COUNT) {
+          NS_WARNING("unable to fetch a byte range; giving up");
+          return NS_ERROR_FAILURE;
+        }
+        // Increase delay with each failure.
+        StartTimer(mInterval * mNonPartialCount);
+        return NS_ERROR_DOWNLOAD_NOT_PARTIAL;
+      }
+      // Since we have been asked to download the rest of the file, we can deal
+      // with a 200 response.  This may result in downloading the beginning of
+      // the file again, but that can't really be helped.
+    } else {
+      NS_WARNING("server response was unexpected");
+      return NS_ERROR_UNEXPECTED;
+    }
+  } else {
+    // We got a partial response, so clear this counter in case the next chunk
+    // results in a 200 response.
+    mNonPartialCount = 0;
+
+    // confirm that the content-range response header is consistent with
+    // expectations on each 206. If it is not then drop this response and
+    // retry with no-cache set.
+    if (!mCacheBust) {
+      nsAutoCString buf;
+      int64_t startByte = 0;
+      bool confirmedOK = false;
+
+      rv = http->GetResponseHeader("Content-Range"_ns, buf);
+      if (NS_FAILED(rv)) {
+        return rv;  // it isn't a useful 206 without a CONTENT-RANGE of some
+      }
+      // sort
+
+      // Content-Range: bytes 0-299999/25604694
+      int32_t p = buf.Find("bytes ");
+
+      // first look for the starting point of the content-range
+      // to make sure it is what we expect
+      if (p != -1) {
+        char* endptr = nullptr;
+        const char* s = buf.get() + p + 6;
+        while (*s && *s == ' ') s++;
+        startByte = strtol(s, &endptr, 10);
+
+        if (*s && endptr && (endptr != s) && (mCurrentSize == startByte)) {
+          // ok the starting point is confirmed. We still need to check the
+          // total size of the range for consistency if this isn't
+          // the first chunk
+          if (mTotalSize == int64_t(-1)) {
+            // first chunk
+            confirmedOK = true;
+          } else {
+            int32_t slash = buf.FindChar('/');
+            int64_t rangeSize = 0;
+            if (slash != kNotFound &&
+                (PR_sscanf(buf.get() + slash + 1, "%lld",
+                           (int64_t*)&rangeSize) == 1) &&
+                rangeSize == mTotalSize) {
+              confirmedOK = true;
+            }
+          }
+        }
+      }
+
+      if (!confirmedOK) {
+        NS_WARNING("unexpected content-range");
+        mCacheBust = true;
+        mChannel = nullptr;
+        if (++mNonPartialCount > MAX_RETRY_COUNT) {
+          NS_WARNING("unable to fetch a byte range; giving up");
+          return NS_ERROR_FAILURE;
+        }
+        // Increase delay with each failure.
+        StartTimer(mInterval * mNonPartialCount);
+        return NS_ERROR_DOWNLOAD_NOT_PARTIAL;
+      }
+    }
+  }
+
+  // Do special processing after the first response.
+  if (mTotalSize == int64_t(-1)) {
+    // Update knowledge of mFinalURI
+    rv = http->GetURI(getter_AddRefs(mFinalURI));
+    if (NS_FAILED(rv)) return rv;
+    Unused << http->GetResponseHeader("Etag"_ns, mPartialValidator);
+    if (StringBeginsWith(mPartialValidator, "W/"_ns)) {
+      mPartialValidator.Truncate();  // don't use weak validators
+    }
+    if (mPartialValidator.IsEmpty()) {
+      rv = http->GetResponseHeader("Last-Modified"_ns, mPartialValidator);
+      if (NS_FAILED(rv)) {
+        LOG(
+            ("nsIncrementalDownload::OnStartRequest\n"
+             "    empty validator\n"));
+      }
+    }
+
+    if (code == 206) {
+      // OK, read the Content-Range header to determine the total size of this
+      // download file.
+      nsAutoCString buf;
+      rv = http->GetResponseHeader("Content-Range"_ns, buf);
+      if (NS_FAILED(rv)) return rv;
+      int32_t slash = buf.FindChar('/');
+      if (slash == kNotFound) {
+        NS_WARNING("server returned invalid Content-Range header!");
+        return NS_ERROR_UNEXPECTED;
+      }
+      if (PR_sscanf(buf.get() + slash + 1, "%lld", (int64_t*)&mTotalSize) !=
+          1) {
+        return NS_ERROR_UNEXPECTED;
+      }
+    } else {
+      rv = http->GetContentLength(&mTotalSize);
+      if (NS_FAILED(rv)) return rv;
+      // We need to know the total size of the thing we're trying to download.
+      if (mTotalSize == int64_t(-1)) {
+        NS_WARNING("server returned no content-length header!");
+        return NS_ERROR_UNEXPECTED;
+      }
+      // Need to truncate (or create, if it doesn't exist) the file since we
+      // are downloading the whole thing.
+      WriteToFile(mDest, nullptr, 0, PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE);
+      mCurrentSize = 0;
+    }
+
+    // Notify observer that we are starting...
+    rv = CallOnStartRequest();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  // Adjust mChunkSize accordingly if mCurrentSize is close to mTotalSize.
+  int64_t diff = mTotalSize - mCurrentSize;
+  if (diff <= int64_t(0)) {
+    NS_WARNING("about to set a bogus chunk size; giving up");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (diff < int64_t(mChunkSize)) mChunkSize = uint32_t(diff);
+
+  mChunk = mozilla::MakeUniqueFallible<char[]>(mChunkSize);
+  if (!mChunk) rv = NS_ERROR_OUT_OF_MEMORY;
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::OnStopRequest(nsIRequest* request, nsresult status) {
+  // Not a real error; just a trick to kill off the channel without our
+  // listener having to care.
+  if (status == NS_ERROR_DOWNLOAD_NOT_PARTIAL) return NS_OK;
+
+  // Not a real error; just a trick used to suppress OnDataAvailable calls.
+  if (status == NS_ERROR_DOWNLOAD_COMPLETE) status = NS_OK;
+
+  if (NS_SUCCEEDED(mStatus)) mStatus = status;
+
+  if (mChunk) {
+    if (NS_SUCCEEDED(mStatus)) mStatus = FlushChunk();
+
+    mChunk = nullptr;  // deletes memory
+    mChunkLen = 0;
+    UpdateProgress();
+  }
+
+  mChannel = nullptr;
+
+  // Notify listener if we hit an error or finished
+  if (NS_FAILED(mStatus) || mCurrentSize == mTotalSize) {
+    CallOnStopRequest();
+    return NS_OK;
+  }
+
+  return StartTimer(mInterval);  // Do next chunk
+}
+
+// nsIStreamListener
+
+NS_IMETHODIMP
+nsIncrementalDownload::OnDataAvailable(nsIRequest* request,
+                                       nsIInputStream* input, uint64_t offset,
+                                       uint32_t count) {
+  while (count) {
+    uint32_t space = mChunkSize - mChunkLen;
+    uint32_t n, len = std::min(space, count);
+
+    nsresult rv = input->Read(&mChunk[mChunkLen], len, &n);
+    if (NS_FAILED(rv)) return rv;
+    if (n != len) return NS_ERROR_UNEXPECTED;
+
+    count -= n;
+    mChunkLen += n;
+
+    if (mChunkLen == mChunkSize) {
+      rv = FlushChunk();
+      if (NS_FAILED(rv)) return rv;
+    }
+  }
+
+  if (PR_Now() > mLastProgressUpdate + UPDATE_PROGRESS_INTERVAL) {
+    UpdateProgress();
+  }
+
+  return NS_OK;
+}
+
+// nsIObserver
+
+NS_IMETHODIMP
+nsIncrementalDownload::Observe(nsISupports* subject, const char* topic,
+                               const char16_t* data) {
+  if (strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
+    Cancel(NS_ERROR_ABORT);
+
+    // Since the app is shutting down, we need to go ahead and notify our
+    // observer here.  Otherwise, we would notify them after XPCOM has been
+    // shutdown or not at all.
+    CallOnStopRequest();
+  }
+  return NS_OK;
+}
+
+// nsITimerCallback
+
+nsIncrementalDownload::TimerCallback::TimerCallback(
+    nsIncrementalDownload* aIncrementalDownload)
+    : mIncrementalDownload(aIncrementalDownload) {}
+
+NS_IMPL_ISUPPORTS(nsIncrementalDownload::TimerCallback, nsITimerCallback,
+                  nsINamed)
+
+NS_IMETHODIMP
+nsIncrementalDownload::TimerCallback::Notify(nsITimer* aTimer) {
+  mIncrementalDownload->mTimer = nullptr;
+
+  nsresult rv = mIncrementalDownload->ProcessTimeout();
+  if (NS_FAILED(rv)) mIncrementalDownload->Cancel(rv);
+
+  return NS_OK;
+}
+
+// nsINamed
+
+NS_IMETHODIMP
+nsIncrementalDownload::TimerCallback::GetName(nsACString& aName) {
+  aName.AssignLiteral("nsIncrementalDownload");
+  return NS_OK;
+}
+
+// nsIInterfaceRequestor
+
+NS_IMETHODIMP
+nsIncrementalDownload::GetInterface(const nsIID& iid, void** result) {
+  if (iid.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    NS_ADDREF_THIS();
+    *result = static_cast<nsIChannelEventSink*>(this);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIInterfaceRequestor> ir = do_QueryInterface(mObserver);
+  if (ir) return ir->GetInterface(iid, result);
+
+  return NS_ERROR_NO_INTERFACE;
+}
+
+nsresult nsIncrementalDownload::ClearRequestHeader(nsIHttpChannel* channel) {
+  NS_ENSURE_ARG(channel);
+
+  // We don't support encodings -- they make the Content-Length not equal
+  // to the actual size of the data.
+  return channel->SetRequestHeader("Accept-Encoding"_ns, ""_ns, false);
+}
+
+// nsIChannelEventSink
+
+NS_IMETHODIMP
+nsIncrementalDownload::AsyncOnChannelRedirect(
+    nsIChannel* oldChannel, nsIChannel* newChannel, uint32_t flags,
+    nsIAsyncVerifyRedirectCallback* cb) {
+  // In response to a redirect, we need to propagate the Range header.  See bug
+  // 311595.  Any failure code returned from this function aborts the redirect.
+
+  nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(oldChannel);
+  NS_ENSURE_STATE(http);
+
+  nsCOMPtr<nsIHttpChannel> newHttpChannel = do_QueryInterface(newChannel);
+  NS_ENSURE_STATE(newHttpChannel);
+
+  constexpr auto rangeHdr = "Range"_ns;
+
+  nsresult rv = ClearRequestHeader(newHttpChannel);
+  if (NS_FAILED(rv)) return rv;
+
+  // If we didn't have a Range header, then we must be doing a full download.
+  nsAutoCString rangeVal;
+  Unused << http->GetRequestHeader(rangeHdr, rangeVal);
+  if (!rangeVal.IsEmpty()) {
+    rv = newHttpChannel->SetRequestHeader(rangeHdr, rangeVal, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // A redirection changes the validator
+  mPartialValidator.Truncate();
+
+  if (mCacheBust) {
+    rv = newHttpChannel->SetRequestHeader("Cache-Control"_ns, "no-cache"_ns,
+                                          false);
+    if (NS_FAILED(rv)) {
+      LOG(
+          ("nsIncrementalDownload::AsyncOnChannelRedirect\n"
+           "    failed to set request header: Cache-Control\n"));
+    }
+    rv = newHttpChannel->SetRequestHeader("Pragma"_ns, "no-cache"_ns, false);
+    if (NS_FAILED(rv)) {
+      LOG(
+          ("nsIncrementalDownload::AsyncOnChannelRedirect\n"
+           "    failed to set request header: Pragma\n"));
+    }
+  }
+
+  // Prepare to receive callback
+  mRedirectCallback = cb;
+  mNewRedirectChannel = newChannel;
+
+  // Give the observer a chance to see this redirect notification.
+  nsCOMPtr<nsIChannelEventSink> sink = do_GetInterface(mObserver);
+  if (sink) {
+    rv = sink->AsyncOnChannelRedirect(oldChannel, newChannel, flags, this);
+    if (NS_FAILED(rv)) {
+      mRedirectCallback = nullptr;
+      mNewRedirectChannel = nullptr;
+    }
+    return rv;
+  }
+  (void)OnRedirectVerifyCallback(NS_OK);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalDownload::OnRedirectVerifyCallback(nsresult result) {
+  NS_ASSERTION(mRedirectCallback, "mRedirectCallback not set in callback");
+  NS_ASSERTION(mNewRedirectChannel, "mNewRedirectChannel not set in callback");
+
+  // Update mChannel, so we can Cancel the new channel.
+  if (NS_SUCCEEDED(result)) mChannel = mNewRedirectChannel;
+
+  mRedirectCallback->OnRedirectVerifyCallback(result);
+  mRedirectCallback = nullptr;
+  mNewRedirectChannel = nullptr;
+  return NS_OK;
+}
+
+extern nsresult net_NewIncrementalDownload(const nsIID& iid, void** result) {
+  RefPtr<nsIncrementalDownload> d = new nsIncrementalDownload();
+  return d->QueryInterface(iid, result);
+}
diff --git a/netwerk/base/nsIncrementalStreamLoader.cpp b/netwerk/base/nsIncrementalStreamLoader.cpp
new file mode 100644
index 0000000000..572fe62fdb
--- /dev/null
+++ b/netwerk/base/nsIncrementalStreamLoader.cpp
@@ -0,0 +1,185 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIncrementalStreamLoader.h"
+#include "nsIInputStream.h"
+#include "nsIChannel.h"
+#include "nsError.h"
+#include "mozilla/ProfilerLabels.h"
+
+#include <limits>
+
+nsIncrementalStreamLoader::nsIncrementalStreamLoader() = default;
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::Init(nsIIncrementalStreamLoaderObserver* observer) {
+  NS_ENSURE_ARG_POINTER(observer);
+  mObserver = observer;
+  return NS_OK;
+}
+
+nsresult nsIncrementalStreamLoader::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsIncrementalStreamLoader> it = new nsIncrementalStreamLoader();
+  return it->QueryInterface(aIID, aResult);
+}
+
+NS_IMPL_ISUPPORTS(nsIncrementalStreamLoader, nsIIncrementalStreamLoader,
+                  nsIRequestObserver, nsIStreamListener,
+                  nsIThreadRetargetableStreamListener)
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::GetNumBytesRead(uint32_t* aNumBytes) {
+  *aNumBytes = mBytesRead;
+  return NS_OK;
+}
+
+/* readonly attribute nsIRequest request; */
+NS_IMETHODIMP
+nsIncrementalStreamLoader::GetRequest(nsIRequest** aRequest) {
+  *aRequest = do_AddRef(mRequest).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::OnStartRequest(nsIRequest* request) {
+  nsCOMPtr<nsIChannel> chan(do_QueryInterface(request));
+  if (chan) {
+    int64_t contentLength = -1;
+    chan->GetContentLength(&contentLength);
+    if (contentLength >= 0) {
+      // On 64bit platforms size of uint64_t coincides with the size of size_t,
+      // so we want to compare with the minimum from size_t and int64_t.
+      if (static_cast<uint64_t>(contentLength) >
+          std::min(std::numeric_limits<size_t>::max(),
+                   static_cast<size_t>(std::numeric_limits<int64_t>::max()))) {
+        // Too big to fit into size_t, so let's bail.
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      // preallocate buffer
+      if (!mData.initCapacity(contentLength)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::OnStopRequest(nsIRequest* request,
+                                         nsresult aStatus) {
+  AUTO_PROFILER_LABEL("nsIncrementalStreamLoader::OnStopRequest", NETWORK);
+
+  if (mObserver) {
+    // provide nsIIncrementalStreamLoader::request during call to
+    // OnStreamComplete
+    mRequest = request;
+    size_t length = mData.length();
+    uint8_t* elems = mData.extractOrCopyRawBuffer();
+    nsresult rv =
+        mObserver->OnStreamComplete(this, mContext, aStatus, length, elems);
+    if (rv != NS_SUCCESS_ADOPTED_DATA) {
+      // The observer didn't take ownership of the extracted data buffer, so
+      // put it back into mData.
+      mData.replaceRawBuffer(elems, length);
+    }
+    // done.. cleanup
+    ReleaseData();
+    mRequest = nullptr;
+    mObserver = nullptr;
+  }
+  return NS_OK;
+}
+
+nsresult nsIncrementalStreamLoader::WriteSegmentFun(
+    nsIInputStream* inStr, void* closure, const char* fromSegment,
+    uint32_t toOffset, uint32_t count, uint32_t* writeCount) {
+  nsIncrementalStreamLoader* self = (nsIncrementalStreamLoader*)closure;
+
+  const uint8_t* data = reinterpret_cast<const uint8_t*>(fromSegment);
+  uint32_t consumedCount = 0;
+  nsresult rv;
+  if (self->mData.empty()) {
+    // Shortcut when observer wants to keep the listener's buffer empty.
+    rv = self->mObserver->OnIncrementalData(self, self->mContext, count, data,
+                                            &consumedCount);
+
+    if (rv != NS_OK) {
+      return rv;
+    }
+
+    if (consumedCount > count) {
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    if (consumedCount < count) {
+      if (!self->mData.append(fromSegment + consumedCount,
+                              count - consumedCount)) {
+        self->mData.clearAndFree();
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+  } else {
+    // We have some non-consumed data from previous OnIncrementalData call,
+    // appending new data and reporting combined data.
+    if (!self->mData.append(fromSegment, count)) {
+      self->mData.clearAndFree();
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    size_t length = self->mData.length();
+    uint32_t reportCount = length > UINT32_MAX ? UINT32_MAX : (uint32_t)length;
+    uint8_t* elems = self->mData.extractOrCopyRawBuffer();
+
+    rv = self->mObserver->OnIncrementalData(self, self->mContext, reportCount,
+                                            elems, &consumedCount);
+
+    // We still own elems, freeing its memory when exiting scope.
+    if (rv != NS_OK) {
+      free(elems);
+      return rv;
+    }
+
+    if (consumedCount > reportCount) {
+      free(elems);
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    if (consumedCount == length) {
+      free(elems);  // good case -- fully consumed data
+    } else {
+      // Adopting elems back (at least its portion).
+      self->mData.replaceRawBuffer(elems, length);
+      if (consumedCount > 0) {
+        self->mData.erase(self->mData.begin() + consumedCount);
+      }
+    }
+  }
+
+  *writeCount = count;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::OnDataAvailable(nsIRequest* request,
+                                           nsIInputStream* inStr,
+                                           uint64_t sourceOffset,
+                                           uint32_t count) {
+  if (mObserver) {
+    // provide nsIIncrementalStreamLoader::request during call to
+    // OnStreamComplete
+    mRequest = request;
+  }
+  uint32_t countRead;
+  nsresult rv = inStr->ReadSegments(WriteSegmentFun, this, count, &countRead);
+  mRequest = nullptr;
+  NS_ENSURE_SUCCESS(rv, rv);
+  mBytesRead += countRead;
+  return rv;
+}
+
+void nsIncrementalStreamLoader::ReleaseData() { mData.clearAndFree(); }
+
+NS_IMETHODIMP
+nsIncrementalStreamLoader::CheckListenerChain() { return NS_OK; }
diff --git a/netwerk/base/nsIncrementalStreamLoader.h b/netwerk/base/nsIncrementalStreamLoader.h
new file mode 100644
index 0000000000..d04af4002a
--- /dev/null
+++ b/netwerk/base/nsIncrementalStreamLoader.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsIncrementalStreamLoader_h__
+#define nsIncrementalStreamLoader_h__
+
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsIIncrementalStreamLoader.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Vector.h"
+
+class nsIRequest;
+
+class nsIncrementalStreamLoader final
+    : public nsIIncrementalStreamLoader,
+      public nsIThreadRetargetableStreamListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINCREMENTALSTREAMLOADER
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+
+  nsIncrementalStreamLoader();
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+ protected:
+  ~nsIncrementalStreamLoader() = default;
+
+  static nsresult WriteSegmentFun(nsIInputStream*, void*, const char*, uint32_t,
+                                  uint32_t, uint32_t*);
+
+  // Utility method to free mData, if present, and update other state to
+  // reflect that no data has been allocated.
+  void ReleaseData();
+
+  nsCOMPtr<nsIIncrementalStreamLoaderObserver> mObserver;
+  nsCOMPtr<nsISupports> mContext;  // the observer's context
+  nsCOMPtr<nsIRequest> mRequest;
+
+  // Buffer to accumulate incoming data. We preallocate if contentSize is
+  // available.
+  mozilla::Vector<uint8_t, 0> mData;
+
+  // Number of bytes read, which may not match the number of bytes in mData at
+  // all, as we incrementally remove from there.
+  mozilla::Atomic<uint32_t, mozilla::MemoryOrdering::Relaxed> mBytesRead;
+};
+
+#endif  // nsIncrementalStreamLoader_h__
diff --git a/netwerk/base/nsInputStreamChannel.cpp b/netwerk/base/nsInputStreamChannel.cpp
new file mode 100644
index 0000000000..e00bc85ad5
--- /dev/null
+++ b/netwerk/base/nsInputStreamChannel.cpp
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsInputStreamChannel.h"
+
+//-----------------------------------------------------------------------------
+// nsInputStreamChannel
+
+namespace mozilla {
+namespace net {
+
+nsresult nsInputStreamChannel::OpenContentStream(bool async,
+                                                 nsIInputStream** result,
+                                                 nsIChannel** channel) {
+  NS_ENSURE_TRUE(mContentStream, NS_ERROR_NOT_INITIALIZED);
+
+  // If content length is unknown, then we must guess.  In this case, we assume
+  // the stream can tell us.  If the stream is a pipe, then this will not work.
+
+  if (mContentLength < 0) {
+    uint64_t avail;
+    nsresult rv = mContentStream->Available(&avail);
+    if (rv == NS_BASE_STREAM_CLOSED) {
+      // This just means there's nothing in the stream
+      avail = 0;
+    } else if (NS_FAILED(rv)) {
+      return rv;
+    }
+    mContentLength = avail;
+  }
+
+  EnableSynthesizedProgressEvents(true);
+
+  *result = do_AddRef(mContentStream).take();
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsInputStreamChannel::nsISupports
+
+NS_IMPL_ISUPPORTS_INHERITED(nsInputStreamChannel, nsBaseChannel,
+                            nsIInputStreamChannel)
+
+//-----------------------------------------------------------------------------
+// nsInputStreamChannel::nsIInputStreamChannel
+
+NS_IMETHODIMP
+nsInputStreamChannel::SetURI(nsIURI* uri) {
+  NS_ENSURE_TRUE(!URI(), NS_ERROR_ALREADY_INITIALIZED);
+  nsBaseChannel::SetURI(uri);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::GetContentStream(nsIInputStream** stream) {
+  *stream = do_AddRef(mContentStream).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::SetContentStream(nsIInputStream* stream) {
+  NS_ENSURE_TRUE(!mContentStream, NS_ERROR_ALREADY_INITIALIZED);
+  mContentStream = stream;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::GetSrcdocData(nsAString& aSrcdocData) {
+  aSrcdocData = mSrcdocData;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::SetSrcdocData(const nsAString& aSrcdocData) {
+  mSrcdocData = aSrcdocData;
+  mIsSrcdocChannel = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::GetIsSrcdocChannel(bool* aIsSrcdocChannel) {
+  *aIsSrcdocChannel = mIsSrcdocChannel;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::GetBaseURI(nsIURI** aBaseURI) {
+  *aBaseURI = do_AddRef(mBaseURI).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamChannel::SetBaseURI(nsIURI* aBaseURI) {
+  mBaseURI = aBaseURI;
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsInputStreamChannel.h b/netwerk/base/nsInputStreamChannel.h
new file mode 100644
index 0000000000..c8c926020b
--- /dev/null
+++ b/netwerk/base/nsInputStreamChannel.h
@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsInputStreamChannel_h__
+#define nsInputStreamChannel_h__
+
+#include "nsBaseChannel.h"
+#include "nsIInputStreamChannel.h"
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+class nsInputStreamChannel : public nsBaseChannel,
+                             public nsIInputStreamChannel {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIINPUTSTREAMCHANNEL
+
+  nsInputStreamChannel() = default;
+
+ protected:
+  virtual ~nsInputStreamChannel() = default;
+
+  virtual nsresult OpenContentStream(bool async, nsIInputStream** result,
+                                     nsIChannel** channel) override;
+
+  virtual void OnChannelDone() override { mContentStream = nullptr; }
+
+ private:
+  nsCOMPtr<nsIInputStream> mContentStream;
+  nsCOMPtr<nsIURI> mBaseURI;
+  nsString mSrcdocData;
+  bool mIsSrcdocChannel{false};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // !nsInputStreamChannel_h__
diff --git a/netwerk/base/nsInputStreamPump.cpp b/netwerk/base/nsInputStreamPump.cpp
new file mode 100644
index 0000000000..11aac4cd9b
--- /dev/null
+++ b/netwerk/base/nsInputStreamPump.cpp
@@ -0,0 +1,786 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sts=2 sw=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIOService.h"
+#include "nsInputStreamPump.h"
+#include "nsIStreamTransportService.h"
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsThreadUtils.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Logging.h"
+#include "mozilla/NonBlockingAsyncInputStream.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/SlicedInputStream.h"
+#include "nsIStreamListener.h"
+#include "nsILoadGroup.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsStreamUtils.h"
+#include <algorithm>
+
+//
+// MOZ_LOG=nsStreamPump:5
+//
+static mozilla::LazyLogModule gStreamPumpLog("nsStreamPump");
+#undef LOG
+#define LOG(args) MOZ_LOG(gStreamPumpLog, mozilla::LogLevel::Debug, args)
+
+//-----------------------------------------------------------------------------
+// nsInputStreamPump methods
+//-----------------------------------------------------------------------------
+
+nsInputStreamPump::nsInputStreamPump() : mOffMainThread(!NS_IsMainThread()) {}
+
+nsresult nsInputStreamPump::Create(nsInputStreamPump** result,
+                                   nsIInputStream* stream, uint32_t segsize,
+                                   uint32_t segcount, bool closeWhenDone,
+                                   nsISerialEventTarget* mainThreadTarget) {
+  nsresult rv = NS_ERROR_OUT_OF_MEMORY;
+  RefPtr<nsInputStreamPump> pump = new nsInputStreamPump();
+  if (pump) {
+    rv = pump->Init(stream, segsize, segcount, closeWhenDone, mainThreadTarget);
+    if (NS_SUCCEEDED(rv)) {
+      pump.forget(result);
+    }
+  }
+  return rv;
+}
+
+struct PeekData {
+  PeekData(nsInputStreamPump::PeekSegmentFun fun, void* closure)
+      : mFunc(fun), mClosure(closure) {}
+
+  nsInputStreamPump::PeekSegmentFun mFunc;
+  void* mClosure;
+};
+
+static nsresult CallPeekFunc(nsIInputStream* aInStream, void* aClosure,
+                             const char* aFromSegment, uint32_t aToOffset,
+                             uint32_t aCount, uint32_t* aWriteCount) {
+  NS_ASSERTION(aToOffset == 0, "Called more than once?");
+  NS_ASSERTION(aCount > 0, "Called without data?");
+
+  PeekData* data = static_cast<PeekData*>(aClosure);
+  data->mFunc(data->mClosure, reinterpret_cast<const uint8_t*>(aFromSegment),
+              aCount);
+  return NS_BINDING_ABORTED;
+}
+
+nsresult nsInputStreamPump::PeekStream(PeekSegmentFun callback, void* closure) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  MOZ_ASSERT(mAsyncStream, "PeekStream called without stream");
+
+  nsresult rv = CreateBufferedStreamIfNeeded();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // See if the pipe is closed by checking the return of Available.
+  uint64_t dummy64;
+  rv = mAsyncStream->Available(&dummy64);
+  if (NS_FAILED(rv)) return rv;
+  uint32_t dummy = (uint32_t)std::min(dummy64, (uint64_t)UINT32_MAX);
+
+  PeekData data(callback, closure);
+  return mAsyncStream->ReadSegments(
+      CallPeekFunc, &data, mozilla::net::nsIOService::gDefaultSegmentSize,
+      &dummy);
+}
+
+nsresult nsInputStreamPump::EnsureWaiting() {
+  mMutex.AssertCurrentThreadIn();
+
+  // no need to worry about multiple threads... an input stream pump lives
+  // on only one thread at a time.
+  MOZ_ASSERT(mAsyncStream);
+  if (!mWaitingForInputStreamReady && !mProcessingCallbacks) {
+    // Ensure OnStateStop is called on the main thread only when this pump is
+    // created on main thread.
+    if (mState == STATE_STOP && !mOffMainThread) {
+      nsCOMPtr<nsISerialEventTarget> mainThread =
+          mLabeledMainThreadTarget
+              ? mLabeledMainThreadTarget
+              : do_AddRef(mozilla::GetMainThreadSerialEventTarget());
+      if (mTargetThread != mainThread) {
+        mTargetThread = mainThread;
+      }
+    }
+    MOZ_ASSERT(mTargetThread);
+    nsresult rv = mAsyncStream->AsyncWait(this, 0, 0, mTargetThread);
+    if (NS_FAILED(rv)) {
+      NS_ERROR("AsyncWait failed");
+      return rv;
+    }
+    // Any retargeting during STATE_START or START_TRANSFER is complete
+    // after the call to AsyncWait; next callback will be on mTargetThread.
+    mRetargeting = false;
+    mWaitingForInputStreamReady = true;
+  }
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsInputStreamPump::nsISupports
+//-----------------------------------------------------------------------------
+
+// although this class can only be accessed from one thread at a time, we do
+// allow its ownership to move from thread to thread, assuming the consumer
+// understands the limitations of this.
+NS_IMPL_ADDREF(nsInputStreamPump)
+NS_IMPL_RELEASE(nsInputStreamPump)
+NS_INTERFACE_MAP_BEGIN(nsInputStreamPump)
+  NS_INTERFACE_MAP_ENTRY(nsIRequest)
+  NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableRequest)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStreamCallback)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStreamPump)
+  NS_INTERFACE_MAP_ENTRY_CONCRETE(nsInputStreamPump)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStreamPump)
+NS_INTERFACE_MAP_END
+
+//-----------------------------------------------------------------------------
+// nsInputStreamPump::nsIRequest
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsInputStreamPump::GetName(nsACString& result) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  result.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::IsPending(bool* result) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  *result = (mState != STATE_IDLE && mState != STATE_DEAD);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::GetStatus(nsresult* status) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  *status = mStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsInputStreamPump::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsInputStreamPump::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsInputStreamPump::CancelWithReason(nsresult aStatus,
+                                                  const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::Cancel(nsresult status) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  AssertOnThread();
+
+  LOG(("nsInputStreamPump::Cancel [this=%p status=%" PRIx32 "]\n", this,
+       static_cast<uint32_t>(status)));
+
+  if (NS_FAILED(mStatus)) {
+    LOG(("  already canceled\n"));
+    return NS_OK;
+  }
+
+  NS_ASSERTION(NS_FAILED(status), "cancel with non-failure status code");
+  mStatus = status;
+
+  // close input stream
+  if (mAsyncStream) {
+    // If mSuspendCount != 0, EnsureWaiting will be called by Resume().
+    // Note that while suspended, OnInputStreamReady will
+    // not do anything, and also note that calling asyncWait
+    // on a closed stream works and will dispatch an event immediately.
+
+    nsCOMPtr<nsIEventTarget> currentTarget = NS_GetCurrentThread();
+    if (mTargetThread && currentTarget != mTargetThread) {
+      nsresult rv = mTargetThread->Dispatch(NS_NewRunnableFunction(
+          "nsInputStreamPump::Cancel", [self = RefPtr{this}, status] {
+            RecursiveMutexAutoLock lock(self->mMutex);
+            if (!self->mAsyncStream) {
+              return;
+            }
+            self->mAsyncStream->CloseWithStatus(status);
+            if (self->mSuspendCount == 0) {
+              self->EnsureWaiting();
+            }
+          }));
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      mAsyncStream->CloseWithStatus(status);
+      if (mSuspendCount == 0) {
+        EnsureWaiting();
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::Suspend() {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  LOG(("nsInputStreamPump::Suspend [this=%p]\n", this));
+  NS_ENSURE_TRUE(mState != STATE_IDLE && mState != STATE_DEAD,
+                 NS_ERROR_UNEXPECTED);
+  ++mSuspendCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::Resume() {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  LOG(("nsInputStreamPump::Resume [this=%p]\n", this));
+  NS_ENSURE_TRUE(mSuspendCount > 0, NS_ERROR_UNEXPECTED);
+  NS_ENSURE_TRUE(mState != STATE_IDLE && mState != STATE_DEAD,
+                 NS_ERROR_UNEXPECTED);
+
+  // There is a brief in-between state when we null out mAsyncStream in
+  // OnStateStop() before calling OnStopRequest, and only afterwards set
+  // STATE_DEAD, which we need to handle gracefully.
+  if (--mSuspendCount == 0 && mAsyncStream) {
+    EnsureWaiting();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::GetLoadFlags(nsLoadFlags* aLoadFlags) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  *aLoadFlags = mLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::SetLoadFlags(nsLoadFlags aLoadFlags) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  mLoadFlags = aLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  *aLoadGroup = do_AddRef(mLoadGroup).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::SetLoadGroup(nsILoadGroup* aLoadGroup) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  mLoadGroup = aLoadGroup;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsInputStreamPump::nsIInputStreamPump implementation
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsInputStreamPump::Init(nsIInputStream* stream, uint32_t segsize,
+                        uint32_t segcount, bool closeWhenDone,
+                        nsISerialEventTarget* mainThreadTarget) {
+  // probably we can't be multithread-accessed yet
+  RecursiveMutexAutoLock lock(mMutex);
+  NS_ENSURE_TRUE(mState == STATE_IDLE, NS_ERROR_IN_PROGRESS);
+
+  mStream = stream;
+  mSegSize = segsize;
+  mSegCount = segcount;
+  mCloseWhenDone = closeWhenDone;
+  mLabeledMainThreadTarget = mainThreadTarget;
+  if (mOffMainThread && mLabeledMainThreadTarget) {
+    MOZ_ASSERT(
+        false,
+        "Init stream pump off main thread with a main thread event target.");
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::AsyncRead(nsIStreamListener* listener) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  // This ensures only one thread can interact with a pump at a time
+  NS_ENSURE_TRUE(mState == STATE_IDLE, NS_ERROR_IN_PROGRESS);
+  NS_ENSURE_ARG_POINTER(listener);
+  MOZ_ASSERT(NS_IsMainThread() || mOffMainThread,
+             "nsInputStreamPump should be read from the "
+             "main thread only.");
+
+  nsresult rv = NS_MakeAsyncNonBlockingInputStream(
+      mStream.forget(), getter_AddRefs(mAsyncStream), mCloseWhenDone, mSegSize,
+      mSegCount);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  MOZ_ASSERT(mAsyncStream);
+
+  // mStreamOffset now holds the number of bytes currently read.
+  mStreamOffset = 0;
+
+  // grab event queue (we must do this here by contract, since all notifications
+  // must go to the thread which called AsyncRead)
+  if (NS_IsMainThread() && mLabeledMainThreadTarget) {
+    mTargetThread = mLabeledMainThreadTarget;
+  } else {
+    mTargetThread = mozilla::GetCurrentSerialEventTarget();
+  }
+  NS_ENSURE_STATE(mTargetThread);
+
+  rv = EnsureWaiting();
+  if (NS_FAILED(rv)) return rv;
+
+  if (mLoadGroup) mLoadGroup->AddRequest(this, nullptr);
+
+  mState = STATE_START;
+  mListener = listener;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsInputStreamPump::nsIInputStreamCallback implementation
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsInputStreamPump::OnInputStreamReady(nsIAsyncInputStream* stream) {
+  LOG(("nsInputStreamPump::OnInputStreamReady [this=%p]\n", this));
+
+  AUTO_PROFILER_LABEL("nsInputStreamPump::OnInputStreamReady", NETWORK);
+
+  // this function has been called from a PLEvent, so we can safely call
+  // any listener or progress sink methods directly from here.
+
+  for (;;) {
+    // There should only be one iteration of this loop happening at a time.
+    // To prevent AsyncWait() (called during callbacks or on other threads)
+    // from creating a parallel OnInputStreamReady(), we use:
+    // -- a mutex; and
+    // -- a boolean mProcessingCallbacks to detect parallel loops
+    //    when exiting the mutex for callbacks.
+    RecursiveMutexAutoLock lock(mMutex);
+
+    // Prevent parallel execution during callbacks, while out of mutex.
+    if (mProcessingCallbacks) {
+      MOZ_ASSERT(!mProcessingCallbacks);
+      break;
+    }
+    mProcessingCallbacks = true;
+    if (mSuspendCount || mState == STATE_IDLE || mState == STATE_DEAD) {
+      mWaitingForInputStreamReady = false;
+      mProcessingCallbacks = false;
+      break;
+    }
+
+    uint32_t nextState;
+    switch (mState) {
+      case STATE_START:
+        nextState = OnStateStart();
+        break;
+      case STATE_TRANSFER:
+        nextState = OnStateTransfer();
+        break;
+      case STATE_STOP:
+        mRetargeting = false;
+        nextState = OnStateStop();
+        break;
+      default:
+        nextState = 0;
+        MOZ_ASSERT_UNREACHABLE("Unknown enum value.");
+        return NS_ERROR_UNEXPECTED;
+    }
+
+    bool stillTransferring =
+        (mState == STATE_TRANSFER && nextState == STATE_TRANSFER);
+    if (stillTransferring) {
+      NS_ASSERTION(NS_SUCCEEDED(mStatus),
+                   "Should not have failed status for ongoing transfer");
+    } else {
+      NS_ASSERTION(mState != nextState,
+                   "Only OnStateTransfer can be called more than once.");
+    }
+    if (mRetargeting) {
+      NS_ASSERTION(mState != STATE_STOP,
+                   "Retargeting should not happen during OnStateStop.");
+    }
+
+    // Set mRetargeting so EnsureWaiting will be called. It ensures that
+    // OnStateStop is called on the main thread.
+    if (nextState == STATE_STOP && !NS_IsMainThread() && !mOffMainThread) {
+      mRetargeting = true;
+    }
+
+    // Unset mProcessingCallbacks here (while we have lock) so our own call to
+    // EnsureWaiting isn't blocked by it.
+    mProcessingCallbacks = false;
+
+    // We must break the loop if suspended during one of the previous
+    // operation.
+    if (mSuspendCount) {
+      mState = nextState;
+      mWaitingForInputStreamReady = false;
+      break;
+    }
+
+    // Wait asynchronously if there is still data to transfer, or we're
+    // switching event delivery to another thread.
+    if (stillTransferring || mRetargeting) {
+      mState = nextState;
+      mWaitingForInputStreamReady = false;
+      nsresult rv = EnsureWaiting();
+      if (NS_SUCCEEDED(rv)) break;
+
+      // Failure to start asynchronous wait: stop transfer.
+      // Do not set mStatus if it was previously set to report a failure.
+      if (NS_SUCCEEDED(mStatus)) {
+        mStatus = rv;
+      }
+      nextState = STATE_STOP;
+    }
+
+    mState = nextState;
+  }
+  return NS_OK;
+}
+
+uint32_t nsInputStreamPump::OnStateStart() {
+  mMutex.AssertCurrentThreadIn();
+
+  AUTO_PROFILER_LABEL("nsInputStreamPump::OnStateStart", NETWORK);
+
+  LOG(("  OnStateStart [this=%p]\n", this));
+
+  nsresult rv;
+
+  // need to check the reason why the stream is ready.  this is required
+  // so our listener can check our status from OnStartRequest.
+  // XXX async streams should have a GetStatus method!
+  if (NS_SUCCEEDED(mStatus)) {
+    uint64_t avail;
+    rv = mAsyncStream->Available(&avail);
+    if (NS_FAILED(rv) && rv != NS_BASE_STREAM_CLOSED) mStatus = rv;
+  }
+
+  {
+    nsCOMPtr<nsIStreamListener> listener = mListener;
+    // We're on the writing thread
+    AssertOnThread();
+
+    // Note: Must exit mutex for call to OnStartRequest to avoid
+    // deadlocks when calls to RetargetDeliveryTo for multiple
+    // nsInputStreamPumps are needed (e.g. nsHttpChannel).
+    RecursiveMutexAutoUnlock unlock(mMutex);
+    rv = listener->OnStartRequest(this);
+  }
+
+  // an error returned from OnStartRequest should cause us to abort; however,
+  // we must not stomp on mStatus if already canceled.
+  if (NS_FAILED(rv) && NS_SUCCEEDED(mStatus)) mStatus = rv;
+
+  return NS_SUCCEEDED(mStatus) ? STATE_TRANSFER : STATE_STOP;
+}
+
+uint32_t nsInputStreamPump::OnStateTransfer() {
+  mMutex.AssertCurrentThreadIn();
+
+  AUTO_PROFILER_LABEL("nsInputStreamPump::OnStateTransfer", NETWORK);
+
+  LOG(("  OnStateTransfer [this=%p]\n", this));
+
+  // if canceled, go directly to STATE_STOP...
+  if (NS_FAILED(mStatus)) return STATE_STOP;
+
+  nsresult rv = CreateBufferedStreamIfNeeded();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return STATE_STOP;
+  }
+
+  uint64_t avail;
+  rv = mAsyncStream->Available(&avail);
+  LOG(("  Available returned [stream=%p rv=%" PRIx32 " avail=%" PRIu64 "]\n",
+       mAsyncStream.get(), static_cast<uint32_t>(rv), avail));
+
+  if (rv == NS_BASE_STREAM_CLOSED) {
+    rv = NS_OK;
+    avail = 0;
+  } else if (NS_SUCCEEDED(rv) && avail) {
+    // we used to limit avail to 16K - we were afraid some ODA handlers
+    // might assume they wouldn't get more than 16K at once
+    // we're removing that limit since it speeds up local file access.
+    // Now there's an implicit 64K limit of 4 16K segments
+    // NOTE: ok, so the story is as follows.  OnDataAvailable impls
+    //       are by contract supposed to consume exactly |avail| bytes.
+    //       however, many do not... mailnews... stream converters...
+    //       cough, cough.  the input stream pump is fairly tolerant
+    //       in this regard; however, if an ODA does not consume any
+    //       data from the stream, then we could potentially end up in
+    //       an infinite loop.  we do our best here to try to catch
+    //       such an error.  (see bug 189672)
+
+    // in most cases this QI will succeed (mAsyncStream is almost always
+    // a nsPipeInputStream, which implements nsITellableStream::Tell).
+    int64_t offsetBefore;
+    nsCOMPtr<nsITellableStream> tellable = do_QueryInterface(mAsyncStream);
+    if (tellable && NS_FAILED(tellable->Tell(&offsetBefore))) {
+      MOZ_ASSERT_UNREACHABLE("Tell failed on readable stream");
+      offsetBefore = 0;
+    }
+
+    uint32_t odaAvail = avail > UINT32_MAX ? UINT32_MAX : uint32_t(avail);
+
+    LOG(("  calling OnDataAvailable [offset=%" PRIu64 " count=%" PRIu64
+         "(%u)]\n",
+         mStreamOffset, avail, odaAvail));
+
+    {
+      // We may be called on non-MainThread even if mOffMainThread is
+      // false, due to RetargetDeliveryTo(), so don't use AssertOnThread()
+      if (mTargetThread) {
+        MOZ_ASSERT(mTargetThread->IsOnCurrentThread());
+      } else {
+        MOZ_ASSERT(NS_IsMainThread());
+      }
+
+      nsCOMPtr<nsIStreamListener> listener = mListener;
+      // Note: Must exit mutex for call to OnStartRequest to avoid
+      // deadlocks when calls to RetargetDeliveryTo for multiple
+      // nsInputStreamPumps are needed (e.g. nsHttpChannel).
+      RecursiveMutexAutoUnlock unlock(mMutex);
+      // We're on the writing thread for mListener and mAsyncStream.
+      // mStreamOffset is only touched in OnStateTransfer, and AsyncRead
+      // shouldn't be called during OnDataAvailable()
+
+      MOZ_PUSH_IGNORE_THREAD_SAFETY
+      rv = listener->OnDataAvailable(this, mAsyncStream, mStreamOffset,
+                                     odaAvail);
+      MOZ_POP_THREAD_SAFETY
+    }
+
+    // don't enter this code if ODA failed or called Cancel
+    if (NS_SUCCEEDED(rv) && NS_SUCCEEDED(mStatus)) {
+      // test to see if this ODA failed to consume data
+      if (tellable) {
+        // NOTE: if Tell fails, which can happen if the stream is
+        // now closed, then we assume that everything was read.
+        int64_t offsetAfter;
+        if (NS_FAILED(tellable->Tell(&offsetAfter))) {
+          offsetAfter = offsetBefore + odaAvail;
+        }
+        if (offsetAfter > offsetBefore) {
+          mStreamOffset += (offsetAfter - offsetBefore);
+        } else if (mSuspendCount == 0) {
+          //
+          // possible infinite loop if we continue pumping data!
+          //
+          // NOTE: although not allowed by nsIStreamListener, we
+          // will allow the ODA impl to Suspend the pump.  IMAP
+          // does this :-(
+          //
+          NS_ERROR("OnDataAvailable implementation consumed no data");
+          mStatus = NS_ERROR_UNEXPECTED;
+        }
+      } else {
+        mStreamOffset += odaAvail;  // assume ODA behaved well
+      }
+    }
+  }
+
+  // an error returned from Available or OnDataAvailable should cause us to
+  // abort; however, we must not stop on mStatus if already canceled.
+
+  if (NS_SUCCEEDED(mStatus)) {
+    if (NS_FAILED(rv)) {
+      mStatus = rv;
+    } else if (avail) {
+      // if stream is now closed, advance to STATE_STOP right away.
+      // Available may return 0 bytes available at the moment; that
+      // would not mean that we are done.
+      // XXX async streams should have a GetStatus method!
+      rv = mAsyncStream->Available(&avail);
+      if (NS_SUCCEEDED(rv)) return STATE_TRANSFER;
+      if (rv != NS_BASE_STREAM_CLOSED) mStatus = rv;
+    }
+  }
+  return STATE_STOP;
+}
+
+nsresult nsInputStreamPump::CallOnStateStop() {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  MOZ_ASSERT(NS_IsMainThread(),
+             "CallOnStateStop should only be called on the main thread.");
+
+  mState = OnStateStop();
+  return NS_OK;
+}
+
+uint32_t nsInputStreamPump::OnStateStop() {
+  mMutex.AssertCurrentThreadIn();
+
+  if (!NS_IsMainThread() && !mOffMainThread) {
+    // This method can be called on a different thread if nsInputStreamPump
+    // is used off the main-thread.
+    nsresult rv = mLabeledMainThreadTarget->Dispatch(
+        mozilla::NewRunnableMethod("nsInputStreamPump::CallOnStateStop", this,
+                                   &nsInputStreamPump::CallOnStateStop));
+    NS_ENSURE_SUCCESS(rv, STATE_DEAD);
+    return STATE_DEAD;
+  }
+
+  AUTO_PROFILER_LABEL("nsInputStreamPump::OnStateStop", NETWORK);
+
+  LOG(("  OnStateStop [this=%p status=%" PRIx32 "]\n", this,
+       static_cast<uint32_t>(mStatus)));
+
+  // if an error occurred, we must be sure to pass the error onto the async
+  // stream.  in some cases, this is redundant, but since close is idempotent,
+  // this is OK.  otherwise, be sure to honor the "close-when-done" option.
+
+  if (!mAsyncStream || !mListener) {
+    MOZ_ASSERT(mAsyncStream, "null mAsyncStream: OnStateStop called twice?");
+    MOZ_ASSERT(mListener, "null mListener: OnStateStop called twice?");
+    return STATE_DEAD;
+  }
+
+  if (NS_FAILED(mStatus)) {
+    mAsyncStream->CloseWithStatus(mStatus);
+  } else if (mCloseWhenDone) {
+    mAsyncStream->Close();
+  }
+
+  mAsyncStream = nullptr;
+  mIsPending = false;
+  {
+    // We're on the writing thread.
+    // We believe that mStatus can't be changed on us here.
+    AssertOnThread();
+
+    nsCOMPtr<nsIStreamListener> listener = mListener;
+    nsresult status = mStatus;
+    // Note: Must exit mutex for call to OnStartRequest to avoid
+    // deadlocks when calls to RetargetDeliveryTo for multiple
+    // nsInputStreamPumps are needed (e.g. nsHttpChannel).
+    RecursiveMutexAutoUnlock unlock(mMutex);
+
+    listener->OnStopRequest(this, status);
+  }
+  mTargetThread = nullptr;
+  mListener = nullptr;
+
+  if (mLoadGroup) mLoadGroup->RemoveRequest(this, nullptr, mStatus);
+
+  return STATE_DEAD;
+}
+
+nsresult nsInputStreamPump::CreateBufferedStreamIfNeeded() {
+  if (mAsyncStreamIsBuffered) {
+    return NS_OK;
+  }
+
+  // ReadSegments is not available for any nsIAsyncInputStream. In order to use
+  // it, we wrap a nsIBufferedInputStream around it, if needed.
+
+  if (NS_InputStreamIsBuffered(mAsyncStream)) {
+    mAsyncStreamIsBuffered = true;
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIInputStream> stream;
+  nsresult rv = NS_NewBufferedInputStream(getter_AddRefs(stream),
+                                          mAsyncStream.forget(), 4096);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // A buffered inputStream must implement nsIAsyncInputStream.
+  mAsyncStream = do_QueryInterface(stream);
+  MOZ_DIAGNOSTIC_ASSERT(mAsyncStream);
+  mAsyncStreamIsBuffered = true;
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsIThreadRetargetableRequest
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsInputStreamPump::RetargetDeliveryTo(nsISerialEventTarget* aNewTarget) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  NS_ENSURE_ARG(aNewTarget);
+  NS_ENSURE_TRUE(mState == STATE_START || mState == STATE_TRANSFER,
+                 NS_ERROR_UNEXPECTED);
+
+  // If canceled, do not retarget. Return with canceled status.
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  if (aNewTarget == mTargetThread) {
+    NS_WARNING("Retargeting delivery to same thread");
+    return NS_OK;
+  }
+
+  if (mOffMainThread) {
+    // Don't support retargeting if this pump is already used off the main
+    // thread.
+    return NS_ERROR_FAILURE;
+  }
+
+  // Ensure that |mListener| and any subsequent listeners can be retargeted
+  // to another thread.
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+      do_QueryInterface(mListener, &rv);
+  if (NS_SUCCEEDED(rv) && retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+    if (NS_SUCCEEDED(rv)) {
+      mTargetThread = aNewTarget;
+      mRetargeting = true;
+    }
+  }
+  LOG(
+      ("nsInputStreamPump::RetargetDeliveryTo [this=%p aNewTarget=%p] "
+       "%s listener [%p] rv[%" PRIx32 "]",
+       this, aNewTarget, (mTargetThread == aNewTarget ? "success" : "failure"),
+       (nsIStreamListener*)mListener, static_cast<uint32_t>(rv)));
+  return rv;
+}
+
+NS_IMETHODIMP
+nsInputStreamPump::GetDeliveryTarget(nsISerialEventTarget** aNewTarget) {
+  RecursiveMutexAutoLock lock(mMutex);
+
+  nsCOMPtr<nsISerialEventTarget> target = mTargetThread;
+  target.forget(aNewTarget);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsInputStreamPump.h b/netwerk/base/nsInputStreamPump.h
new file mode 100644
index 0000000000..21e75c0276
--- /dev/null
+++ b/netwerk/base/nsInputStreamPump.h
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsInputStreamPump_h__
+#define nsInputStreamPump_h__
+
+#include "nsIInputStreamPump.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIThreadRetargetableRequest.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/RecursiveMutex.h"
+
+#ifdef DEBUG
+#  include "MainThreadUtils.h"
+#  include "nsISerialEventTarget.h"
+#endif
+
+class nsIInputStream;
+class nsILoadGroup;
+class nsIStreamListener;
+
+#define NS_INPUT_STREAM_PUMP_IID                     \
+  {                                                  \
+    0x42f1cc9b, 0xdf5f, 0x4c9b, {                    \
+      0xbd, 0x71, 0x8d, 0x4a, 0xe2, 0x27, 0xc1, 0x8a \
+    }                                                \
+  }
+
+class nsInputStreamPump final : public nsIInputStreamPump,
+                                public nsIInputStreamCallback,
+                                public nsIThreadRetargetableRequest {
+  ~nsInputStreamPump() = default;
+
+ public:
+  using RecursiveMutexAutoLock = mozilla::RecursiveMutexAutoLock;
+  using RecursiveMutexAutoUnlock = mozilla::RecursiveMutexAutoUnlock;
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSIINPUTSTREAMPUMP
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSITHREADRETARGETABLEREQUEST
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_INPUT_STREAM_PUMP_IID)
+
+  nsInputStreamPump();
+
+  static nsresult Create(nsInputStreamPump** result, nsIInputStream* stream,
+                         uint32_t segsize = 0, uint32_t segcount = 0,
+                         bool closeWhenDone = false,
+                         nsISerialEventTarget* mainThreadTarget = nullptr);
+
+  using PeekSegmentFun = void (*)(void*, const uint8_t*, uint32_t);
+  /**
+   * Peek into the first chunk of data that's in the stream. Note that this
+   * method will not call the callback when there is no data in the stream.
+   * The callback will be called at most once.
+   *
+   * The data from the stream will not be consumed, i.e. the pump's listener
+   * can still read all the data
+   *
+   * Do not call before asyncRead. Do not call after onStopRequest.
+   */
+  nsresult PeekStream(PeekSegmentFun callback, void* closure);
+
+  /**
+   * Dispatched (to the main thread) by OnStateStop if it's called off main
+   * thread. Updates mState based on return value of OnStateStop.
+   */
+  nsresult CallOnStateStop();
+
+ protected:
+  enum { STATE_IDLE, STATE_START, STATE_TRANSFER, STATE_STOP, STATE_DEAD };
+
+  nsresult EnsureWaiting();
+  uint32_t OnStateStart();
+  uint32_t OnStateTransfer();
+  uint32_t OnStateStop();
+  nsresult CreateBufferedStreamIfNeeded() MOZ_REQUIRES(mMutex);
+
+  // This should optimize away in non-DEBUG builds
+  MOZ_ALWAYS_INLINE void AssertOnThread() const MOZ_REQUIRES(mMutex) {
+    if (mOffMainThread) {
+      MOZ_ASSERT(mTargetThread->IsOnCurrentThread());
+    } else {
+      MOZ_ASSERT(NS_IsMainThread());
+    }
+  }
+
+  uint32_t mState MOZ_GUARDED_BY(mMutex){STATE_IDLE};
+  nsCOMPtr<nsILoadGroup> mLoadGroup MOZ_GUARDED_BY(mMutex);
+  // mListener is written on a single thread (either MainThread or an
+  // off-MainThread thread), read from that thread and perhaps others (in
+  // RetargetDeliveryTo)
+  nsCOMPtr<nsIStreamListener> mListener MOZ_GUARDED_BY(mMutex);
+  nsCOMPtr<nsISerialEventTarget> mTargetThread MOZ_GUARDED_BY(mMutex);
+  nsCOMPtr<nsISerialEventTarget> mLabeledMainThreadTarget
+      MOZ_GUARDED_BY(mMutex);
+  nsCOMPtr<nsIInputStream> mStream MOZ_GUARDED_BY(mMutex);
+  // mAsyncStream is written on a single thread (either MainThread or an
+  // off-MainThread thread), and lives from AsyncRead() to OnStateStop().
+  nsCOMPtr<nsIAsyncInputStream> mAsyncStream MOZ_GUARDED_BY(mMutex);
+  uint64_t mStreamOffset MOZ_GUARDED_BY(mMutex){0};
+  uint64_t mStreamLength MOZ_GUARDED_BY(mMutex){0};
+  uint32_t mSegSize MOZ_GUARDED_BY(mMutex){0};
+  uint32_t mSegCount MOZ_GUARDED_BY(mMutex){0};
+  nsresult mStatus MOZ_GUARDED_BY(mMutex){NS_OK};
+  uint32_t mSuspendCount MOZ_GUARDED_BY(mMutex){0};
+  uint32_t mLoadFlags MOZ_GUARDED_BY(mMutex){LOAD_NORMAL};
+  bool mIsPending MOZ_GUARDED_BY(mMutex){false};
+  // True while in OnInputStreamReady, calling OnStateStart, OnStateTransfer
+  // and OnStateStop. Used to prevent calls to AsyncWait during callbacks.
+  bool mProcessingCallbacks MOZ_GUARDED_BY(mMutex){false};
+  // True if waiting on the "input stream ready" callback.
+  bool mWaitingForInputStreamReady MOZ_GUARDED_BY(mMutex){false};
+  bool mCloseWhenDone MOZ_GUARDED_BY(mMutex){false};
+  bool mRetargeting MOZ_GUARDED_BY(mMutex){false};
+  bool mAsyncStreamIsBuffered MOZ_GUARDED_BY(mMutex){false};
+  // Indicate whether nsInputStreamPump is used completely off main thread.
+  // If true, OnStateStop() is executed off main thread. Set at creation.
+  const bool mOffMainThread;
+  // Protects state/member var accesses across multiple threads.
+  mozilla::RecursiveMutex mMutex{"nsInputStreamPump"};
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsInputStreamPump, NS_INPUT_STREAM_PUMP_IID)
+
+#endif  // !nsInputStreamChannel_h__
diff --git a/netwerk/base/nsLoadGroup.cpp b/netwerk/base/nsLoadGroup.cpp
new file mode 100644
index 0000000000..e3f88fc554
--- /dev/null
+++ b/netwerk/base/nsLoadGroup.cpp
@@ -0,0 +1,1112 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=4 sts=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#include "nsLoadGroup.h"
+
+#include "nsArrayEnumerator.h"
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsContentUtils.h"
+#include "mozilla/Logging.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "mozilla/Telemetry.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsITimedChannel.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIRequestObserver.h"
+#include "CacheObserver.h"
+#include "MainThreadUtils.h"
+#include "RequestContextService.h"
+#include "mozilla/StoragePrincipalHelper.h"
+#include "mozilla/Unused.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/StaticPrefs_network.h"
+
+namespace mozilla {
+namespace net {
+
+//
+// Log module for nsILoadGroup logging...
+//
+// To enable logging (see prlog.h for full details):
+//
+//    set MOZ_LOG=LoadGroup:5
+//    set MOZ_LOG_FILE=network.log
+//
+// This enables LogLevel::Debug level information and places all output in
+// the file network.log.
+//
+static LazyLogModule gLoadGroupLog("LoadGroup");
+#undef LOG
+#define LOG(args) MOZ_LOG(gLoadGroupLog, mozilla::LogLevel::Debug, args)
+
+////////////////////////////////////////////////////////////////////////////////
+
+class RequestMapEntry : public PLDHashEntryHdr {
+ public:
+  explicit RequestMapEntry(nsIRequest* aRequest) : mKey(aRequest) {}
+
+  nsCOMPtr<nsIRequest> mKey;
+};
+
+static bool RequestHashMatchEntry(const PLDHashEntryHdr* entry,
+                                  const void* key) {
+  const RequestMapEntry* e = static_cast<const RequestMapEntry*>(entry);
+  const nsIRequest* request = static_cast<const nsIRequest*>(key);
+
+  return e->mKey == request;
+}
+
+static void RequestHashClearEntry(PLDHashTable* table, PLDHashEntryHdr* entry) {
+  RequestMapEntry* e = static_cast<RequestMapEntry*>(entry);
+
+  // An entry is being cleared, let the entry do its own cleanup.
+  e->~RequestMapEntry();
+}
+
+static void RequestHashInitEntry(PLDHashEntryHdr* entry, const void* key) {
+  const nsIRequest* const_request = static_cast<const nsIRequest*>(key);
+  nsIRequest* request = const_cast<nsIRequest*>(const_request);
+
+  // Initialize the entry with placement new
+  new (entry) RequestMapEntry(request);
+}
+
+static const PLDHashTableOps sRequestHashOps = {
+    PLDHashTable::HashVoidPtrKeyStub, RequestHashMatchEntry,
+    PLDHashTable::MoveEntryStub, RequestHashClearEntry, RequestHashInitEntry};
+
+static void RescheduleRequest(nsIRequest* aRequest, int32_t delta) {
+  nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(aRequest);
+  if (p) p->AdjustPriority(delta);
+}
+
+nsLoadGroup::nsLoadGroup()
+    : mRequests(&sRequestHashOps, sizeof(RequestMapEntry)) {
+  LOG(("LOADGROUP [%p]: Created.\n", this));
+}
+
+nsLoadGroup::~nsLoadGroup() {
+  DebugOnly<nsresult> rv =
+      CancelWithReason(NS_BINDING_ABORTED, "nsLoadGroup::~nsLoadGroup"_ns);
+  NS_ASSERTION(NS_SUCCEEDED(rv), "Cancel failed");
+
+  mDefaultLoadRequest = nullptr;
+
+  if (mRequestContext && !mExternalRequestContext) {
+    mRequestContextService->RemoveRequestContext(mRequestContext->GetID());
+    if (IsNeckoChild() && gNeckoChild) {
+      gNeckoChild->SendRemoveRequestContext(mRequestContext->GetID());
+    }
+  }
+
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (os) {
+    Unused << os->RemoveObserver(this, "last-pb-context-exited");
+  }
+
+  LOG(("LOADGROUP [%p]: Destroyed.\n", this));
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsISupports methods:
+
+NS_IMPL_ISUPPORTS(nsLoadGroup, nsILoadGroup, nsILoadGroupChild, nsIRequest,
+                  nsISupportsPriority, nsISupportsWeakReference, nsIObserver)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsLoadGroup::GetName(nsACString& result) {
+  // XXX is this the right "name" for a load group?
+
+  if (!mDefaultLoadRequest) {
+    result.Truncate();
+    return NS_OK;
+  }
+
+  return mDefaultLoadRequest->GetName(result);
+}
+
+NS_IMETHODIMP
+nsLoadGroup::IsPending(bool* aResult) {
+  *aResult = mForegroundCount > 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetStatus(nsresult* status) {
+  if (NS_SUCCEEDED(mStatus) && mDefaultLoadRequest) {
+    return mDefaultLoadRequest->GetStatus(status);
+  }
+
+  *status = mStatus;
+  return NS_OK;
+}
+
+static bool AppendRequestsToArray(PLDHashTable* aTable,
+                                  nsTArray<nsIRequest*>* aArray) {
+  for (auto iter = aTable->Iter(); !iter.Done(); iter.Next()) {
+    auto* e = static_cast<RequestMapEntry*>(iter.Get());
+    nsIRequest* request = e->mKey;
+    MOZ_DIAGNOSTIC_ASSERT(request, "Null key in mRequests PLDHashTable entry");
+
+    // XXX(Bug 1631371) Check if this should use a fallible operation as it
+    // pretended earlier.
+    aArray->AppendElement(request);
+    NS_ADDREF(request);
+  }
+
+  if (aArray->Length() != aTable->EntryCount()) {
+    for (uint32_t i = 0, len = aArray->Length(); i < len; ++i) {
+      NS_RELEASE((*aArray)[i]);
+    }
+    return false;
+  }
+  return true;
+}
+
+NS_IMETHODIMP nsLoadGroup::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsLoadGroup::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsLoadGroup::CancelWithReason(nsresult aStatus,
+                                            const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsLoadGroup::Cancel(nsresult status) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  NS_ASSERTION(NS_FAILED(status), "shouldn't cancel with a success code");
+  nsresult rv;
+  uint32_t count = mRequests.EntryCount();
+
+  AutoTArray<nsIRequest*, 8> requests;
+
+  if (!AppendRequestsToArray(&mRequests, &requests)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // set the load group status to our cancel status while we cancel
+  // all our requests...once the cancel is done, we'll reset it...
+  //
+  mStatus = status;
+
+  // Set the flag indicating that the loadgroup is being canceled...  This
+  // prevents any new channels from being added during the operation.
+  //
+  mIsCanceling = true;
+
+  nsresult firstError = NS_OK;
+  while (count > 0) {
+    nsCOMPtr<nsIRequest> request = requests.ElementAt(--count);
+
+    NS_ASSERTION(request, "NULL request found in list.");
+
+    if (!mRequests.Search(request)) {
+      // |request| was removed already
+      // We need to null out the entry in the request array so we don't try
+      // to notify the observers for this request.
+      nsCOMPtr<nsIRequest> request = dont_AddRef(requests.ElementAt(count));
+      requests.ElementAt(count) = nullptr;
+
+      continue;
+    }
+
+    if (MOZ_LOG_TEST(gLoadGroupLog, LogLevel::Debug)) {
+      nsAutoCString nameStr;
+      request->GetName(nameStr);
+      LOG(("LOADGROUP [%p]: Canceling request %p %s.\n", this, request.get(),
+           nameStr.get()));
+    }
+
+    // Cancel the request...
+    rv = request->CancelWithReason(status, mCanceledReason);
+
+    // Remember the first failure and return it...
+    if (NS_FAILED(rv) && NS_SUCCEEDED(firstError)) firstError = rv;
+
+    if (NS_FAILED(RemoveRequestFromHashtable(request, status))) {
+      // It's possible that request->Cancel causes the request to be removed
+      // from the loadgroup causing RemoveRequestFromHashtable to fail.
+      // In that case we shouldn't call NotifyRemovalObservers or decrement
+      // mForegroundCount since that has already happened.
+      nsCOMPtr<nsIRequest> request = dont_AddRef(requests.ElementAt(count));
+      requests.ElementAt(count) = nullptr;
+
+      continue;
+    }
+  }
+
+  for (count = requests.Length(); count > 0;) {
+    nsCOMPtr<nsIRequest> request = dont_AddRef(requests.ElementAt(--count));
+    (void)NotifyRemovalObservers(request, status);
+  }
+
+  if (mRequestContext) {
+    Unused << mRequestContext->CancelTailPendingRequests(status);
+  }
+
+#if defined(DEBUG)
+  NS_ASSERTION(mRequests.EntryCount() == 0, "Request list is not empty.");
+  NS_ASSERTION(mForegroundCount == 0, "Foreground URLs are active.");
+#endif
+
+  mStatus = NS_OK;
+  mIsCanceling = false;
+
+  return firstError;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::Suspend() {
+  nsresult rv, firstError;
+  uint32_t count = mRequests.EntryCount();
+
+  AutoTArray<nsIRequest*, 8> requests;
+
+  if (!AppendRequestsToArray(&mRequests, &requests)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  firstError = NS_OK;
+  //
+  // Operate the elements from back to front so that if items get
+  // get removed from the list it won't affect our iteration
+  //
+  while (count > 0) {
+    nsCOMPtr<nsIRequest> request = dont_AddRef(requests.ElementAt(--count));
+
+    NS_ASSERTION(request, "NULL request found in list.");
+    if (!request) continue;
+
+    if (MOZ_LOG_TEST(gLoadGroupLog, LogLevel::Debug)) {
+      nsAutoCString nameStr;
+      request->GetName(nameStr);
+      LOG(("LOADGROUP [%p]: Suspending request %p %s.\n", this, request.get(),
+           nameStr.get()));
+    }
+
+    // Suspend the request...
+    rv = request->Suspend();
+
+    // Remember the first failure and return it...
+    if (NS_FAILED(rv) && NS_SUCCEEDED(firstError)) firstError = rv;
+  }
+
+  return firstError;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::Resume() {
+  nsresult rv, firstError;
+  uint32_t count = mRequests.EntryCount();
+
+  AutoTArray<nsIRequest*, 8> requests;
+
+  if (!AppendRequestsToArray(&mRequests, &requests)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  firstError = NS_OK;
+  //
+  // Operate the elements from back to front so that if items get
+  // get removed from the list it won't affect our iteration
+  //
+  while (count > 0) {
+    nsCOMPtr<nsIRequest> request = dont_AddRef(requests.ElementAt(--count));
+
+    NS_ASSERTION(request, "NULL request found in list.");
+    if (!request) continue;
+
+    if (MOZ_LOG_TEST(gLoadGroupLog, LogLevel::Debug)) {
+      nsAutoCString nameStr;
+      request->GetName(nameStr);
+      LOG(("LOADGROUP [%p]: Resuming request %p %s.\n", this, request.get(),
+           nameStr.get()));
+    }
+
+    // Resume the request...
+    rv = request->Resume();
+
+    // Remember the first failure and return it...
+    if (NS_FAILED(rv) && NS_SUCCEEDED(firstError)) firstError = rv;
+  }
+
+  return firstError;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetLoadFlags(uint32_t* aLoadFlags) {
+  *aLoadFlags = mLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetLoadFlags(uint32_t aLoadFlags) {
+  mLoadFlags = aLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetLoadGroup(nsILoadGroup** loadGroup) {
+  nsCOMPtr<nsILoadGroup> result = mLoadGroup;
+  result.forget(loadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetLoadGroup(nsILoadGroup* loadGroup) {
+  mLoadGroup = loadGroup;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsILoadGroup methods:
+
+NS_IMETHODIMP
+nsLoadGroup::GetDefaultLoadRequest(nsIRequest** aRequest) {
+  nsCOMPtr<nsIRequest> result = mDefaultLoadRequest;
+  result.forget(aRequest);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetDefaultLoadRequest(nsIRequest* aRequest) {
+  LOG(("nsLoadGroup::SetDefaultLoadRequest this=%p default-request=%p", this,
+       aRequest));
+
+  mDefaultLoadRequest = aRequest;
+  // Inherit the group load flags from the default load request
+  if (mDefaultLoadRequest) {
+    mDefaultLoadRequest->GetLoadFlags(&mLoadFlags);
+    //
+    // Mask off any bits that are not part of the nsIRequest flags.
+    // in particular, nsIChannel::LOAD_DOCUMENT_URI...
+    //
+    mLoadFlags &= nsIRequest::LOAD_REQUESTMASK;
+
+    nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(aRequest);
+    mDefaultLoadIsTimed = timedChannel != nullptr;
+    if (mDefaultLoadIsTimed) {
+      timedChannel->GetChannelCreation(&mDefaultRequestCreationTime);
+      timedChannel->SetTimingEnabled(true);
+    }
+  }
+  // Else, do not change the group's load flags (see bug 95981)
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::AddRequest(nsIRequest* request, nsISupports* ctxt) {
+  nsresult rv;
+
+  if (MOZ_LOG_TEST(gLoadGroupLog, LogLevel::Debug)) {
+    nsAutoCString nameStr;
+    request->GetName(nameStr);
+    LOG(("LOADGROUP [%p]: Adding request %p %s (count=%d).\n", this, request,
+         nameStr.get(), mRequests.EntryCount()));
+  }
+
+  NS_ASSERTION(!mRequests.Search(request),
+               "Entry added to loadgroup twice, don't do that");
+
+  //
+  // Do not add the channel, if the loadgroup is being canceled...
+  //
+  if (mIsCanceling) {
+    LOG(
+        ("LOADGROUP [%p]: AddChannel() ABORTED because LoadGroup is"
+         " being canceled!!\n",
+         this));
+
+    return NS_BINDING_ABORTED;
+  }
+
+  nsLoadFlags flags;
+  // if the request is the default load request or if the default load
+  // request is null, then the load group should inherit its load flags from
+  // the request, but also we need to enforce defaultLoadFlags.
+  if (mDefaultLoadRequest == request || !mDefaultLoadRequest) {
+    rv = MergeDefaultLoadFlags(request, flags);
+  } else {
+    rv = MergeLoadFlags(request, flags);
+  }
+  if (NS_FAILED(rv)) return rv;
+
+  //
+  // Add the request to the list of active requests...
+  //
+
+  auto* entry = static_cast<RequestMapEntry*>(mRequests.Add(request, fallible));
+  if (!entry) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (mPriority != 0) RescheduleRequest(request, mPriority);
+
+  nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(request);
+  if (timedChannel) timedChannel->SetTimingEnabled(true);
+
+  bool foreground = !(flags & nsIRequest::LOAD_BACKGROUND);
+  if (foreground) {
+    // Update the count of foreground URIs..
+    mForegroundCount += 1;
+  }
+
+  if (foreground || mNotifyObserverAboutBackgroundRequests) {
+    //
+    // Fire the OnStartRequest notification out to the observer...
+    //
+    // If the notification fails then DO NOT add the request to
+    // the load group.
+    //
+    nsCOMPtr<nsIRequestObserver> observer = do_QueryReferent(mObserver);
+    if (observer) {
+      LOG(
+          ("LOADGROUP [%p]: Firing OnStartRequest for request %p."
+           "(foreground count=%d).\n",
+           this, request, mForegroundCount));
+
+      rv = observer->OnStartRequest(request);
+      if (NS_FAILED(rv)) {
+        LOG(("LOADGROUP [%p]: OnStartRequest for request %p FAILED.\n", this,
+             request));
+        //
+        // The URI load has been canceled by the observer.  Clean up
+        // the damage...
+        //
+
+        mRequests.Remove(request);
+
+        rv = NS_OK;
+
+        if (foreground) {
+          mForegroundCount -= 1;
+        }
+      }
+    }
+
+    // Ensure that we're part of our loadgroup while pending
+    if (foreground && mForegroundCount == 1 && mLoadGroup) {
+      mLoadGroup->AddRequest(this, nullptr);
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::RemoveRequest(nsIRequest* request, nsISupports* ctxt,
+                           nsresult aStatus) {
+  // Make sure we have a owning reference to the request we're about
+  // to remove.
+  nsCOMPtr<nsIRequest> kungFuDeathGrip(request);
+
+  nsresult rv = RemoveRequestFromHashtable(request, aStatus);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NotifyRemovalObservers(request, aStatus);
+}
+
+nsresult nsLoadGroup::RemoveRequestFromHashtable(nsIRequest* request,
+                                                 nsresult aStatus) {
+  NS_ENSURE_ARG_POINTER(request);
+  nsresult rv;
+
+  if (MOZ_LOG_TEST(gLoadGroupLog, LogLevel::Debug)) {
+    nsAutoCString nameStr;
+    request->GetName(nameStr);
+    LOG(("LOADGROUP [%p]: Removing request %p %s status %" PRIx32
+         " (count=%d).\n",
+         this, request, nameStr.get(), static_cast<uint32_t>(aStatus),
+         mRequests.EntryCount() - 1));
+  }
+
+  //
+  // Remove the request from the group.  If this fails, it means that
+  // the request was *not* in the group so do not update the foreground
+  // count or it will get messed up...
+  //
+  auto* entry = static_cast<RequestMapEntry*>(mRequests.Search(request));
+
+  if (!entry) {
+    LOG(("LOADGROUP [%p]: Unable to remove request %p. Not in group!\n", this,
+         request));
+
+    return NS_ERROR_FAILURE;
+  }
+
+  mRequests.RemoveEntry(entry);
+
+  // Collect telemetry stats only when default request is a timed channel.
+  // Don't include failed requests in the timing statistics.
+  if (mDefaultLoadIsTimed && NS_SUCCEEDED(aStatus)) {
+    nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(request);
+    if (timedChannel) {
+      // Figure out if this request was served from the cache
+      ++mTimedRequests;
+      TimeStamp timeStamp;
+      rv = timedChannel->GetCacheReadStart(&timeStamp);
+      if (NS_SUCCEEDED(rv) && !timeStamp.IsNull()) {
+        ++mCachedRequests;
+      }
+
+      rv = timedChannel->GetAsyncOpen(&timeStamp);
+      if (NS_SUCCEEDED(rv) && !timeStamp.IsNull()) {
+        Telemetry::AccumulateTimeDelta(
+            Telemetry::HTTP_SUBITEM_OPEN_LATENCY_TIME,
+            mDefaultRequestCreationTime, timeStamp);
+      }
+
+      rv = timedChannel->GetResponseStart(&timeStamp);
+      if (NS_SUCCEEDED(rv) && !timeStamp.IsNull()) {
+        Telemetry::AccumulateTimeDelta(
+            Telemetry::HTTP_SUBITEM_FIRST_BYTE_LATENCY_TIME,
+            mDefaultRequestCreationTime, timeStamp);
+      }
+
+      TelemetryReportChannel(timedChannel, false);
+    }
+  }
+
+  if (mRequests.EntryCount() == 0) {
+    TelemetryReport();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsLoadGroup::NotifyRemovalObservers(nsIRequest* request,
+                                             nsresult aStatus) {
+  NS_ENSURE_ARG_POINTER(request);
+  // Undo any group priority delta...
+  if (mPriority != 0) RescheduleRequest(request, -mPriority);
+
+  nsLoadFlags flags;
+  nsresult rv = request->GetLoadFlags(&flags);
+  if (NS_FAILED(rv)) return rv;
+
+  bool foreground = !(flags & nsIRequest::LOAD_BACKGROUND);
+  if (foreground) {
+    NS_ASSERTION(mForegroundCount > 0, "ForegroundCount messed up");
+    mForegroundCount -= 1;
+  }
+
+  if (foreground || mNotifyObserverAboutBackgroundRequests) {
+    // Fire the OnStopRequest out to the observer...
+    nsCOMPtr<nsIRequestObserver> observer = do_QueryReferent(mObserver);
+    if (observer) {
+      LOG(
+          ("LOADGROUP [%p]: Firing OnStopRequest for request %p."
+           "(foreground count=%d).\n",
+           this, request, mForegroundCount));
+
+      rv = observer->OnStopRequest(request, aStatus);
+
+      if (NS_FAILED(rv)) {
+        LOG(("LOADGROUP [%p]: OnStopRequest for request %p FAILED.\n", this,
+             request));
+      }
+    }
+
+    // If that was the last request -> remove ourselves from loadgroup
+    if (foreground && mForegroundCount == 0 && mLoadGroup) {
+      mLoadGroup->RemoveRequest(this, nullptr, aStatus);
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetRequests(nsISimpleEnumerator** aRequests) {
+  nsCOMArray<nsIRequest> requests;
+  requests.SetCapacity(mRequests.EntryCount());
+
+  for (auto iter = mRequests.Iter(); !iter.Done(); iter.Next()) {
+    auto* e = static_cast<RequestMapEntry*>(iter.Get());
+    requests.AppendObject(e->mKey);
+  }
+
+  return NS_NewArrayEnumerator(aRequests, requests, NS_GET_IID(nsIRequest));
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetGroupObserver(nsIRequestObserver* aObserver) {
+  SetGroupObserver(aObserver, false);
+  return NS_OK;
+}
+
+void nsLoadGroup::SetGroupObserver(nsIRequestObserver* aObserver,
+                                   bool aIncludeBackgroundRequests) {
+  mObserver = do_GetWeakReference(aObserver);
+  mNotifyObserverAboutBackgroundRequests = aIncludeBackgroundRequests;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetGroupObserver(nsIRequestObserver** aResult) {
+  nsCOMPtr<nsIRequestObserver> observer = do_QueryReferent(mObserver);
+  observer.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetActiveCount(uint32_t* aResult) {
+  *aResult = mForegroundCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetNotificationCallbacks(nsIInterfaceRequestor** aCallbacks) {
+  NS_ENSURE_ARG_POINTER(aCallbacks);
+  nsCOMPtr<nsIInterfaceRequestor> callbacks = mCallbacks;
+  callbacks.forget(aCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetNotificationCallbacks(nsIInterfaceRequestor* aCallbacks) {
+  mCallbacks = aCallbacks;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetRequestContextID(uint64_t* aRCID) {
+  if (!mRequestContext) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  *aRCID = mRequestContext->GetID();
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsILoadGroupChild methods:
+
+NS_IMETHODIMP
+nsLoadGroup::GetParentLoadGroup(nsILoadGroup** aParentLoadGroup) {
+  *aParentLoadGroup = nullptr;
+  nsCOMPtr<nsILoadGroup> parent = do_QueryReferent(mParentLoadGroup);
+  if (!parent) return NS_OK;
+  parent.forget(aParentLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetParentLoadGroup(nsILoadGroup* aParentLoadGroup) {
+  mParentLoadGroup = do_GetWeakReference(aParentLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetChildLoadGroup(nsILoadGroup** aChildLoadGroup) {
+  *aChildLoadGroup = do_AddRef(this).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetRootLoadGroup(nsILoadGroup** aRootLoadGroup) {
+  // first recursively try the root load group of our parent
+  nsCOMPtr<nsILoadGroupChild> ancestor = do_QueryReferent(mParentLoadGroup);
+  if (ancestor) return ancestor->GetRootLoadGroup(aRootLoadGroup);
+
+  // next recursively try the root load group of our own load grop
+  ancestor = do_QueryInterface(mLoadGroup);
+  if (ancestor) return ancestor->GetRootLoadGroup(aRootLoadGroup);
+
+  // finally just return this
+  *aRootLoadGroup = do_AddRef(this).take();
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsISupportsPriority methods:
+
+NS_IMETHODIMP
+nsLoadGroup::GetPriority(int32_t* aValue) {
+  *aValue = mPriority;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetPriority(int32_t aValue) {
+  return AdjustPriority(aValue - mPriority);
+}
+
+NS_IMETHODIMP
+nsLoadGroup::AdjustPriority(int32_t aDelta) {
+  // Update the priority for each request that supports nsISupportsPriority
+  if (aDelta != 0) {
+    mPriority += aDelta;
+    for (auto iter = mRequests.Iter(); !iter.Done(); iter.Next()) {
+      auto* e = static_cast<RequestMapEntry*>(iter.Get());
+      RescheduleRequest(e->mKey, aDelta);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetDefaultLoadFlags(uint32_t* aFlags) {
+  *aFlags = mDefaultLoadFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::SetDefaultLoadFlags(uint32_t aFlags) {
+  mDefaultLoadFlags = aFlags;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+void nsLoadGroup::TelemetryReport() {
+  nsresult defaultStatus = NS_ERROR_INVALID_ARG;
+  // We should only report HTTP_PAGE_* telemetry if the defaultRequest was
+  // actually successful.
+  if (mDefaultLoadRequest) {
+    mDefaultLoadRequest->GetStatus(&defaultStatus);
+  }
+  if (mDefaultLoadIsTimed && NS_SUCCEEDED(defaultStatus)) {
+    Telemetry::Accumulate(Telemetry::HTTP_REQUEST_PER_PAGE, mTimedRequests);
+    if (mTimedRequests) {
+      Telemetry::Accumulate(Telemetry::HTTP_REQUEST_PER_PAGE_FROM_CACHE,
+                            mCachedRequests * 100 / mTimedRequests);
+    }
+
+    nsCOMPtr<nsITimedChannel> timedChannel =
+        do_QueryInterface(mDefaultLoadRequest);
+    if (timedChannel) TelemetryReportChannel(timedChannel, true);
+  }
+
+  mTimedRequests = 0;
+  mCachedRequests = 0;
+  mDefaultLoadIsTimed = false;
+}
+
+void nsLoadGroup::TelemetryReportChannel(nsITimedChannel* aTimedChannel,
+                                         bool aDefaultRequest) {
+  nsresult rv;
+  bool timingEnabled;
+  rv = aTimedChannel->GetTimingEnabled(&timingEnabled);
+  if (NS_FAILED(rv) || !timingEnabled) return;
+
+  TimeStamp asyncOpen;
+  rv = aTimedChannel->GetAsyncOpen(&asyncOpen);
+  // We do not check !asyncOpen.IsNull() bellow, prevent ASSERTIONs this way
+  if (NS_FAILED(rv) || asyncOpen.IsNull()) return;
+
+  TimeStamp cacheReadStart;
+  rv = aTimedChannel->GetCacheReadStart(&cacheReadStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp cacheReadEnd;
+  rv = aTimedChannel->GetCacheReadEnd(&cacheReadEnd);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp domainLookupStart;
+  rv = aTimedChannel->GetDomainLookupStart(&domainLookupStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp domainLookupEnd;
+  rv = aTimedChannel->GetDomainLookupEnd(&domainLookupEnd);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp connectStart;
+  rv = aTimedChannel->GetConnectStart(&connectStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp secureConnectionStart;
+  rv = aTimedChannel->GetSecureConnectionStart(&secureConnectionStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp connectEnd;
+  rv = aTimedChannel->GetConnectEnd(&connectEnd);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp requestStart;
+  rv = aTimedChannel->GetRequestStart(&requestStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp responseStart;
+  rv = aTimedChannel->GetResponseStart(&responseStart);
+  if (NS_FAILED(rv)) return;
+
+  TimeStamp responseEnd;
+  rv = aTimedChannel->GetResponseEnd(&responseEnd);
+  if (NS_FAILED(rv)) return;
+
+  bool useHttp3 = false;
+  bool supportHttp3 = false;
+  nsCOMPtr<nsIHttpChannelInternal> httpChannel =
+      do_QueryInterface(aTimedChannel);
+  if (httpChannel) {
+    uint32_t major;
+    uint32_t minor;
+    if (NS_SUCCEEDED(httpChannel->GetResponseVersion(&major, &minor))) {
+      useHttp3 = major == 3;
+      if (major == 2) {
+        if (NS_FAILED(httpChannel->GetSupportsHTTP3(&supportHttp3))) {
+          supportHttp3 = false;
+        }
+      }
+    }
+  }
+
+#define HTTP_REQUEST_HISTOGRAMS(prefix)                                        \
+  if (!domainLookupStart.IsNull()) {                                           \
+    Telemetry::AccumulateTimeDelta(Telemetry::HTTP_##prefix##_DNS_ISSUE_TIME,  \
+                                   asyncOpen, domainLookupStart);              \
+  }                                                                            \
+                                                                               \
+  if (!domainLookupStart.IsNull() && !domainLookupEnd.IsNull()) {              \
+    Telemetry::AccumulateTimeDelta(Telemetry::HTTP_##prefix##_DNS_LOOKUP_TIME, \
+                                   domainLookupStart, domainLookupEnd);        \
+  }                                                                            \
+                                                                               \
+  if (!secureConnectionStart.IsNull() && !connectEnd.IsNull()) {               \
+    Telemetry::AccumulateTimeDelta(Telemetry::HTTP_##prefix##_TLS_HANDSHAKE,   \
+                                   secureConnectionStart, connectEnd);         \
+  }                                                                            \
+                                                                               \
+  if (!connectStart.IsNull() && !connectEnd.IsNull()) {                        \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_TCP_CONNECTION_2, connectStart,             \
+        connectEnd);                                                           \
+  }                                                                            \
+                                                                               \
+  if (!requestStart.IsNull() && !responseEnd.IsNull()) {                       \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_OPEN_TO_FIRST_SENT, asyncOpen,              \
+        requestStart);                                                         \
+                                                                               \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_FIRST_SENT_TO_LAST_RECEIVED, requestStart,  \
+        responseEnd);                                                          \
+                                                                               \
+    if (cacheReadStart.IsNull() && !responseStart.IsNull()) {                  \
+      Telemetry::AccumulateTimeDelta(                                          \
+          Telemetry::HTTP_##prefix##_OPEN_TO_FIRST_RECEIVED, asyncOpen,        \
+          responseStart);                                                      \
+    }                                                                          \
+  }                                                                            \
+                                                                               \
+  if (!cacheReadStart.IsNull() && !cacheReadEnd.IsNull()) {                    \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_OPEN_TO_FIRST_FROM_CACHE_V2, asyncOpen,     \
+        cacheReadStart);                                                       \
+                                                                               \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_CACHE_READ_TIME_V2, cacheReadStart,         \
+        cacheReadEnd);                                                         \
+                                                                               \
+    if (!requestStart.IsNull() && !responseEnd.IsNull()) {                     \
+      Telemetry::AccumulateTimeDelta(Telemetry::HTTP_##prefix##_REVALIDATION,  \
+                                     requestStart, responseEnd);               \
+    }                                                                          \
+  }                                                                            \
+                                                                               \
+  if (!cacheReadEnd.IsNull()) {                                                \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_COMPLETE_LOAD_V2, asyncOpen, cacheReadEnd); \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_COMPLETE_LOAD_CACHED_V2, asyncOpen,         \
+        cacheReadEnd);                                                         \
+  } else if (!responseEnd.IsNull()) {                                          \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_COMPLETE_LOAD_V2, asyncOpen, responseEnd);  \
+    Telemetry::AccumulateTimeDelta(                                            \
+        Telemetry::HTTP_##prefix##_COMPLETE_LOAD_NET_V2, asyncOpen,            \
+        responseEnd);                                                          \
+  }
+
+  if (aDefaultRequest) {
+    HTTP_REQUEST_HISTOGRAMS(PAGE)
+  } else {
+    HTTP_REQUEST_HISTOGRAMS(SUB)
+  }
+
+  if ((useHttp3 || supportHttp3) && cacheReadStart.IsNull() &&
+      cacheReadEnd.IsNull()) {
+    nsCString key = (useHttp3) ? ((aDefaultRequest) ? "uses_http3_page"_ns
+                                                    : "uses_http3_sub"_ns)
+                               : ((aDefaultRequest) ? "supports_http3_page"_ns
+                                                    : "supports_http3_sub"_ns);
+
+    if (!secureConnectionStart.IsNull() && !connectEnd.IsNull()) {
+      Telemetry::AccumulateTimeDelta(Telemetry::HTTP3_TLS_HANDSHAKE, key,
+                                     secureConnectionStart, connectEnd);
+    }
+
+    if (supportHttp3 && !connectStart.IsNull() && !connectEnd.IsNull()) {
+      Telemetry::AccumulateTimeDelta(Telemetry::SUP_HTTP3_TCP_CONNECTION, key,
+                                     connectStart, connectEnd);
+    }
+
+    if (!requestStart.IsNull() && !responseEnd.IsNull()) {
+      Telemetry::AccumulateTimeDelta(Telemetry::HTTP3_OPEN_TO_FIRST_SENT, key,
+                                     asyncOpen, requestStart);
+
+      Telemetry::AccumulateTimeDelta(
+          Telemetry::HTTP3_FIRST_SENT_TO_LAST_RECEIVED, key, requestStart,
+          responseEnd);
+
+      if (!responseStart.IsNull()) {
+        Telemetry::AccumulateTimeDelta(Telemetry::HTTP3_OPEN_TO_FIRST_RECEIVED,
+                                       key, asyncOpen, responseStart);
+      }
+
+      if (!responseEnd.IsNull()) {
+        Telemetry::AccumulateTimeDelta(Telemetry::HTTP3_COMPLETE_LOAD, key,
+                                       asyncOpen, responseEnd);
+      }
+    }
+  }
+
+  bool hasHTTPSRR = false;
+  if (httpChannel && NS_SUCCEEDED(httpChannel->GetHasHTTPSRR(&hasHTTPSRR)) &&
+      cacheReadStart.IsNull() && cacheReadEnd.IsNull() &&
+      !requestStart.IsNull()) {
+    nsCString key = (hasHTTPSRR) ? ((aDefaultRequest) ? "uses_https_rr_page"_ns
+                                                      : "uses_https_rr_sub"_ns)
+                                 : ((aDefaultRequest) ? "no_https_rr_page"_ns
+                                                      : "no_https_rr_sub"_ns);
+    Telemetry::AccumulateTimeDelta(Telemetry::HTTPS_RR_OPEN_TO_FIRST_SENT, key,
+                                   asyncOpen, requestStart);
+  }
+
+#undef HTTP_REQUEST_HISTOGRAMS
+}
+
+nsresult nsLoadGroup::MergeLoadFlags(nsIRequest* aRequest,
+                                     nsLoadFlags& outFlags) {
+  nsresult rv;
+  nsLoadFlags flags, oldFlags;
+
+  rv = aRequest->GetLoadFlags(&flags);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  oldFlags = flags;
+
+  // Inherit the following bits...
+  flags |= (mLoadFlags &
+            (LOAD_BACKGROUND | LOAD_BYPASS_CACHE | LOAD_FROM_CACHE |
+             VALIDATE_ALWAYS | VALIDATE_ONCE_PER_SESSION | VALIDATE_NEVER));
+
+  // ... and force the default flags.
+  flags |= mDefaultLoadFlags;
+
+  if (flags != oldFlags) {
+    rv = aRequest->SetLoadFlags(flags);
+  }
+
+  outFlags = flags;
+  return rv;
+}
+
+nsresult nsLoadGroup::MergeDefaultLoadFlags(nsIRequest* aRequest,
+                                            nsLoadFlags& outFlags) {
+  nsresult rv;
+  nsLoadFlags flags, oldFlags;
+
+  rv = aRequest->GetLoadFlags(&flags);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  oldFlags = flags;
+  // ... and force the default flags.
+  flags |= mDefaultLoadFlags;
+
+  if (flags != oldFlags) {
+    rv = aRequest->SetLoadFlags(flags);
+  }
+  outFlags = flags;
+  return rv;
+}
+
+nsresult nsLoadGroup::Init() {
+  mRequestContextService = RequestContextService::GetOrCreate();
+  if (mRequestContextService) {
+    Unused << mRequestContextService->NewRequestContext(
+        getter_AddRefs(mRequestContext));
+  }
+
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  NS_ENSURE_STATE(os);
+
+  Unused << os->AddObserver(this, "last-pb-context-exited", true);
+
+  return NS_OK;
+}
+
+nsresult nsLoadGroup::InitWithRequestContextId(
+    const uint64_t& aRequestContextId) {
+  mRequestContextService = RequestContextService::GetOrCreate();
+  if (mRequestContextService) {
+    Unused << mRequestContextService->GetRequestContext(
+        aRequestContextId, getter_AddRefs(mRequestContext));
+  }
+  mExternalRequestContext = true;
+
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  NS_ENSURE_STATE(os);
+
+  Unused << os->AddObserver(this, "last-pb-context-exited", true);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::Observe(nsISupports* aSubject, const char* aTopic,
+                     const char16_t* aData) {
+  MOZ_ASSERT(!strcmp(aTopic, "last-pb-context-exited"));
+
+  OriginAttributes attrs;
+  StoragePrincipalHelper::GetRegularPrincipalOriginAttributes(this, attrs);
+  if (attrs.mPrivateBrowsingId == 0) {
+    return NS_OK;
+  }
+
+  mBrowsingContextDiscarded = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroup::GetIsBrowsingContextDiscarded(bool* aIsBrowsingContextDiscarded) {
+  *aIsBrowsingContextDiscarded = mBrowsingContextDiscarded;
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
+
+#undef LOG
diff --git a/netwerk/base/nsLoadGroup.h b/netwerk/base/nsLoadGroup.h
new file mode 100644
index 0000000000..055e1804d6
--- /dev/null
+++ b/netwerk/base/nsLoadGroup.h
@@ -0,0 +1,111 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsLoadGroup_h__
+#define nsLoadGroup_h__
+
+#include "nsILoadGroup.h"
+#include "nsILoadGroupChild.h"
+#include "nsIObserver.h"
+#include "nsCOMPtr.h"
+#include "nsWeakReference.h"
+#include "nsISupportsPriority.h"
+#include "PLDHashTable.h"
+#include "mozilla/TimeStamp.h"
+
+class nsIRequestContext;
+class nsIRequestContextService;
+class nsITimedChannel;
+
+namespace mozilla {
+namespace net {
+
+class nsLoadGroup : public nsILoadGroup,
+                    public nsILoadGroupChild,
+                    public nsIObserver,
+                    public nsISupportsPriority,
+                    public nsSupportsWeakReference {
+ public:
+  NS_DECL_ISUPPORTS
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsIRequest methods:
+  NS_DECL_NSIREQUEST
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsILoadGroup methods:
+  NS_DECL_NSILOADGROUP
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsILoadGroupChild methods:
+  NS_DECL_NSILOADGROUPCHILD
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsISupportsPriority methods:
+  NS_DECL_NSISUPPORTSPRIORITY
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsIObserver methods:
+  NS_DECL_NSIOBSERVER
+
+  ////////////////////////////////////////////////////////////////////////////
+  // nsLoadGroup methods:
+
+  nsLoadGroup();
+
+  nsresult Init();
+  nsresult InitWithRequestContextId(const uint64_t& aRequestContextId);
+
+  void SetGroupObserver(nsIRequestObserver* aObserver,
+                        bool aIncludeBackgroundRequests);
+
+ protected:
+  virtual ~nsLoadGroup();
+
+  nsresult MergeLoadFlags(nsIRequest* aRequest, nsLoadFlags& flags);
+  nsresult MergeDefaultLoadFlags(nsIRequest* aRequest, nsLoadFlags& flags);
+
+ private:
+  void TelemetryReport();
+  void TelemetryReportChannel(nsITimedChannel* timedChannel,
+                              bool defaultRequest);
+
+  nsresult RemoveRequestFromHashtable(nsIRequest* aRequest, nsresult aStatus);
+  nsresult NotifyRemovalObservers(nsIRequest* aRequest, nsresult aStatus);
+
+ protected:
+  uint32_t mForegroundCount{0};
+  uint32_t mLoadFlags{LOAD_NORMAL};
+  uint32_t mDefaultLoadFlags{0};
+  int32_t mPriority{PRIORITY_NORMAL};
+
+  nsCOMPtr<nsILoadGroup> mLoadGroup;  // load groups can contain load groups
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsIRequestContext> mRequestContext;
+  nsCOMPtr<nsIRequestContextService> mRequestContextService;
+
+  nsCOMPtr<nsIRequest> mDefaultLoadRequest;
+  PLDHashTable mRequests;
+
+  nsWeakPtr mObserver;
+  nsWeakPtr mParentLoadGroup;
+
+  nsresult mStatus{NS_OK};
+  bool mIsCanceling{false};
+  bool mDefaultLoadIsTimed{false};
+  bool mBrowsingContextDiscarded{false};
+  bool mExternalRequestContext{false};
+  bool mNotifyObserverAboutBackgroundRequests{false};
+
+  /* Telemetry */
+  mozilla::TimeStamp mDefaultRequestCreationTime;
+  uint32_t mTimedRequests{0};
+  uint32_t mCachedRequests{0};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsLoadGroup_h__
diff --git a/netwerk/base/nsMIMEInputStream.cpp b/netwerk/base/nsMIMEInputStream.cpp
new file mode 100644
index 0000000000..d0d9fe09a5
--- /dev/null
+++ b/netwerk/base/nsMIMEInputStream.cpp
@@ -0,0 +1,500 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * The MIME stream separates headers and a datastream. It also allows
+ * automatic creation of the content-length header.
+ */
+
+#include "nsMIMEInputStream.h"
+
+#include <utility>
+
+#include "ipc/IPCMessageUtils.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/ipc/InputStreamUtils.h"
+#include "nsCOMPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIHttpHeaderVisitor.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsIInputStreamLength.h"
+#include "nsIMIMEInputStream.h"
+#include "nsISeekableStream.h"
+#include "nsString.h"
+
+using namespace mozilla::ipc;
+using mozilla::Maybe;
+
+class nsMIMEInputStream : public nsIMIMEInputStream,
+                          public nsISeekableStream,
+                          public nsIIPCSerializableInputStream,
+                          public nsIAsyncInputStream,
+                          public nsIInputStreamCallback,
+                          public nsIInputStreamLength,
+                          public nsIAsyncInputStreamLength,
+                          public nsIInputStreamLengthCallback,
+                          public nsICloneableInputStream {
+  virtual ~nsMIMEInputStream() = default;
+
+ public:
+  nsMIMEInputStream() = default;
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIMIMEINPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSIINPUTSTREAMLENGTH
+  NS_DECL_NSIASYNCINPUTSTREAMLENGTH
+  NS_DECL_NSIINPUTSTREAMLENGTHCALLBACK
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+
+ private:
+  struct MOZ_STACK_CLASS ReadSegmentsState {
+    nsCOMPtr<nsIInputStream> mThisStream;
+    nsWriteSegmentFun mWriter{nullptr};
+    void* mClosure{nullptr};
+  };
+  static nsresult ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                            const char* aFromRawSegment, uint32_t aToOffset,
+                            uint32_t aCount, uint32_t* aWriteCount);
+
+  bool IsSeekableInputStream() const;
+  bool IsAsyncInputStream() const;
+  bool IsInputStreamLength() const;
+  bool IsAsyncInputStreamLength() const;
+  bool IsCloneableInputStream() const;
+
+  nsTArray<HeaderEntry> mHeaders;
+
+  nsCOMPtr<nsIInputStream> mStream;
+  mozilla::Atomic<bool, mozilla::Relaxed> mStartedReading{false};
+
+  mozilla::Mutex mMutex{"nsMIMEInputStream::mMutex"};
+  nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback MOZ_GUARDED_BY(mMutex);
+
+  // This is protected by mutex.
+  nsCOMPtr<nsIInputStreamLengthCallback> mAsyncInputStreamLengthCallback;
+};
+
+NS_IMPL_ADDREF(nsMIMEInputStream)
+NS_IMPL_RELEASE(nsMIMEInputStream)
+
+NS_IMPL_CLASSINFO(nsMIMEInputStream, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_MIMEINPUTSTREAM_CID)
+
+NS_INTERFACE_MAP_BEGIN(nsMIMEInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsIMIMEInputStream)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsIInputStream, nsIMIMEInputStream)
+  NS_INTERFACE_MAP_ENTRY(nsITellableStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISeekableStream, IsSeekableInputStream())
+  NS_INTERFACE_MAP_ENTRY(nsIIPCSerializableInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, IsAsyncInputStream())
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback,
+                                     IsAsyncInputStream())
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMIMEInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLength,
+                                     IsInputStreamLength())
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStreamLength,
+                                     IsAsyncInputStreamLength())
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLengthCallback,
+                                     IsAsyncInputStreamLength())
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream,
+                                     IsCloneableInputStream())
+  NS_IMPL_QUERY_CLASSINFO(nsMIMEInputStream)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CI_INTERFACE_GETTER(nsMIMEInputStream, nsIMIMEInputStream,
+                            nsIAsyncInputStream, nsIInputStream,
+                            nsISeekableStream, nsITellableStream)
+
+NS_IMETHODIMP
+nsMIMEInputStream::AddHeader(const char* aName, const char* aValue) {
+  NS_ENSURE_FALSE(mStartedReading, NS_ERROR_FAILURE);
+
+  HeaderEntry* entry = mHeaders.AppendElement();
+  entry->name().Append(aName);
+  entry->value().Append(aValue);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::VisitHeaders(nsIHttpHeaderVisitor* visitor) {
+  nsresult rv;
+
+  for (auto& header : mHeaders) {
+    rv = visitor->VisitHeader(header.name(), header.value());
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::SetData(nsIInputStream* aStream) {
+  NS_ENSURE_FALSE(mStartedReading, NS_ERROR_FAILURE);
+
+  mStream = aStream;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::GetData(nsIInputStream** aStream) {
+  NS_ENSURE_ARG_POINTER(aStream);
+  *aStream = do_AddRef(mStream).take();
+  return NS_OK;
+}
+
+#define INITSTREAMS                               \
+  if (!mStartedReading) {                         \
+    NS_ENSURE_TRUE(mStream, NS_ERROR_UNEXPECTED); \
+    mStartedReading = true;                       \
+  }
+
+// Reset mStartedReading when Seek-ing to start
+NS_IMETHODIMP
+nsMIMEInputStream::Seek(int32_t whence, int64_t offset) {
+  NS_ENSURE_TRUE(mStream, NS_ERROR_UNEXPECTED);
+
+  nsresult rv;
+  nsCOMPtr<nsISeekableStream> stream = do_QueryInterface(mStream);
+
+  if (whence == NS_SEEK_SET && offset == 0) {
+    rv = stream->Seek(whence, offset);
+    if (NS_SUCCEEDED(rv)) mStartedReading = false;
+  } else {
+    INITSTREAMS;
+    rv = stream->Seek(whence, offset);
+  }
+
+  return rv;
+}
+
+// Proxy ReadSegments since we need to be a good little nsIInputStream
+NS_IMETHODIMP nsMIMEInputStream::ReadSegments(nsWriteSegmentFun aWriter,
+                                              void* aClosure, uint32_t aCount,
+                                              uint32_t* _retval) {
+  INITSTREAMS;
+  ReadSegmentsState state;
+  // Disambiguate ambiguous nsIInputStream.
+  state.mThisStream =
+      static_cast<nsIInputStream*>(static_cast<nsIMIMEInputStream*>(this));
+  state.mWriter = aWriter;
+  state.mClosure = aClosure;
+  return mStream->ReadSegments(ReadSegCb, &state, aCount, _retval);
+}
+
+nsresult nsMIMEInputStream::ReadSegCb(nsIInputStream* aIn, void* aClosure,
+                                      const char* aFromRawSegment,
+                                      uint32_t aToOffset, uint32_t aCount,
+                                      uint32_t* aWriteCount) {
+  ReadSegmentsState* state = (ReadSegmentsState*)aClosure;
+  return (state->mWriter)(state->mThisStream, state->mClosure, aFromRawSegment,
+                          aToOffset, aCount, aWriteCount);
+}
+
+/**
+ * Forward everything else to the mStream after calling INITSTREAMS
+ */
+
+// nsIInputStream
+NS_IMETHODIMP nsMIMEInputStream::Close(void) {
+  INITSTREAMS;
+  return mStream->Close();
+}
+NS_IMETHODIMP nsMIMEInputStream::Available(uint64_t* _retval) {
+  INITSTREAMS;
+  return mStream->Available(_retval);
+}
+NS_IMETHODIMP nsMIMEInputStream::StreamStatus() {
+  INITSTREAMS;
+  return mStream->StreamStatus();
+}
+NS_IMETHODIMP nsMIMEInputStream::Read(char* buf, uint32_t count,
+                                      uint32_t* _retval) {
+  INITSTREAMS;
+  return mStream->Read(buf, count, _retval);
+}
+NS_IMETHODIMP nsMIMEInputStream::IsNonBlocking(bool* aNonBlocking) {
+  INITSTREAMS;
+  return mStream->IsNonBlocking(aNonBlocking);
+}
+
+// nsIAsyncInputStream
+NS_IMETHODIMP
+nsMIMEInputStream::CloseWithStatus(nsresult aStatus) {
+  INITSTREAMS;
+  nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(mStream);
+  return asyncStream->CloseWithStatus(aStatus);
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
+                             uint32_t aRequestedCount,
+                             nsIEventTarget* aEventTarget) {
+  INITSTREAMS;
+  nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(mStream);
+  if (NS_WARN_IF(!asyncStream)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIInputStreamCallback> callback = aCallback ? this : nullptr;
+  {
+    mozilla::MutexAutoLock lock(mMutex);
+    if (NS_WARN_IF(mAsyncWaitCallback && aCallback &&
+                   mAsyncWaitCallback != aCallback)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mAsyncWaitCallback = aCallback;
+  }
+
+  return asyncStream->AsyncWait(callback, aFlags, aRequestedCount,
+                                aEventTarget);
+}
+
+// nsIInputStreamCallback
+
+NS_IMETHODIMP
+nsMIMEInputStream::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  nsCOMPtr<nsIInputStreamCallback> callback;
+
+  {
+    mozilla::MutexAutoLock lock(mMutex);
+
+    // We have been canceled in the meanwhile.
+    if (!mAsyncWaitCallback) {
+      return NS_OK;
+    }
+
+    callback.swap(mAsyncWaitCallback);
+  }
+
+  MOZ_ASSERT(callback);
+  return callback->OnInputStreamReady(this);
+}
+
+// nsITellableStream
+NS_IMETHODIMP nsMIMEInputStream::Tell(int64_t* _retval) {
+  INITSTREAMS;
+  nsCOMPtr<nsITellableStream> stream = do_QueryInterface(mStream);
+  return stream->Tell(_retval);
+}
+
+// nsISeekableStream
+NS_IMETHODIMP nsMIMEInputStream::SetEOF(void) {
+  INITSTREAMS;
+  nsCOMPtr<nsISeekableStream> stream = do_QueryInterface(mStream);
+  return stream->SetEOF();
+}
+
+/**
+ * Factory method used by do_CreateInstance
+ */
+
+nsresult nsMIMEInputStreamConstructor(REFNSIID iid, void** result) {
+  *result = nullptr;
+
+  RefPtr<nsMIMEInputStream> inst = new nsMIMEInputStream();
+  if (!inst) return NS_ERROR_OUT_OF_MEMORY;
+
+  return inst->QueryInterface(iid, result);
+}
+
+void nsMIMEInputStream::SerializedComplexity(uint32_t aMaxSize,
+                                             uint32_t* aSizeUsed,
+                                             uint32_t* aPipes,
+                                             uint32_t* aTransferables) {
+  if (nsCOMPtr<nsIIPCSerializableInputStream> serializable =
+          do_QueryInterface(mStream)) {
+    InputStreamHelper::SerializedComplexity(mStream, aMaxSize, aSizeUsed,
+                                            aPipes, aTransferables);
+  } else {
+    *aPipes = 1;
+  }
+}
+
+void nsMIMEInputStream::Serialize(InputStreamParams& aParams, uint32_t aMaxSize,
+                                  uint32_t* aSizeUsed) {
+  MOZ_ASSERT(aSizeUsed);
+  *aSizeUsed = 0;
+
+  MIMEInputStreamParams params;
+  params.headers() = mHeaders.Clone();
+  params.startedReading() = mStartedReading;
+
+  if (!mStream) {
+    aParams = params;
+    return;
+  }
+
+  InputStreamParams wrappedParams;
+
+  if (nsCOMPtr<nsIIPCSerializableInputStream> serializable =
+          do_QueryInterface(mStream)) {
+    InputStreamHelper::SerializeInputStream(mStream, wrappedParams, aMaxSize,
+                                            aSizeUsed);
+  } else {
+    // Falling back to sending the underlying stream over a pipe when
+    // sending an nsMIMEInputStream over IPC is potentially wasteful
+    // if it is sent several times. This can possibly happen with
+    // fission. There are two ways to improve this, see bug 1648369
+    // and bug 1648370.
+    InputStreamHelper::SerializeInputStreamAsPipe(mStream, wrappedParams);
+  }
+
+  NS_ASSERTION(wrappedParams.type() != InputStreamParams::T__None,
+               "Wrapped stream failed to serialize!");
+
+  params.optionalStream().emplace(wrappedParams);
+  aParams = params;
+}
+
+bool nsMIMEInputStream::Deserialize(const InputStreamParams& aParams) {
+  if (aParams.type() != InputStreamParams::TMIMEInputStreamParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const MIMEInputStreamParams& params = aParams.get_MIMEInputStreamParams();
+  const Maybe<InputStreamParams>& wrappedParams = params.optionalStream();
+
+  if (wrappedParams.isSome()) {
+    nsCOMPtr<nsIInputStream> stream;
+    stream = InputStreamHelper::DeserializeInputStream(wrappedParams.ref());
+    if (!stream) {
+      NS_WARNING("Failed to deserialize wrapped stream!");
+      return false;
+    }
+
+    MOZ_ALWAYS_SUCCEEDS(SetData(stream));
+  }
+
+  mHeaders = params.headers().Clone();
+  mStartedReading = params.startedReading();
+
+  return true;
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::Length(int64_t* aLength) {
+  nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
+  if (NS_WARN_IF(!stream)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return stream->Length(aLength);
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::AsyncLengthWait(nsIInputStreamLengthCallback* aCallback,
+                                   nsIEventTarget* aEventTarget) {
+  nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
+  if (NS_WARN_IF(!stream)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback ? this : nullptr;
+  {
+    mozilla::MutexAutoLock lock(mMutex);
+    mAsyncInputStreamLengthCallback = aCallback;
+  }
+
+  return stream->AsyncLengthWait(callback, aEventTarget);
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::OnInputStreamLengthReady(nsIAsyncInputStreamLength* aStream,
+                                            int64_t aLength) {
+  nsCOMPtr<nsIInputStreamLengthCallback> callback;
+  {
+    mozilla::MutexAutoLock lock(mMutex);
+    // We have been canceled in the meanwhile.
+    if (!mAsyncInputStreamLengthCallback) {
+      return NS_OK;
+    }
+
+    callback.swap(mAsyncInputStreamLengthCallback);
+  }
+
+  MOZ_ASSERT(callback);
+  return callback->OnInputStreamLengthReady(this, aLength);
+}
+
+bool nsMIMEInputStream::IsSeekableInputStream() const {
+  nsCOMPtr<nsISeekableStream> seekable = do_QueryInterface(mStream);
+  return !!seekable;
+}
+
+bool nsMIMEInputStream::IsAsyncInputStream() const {
+  nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(mStream);
+  return !!asyncStream;
+}
+
+bool nsMIMEInputStream::IsInputStreamLength() const {
+  nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
+  return !!stream;
+}
+
+bool nsMIMEInputStream::IsAsyncInputStreamLength() const {
+  nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
+  return !!stream;
+}
+
+bool nsMIMEInputStream::IsCloneableInputStream() const {
+  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+  return !!stream;
+}
+
+// nsICloneableInputStream interface
+
+NS_IMETHODIMP
+nsMIMEInputStream::GetCloneable(bool* aCloneable) {
+  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+  if (!mStream) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return stream->GetCloneable(aCloneable);
+}
+
+NS_IMETHODIMP
+nsMIMEInputStream::Clone(nsIInputStream** aResult) {
+  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
+  if (!mStream) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIInputStream> clonedStream;
+  nsresult rv = stream->Clone(getter_AddRefs(clonedStream));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIMIMEInputStream> mimeStream = new nsMIMEInputStream();
+
+  rv = mimeStream->SetData(clonedStream);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  for (const HeaderEntry& entry : mHeaders) {
+    rv = mimeStream->AddHeader(entry.name().get(), entry.value().get());
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+  }
+
+  static_cast<nsMIMEInputStream*>(mimeStream.get())->mStartedReading =
+      static_cast<bool>(mStartedReading);
+
+  mimeStream.forget(aResult);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsMIMEInputStream.h b/netwerk/base/nsMIMEInputStream.h
new file mode 100644
index 0000000000..adfc5532b1
--- /dev/null
+++ b/netwerk/base/nsMIMEInputStream.h
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * The MIME stream separates headers and a datastream. It also allows
+ * automatic creation of the content-length header.
+ */
+
+#ifndef _nsMIMEInputStream_h_
+#define _nsMIMEInputStream_h_
+
+#include "ErrorList.h"
+#include "nsID.h"
+
+#define NS_MIMEINPUTSTREAM_CONTRACTID "@mozilla.org/network/mime-input-stream;1"
+#define NS_MIMEINPUTSTREAM_CID                       \
+  { /* 58a1c31c-1dd2-11b2-a3f6-d36949d48268 */       \
+    0x58a1c31c, 0x1dd2, 0x11b2, {                    \
+      0xa3, 0xf6, 0xd3, 0x69, 0x49, 0xd4, 0x82, 0x68 \
+    }                                                \
+  }
+
+extern nsresult nsMIMEInputStreamConstructor(REFNSIID iid, void** result);
+
+#endif  // _nsMIMEInputStream_h_
diff --git a/netwerk/base/nsMediaFragmentURIParser.cpp b/netwerk/base/nsMediaFragmentURIParser.cpp
new file mode 100644
index 0000000000..bfa82530c6
--- /dev/null
+++ b/netwerk/base/nsMediaFragmentURIParser.cpp
@@ -0,0 +1,354 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsTArray.h"
+#include "nsCharSeparatedTokenizer.h"
+#include "nsEscape.h"
+#include "nsIURI.h"
+#include <utility>
+
+#include "nsMediaFragmentURIParser.h"
+
+using std::make_pair;
+using std::pair;
+
+namespace mozilla {
+namespace net {
+
+nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsIURI* aURI)
+    : mClipUnit(eClipUnit_Pixel) {
+  nsAutoCString ref;
+  aURI->GetRef(ref);
+  Parse(ref);
+}
+
+nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsCString& aRef)
+    : mClipUnit(eClipUnit_Pixel) {
+  Parse(aRef);
+}
+
+bool nsMediaFragmentURIParser::ParseNPT(nsDependentSubstring aString) {
+  nsDependentSubstring original(aString);
+  if (aString.Length() > 4 && aString[0] == 'n' && aString[1] == 'p' &&
+      aString[2] == 't' && aString[3] == ':') {
+    aString.Rebind(aString, 4);
+  }
+
+  if (aString.Length() == 0) {
+    return false;
+  }
+
+  double start = -1.0;
+  double end = -1.0;
+
+  ParseNPTTime(aString, start);
+
+  if (aString.Length() == 0) {
+    mStart.emplace(start);
+    return true;
+  }
+
+  if (aString[0] != ',') {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  aString.Rebind(aString, 1);
+
+  if (aString.Length() == 0) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  ParseNPTTime(aString, end);
+
+  if (end <= start || aString.Length() != 0) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  mStart.emplace(start);
+  mEnd.emplace(end);
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTTime(nsDependentSubstring& aString,
+                                            double& aTime) {
+  if (aString.Length() == 0) {
+    return false;
+  }
+
+  return ParseNPTHHMMSS(aString, aTime) || ParseNPTMMSS(aString, aTime) ||
+         ParseNPTSec(aString, aTime);
+}
+
+// Return true if the given character is a numeric character
+static bool IsDigit(nsDependentSubstring::char_type aChar) {
+  return (aChar >= '0' && aChar <= '9');
+}
+
+// Return the index of the first character in the string that is not
+// a numerical digit, starting from 'aStart'.
+static uint32_t FirstNonDigit(nsDependentSubstring& aString, uint32_t aStart) {
+  while (aStart < aString.Length() && IsDigit(aString[aStart])) {
+    ++aStart;
+  }
+  return aStart;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTSec(nsDependentSubstring& aString,
+                                           double& aSec) {
+  nsDependentSubstring original(aString);
+  if (aString.Length() == 0) {
+    return false;
+  }
+
+  uint32_t index = FirstNonDigit(aString, 0);
+  if (index == 0) {
+    return false;
+  }
+
+  nsDependentSubstring n(aString, 0, index);
+  nsresult ec;
+  int32_t s = n.ToInteger(&ec);
+  if (NS_FAILED(ec)) {
+    return false;
+  }
+
+  aString.Rebind(aString, index);
+  double fraction = 0.0;
+  if (!ParseNPTFraction(aString, fraction)) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  aSec = s + fraction;
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTMMSS(nsDependentSubstring& aString,
+                                            double& aTime) {
+  nsDependentSubstring original(aString);
+  uint32_t mm = 0;
+  uint32_t ss = 0;
+  double fraction = 0.0;
+  if (!ParseNPTMM(aString, mm)) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  if (aString.Length() < 2 || aString[0] != ':') {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  aString.Rebind(aString, 1);
+  if (!ParseNPTSS(aString, ss)) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  if (!ParseNPTFraction(aString, fraction)) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+  aTime = mm * 60 + ss + fraction;
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTFraction(nsDependentSubstring& aString,
+                                                double& aFraction) {
+  double fraction = 0.0;
+
+  if (aString.Length() > 0 && aString[0] == '.') {
+    uint32_t index = FirstNonDigit(aString, 1);
+
+    if (index > 1) {
+      nsDependentSubstring number(aString, 0, index);
+      nsresult ec;
+      fraction = PromiseFlatString(number).ToDouble(&ec);
+      if (NS_FAILED(ec)) {
+        return false;
+      }
+    }
+    aString.Rebind(aString, index);
+  }
+
+  aFraction = fraction;
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTHHMMSS(nsDependentSubstring& aString,
+                                              double& aTime) {
+  nsDependentSubstring original(aString);
+  uint32_t hh = 0;
+  double seconds = 0.0;
+  if (!ParseNPTHH(aString, hh)) {
+    return false;
+  }
+
+  if (aString.Length() < 2 || aString[0] != ':') {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  aString.Rebind(aString, 1);
+  if (!ParseNPTMMSS(aString, seconds)) {
+    aString.Rebind(original, 0);
+    return false;
+  }
+
+  aTime = hh * 3600 + seconds;
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTHH(nsDependentSubstring& aString,
+                                          uint32_t& aHour) {
+  if (aString.Length() == 0) {
+    return false;
+  }
+
+  uint32_t index = FirstNonDigit(aString, 0);
+  if (index == 0) {
+    return false;
+  }
+
+  nsDependentSubstring n(aString, 0, index);
+  nsresult ec;
+  int32_t u = n.ToInteger(&ec);
+  if (NS_FAILED(ec)) {
+    return false;
+  }
+
+  aString.Rebind(aString, index);
+  aHour = u;
+  return true;
+}
+
+bool nsMediaFragmentURIParser::ParseNPTMM(nsDependentSubstring& aString,
+                                          uint32_t& aMinute) {
+  return ParseNPTSS(aString, aMinute);
+}
+
+bool nsMediaFragmentURIParser::ParseNPTSS(nsDependentSubstring& aString,
+                                          uint32_t& aSecond) {
+  if (aString.Length() < 2) {
+    return false;
+  }
+
+  if (IsDigit(aString[0]) && IsDigit(aString[1])) {
+    nsDependentSubstring n(aString, 0, 2);
+    nsresult ec;
+    int32_t u = n.ToInteger(&ec);
+    if (NS_FAILED(ec)) {
+      return false;
+    }
+
+    aString.Rebind(aString, 2);
+    if (u >= 60) return false;
+
+    aSecond = u;
+    return true;
+  }
+
+  return false;
+}
+
+static bool ParseInteger(nsDependentSubstring& aString, int32_t& aResult) {
+  uint32_t index = FirstNonDigit(aString, 0);
+  if (index == 0) {
+    return false;
+  }
+
+  nsDependentSubstring n(aString, 0, index);
+  nsresult ec;
+  int32_t s = n.ToInteger(&ec);
+  if (NS_FAILED(ec)) {
+    return false;
+  }
+
+  aString.Rebind(aString, index);
+  aResult = s;
+  return true;
+}
+
+static bool ParseCommaSeparator(nsDependentSubstring& aString) {
+  if (aString.Length() > 1 && aString[0] == ',') {
+    aString.Rebind(aString, 1);
+    return true;
+  }
+
+  return false;
+}
+
+bool nsMediaFragmentURIParser::ParseXYWH(nsDependentSubstring aString) {
+  int32_t x, y, w, h;
+  ClipUnit clipUnit;
+
+  // Determine units.
+  if (StringBeginsWith(aString, u"pixel:"_ns)) {
+    clipUnit = eClipUnit_Pixel;
+    aString.Rebind(aString, 6);
+  } else if (StringBeginsWith(aString, u"percent:"_ns)) {
+    clipUnit = eClipUnit_Percent;
+    aString.Rebind(aString, 8);
+  } else {
+    clipUnit = eClipUnit_Pixel;
+  }
+
+  // Read and validate coordinates.
+  if (ParseInteger(aString, x) && x >= 0 && ParseCommaSeparator(aString) &&
+      ParseInteger(aString, y) && y >= 0 && ParseCommaSeparator(aString) &&
+      ParseInteger(aString, w) && w > 0 && ParseCommaSeparator(aString) &&
+      ParseInteger(aString, h) && h > 0 && aString.Length() == 0) {
+    // Reject invalid percentage coordinates.
+    if (clipUnit == eClipUnit_Percent && (x + w > 100 || y + h > 100)) {
+      return false;
+    }
+
+    mClip.emplace(x, y, w, h);
+    mClipUnit = clipUnit;
+    return true;
+  }
+
+  return false;
+}
+
+void nsMediaFragmentURIParser::Parse(nsACString& aRef) {
+  // Create an array of possibly-invalid media fragments.
+  nsTArray<std::pair<nsCString, nsCString> > fragments;
+
+  for (const nsACString& nv : nsCCharSeparatedTokenizer(aRef, '&').ToRange()) {
+    int32_t index = nv.FindChar('=');
+    if (index >= 0) {
+      nsAutoCString name;
+      nsAutoCString value;
+      NS_UnescapeURL(StringHead(nv, index), esc_Ref | esc_AlwaysCopy, name);
+      NS_UnescapeURL(Substring(nv, index + 1, nv.Length()),
+                     esc_Ref | esc_AlwaysCopy, value);
+      fragments.AppendElement(make_pair(name, value));
+    }
+  }
+
+  // Parse the media fragment values.
+  bool gotTemporal = false, gotSpatial = false;
+  for (int i = fragments.Length() - 1; i >= 0; --i) {
+    if (gotTemporal && gotSpatial) {
+      // We've got one of each possible type. No need to look at the rest.
+      break;
+    }
+    if (!gotTemporal && fragments[i].first.EqualsLiteral("t")) {
+      nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
+      gotTemporal = ParseNPT(nsDependentSubstring(value, 0));
+    } else if (!gotSpatial && fragments[i].first.EqualsLiteral("xywh")) {
+      nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
+      gotSpatial = ParseXYWH(nsDependentSubstring(value, 0));
+    }
+  }
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsMediaFragmentURIParser.h b/netwerk/base/nsMediaFragmentURIParser.h
new file mode 100644
index 0000000000..4c277fead8
--- /dev/null
+++ b/netwerk/base/nsMediaFragmentURIParser.h
@@ -0,0 +1,99 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#if !defined(nsMediaFragmentURIParser_h__)
+#  define nsMediaFragmentURIParser_h__
+
+#  include "mozilla/Maybe.h"
+#  include "nsStringFwd.h"
+#  include "nsRect.h"
+
+class nsIURI;
+
+// Class to handle parsing of a W3C media fragment URI as per
+// spec at: http://www.w3.org/TR/media-frags/
+// Only the temporaral URI portion of the spec is implemented.
+// To use:
+// a) Construct an instance with the URI containing the fragment
+// b) Check for the validity of the values you are interested in
+//    using e.g. HasStartTime().
+// c) If the values are valid, obtain them using e.g. GetStartTime().
+
+namespace mozilla {
+namespace net {
+
+enum ClipUnit {
+  eClipUnit_Pixel,
+  eClipUnit_Percent,
+};
+
+class nsMediaFragmentURIParser {
+ public:
+  // Create a parser with the provided URI.
+  explicit nsMediaFragmentURIParser(nsIURI* aURI);
+
+  // Create a parser with the provided URI reference portion.
+  explicit nsMediaFragmentURIParser(nsCString& aRef);
+
+  // True if a valid temporal media fragment indicated a start time.
+  bool HasStartTime() const { return mStart.isSome(); }
+
+  // If a valid temporal media fragment indicated a start time, returns
+  // it in units of seconds. If not, defaults to 0.
+  double GetStartTime() const { return *mStart; }
+
+  // True if a valid temporal media fragment indicated an end time.
+  bool HasEndTime() const { return mEnd.isSome(); }
+
+  // If a valid temporal media fragment indicated an end time, returns
+  // it in units of seconds. If not, defaults to -1.
+  double GetEndTime() const { return *mEnd; }
+
+  // True if a valid spatial media fragment indicated a clipping region.
+  bool HasClip() const { return mClip.isSome(); }
+
+  // If a valid spatial media fragment indicated a clipping region,
+  // returns the region. If not, returns an empty region. The unit
+  // used depends on the value returned by GetClipUnit().
+  nsIntRect GetClip() const { return *mClip; }
+
+  // If a valid spatial media fragment indicated a clipping region,
+  // returns the unit used.
+  ClipUnit GetClipUnit() const { return mClipUnit; }
+
+ private:
+  // Parse the URI ref provided, looking for media fragments. This is
+  // the top-level parser the invokes the others below.
+  void Parse(nsACString& aRef);
+
+  // The following methods parse the fragment as per the media
+  // fragments specification. 'aString' contains the remaining
+  // fragment data to be parsed. The method returns true
+  // if the parse was successful and leaves the remaining unparsed
+  // data in 'aString'. If the parse fails then false is returned
+  // and 'aString' is left as it was when called.
+  bool ParseNPT(nsDependentSubstring aString);
+  bool ParseNPTTime(nsDependentSubstring& aString, double& aTime);
+  bool ParseNPTSec(nsDependentSubstring& aString, double& aSec);
+  bool ParseNPTFraction(nsDependentSubstring& aString, double& aFraction);
+  bool ParseNPTMMSS(nsDependentSubstring& aString, double& aTime);
+  bool ParseNPTHHMMSS(nsDependentSubstring& aString, double& aTime);
+  bool ParseNPTHH(nsDependentSubstring& aString, uint32_t& aHour);
+  bool ParseNPTMM(nsDependentSubstring& aString, uint32_t& aMinute);
+  bool ParseNPTSS(nsDependentSubstring& aString, uint32_t& aSecond);
+  bool ParseXYWH(nsDependentSubstring aString);
+  bool ParseMozResolution(nsDependentSubstring aString);
+
+  // Media fragment information.
+  Maybe<double> mStart;
+  Maybe<double> mEnd;
+  Maybe<nsIntRect> mClip;
+  ClipUnit mClipUnit;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/nsNetAddr.cpp b/netwerk/base/nsNetAddr.cpp
new file mode 100644
index 0000000000..d0cbe69bae
--- /dev/null
+++ b/netwerk/base/nsNetAddr.cpp
@@ -0,0 +1,138 @@
+/* vim: et ts=2 sw=2 tw=80
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsNetAddr.h"
+#include "nsString.h"
+#include "mozilla/net/DNS.h"
+
+using namespace mozilla::net;
+
+NS_IMPL_ISUPPORTS(nsNetAddr, nsINetAddr)
+
+NS_IMETHODIMP nsNetAddr::GetFamily(uint16_t* aFamily) {
+  switch (mAddr.raw.family) {
+    case AF_INET:
+      *aFamily = nsINetAddr::FAMILY_INET;
+      break;
+    case AF_INET6:
+      *aFamily = nsINetAddr::FAMILY_INET6;
+      break;
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+      *aFamily = nsINetAddr::FAMILY_LOCAL;
+      break;
+#endif
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetAddress(nsACString& aAddress) {
+  switch (mAddr.raw.family) {
+    /* PR_NetAddrToString can handle INET and INET6, but not LOCAL. */
+    case AF_INET:
+      aAddress.SetLength(kIPv4CStrBufSize);
+      mAddr.ToStringBuffer(aAddress.BeginWriting(), kIPv4CStrBufSize);
+      aAddress.SetLength(strlen(aAddress.BeginReading()));
+      break;
+    case AF_INET6:
+      aAddress.SetLength(kIPv6CStrBufSize);
+      mAddr.ToStringBuffer(aAddress.BeginWriting(), kIPv6CStrBufSize);
+      aAddress.SetLength(strlen(aAddress.BeginReading()));
+      break;
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+      aAddress.Assign(mAddr.local.path);
+      break;
+#endif
+    // PR_AF_LOCAL falls through to default when not XP_UNIX
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetPort(uint16_t* aPort) {
+  switch (mAddr.raw.family) {
+    case AF_INET:
+      *aPort = ntohs(mAddr.inet.port);
+      break;
+    case AF_INET6:
+      *aPort = ntohs(mAddr.inet6.port);
+      break;
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+      // There is no port number for local / connections.
+      return NS_ERROR_NOT_AVAILABLE;
+#endif
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetFlow(uint32_t* aFlow) {
+  switch (mAddr.raw.family) {
+    case AF_INET6:
+      *aFlow = ntohl(mAddr.inet6.flowinfo);
+      break;
+    case AF_INET:
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+#endif
+      // only for IPv6
+      return NS_ERROR_NOT_AVAILABLE;
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetScope(uint32_t* aScope) {
+  switch (mAddr.raw.family) {
+    case AF_INET6:
+      *aScope = ntohl(mAddr.inet6.scope_id);
+      break;
+    case AF_INET:
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+#endif
+      // only for IPv6
+      return NS_ERROR_NOT_AVAILABLE;
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetIsV4Mapped(bool* aIsV4Mapped) {
+  switch (mAddr.raw.family) {
+    case AF_INET6:
+      *aIsV4Mapped = IPv6ADDR_IS_V4MAPPED(&mAddr.inet6.ip);
+      break;
+    case AF_INET:
+#if defined(XP_UNIX)
+    case AF_LOCAL:
+#endif
+      // only for IPv6
+      return NS_ERROR_NOT_AVAILABLE;
+    default:
+      return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsNetAddr::GetNetAddr(NetAddr* aResult) {
+  memcpy(aResult, &mAddr, sizeof(mAddr));
+  return NS_OK;
+}
diff --git a/netwerk/base/nsNetAddr.h b/netwerk/base/nsNetAddr.h
new file mode 100644
index 0000000000..49d43ccaee
--- /dev/null
+++ b/netwerk/base/nsNetAddr.h
@@ -0,0 +1,30 @@
+/* vim: et ts=2 sw=2 tw=80
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsNetAddr_h__
+#define nsNetAddr_h__
+
+#include "nsINetAddr.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/Attributes.h"
+
+class nsNetAddr final : public nsINetAddr {
+  ~nsNetAddr() = default;
+
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSINETADDR
+
+  explicit nsNetAddr(const mozilla::net::NetAddr* addr) : mAddr(*addr) {}
+
+ private:
+  mozilla::net::NetAddr mAddr;
+
+ protected:
+  /* additional members */
+};
+
+#endif  // !nsNetAddr_h__
diff --git a/netwerk/base/nsNetSegmentUtils.h b/netwerk/base/nsNetSegmentUtils.h
new file mode 100644
index 0000000000..a65defdb50
--- /dev/null
+++ b/netwerk/base/nsNetSegmentUtils.h
@@ -0,0 +1,20 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsNetSegmentUtils_h__
+#define nsNetSegmentUtils_h__
+
+#include "nsIOService.h"
+
+/**
+ * applies defaults to segment params in a consistent way.
+ */
+static inline void net_ResolveSegmentParams(uint32_t& segsize,
+                                            uint32_t& segcount) {
+  if (!segsize) segsize = mozilla::net::nsIOService::gDefaultSegmentSize;
+
+  if (!segcount) segcount = mozilla::net::nsIOService::gDefaultSegmentCount;
+}
+
+#endif  // !nsNetSegmentUtils_h__
diff --git a/netwerk/base/nsNetUtil.cpp b/netwerk/base/nsNetUtil.cpp
new file mode 100644
index 0000000000..897656acbb
--- /dev/null
+++ b/netwerk/base/nsNetUtil.cpp
@@ -0,0 +1,3967 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 sts=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// HttpLog.h should generally be included first
+#include "DecoderDoctorDiagnostics.h"
+#include "HttpLog.h"
+
+#include "nsNetUtil.h"
+
+#include "mozilla/Atomics.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/Components.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/LoadContext.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StaticPrefs_privacy.h"
+#include "mozilla/StoragePrincipalHelper.h"
+#include "mozilla/TaskQueue.h"
+#include "mozilla/Telemetry.h"
+#include "nsBufferedStreams.h"
+#include "nsCategoryCache.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsEscape.h"
+#include "nsFileStreams.h"
+#include "nsHashKeys.h"
+#include "nsHttp.h"
+#include "nsMimeTypes.h"
+#include "nsIAuthPrompt.h"
+#include "nsIAuthPrompt2.h"
+#include "nsIAuthPromptAdapterFactory.h"
+#include "nsIBufferedStreams.h"
+#include "nsBufferedStreams.h"
+#include "nsIChannelEventSink.h"
+#include "nsIContentSniffer.h"
+#include "mozilla/dom/Document.h"
+#include "nsIDownloader.h"
+#include "nsIFileProtocolHandler.h"
+#include "nsIFileStreams.h"
+#include "nsIFileURL.h"
+#include "nsIIDNService.h"
+#include "nsIInputStreamChannel.h"
+#include "nsIInputStreamPump.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsILoadContext.h"
+#include "nsIMIMEHeaderParam.h"
+#include "nsINode.h"
+#include "nsIObjectLoadingContent.h"
+#include "nsPersistentProperties.h"
+#include "nsIPrivateBrowsingChannel.h"
+#include "nsIPropertyBag2.h"
+#include "nsIProtocolProxyService.h"
+#include "mozilla/net/RedirectChannelRegistrar.h"
+#include "nsRequestObserverProxy.h"
+#include "nsISensitiveInfoHiddenURI.h"
+#include "nsISimpleStreamListener.h"
+#include "nsISocketProvider.h"
+#include "nsIStandardURL.h"
+#include "nsIStreamLoader.h"
+#include "nsIIncrementalStreamLoader.h"
+#include "nsStringStream.h"
+#include "nsSyncStreamListener.h"
+#include "nsITextToSubURI.h"
+#include "nsIURIWithSpecialOrigin.h"
+#include "nsIViewSourceChannel.h"
+#include "nsInterfaceRequestorAgg.h"
+#include "nsINestedURI.h"
+#include "mozilla/dom/nsCSPUtils.h"
+#include "mozilla/dom/nsHTTPSOnlyUtils.h"
+#include "mozilla/dom/nsMixedContentBlocker.h"
+#include "mozilla/dom/BlobURLProtocolHandler.h"
+#include "mozilla/net/HttpBaseChannel.h"
+#include "nsIScriptError.h"
+#include "nsISiteSecurityService.h"
+#include "nsHttpHandler.h"
+#include "nsNSSComponent.h"
+#include "nsIRedirectHistoryEntry.h"
+#include "nsICertStorage.h"
+#include "nsICertOverrideService.h"
+#include "nsQueryObject.h"
+#include "mozIThirdPartyUtil.h"
+#include "../mime/nsMIMEHeaderParamImpl.h"
+#include "nsStandardURL.h"
+#include "DefaultURI.h"
+#include "nsChromeProtocolHandler.h"
+#include "nsJSProtocolHandler.h"
+#include "nsDataHandler.h"
+#include "mozilla/dom/BlobURLProtocolHandler.h"
+#include "nsStreamUtils.h"
+#include "nsSocketTransportService2.h"
+#include "nsViewSourceHandler.h"
+#include "nsJARURI.h"
+#include "nsIconURI.h"
+#include "nsAboutProtocolHandler.h"
+#include "nsResProtocolHandler.h"
+#include "mozilla/net/ExtensionProtocolHandler.h"
+#include "mozilla/net/PageThumbProtocolHandler.h"
+#include "mozilla/net/SFVService.h"
+#include <limits>
+#include "nsIXPConnect.h"
+#include "nsParserConstants.h"
+#include "nsCRT.h"
+#include "nsServiceManagerUtils.h"
+#include "mozilla/dom/MediaList.h"
+#include "MediaContainerType.h"
+#include "DecoderTraits.h"
+#include "imgLoader.h"
+
+#if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
+#  include "nsNewMailnewsURI.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::net;
+using mozilla::dom::BlobURLProtocolHandler;
+using mozilla::dom::ClientInfo;
+using mozilla::dom::PerformanceStorage;
+using mozilla::dom::ServiceWorkerDescriptor;
+
+#define MAX_RECURSION_COUNT 50
+
+already_AddRefed<nsIIOService> do_GetIOService(nsresult* error /* = 0 */) {
+  nsCOMPtr<nsIIOService> io = mozilla::components::IO::Service();
+  if (error) *error = io ? NS_OK : NS_ERROR_FAILURE;
+  return io.forget();
+}
+
+nsresult NS_NewLocalFileInputStream(nsIInputStream** result, nsIFile* file,
+                                    int32_t ioFlags /* = -1 */,
+                                    int32_t perm /* = -1 */,
+                                    int32_t behaviorFlags /* = 0 */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileInputStream> in =
+      do_CreateInstance(NS_LOCALFILEINPUTSTREAM_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = in->Init(file, ioFlags, perm, behaviorFlags);
+    if (NS_SUCCEEDED(rv)) in.forget(result);
+  }
+  return rv;
+}
+
+Result<nsCOMPtr<nsIInputStream>, nsresult> NS_NewLocalFileInputStream(
+    nsIFile* file, int32_t ioFlags /* = -1 */, int32_t perm /* = -1 */,
+    int32_t behaviorFlags /* = 0 */) {
+  nsCOMPtr<nsIInputStream> stream;
+  const nsresult rv = NS_NewLocalFileInputStream(getter_AddRefs(stream), file,
+                                                 ioFlags, perm, behaviorFlags);
+  if (NS_SUCCEEDED(rv)) {
+    return stream;
+  }
+  return Err(rv);
+}
+
+nsresult NS_NewLocalFileOutputStream(nsIOutputStream** result, nsIFile* file,
+                                     int32_t ioFlags /* = -1 */,
+                                     int32_t perm /* = -1 */,
+                                     int32_t behaviorFlags /* = 0 */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileOutputStream> out =
+      do_CreateInstance(NS_LOCALFILEOUTPUTSTREAM_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = out->Init(file, ioFlags, perm, behaviorFlags);
+    if (NS_SUCCEEDED(rv)) out.forget(result);
+  }
+  return rv;
+}
+
+Result<nsCOMPtr<nsIOutputStream>, nsresult> NS_NewLocalFileOutputStream(
+    nsIFile* file, int32_t ioFlags /* = -1 */, int32_t perm /* = -1 */,
+    int32_t behaviorFlags /* = 0 */) {
+  nsCOMPtr<nsIOutputStream> stream;
+  const nsresult rv = NS_NewLocalFileOutputStream(getter_AddRefs(stream), file,
+                                                  ioFlags, perm, behaviorFlags);
+  if (NS_SUCCEEDED(rv)) {
+    return stream;
+  }
+  return Err(rv);
+}
+
+nsresult NS_NewLocalFileOutputStream(nsIOutputStream** result,
+                                     const mozilla::ipc::FileDescriptor& fd) {
+  nsCOMPtr<nsIFileOutputStream> out;
+  nsFileOutputStream::Create(NS_GET_IID(nsIFileOutputStream),
+                             getter_AddRefs(out));
+
+  nsresult rv =
+      static_cast<nsFileOutputStream*>(out.get())->InitWithFileDescriptor(fd);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  out.forget(result);
+  return NS_OK;
+}
+
+nsresult net_EnsureIOService(nsIIOService** ios, nsCOMPtr<nsIIOService>& grip) {
+  nsresult rv = NS_OK;
+  if (!*ios) {
+    grip = do_GetIOService(&rv);
+    *ios = grip;
+  }
+  return rv;
+}
+
+nsresult NS_NewFileURI(
+    nsIURI** result, nsIFile* spec,
+    nsIIOService*
+        ioService /* = nullptr */)  // pass in nsIIOService to optimize callers
+{
+  nsresult rv;
+  nsCOMPtr<nsIIOService> grip;
+  rv = net_EnsureIOService(&ioService, grip);
+  if (ioService) rv = ioService->NewFileURI(spec, result);
+  return rv;
+}
+
+nsresult NS_GetURIWithNewRef(nsIURI* aInput, const nsACString& aRef,
+                             nsIURI** aOutput) {
+  MOZ_DIAGNOSTIC_ASSERT(aRef.IsEmpty() || aRef[0] == '#');
+
+  if (NS_WARN_IF(!aInput || !aOutput)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  bool hasRef;
+  nsresult rv = aInput->GetHasRef(&hasRef);
+
+  nsAutoCString ref;
+  if (NS_SUCCEEDED(rv)) {
+    rv = aInput->GetRef(ref);
+  }
+
+  // If the ref is already equal to the new ref, we do not need to do anything.
+  // Also, if the GetRef failed (it could return NS_ERROR_NOT_IMPLEMENTED)
+  // we can assume SetRef would fail as well, so returning the original
+  // URI is OK.
+  //
+  // Note that aRef contains the hash, but ref doesn't, so need to account for
+  // that in the equality check.
+  if (NS_FAILED(rv) || (!hasRef && aRef.IsEmpty()) ||
+      (!aRef.IsEmpty() && hasRef &&
+       Substring(aRef.Data() + 1, aRef.Length() - 1) == ref)) {
+    nsCOMPtr<nsIURI> uri = aInput;
+    uri.forget(aOutput);
+    return NS_OK;
+  }
+
+  return NS_MutateURI(aInput).SetRef(aRef).Finalize(aOutput);
+}
+
+nsresult NS_GetURIWithoutRef(nsIURI* aInput, nsIURI** aOutput) {
+  return NS_GetURIWithNewRef(aInput, ""_ns, aOutput);
+}
+
+nsresult NS_NewChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, nsILoadInfo* aLoadInfo,
+    PerformanceStorage* aPerformanceStorage /* = nullptr */,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+    nsIIOService* aIoService /* = nullptr */) {
+  // NS_NewChannelInternal is mostly called for channel redirects. We should
+  // allow the creation of a channel even if the original channel did not have a
+  // loadinfo attached.
+  NS_ENSURE_ARG_POINTER(outChannel);
+
+  nsCOMPtr<nsIIOService> grip;
+  nsresult rv = net_EnsureIOService(&aIoService, grip);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = aIoService->NewChannelFromURIWithLoadInfo(aUri, aLoadInfo,
+                                                 getter_AddRefs(channel));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aLoadGroup) {
+    rv = channel->SetLoadGroup(aLoadGroup);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aCallbacks) {
+    rv = channel->SetNotificationCallbacks(aCallbacks);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+#ifdef DEBUG
+  nsLoadFlags channelLoadFlags = 0;
+  channel->GetLoadFlags(&channelLoadFlags);
+  // Will be removed when we remove LOAD_REPLACE altogether
+  // This check is trying to catch protocol handlers that still
+  // try to set the LOAD_REPLACE flag.
+  MOZ_DIAGNOSTIC_ASSERT(!(channelLoadFlags & nsIChannel::LOAD_REPLACE));
+#endif
+
+  if (aLoadFlags != nsIRequest::LOAD_NORMAL) {
+    rv = channel->SetLoadFlags(aLoadFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aPerformanceStorage) {
+    nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+    loadInfo->SetPerformanceStorage(aPerformanceStorage);
+  }
+
+  channel.forget(outChannel);
+  return NS_OK;
+}
+
+namespace {
+
+void AssertLoadingPrincipalAndClientInfoMatch(
+    nsIPrincipal* aLoadingPrincipal, const ClientInfo& aLoadingClientInfo,
+    nsContentPolicyType aType) {
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+  // Verify that the provided loading ClientInfo matches the loading
+  // principal.  Unfortunately we can't just use nsIPrincipal::Equals() here
+  // because of some corner cases:
+  //
+  //  1. Worker debugger scripts want to use a system loading principal for
+  //     worker scripts with a content principal.  We exempt these from this
+  //     check.
+  //  2. Null principals currently require exact object identity for
+  //     nsIPrincipal::Equals() to return true.  This doesn't work here because
+  //     ClientInfo::GetPrincipal() uses PrincipalInfoToPrincipal() to allocate
+  //     a new object.  To work around this we compare the principal origin
+  //     string itself.  If bug 1431771 is fixed then we could switch to
+  //     Equals().
+
+  // Allow worker debugger to load with a system principal.
+  if (aLoadingPrincipal->IsSystemPrincipal() &&
+      (aType == nsIContentPolicy::TYPE_INTERNAL_WORKER ||
+       aType == nsIContentPolicy::TYPE_INTERNAL_SHARED_WORKER ||
+       aType == nsIContentPolicy::TYPE_INTERNAL_SERVICE_WORKER ||
+       aType == nsIContentPolicy::TYPE_INTERNAL_WORKER_IMPORT_SCRIPTS ||
+       aType == nsIContentPolicy::TYPE_INTERNAL_WORKER_STATIC_MODULE)) {
+    return;
+  }
+
+  // Perform a fast comparison for most principal checks.
+  auto clientPrincipalOrErr(aLoadingClientInfo.GetPrincipal());
+  if (clientPrincipalOrErr.isOk()) {
+    nsCOMPtr<nsIPrincipal> clientPrincipal = clientPrincipalOrErr.unwrap();
+    if (aLoadingPrincipal->Equals(clientPrincipal)) {
+      return;
+    }
+    // Fall back to a slower origin equality test to support null principals.
+    nsAutoCString loadingOriginNoSuffix;
+    MOZ_ALWAYS_SUCCEEDS(
+        aLoadingPrincipal->GetOriginNoSuffix(loadingOriginNoSuffix));
+
+    nsAutoCString clientOriginNoSuffix;
+    MOZ_ALWAYS_SUCCEEDS(
+        clientPrincipal->GetOriginNoSuffix(clientOriginNoSuffix));
+
+    // The client principal will have the partitionKey set if it's in a third
+    // party context, but the loading principal won't. So, we ignore he
+    // partitionKey when doing the verification here.
+    MOZ_DIAGNOSTIC_ASSERT(loadingOriginNoSuffix == clientOriginNoSuffix);
+    MOZ_DIAGNOSTIC_ASSERT(
+        aLoadingPrincipal->OriginAttributesRef().EqualsIgnoringPartitionKey(
+            clientPrincipal->OriginAttributesRef()));
+  }
+#endif
+}
+
+}  // namespace
+
+nsresult NS_NewChannel(nsIChannel** outChannel, nsIURI* aUri,
+                       nsIPrincipal* aLoadingPrincipal,
+                       nsSecurityFlags aSecurityFlags,
+                       nsContentPolicyType aContentPolicyType,
+                       nsICookieJarSettings* aCookieJarSettings /* = nullptr */,
+                       PerformanceStorage* aPerformanceStorage /* = nullptr */,
+                       nsILoadGroup* aLoadGroup /* = nullptr */,
+                       nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+                       nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+                       nsIIOService* aIoService /* = nullptr */,
+                       uint32_t aSandboxFlags /* = 0 */,
+                       bool aSkipCheckForBrokenURLOrZeroSized /* = false */) {
+  return NS_NewChannelInternal(
+      outChannel, aUri,
+      nullptr,  // aLoadingNode,
+      aLoadingPrincipal,
+      nullptr,  // aTriggeringPrincipal
+      Maybe<ClientInfo>(), Maybe<ServiceWorkerDescriptor>(), aSecurityFlags,
+      aContentPolicyType, aCookieJarSettings, aPerformanceStorage, aLoadGroup,
+      aCallbacks, aLoadFlags, aIoService, aSandboxFlags,
+      aSkipCheckForBrokenURLOrZeroSized);
+}
+
+nsresult NS_NewChannel(nsIChannel** outChannel, nsIURI* aUri,
+                       nsIPrincipal* aLoadingPrincipal,
+                       const ClientInfo& aLoadingClientInfo,
+                       const Maybe<ServiceWorkerDescriptor>& aController,
+                       nsSecurityFlags aSecurityFlags,
+                       nsContentPolicyType aContentPolicyType,
+                       nsICookieJarSettings* aCookieJarSettings /* = nullptr */,
+                       PerformanceStorage* aPerformanceStorage /* = nullptr */,
+                       nsILoadGroup* aLoadGroup /* = nullptr */,
+                       nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+                       nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+                       nsIIOService* aIoService /* = nullptr */,
+                       uint32_t aSandboxFlags /* = 0 */,
+                       bool aSkipCheckForBrokenURLOrZeroSized /* = false */) {
+  AssertLoadingPrincipalAndClientInfoMatch(
+      aLoadingPrincipal, aLoadingClientInfo, aContentPolicyType);
+
+  Maybe<ClientInfo> loadingClientInfo;
+  loadingClientInfo.emplace(aLoadingClientInfo);
+
+  return NS_NewChannelInternal(
+      outChannel, aUri,
+      nullptr,  // aLoadingNode,
+      aLoadingPrincipal,
+      nullptr,  // aTriggeringPrincipal
+      loadingClientInfo, aController, aSecurityFlags, aContentPolicyType,
+      aCookieJarSettings, aPerformanceStorage, aLoadGroup, aCallbacks,
+      aLoadFlags, aIoService, aSandboxFlags, aSkipCheckForBrokenURLOrZeroSized);
+}
+
+nsresult NS_NewChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    const Maybe<ClientInfo>& aLoadingClientInfo,
+    const Maybe<ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings /* = nullptr */,
+    PerformanceStorage* aPerformanceStorage /* = nullptr */,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+    nsIIOService* aIoService /* = nullptr */, uint32_t aSandboxFlags /* = 0 */,
+    bool aSkipCheckForBrokenURLOrZeroSized /* = false */) {
+  NS_ENSURE_ARG_POINTER(outChannel);
+
+  nsCOMPtr<nsIIOService> grip;
+  nsresult rv = net_EnsureIOService(&aIoService, grip);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = aIoService->NewChannelFromURIWithClientAndController(
+      aUri, aLoadingNode, aLoadingPrincipal, aTriggeringPrincipal,
+      aLoadingClientInfo, aController, aSecurityFlags, aContentPolicyType,
+      aSandboxFlags, aSkipCheckForBrokenURLOrZeroSized,
+      getter_AddRefs(channel));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (aLoadGroup) {
+    rv = channel->SetLoadGroup(aLoadGroup);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aCallbacks) {
+    rv = channel->SetNotificationCallbacks(aCallbacks);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+#ifdef DEBUG
+  nsLoadFlags channelLoadFlags = 0;
+  channel->GetLoadFlags(&channelLoadFlags);
+  // Will be removed when we remove LOAD_REPLACE altogether
+  // This check is trying to catch protocol handlers that still
+  // try to set the LOAD_REPLACE flag.
+  MOZ_DIAGNOSTIC_ASSERT(!(channelLoadFlags & nsIChannel::LOAD_REPLACE));
+#endif
+
+  if (aLoadFlags != nsIRequest::LOAD_NORMAL) {
+    rv = channel->SetLoadFlags(aLoadFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aPerformanceStorage || aCookieJarSettings) {
+    nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+
+    if (aPerformanceStorage) {
+      loadInfo->SetPerformanceStorage(aPerformanceStorage);
+    }
+
+    if (aCookieJarSettings) {
+      loadInfo->SetCookieJarSettings(aCookieJarSettings);
+    }
+  }
+
+  channel.forget(outChannel);
+  return NS_OK;
+}
+
+nsresult /*NS_NewChannelWithNodeAndTriggeringPrincipal */
+NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsINode* aLoadingNode,
+    nsIPrincipal* aTriggeringPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    PerformanceStorage* aPerformanceStorage /* = nullptr */,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+    nsIIOService* aIoService /* = nullptr */) {
+  MOZ_ASSERT(aLoadingNode);
+  NS_ASSERTION(aTriggeringPrincipal,
+               "Can not create channel without a triggering Principal!");
+  return NS_NewChannelInternal(
+      outChannel, aUri, aLoadingNode, aLoadingNode->NodePrincipal(),
+      aTriggeringPrincipal, Maybe<ClientInfo>(),
+      Maybe<ServiceWorkerDescriptor>(), aSecurityFlags, aContentPolicyType,
+      aLoadingNode->OwnerDoc()->CookieJarSettings(), aPerformanceStorage,
+      aLoadGroup, aCallbacks, aLoadFlags, aIoService);
+}
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings /* = nullptr */,
+    PerformanceStorage* aPerformanceStorage /* = nullptr */,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+    nsIIOService* aIoService /* = nullptr */) {
+  NS_ASSERTION(aLoadingPrincipal,
+               "Can not create channel without a loading Principal!");
+  return NS_NewChannelInternal(
+      outChannel, aUri,
+      nullptr,  // aLoadingNode
+      aLoadingPrincipal, aTriggeringPrincipal, Maybe<ClientInfo>(),
+      Maybe<ServiceWorkerDescriptor>(), aSecurityFlags, aContentPolicyType,
+      aCookieJarSettings, aPerformanceStorage, aLoadGroup, aCallbacks,
+      aLoadFlags, aIoService);
+}
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal, const ClientInfo& aLoadingClientInfo,
+    const Maybe<ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings /* = nullptr */,
+    PerformanceStorage* aPerformanceStorage /* = nullptr */,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+    nsIIOService* aIoService /* = nullptr */) {
+  AssertLoadingPrincipalAndClientInfoMatch(
+      aLoadingPrincipal, aLoadingClientInfo, aContentPolicyType);
+
+  Maybe<ClientInfo> loadingClientInfo;
+  loadingClientInfo.emplace(aLoadingClientInfo);
+
+  return NS_NewChannelInternal(
+      outChannel, aUri,
+      nullptr,  // aLoadingNode
+      aLoadingPrincipal, aTriggeringPrincipal, loadingClientInfo, aController,
+      aSecurityFlags, aContentPolicyType, aCookieJarSettings,
+      aPerformanceStorage, aLoadGroup, aCallbacks, aLoadFlags, aIoService);
+}
+
+nsresult NS_NewChannel(nsIChannel** outChannel, nsIURI* aUri,
+                       nsINode* aLoadingNode, nsSecurityFlags aSecurityFlags,
+                       nsContentPolicyType aContentPolicyType,
+                       PerformanceStorage* aPerformanceStorage /* = nullptr */,
+                       nsILoadGroup* aLoadGroup /* = nullptr */,
+                       nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+                       nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */,
+                       nsIIOService* aIoService /* = nullptr */,
+                       uint32_t aSandboxFlags /* = 0 */,
+                       bool aSkipCheckForBrokenURLOrZeroSized /* = false */) {
+  NS_ASSERTION(aLoadingNode, "Can not create channel without a loading Node!");
+  return NS_NewChannelInternal(
+      outChannel, aUri, aLoadingNode, aLoadingNode->NodePrincipal(),
+      nullptr,  // aTriggeringPrincipal
+      Maybe<ClientInfo>(), Maybe<ServiceWorkerDescriptor>(), aSecurityFlags,
+      aContentPolicyType, aLoadingNode->OwnerDoc()->CookieJarSettings(),
+      aPerformanceStorage, aLoadGroup, aCallbacks, aLoadFlags, aIoService,
+      aSandboxFlags, aSkipCheckForBrokenURLOrZeroSized);
+}
+
+nsresult NS_GetIsDocumentChannel(nsIChannel* aChannel, bool* aIsDocument) {
+  // Check if this channel is going to be used to create a document. If it has
+  // LOAD_DOCUMENT_URI set it is trivially creating a document. If
+  // LOAD_HTML_OBJECT_DATA is set it may or may not be used to create a
+  // document, depending on its MIME type.
+
+  if (!aChannel || !aIsDocument) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aIsDocument = false;
+  nsLoadFlags loadFlags;
+  nsresult rv = aChannel->GetLoadFlags(&loadFlags);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI) {
+    *aIsDocument = true;
+    return NS_OK;
+  }
+  if (!(loadFlags & nsIRequest::LOAD_HTML_OBJECT_DATA)) {
+    *aIsDocument = false;
+    return NS_OK;
+  }
+  nsAutoCString mimeType;
+  rv = aChannel->GetContentType(mimeType);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (nsContentUtils::HtmlObjectContentTypeForMIMEType(mimeType, false) ==
+      nsIObjectLoadingContent::TYPE_DOCUMENT) {
+    *aIsDocument = true;
+    return NS_OK;
+  }
+  *aIsDocument = false;
+  return NS_OK;
+}
+
+nsresult NS_MakeAbsoluteURI(nsACString& result, const nsACString& spec,
+                            nsIURI* baseURI) {
+  nsresult rv;
+  if (!baseURI) {
+    NS_WARNING("It doesn't make sense to not supply a base URI");
+    result = spec;
+    rv = NS_OK;
+  } else if (spec.IsEmpty()) {
+    rv = baseURI->GetSpec(result);
+  } else {
+    rv = baseURI->Resolve(spec, result);
+  }
+  return rv;
+}
+
+nsresult NS_MakeAbsoluteURI(char** result, const char* spec, nsIURI* baseURI) {
+  nsresult rv;
+  nsAutoCString resultBuf;
+  rv = NS_MakeAbsoluteURI(resultBuf, nsDependentCString(spec), baseURI);
+  if (NS_SUCCEEDED(rv)) {
+    *result = ToNewCString(resultBuf, mozilla::fallible);
+    if (!*result) rv = NS_ERROR_OUT_OF_MEMORY;
+  }
+  return rv;
+}
+
+nsresult NS_MakeAbsoluteURI(nsAString& result, const nsAString& spec,
+                            nsIURI* baseURI) {
+  nsresult rv;
+  if (!baseURI) {
+    NS_WARNING("It doesn't make sense to not supply a base URI");
+    result = spec;
+    rv = NS_OK;
+  } else {
+    nsAutoCString resultBuf;
+    if (spec.IsEmpty()) {
+      rv = baseURI->GetSpec(resultBuf);
+    } else {
+      rv = baseURI->Resolve(NS_ConvertUTF16toUTF8(spec), resultBuf);
+    }
+    if (NS_SUCCEEDED(rv)) CopyUTF8toUTF16(resultBuf, result);
+  }
+  return rv;
+}
+
+int32_t NS_GetDefaultPort(const char* scheme,
+                          nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+
+  // Getting the default port through the protocol handler previously had a lot
+  // of XPCOM overhead involved.  We optimize the protocols that matter for Web
+  // pages (HTTP and HTTPS) by hardcoding their default ports here.
+  //
+  // XXX: This might not be necessary for performance anymore.
+  if (strncmp(scheme, "http", 4) == 0) {
+    if (scheme[4] == 's' && scheme[5] == '\0') {
+      return 443;
+    }
+    if (scheme[4] == '\0') {
+      return 80;
+    }
+  }
+
+  nsCOMPtr<nsIIOService> grip;
+  net_EnsureIOService(&ioService, grip);
+  if (!ioService) return -1;
+
+  int32_t port;
+  rv = ioService->GetDefaultPort(scheme, &port);
+  return NS_SUCCEEDED(rv) ? port : -1;
+}
+
+/**
+ * This function is a helper function to apply the ToAscii conversion
+ * to a string
+ */
+bool NS_StringToACE(const nsACString& idn, nsACString& result) {
+  nsCOMPtr<nsIIDNService> idnSrv = do_GetService(NS_IDNSERVICE_CONTRACTID);
+  if (!idnSrv) return false;
+  nsresult rv = idnSrv->ConvertUTF8toACE(idn, result);
+  return NS_SUCCEEDED(rv);
+}
+
+int32_t NS_GetRealPort(nsIURI* aURI) {
+  int32_t port;
+  nsresult rv = aURI->GetPort(&port);
+  if (NS_FAILED(rv)) return -1;
+
+  if (port != -1) return port;  // explicitly specified
+
+  // Otherwise, we have to get the default port from the protocol handler
+
+  // Need the scheme first
+  nsAutoCString scheme;
+  rv = aURI->GetScheme(scheme);
+  if (NS_FAILED(rv)) return -1;
+
+  return NS_GetDefaultPort(scheme.get());
+}
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri,
+    already_AddRefed<nsIInputStream> aStream, const nsACString& aContentType,
+    const nsACString& aContentCharset, nsILoadInfo* aLoadInfo) {
+  nsresult rv;
+  nsCOMPtr<nsIInputStreamChannel> isc =
+      do_CreateInstance(NS_INPUTSTREAMCHANNEL_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = isc->SetURI(aUri);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIInputStream> stream = std::move(aStream);
+  rv = isc->SetContentStream(stream);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(isc, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!aContentType.IsEmpty()) {
+    rv = channel->SetContentType(aContentType);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!aContentCharset.IsEmpty()) {
+    rv = channel->SetContentCharset(aContentCharset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  MOZ_ASSERT(aLoadInfo, "need a loadinfo to create a inputstreamchannel");
+  channel->SetLoadInfo(aLoadInfo);
+
+  // If we're sandboxed, make sure to clear any owner the channel
+  // might already have.
+  if (aLoadInfo && aLoadInfo->GetLoadingSandboxed()) {
+    channel->SetOwner(nullptr);
+  }
+
+  channel.forget(outChannel);
+  return NS_OK;
+}
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri,
+    already_AddRefed<nsIInputStream> aStream, const nsACString& aContentType,
+    const nsACString& aContentCharset, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType) {
+  nsCOMPtr<nsILoadInfo> loadInfo = new mozilla::net::LoadInfo(
+      aLoadingPrincipal, aTriggeringPrincipal, aLoadingNode, aSecurityFlags,
+      aContentPolicyType);
+  if (!loadInfo) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIInputStream> stream = std::move(aStream);
+
+  return NS_NewInputStreamChannelInternal(outChannel, aUri, stream.forget(),
+                                          aContentType, aContentCharset,
+                                          loadInfo);
+}
+
+nsresult NS_NewInputStreamChannel(
+    nsIChannel** outChannel, nsIURI* aUri,
+    already_AddRefed<nsIInputStream> aStream, nsIPrincipal* aLoadingPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    const nsACString& aContentType /* = ""_ns */,
+    const nsACString& aContentCharset /* = ""_ns */) {
+  nsCOMPtr<nsIInputStream> stream = aStream;
+  return NS_NewInputStreamChannelInternal(outChannel, aUri, stream.forget(),
+                                          aContentType, aContentCharset,
+                                          nullptr,  // aLoadingNode
+                                          aLoadingPrincipal,
+                                          nullptr,  // aTriggeringPrincipal
+                                          aSecurityFlags, aContentPolicyType);
+}
+
+nsresult NS_NewInputStreamChannelInternal(nsIChannel** outChannel, nsIURI* aUri,
+                                          const nsAString& aData,
+                                          const nsACString& aContentType,
+                                          nsILoadInfo* aLoadInfo,
+                                          bool aIsSrcdocChannel /* = false */) {
+  nsresult rv;
+  nsCOMPtr<nsIStringInputStream> stream;
+  stream = do_CreateInstance(NS_STRINGINPUTSTREAM_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t len;
+  char* utf8Bytes = ToNewUTF8String(aData, &len);
+  rv = stream->AdoptData(utf8Bytes, len);
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = NS_NewInputStreamChannelInternal(getter_AddRefs(channel), aUri,
+                                        stream.forget(), aContentType,
+                                        "UTF-8"_ns, aLoadInfo);
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aIsSrcdocChannel) {
+    nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(channel);
+    NS_ENSURE_TRUE(inStrmChan, NS_ERROR_FAILURE);
+    inStrmChan->SetSrcdocData(aData);
+  }
+  channel.forget(outChannel);
+  return NS_OK;
+}
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, const nsAString& aData,
+    const nsACString& aContentType, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    bool aIsSrcdocChannel /* = false */) {
+  nsCOMPtr<nsILoadInfo> loadInfo = new mozilla::net::LoadInfo(
+      aLoadingPrincipal, aTriggeringPrincipal, aLoadingNode, aSecurityFlags,
+      aContentPolicyType);
+  return NS_NewInputStreamChannelInternal(outChannel, aUri, aData, aContentType,
+                                          loadInfo, aIsSrcdocChannel);
+}
+
+nsresult NS_NewInputStreamChannel(nsIChannel** outChannel, nsIURI* aUri,
+                                  const nsAString& aData,
+                                  const nsACString& aContentType,
+                                  nsIPrincipal* aLoadingPrincipal,
+                                  nsSecurityFlags aSecurityFlags,
+                                  nsContentPolicyType aContentPolicyType,
+                                  bool aIsSrcdocChannel /* = false */) {
+  return NS_NewInputStreamChannelInternal(outChannel, aUri, aData, aContentType,
+                                          nullptr,  // aLoadingNode
+                                          aLoadingPrincipal,
+                                          nullptr,  // aTriggeringPrincipal
+                                          aSecurityFlags, aContentPolicyType,
+                                          aIsSrcdocChannel);
+}
+
+nsresult NS_NewInputStreamPump(
+    nsIInputStreamPump** aResult, already_AddRefed<nsIInputStream> aStream,
+    uint32_t aSegsize /* = 0 */, uint32_t aSegcount /* = 0 */,
+    bool aCloseWhenDone /* = false */,
+    nsISerialEventTarget* aMainThreadTarget /* = nullptr */) {
+  nsCOMPtr<nsIInputStream> stream = std::move(aStream);
+
+  nsresult rv;
+  nsCOMPtr<nsIInputStreamPump> pump =
+      do_CreateInstance(NS_INPUTSTREAMPUMP_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = pump->Init(stream, aSegsize, aSegcount, aCloseWhenDone,
+                    aMainThreadTarget);
+    if (NS_SUCCEEDED(rv)) {
+      *aResult = nullptr;
+      pump.swap(*aResult);
+    }
+  }
+  return rv;
+}
+
+nsresult NS_NewLoadGroup(nsILoadGroup** result, nsIRequestObserver* obs) {
+  nsresult rv;
+  nsCOMPtr<nsILoadGroup> group =
+      do_CreateInstance(NS_LOADGROUP_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = group->SetGroupObserver(obs);
+    if (NS_SUCCEEDED(rv)) {
+      *result = nullptr;
+      group.swap(*result);
+    }
+  }
+  return rv;
+}
+
+bool NS_IsReasonableHTTPHeaderValue(const nsACString& aValue) {
+  return mozilla::net::nsHttp::IsReasonableHeaderValue(aValue);
+}
+
+bool NS_IsValidHTTPToken(const nsACString& aToken) {
+  return mozilla::net::nsHttp::IsValidToken(aToken);
+}
+
+void NS_TrimHTTPWhitespace(const nsACString& aSource, nsACString& aDest) {
+  mozilla::net::nsHttp::TrimHTTPWhitespace(aSource, aDest);
+}
+
+nsresult NS_NewLoadGroup(nsILoadGroup** aResult, nsIPrincipal* aPrincipal) {
+  using mozilla::LoadContext;
+  nsresult rv;
+
+  nsCOMPtr<nsILoadGroup> group =
+      do_CreateInstance(NS_LOADGROUP_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<LoadContext> loadContext = new LoadContext(aPrincipal);
+  rv = group->SetNotificationCallbacks(loadContext);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  group.forget(aResult);
+  return rv;
+}
+
+bool NS_LoadGroupMatchesPrincipal(nsILoadGroup* aLoadGroup,
+                                  nsIPrincipal* aPrincipal) {
+  if (!aPrincipal) {
+    return false;
+  }
+
+  // If this is a null principal then the load group doesn't really matter.
+  // The principal will not be allowed to perform any actions that actually
+  // use the load group.  Unconditionally treat null principals as a match.
+  if (aPrincipal->GetIsNullPrincipal()) {
+    return true;
+  }
+
+  if (!aLoadGroup) {
+    return false;
+  }
+
+  nsCOMPtr<nsILoadContext> loadContext;
+  NS_QueryNotificationCallbacks(nullptr, aLoadGroup, NS_GET_IID(nsILoadContext),
+                                getter_AddRefs(loadContext));
+  NS_ENSURE_TRUE(loadContext, false);
+
+  return true;
+}
+
+nsresult NS_NewDownloader(nsIStreamListener** result,
+                          nsIDownloadObserver* observer,
+                          nsIFile* downloadLocation /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIDownloader> downloader =
+      do_CreateInstance(NS_DOWNLOADER_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = downloader->Init(observer, downloadLocation);
+    if (NS_SUCCEEDED(rv)) {
+      downloader.forget(result);
+    }
+  }
+  return rv;
+}
+
+nsresult NS_NewIncrementalStreamLoader(
+    nsIIncrementalStreamLoader** result,
+    nsIIncrementalStreamLoaderObserver* observer) {
+  nsresult rv;
+  nsCOMPtr<nsIIncrementalStreamLoader> loader =
+      do_CreateInstance(NS_INCREMENTALSTREAMLOADER_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = loader->Init(observer);
+    if (NS_SUCCEEDED(rv)) {
+      *result = nullptr;
+      loader.swap(*result);
+    }
+  }
+  return rv;
+}
+
+nsresult NS_NewStreamLoader(
+    nsIStreamLoader** result, nsIStreamLoaderObserver* observer,
+    nsIRequestObserver* requestObserver /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIStreamLoader> loader =
+      do_CreateInstance(NS_STREAMLOADER_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = loader->Init(observer, requestObserver);
+    if (NS_SUCCEEDED(rv)) {
+      *result = nullptr;
+      loader.swap(*result);
+    }
+  }
+  return rv;
+}
+
+nsresult NS_NewStreamLoaderInternal(
+    nsIStreamLoader** outStream, nsIURI* aUri,
+    nsIStreamLoaderObserver* aObserver, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */) {
+  nsCOMPtr<nsIChannel> channel;
+  nsresult rv = NS_NewChannelInternal(
+      getter_AddRefs(channel), aUri, aLoadingNode, aLoadingPrincipal,
+      nullptr,  // aTriggeringPrincipal
+      Maybe<ClientInfo>(), Maybe<ServiceWorkerDescriptor>(), aSecurityFlags,
+      aContentPolicyType,
+      nullptr,  // nsICookieJarSettings
+      nullptr,  // PerformanceStorage
+      aLoadGroup, aCallbacks, aLoadFlags);
+
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = NS_NewStreamLoader(outStream, aObserver);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return channel->AsyncOpen(*outStream);
+}
+
+nsresult NS_NewStreamLoader(
+    nsIStreamLoader** outStream, nsIURI* aUri,
+    nsIStreamLoaderObserver* aObserver, nsINode* aLoadingNode,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */) {
+  NS_ASSERTION(aLoadingNode,
+               "Can not create stream loader without a loading Node!");
+  return NS_NewStreamLoaderInternal(
+      outStream, aUri, aObserver, aLoadingNode, aLoadingNode->NodePrincipal(),
+      aSecurityFlags, aContentPolicyType, aLoadGroup, aCallbacks, aLoadFlags);
+}
+
+nsresult NS_NewStreamLoader(
+    nsIStreamLoader** outStream, nsIURI* aUri,
+    nsIStreamLoaderObserver* aObserver, nsIPrincipal* aLoadingPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsILoadGroup* aLoadGroup /* = nullptr */,
+    nsIInterfaceRequestor* aCallbacks /* = nullptr */,
+    nsLoadFlags aLoadFlags /* = nsIRequest::LOAD_NORMAL */) {
+  return NS_NewStreamLoaderInternal(outStream, aUri, aObserver,
+                                    nullptr,  // aLoadingNode
+                                    aLoadingPrincipal, aSecurityFlags,
+                                    aContentPolicyType, aLoadGroup, aCallbacks,
+                                    aLoadFlags);
+}
+
+nsresult NS_NewSyncStreamListener(nsIStreamListener** result,
+                                  nsIInputStream** stream) {
+  nsCOMPtr<nsISyncStreamListener> listener = new nsSyncStreamListener();
+  nsresult rv = listener->GetInputStream(stream);
+  if (NS_SUCCEEDED(rv)) {
+    listener.forget(result);
+  }
+  return rv;
+}
+
+nsresult NS_ImplementChannelOpen(nsIChannel* channel, nsIInputStream** result) {
+  nsCOMPtr<nsIStreamListener> listener;
+  nsCOMPtr<nsIInputStream> stream;
+  nsresult rv = NS_NewSyncStreamListener(getter_AddRefs(listener),
+                                         getter_AddRefs(stream));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = channel->AsyncOpen(listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint64_t n;
+  // block until the initial response is received or an error occurs.
+  rv = stream->Available(&n);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *result = nullptr;
+  stream.swap(*result);
+
+  return NS_OK;
+}
+
+nsresult NS_NewRequestObserverProxy(nsIRequestObserver** result,
+                                    nsIRequestObserver* observer,
+                                    nsISupports* context) {
+  nsCOMPtr<nsIRequestObserverProxy> proxy = new nsRequestObserverProxy();
+  nsresult rv = proxy->Init(observer, context);
+  if (NS_SUCCEEDED(rv)) {
+    proxy.forget(result);
+  }
+  return rv;
+}
+
+nsresult NS_NewSimpleStreamListener(
+    nsIStreamListener** result, nsIOutputStream* sink,
+    nsIRequestObserver* observer /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsISimpleStreamListener> listener =
+      do_CreateInstance(NS_SIMPLESTREAMLISTENER_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = listener->Init(sink, observer);
+    if (NS_SUCCEEDED(rv)) {
+      listener.forget(result);
+    }
+  }
+  return rv;
+}
+
+nsresult NS_CheckPortSafety(int32_t port, const char* scheme,
+                            nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIIOService> grip;
+  rv = net_EnsureIOService(&ioService, grip);
+  if (ioService) {
+    bool allow;
+    rv = ioService->AllowPort(port, scheme, &allow);
+    if (NS_SUCCEEDED(rv) && !allow) {
+      NS_WARNING("port blocked");
+      rv = NS_ERROR_PORT_ACCESS_NOT_ALLOWED;
+    }
+  }
+  return rv;
+}
+
+nsresult NS_CheckPortSafety(nsIURI* uri) {
+  int32_t port;
+  nsresult rv = uri->GetPort(&port);
+  if (NS_FAILED(rv) || port == -1) {  // port undefined or default-valued
+    return NS_OK;
+  }
+  nsAutoCString scheme;
+  uri->GetScheme(scheme);
+  return NS_CheckPortSafety(port, scheme.get());
+}
+
+nsresult NS_NewProxyInfo(const nsACString& type, const nsACString& host,
+                         int32_t port, uint32_t flags, nsIProxyInfo** result) {
+  nsresult rv;
+  nsCOMPtr<nsIProtocolProxyService> pps =
+      do_GetService(NS_PROTOCOLPROXYSERVICE_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = pps->NewProxyInfo(type, host, port, ""_ns, ""_ns, flags, UINT32_MAX,
+                           nullptr, result);
+  }
+  return rv;
+}
+
+nsresult NS_GetFileProtocolHandler(nsIFileProtocolHandler** result,
+                                   nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIIOService> grip;
+  rv = net_EnsureIOService(&ioService, grip);
+  if (ioService) {
+    nsCOMPtr<nsIProtocolHandler> handler;
+    rv = ioService->GetProtocolHandler("file", getter_AddRefs(handler));
+    if (NS_SUCCEEDED(rv)) rv = CallQueryInterface(handler, result);
+  }
+  return rv;
+}
+
+nsresult NS_GetFileFromURLSpec(const nsACString& inURL, nsIFile** result,
+                               nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileProtocolHandler> fileHandler;
+  rv = NS_GetFileProtocolHandler(getter_AddRefs(fileHandler), ioService);
+  if (NS_SUCCEEDED(rv)) rv = fileHandler->GetFileFromURLSpec(inURL, result);
+  return rv;
+}
+
+nsresult NS_GetURLSpecFromFile(nsIFile* file, nsACString& url,
+                               nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileProtocolHandler> fileHandler;
+  rv = NS_GetFileProtocolHandler(getter_AddRefs(fileHandler), ioService);
+  if (NS_SUCCEEDED(rv)) rv = fileHandler->GetURLSpecFromFile(file, url);
+  return rv;
+}
+
+nsresult NS_GetURLSpecFromActualFile(nsIFile* file, nsACString& url,
+                                     nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileProtocolHandler> fileHandler;
+  rv = NS_GetFileProtocolHandler(getter_AddRefs(fileHandler), ioService);
+  if (NS_SUCCEEDED(rv)) rv = fileHandler->GetURLSpecFromActualFile(file, url);
+  return rv;
+}
+
+nsresult NS_GetURLSpecFromDir(nsIFile* file, nsACString& url,
+                              nsIIOService* ioService /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileProtocolHandler> fileHandler;
+  rv = NS_GetFileProtocolHandler(getter_AddRefs(fileHandler), ioService);
+  if (NS_SUCCEEDED(rv)) rv = fileHandler->GetURLSpecFromDir(file, url);
+  return rv;
+}
+
+void NS_GetReferrerFromChannel(nsIChannel* channel, nsIURI** referrer) {
+  *referrer = nullptr;
+
+  if (nsCOMPtr<nsIPropertyBag2> props = do_QueryInterface(channel)) {
+    // We have to check for a property on a property bag because the
+    // referrer may be empty for security reasons (for example, when loading
+    // an http page with an https referrer).
+    nsresult rv;
+    nsCOMPtr<nsIURI> uri(
+        do_GetProperty(props, u"docshell.internalReferrer"_ns, &rv));
+    if (NS_SUCCEEDED(rv)) {
+      uri.forget(referrer);
+      return;
+    }
+  }
+
+  // if that didn't work, we can still try to get the referrer from the
+  // nsIHttpChannel (if we can QI to it)
+  nsCOMPtr<nsIHttpChannel> chan(do_QueryInterface(channel));
+  if (!chan) {
+    return;
+  }
+
+  nsCOMPtr<nsIReferrerInfo> referrerInfo = chan->GetReferrerInfo();
+  if (!referrerInfo) {
+    return;
+  }
+
+  referrerInfo->GetOriginalReferrer(referrer);
+}
+
+already_AddRefed<nsINetUtil> do_GetNetUtil(nsresult* error /* = 0 */) {
+  nsCOMPtr<nsIIOService> io = mozilla::components::IO::Service();
+  nsCOMPtr<nsINetUtil> util;
+  if (io) util = do_QueryInterface(io);
+
+  if (error) *error = !!util ? NS_OK : NS_ERROR_FAILURE;
+  return util.forget();
+}
+
+nsresult NS_ParseRequestContentType(const nsACString& rawContentType,
+                                    nsCString& contentType,
+                                    nsCString& contentCharset) {
+  // contentCharset is left untouched if not present in rawContentType
+  nsresult rv;
+  nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCString charset;
+  bool hadCharset;
+  rv = util->ParseRequestContentType(rawContentType, charset, &hadCharset,
+                                     contentType);
+  if (NS_SUCCEEDED(rv) && hadCharset) contentCharset = charset;
+  return rv;
+}
+
+nsresult NS_ParseResponseContentType(const nsACString& rawContentType,
+                                     nsCString& contentType,
+                                     nsCString& contentCharset) {
+  // contentCharset is left untouched if not present in rawContentType
+  nsresult rv;
+  nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCString charset;
+  bool hadCharset;
+  rv = util->ParseResponseContentType(rawContentType, charset, &hadCharset,
+                                      contentType);
+  if (NS_SUCCEEDED(rv) && hadCharset) contentCharset = charset;
+  return rv;
+}
+
+nsresult NS_ExtractCharsetFromContentType(const nsACString& rawContentType,
+                                          nsCString& contentCharset,
+                                          bool* hadCharset,
+                                          int32_t* charsetStart,
+                                          int32_t* charsetEnd) {
+  // contentCharset is left untouched if not present in rawContentType
+  nsresult rv;
+  nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return util->ExtractCharsetFromContentType(
+      rawContentType, contentCharset, charsetStart, charsetEnd, hadCharset);
+}
+
+nsresult NS_NewAtomicFileOutputStream(nsIOutputStream** result, nsIFile* file,
+                                      int32_t ioFlags /* = -1 */,
+                                      int32_t perm /* = -1 */,
+                                      int32_t behaviorFlags /* = 0 */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileOutputStream> out =
+      do_CreateInstance(NS_ATOMICLOCALFILEOUTPUTSTREAM_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = out->Init(file, ioFlags, perm, behaviorFlags);
+    if (NS_SUCCEEDED(rv)) out.forget(result);
+  }
+  return rv;
+}
+
+nsresult NS_NewSafeLocalFileOutputStream(nsIOutputStream** result,
+                                         nsIFile* file,
+                                         int32_t ioFlags /* = -1 */,
+                                         int32_t perm /* = -1 */,
+                                         int32_t behaviorFlags /* = 0 */) {
+  nsresult rv;
+  nsCOMPtr<nsIFileOutputStream> out =
+      do_CreateInstance(NS_SAFELOCALFILEOUTPUTSTREAM_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = out->Init(file, ioFlags, perm, behaviorFlags);
+    if (NS_SUCCEEDED(rv)) out.forget(result);
+  }
+  return rv;
+}
+
+nsresult NS_NewLocalFileRandomAccessStream(nsIRandomAccessStream** result,
+                                           nsIFile* file,
+                                           int32_t ioFlags /* = -1 */,
+                                           int32_t perm /* = -1 */,
+                                           int32_t behaviorFlags /* = 0 */) {
+  nsCOMPtr<nsIFileRandomAccessStream> stream = new nsFileRandomAccessStream();
+  nsresult rv = stream->Init(file, ioFlags, perm, behaviorFlags);
+  if (NS_SUCCEEDED(rv)) {
+    stream.forget(result);
+  }
+  return rv;
+}
+
+mozilla::Result<nsCOMPtr<nsIRandomAccessStream>, nsresult>
+NS_NewLocalFileRandomAccessStream(nsIFile* file, int32_t ioFlags /* = -1 */,
+                                  int32_t perm /* = -1 */,
+                                  int32_t behaviorFlags /* = 0 */) {
+  nsCOMPtr<nsIRandomAccessStream> stream;
+  const nsresult rv = NS_NewLocalFileRandomAccessStream(
+      getter_AddRefs(stream), file, ioFlags, perm, behaviorFlags);
+  if (NS_SUCCEEDED(rv)) {
+    return stream;
+  }
+  return Err(rv);
+}
+
+nsresult NS_NewBufferedOutputStream(
+    nsIOutputStream** aResult, already_AddRefed<nsIOutputStream> aOutputStream,
+    uint32_t aBufferSize) {
+  nsCOMPtr<nsIOutputStream> outputStream = std::move(aOutputStream);
+
+  nsresult rv;
+  nsCOMPtr<nsIBufferedOutputStream> out =
+      do_CreateInstance(NS_BUFFEREDOUTPUTSTREAM_CONTRACTID, &rv);
+  if (NS_SUCCEEDED(rv)) {
+    rv = out->Init(outputStream, aBufferSize);
+    if (NS_SUCCEEDED(rv)) {
+      out.forget(aResult);
+    }
+  }
+  return rv;
+}
+
+[[nodiscard]] nsresult NS_NewBufferedInputStream(
+    nsIInputStream** aResult, already_AddRefed<nsIInputStream> aInputStream,
+    uint32_t aBufferSize) {
+  nsCOMPtr<nsIInputStream> inputStream = std::move(aInputStream);
+
+  nsCOMPtr<nsIBufferedInputStream> in;
+  nsresult rv = nsBufferedInputStream::Create(
+      NS_GET_IID(nsIBufferedInputStream), getter_AddRefs(in));
+  if (NS_SUCCEEDED(rv)) {
+    rv = in->Init(inputStream, aBufferSize);
+    if (NS_SUCCEEDED(rv)) {
+      *aResult = static_cast<nsBufferedInputStream*>(in.get())
+                     ->GetInputStream()
+                     .take();
+    }
+  }
+  return rv;
+}
+
+Result<nsCOMPtr<nsIInputStream>, nsresult> NS_NewBufferedInputStream(
+    already_AddRefed<nsIInputStream> aInputStream, uint32_t aBufferSize) {
+  nsCOMPtr<nsIInputStream> stream;
+  const nsresult rv = NS_NewBufferedInputStream(
+      getter_AddRefs(stream), std::move(aInputStream), aBufferSize);
+  if (NS_SUCCEEDED(rv)) {
+    return stream;
+  }
+  return Err(rv);
+}
+
+namespace {
+
+#define BUFFER_SIZE 8192
+
+class BufferWriter final : public nsIInputStreamCallback {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  BufferWriter(nsIInputStream* aInputStream, void* aBuffer, int64_t aCount)
+      : mMonitor("BufferWriter.mMonitor"),
+        mInputStream(aInputStream),
+        mBuffer(aBuffer),
+        mCount(aCount),
+        mWrittenData(0),
+        mBufferType(aBuffer ? eExternal : eInternal),
+        mBufferSize(0) {
+    MOZ_ASSERT(aInputStream);
+    MOZ_ASSERT(aCount == -1 || aCount > 0);
+    MOZ_ASSERT_IF(mBuffer, aCount > 0);
+  }
+
+  nsresult Write() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+
+    // Let's make the inputStream buffered if it's not.
+    if (!NS_InputStreamIsBuffered(mInputStream)) {
+      nsCOMPtr<nsIInputStream> bufferedStream;
+      nsresult rv = NS_NewBufferedInputStream(
+          getter_AddRefs(bufferedStream), mInputStream.forget(), BUFFER_SIZE);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      mInputStream = bufferedStream;
+    }
+
+    mAsyncInputStream = do_QueryInterface(mInputStream);
+
+    if (!mAsyncInputStream) {
+      return WriteSync();
+    }
+
+    // Let's use mAsyncInputStream only.
+    mInputStream = nullptr;
+
+    return WriteAsync();
+  }
+
+  uint64_t WrittenData() const {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+    return mWrittenData;
+  }
+
+  void* StealBuffer() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+    MOZ_ASSERT(mBufferType == eInternal);
+
+    void* buffer = mBuffer;
+
+    mBuffer = nullptr;
+    mBufferSize = 0;
+
+    return buffer;
+  }
+
+ private:
+  ~BufferWriter() {
+    if (mBuffer && mBufferType == eInternal) {
+      free(mBuffer);
+    }
+
+    if (mTaskQueue) {
+      mTaskQueue->BeginShutdown();
+    }
+  }
+
+  nsresult WriteSync() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+
+    uint64_t length = (uint64_t)mCount;
+
+    if (mCount == -1) {
+      nsresult rv = mInputStream->Available(&length);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (length == 0) {
+        // nothing to read.
+        return NS_OK;
+      }
+    }
+
+    if (mBufferType == eInternal) {
+      mBuffer = malloc(length);
+      if (NS_WARN_IF(!mBuffer)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+
+    uint32_t writtenData;
+    nsresult rv = mInputStream->ReadSegments(NS_CopySegmentToBuffer, mBuffer,
+                                             length, &writtenData);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mWrittenData = writtenData;
+    return NS_OK;
+  }
+
+  nsresult WriteAsync() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+
+    if (mCount > 0 && mBufferType == eInternal) {
+      mBuffer = malloc(mCount);
+      if (NS_WARN_IF(!mBuffer)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+
+    while (true) {
+      if (mCount == -1 && !MaybeExpandBufferSize()) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      uint64_t offset = mWrittenData;
+      uint64_t length = mCount == -1 ? BUFFER_SIZE : mCount;
+
+      // Let's try to read data directly.
+      uint32_t writtenData;
+      nsresult rv = mAsyncInputStream->ReadSegments(
+          NS_CopySegmentToBuffer, static_cast<char*>(mBuffer) + offset, length,
+          &writtenData);
+
+      // Operation completed. Nothing more to read.
+      if (NS_SUCCEEDED(rv) && writtenData == 0) {
+        return NS_OK;
+      }
+
+      // If we succeeded, let's try to read again.
+      if (NS_SUCCEEDED(rv)) {
+        mWrittenData += writtenData;
+        if (mCount != -1) {
+          MOZ_ASSERT(mCount >= writtenData);
+          mCount -= writtenData;
+
+          // Is this the end of the reading?
+          if (mCount == 0) {
+            return NS_OK;
+          }
+        }
+
+        continue;
+      }
+
+      // Async wait...
+      if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
+        rv = MaybeCreateTaskQueue();
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+
+        MonitorAutoLock lock(mMonitor);
+
+        rv = mAsyncInputStream->AsyncWait(this, 0, length, mTaskQueue);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+
+        lock.Wait();
+        continue;
+      }
+
+      // Otherwise, let's propagate the error.
+      return rv;
+    }
+
+    MOZ_ASSERT_UNREACHABLE("We should not be here");
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult MaybeCreateTaskQueue() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+
+    if (!mTaskQueue) {
+      nsCOMPtr<nsIEventTarget> target =
+          do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+      if (!target) {
+        return NS_ERROR_FAILURE;
+      }
+
+      mTaskQueue = TaskQueue::Create(target.forget(), "nsNetUtil:BufferWriter");
+    }
+
+    return NS_OK;
+  }
+
+  NS_IMETHOD
+  OnInputStreamReady(nsIAsyncInputStream* aStream) override {
+    MOZ_ASSERT(!NS_IsMainThread());
+
+    // We have something to read. Let's unlock the main-thread.
+    MonitorAutoLock lock(mMonitor);
+    lock.Notify();
+    return NS_OK;
+  }
+
+  bool MaybeExpandBufferSize() {
+    NS_ASSERT_OWNINGTHREAD(BufferWriter);
+
+    MOZ_ASSERT(mCount == -1);
+
+    if (mBufferSize >= mWrittenData + BUFFER_SIZE) {
+      // The buffer is big enough.
+      return true;
+    }
+
+    CheckedUint32 bufferSize =
+        std::max<uint32_t>(static_cast<uint32_t>(mWrittenData), BUFFER_SIZE);
+    while (bufferSize.isValid() &&
+           bufferSize.value() < mWrittenData + BUFFER_SIZE) {
+      bufferSize *= 2;
+    }
+
+    if (!bufferSize.isValid()) {
+      return false;
+    }
+
+    void* buffer = realloc(mBuffer, bufferSize.value());
+    if (!buffer) {
+      return false;
+    }
+
+    mBuffer = buffer;
+    mBufferSize = bufferSize.value();
+    return true;
+  }
+
+  // All the members of this class are touched on the owning thread only. The
+  // monitor is only used to communicate when there is more data to read.
+  Monitor mMonitor MOZ_UNANNOTATED;
+
+  nsCOMPtr<nsIInputStream> mInputStream;
+  nsCOMPtr<nsIAsyncInputStream> mAsyncInputStream;
+
+  RefPtr<TaskQueue> mTaskQueue;
+
+  void* mBuffer;
+  int64_t mCount;
+  uint64_t mWrittenData;
+
+  enum {
+    // The buffer is allocated internally and this object must release it
+    // in the DTOR if not stolen. The buffer can be reallocated.
+    eInternal,
+
+    // The buffer is not owned by this object and it cannot be reallocated.
+    eExternal,
+  } mBufferType;
+
+  // The following set if needed for the async read.
+  uint64_t mBufferSize;
+};
+
+NS_IMPL_ISUPPORTS(BufferWriter, nsIInputStreamCallback)
+
+}  // anonymous namespace
+
+nsresult NS_ReadInputStreamToBuffer(nsIInputStream* aInputStream, void** aDest,
+                                    int64_t aCount, uint64_t* aWritten) {
+  MOZ_ASSERT(aInputStream);
+  MOZ_ASSERT(aCount >= -1);
+
+  uint64_t dummyWritten;
+  if (!aWritten) {
+    aWritten = &dummyWritten;
+  }
+
+  if (aCount == 0) {
+    *aWritten = 0;
+    return NS_OK;
+  }
+
+  // This will take care of allocating and reallocating aDest.
+  RefPtr<BufferWriter> writer = new BufferWriter(aInputStream, *aDest, aCount);
+
+  nsresult rv = writer->Write();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aWritten = writer->WrittenData();
+
+  if (!*aDest) {
+    *aDest = writer->StealBuffer();
+  }
+
+  return NS_OK;
+}
+
+nsresult NS_ReadInputStreamToString(nsIInputStream* aInputStream,
+                                    nsACString& aDest, int64_t aCount,
+                                    uint64_t* aWritten) {
+  uint64_t dummyWritten;
+  if (!aWritten) {
+    aWritten = &dummyWritten;
+  }
+
+  // Nothing to do if aCount is 0.
+  if (aCount == 0) {
+    aDest.Truncate();
+    *aWritten = 0;
+    return NS_OK;
+  }
+
+  // If we have the size, we can pre-allocate the buffer.
+  if (aCount > 0) {
+    if (NS_WARN_IF(aCount >= INT32_MAX) ||
+        NS_WARN_IF(!aDest.SetLength(aCount, mozilla::fallible))) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    void* dest = aDest.BeginWriting();
+    nsresult rv =
+        NS_ReadInputStreamToBuffer(aInputStream, &dest, aCount, aWritten);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if ((uint64_t)aCount > *aWritten) {
+      aDest.Truncate(*aWritten);
+    }
+
+    return NS_OK;
+  }
+
+  // If the size is unknown, BufferWriter will allocate the buffer.
+  void* dest = nullptr;
+  nsresult rv =
+      NS_ReadInputStreamToBuffer(aInputStream, &dest, aCount, aWritten);
+  MOZ_ASSERT_IF(NS_FAILED(rv), dest == nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!dest) {
+    MOZ_ASSERT(*aWritten == 0);
+    aDest.Truncate();
+    return NS_OK;
+  }
+
+  aDest.Adopt(reinterpret_cast<char*>(dest), *aWritten);
+  return NS_OK;
+}
+
+nsresult NS_NewURI(nsIURI** result, const nsACString& spec,
+                   NotNull<const Encoding*> encoding,
+                   nsIURI* baseURI /* = nullptr */) {
+  nsAutoCString charset;
+  encoding->Name(charset);
+  return NS_NewURI(result, spec, charset.get(), baseURI);
+}
+
+nsresult NS_NewURI(nsIURI** result, const nsAString& aSpec,
+                   const char* charset /* = nullptr */,
+                   nsIURI* baseURI /* = nullptr */) {
+  nsAutoCString spec;
+  if (!AppendUTF16toUTF8(aSpec, spec, mozilla::fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  return NS_NewURI(result, spec, charset, baseURI);
+}
+
+nsresult NS_NewURI(nsIURI** result, const nsAString& aSpec,
+                   NotNull<const Encoding*> encoding,
+                   nsIURI* baseURI /* = nullptr */) {
+  nsAutoCString spec;
+  if (!AppendUTF16toUTF8(aSpec, spec, mozilla::fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  return NS_NewURI(result, spec, encoding, baseURI);
+}
+
+nsresult NS_NewURI(nsIURI** result, const char* spec,
+                   nsIURI* baseURI /* = nullptr */) {
+  return NS_NewURI(result, nsDependentCString(spec), nullptr, baseURI);
+}
+
+static nsresult NewStandardURI(const nsACString& aSpec, const char* aCharset,
+                               nsIURI* aBaseURI, int32_t aDefaultPort,
+                               nsIURI** aURI) {
+  return NS_MutateURI(new nsStandardURL::Mutator())
+      .Apply(&nsIStandardURLMutator::Init, nsIStandardURL::URLTYPE_AUTHORITY,
+             aDefaultPort, aSpec, aCharset, aBaseURI, nullptr)
+      .Finalize(aURI);
+}
+
+nsresult NS_GetSpecWithNSURLEncoding(nsACString& aResult,
+                                     const nsACString& aSpec) {
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_NewURIWithNSURLEncoding(getter_AddRefs(uri), aSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return uri->GetAsciiSpec(aResult);
+}
+
+nsresult NS_NewURIWithNSURLEncoding(nsIURI** aResult, const nsACString& aSpec) {
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Escape the ref portion of the URL. NSURL is more strict about which
+  // characters in the URL must be % encoded. For example, an unescaped '#'
+  // to indicate the beginning of the ref component is accepted by NSURL, but
+  // '#' characters in the ref must be escaped. Also adds encoding for other
+  // characters not accepted by NSURL in the ref such as '{', '|', '}', and '^'.
+  // The ref returned from GetRef() does not include the leading '#'.
+  nsAutoCString ref, escapedRef;
+  if (NS_SUCCEEDED(uri->GetRef(ref)) && !ref.IsEmpty()) {
+    if (!NS_Escape(ref, escapedRef, url_NSURLRef)) {
+      return NS_ERROR_INVALID_ARG;
+    }
+    rv = NS_MutateURI(uri).SetRef(escapedRef).Finalize(uri);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  uri.forget(aResult);
+  return NS_OK;
+}
+
+extern MOZ_THREAD_LOCAL(uint32_t) gTlsURLRecursionCount;
+
+template <typename T>
+class TlsAutoIncrement {
+ public:
+  explicit TlsAutoIncrement(T& var) : mVar(var) {
+    mValue = mVar.get();
+    mVar.set(mValue + 1);
+  }
+  ~TlsAutoIncrement() {
+    typename T::Type value = mVar.get();
+    MOZ_ASSERT(value == mValue + 1);
+    mVar.set(value - 1);
+  }
+
+  typename T::Type value() { return mValue; }
+
+ private:
+  typename T::Type mValue;
+  T& mVar;
+};
+
+nsresult NS_NewURI(nsIURI** aURI, const nsACString& aSpec,
+                   const char* aCharset /* = nullptr */,
+                   nsIURI* aBaseURI /* = nullptr */) {
+  TlsAutoIncrement<decltype(gTlsURLRecursionCount)> inc(gTlsURLRecursionCount);
+  if (inc.value() >= MAX_RECURSION_COUNT) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsCOMPtr<nsIIOService> ioService = do_GetIOService();
+  if (!ioService) {
+    // Individual protocol handlers unfortunately rely on the ioservice, let's
+    // return an error here instead of causing unpredictable crashes later.
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (StaticPrefs::network_url_max_length() &&
+      aSpec.Length() > StaticPrefs::network_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsAutoCString scheme;
+  nsresult rv = net_ExtractURLScheme(aSpec, scheme);
+  if (NS_FAILED(rv)) {
+    // then aSpec is relative
+    if (!aBaseURI) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+
+    if (!aSpec.IsEmpty() && aSpec[0] == '#') {
+      // Looks like a reference instead of a fully-specified URI.
+      // --> initialize |uri| as a clone of |aBaseURI|, with ref appended.
+      return NS_GetURIWithNewRef(aBaseURI, aSpec, aURI);
+    }
+
+    rv = aBaseURI->GetScheme(scheme);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  if (scheme.EqualsLiteral("http") || scheme.EqualsLiteral("ws")) {
+    return NewStandardURI(aSpec, aCharset, aBaseURI, NS_HTTP_DEFAULT_PORT,
+                          aURI);
+  }
+  if (scheme.EqualsLiteral("https") || scheme.EqualsLiteral("wss")) {
+    return NewStandardURI(aSpec, aCharset, aBaseURI, NS_HTTPS_DEFAULT_PORT,
+                          aURI);
+  }
+  if (scheme.EqualsLiteral("ftp")) {
+    return NewStandardURI(aSpec, aCharset, aBaseURI, 21, aURI);
+  }
+  if (scheme.EqualsLiteral("ssh")) {
+    return NewStandardURI(aSpec, aCharset, aBaseURI, 22, aURI);
+  }
+
+  if (scheme.EqualsLiteral("file")) {
+    nsAutoCString buf(aSpec);
+#if defined(XP_WIN)
+    buf.Truncate();
+    if (!net_NormalizeFileURL(aSpec, buf)) {
+      buf = aSpec;
+    }
+#endif
+
+    return NS_MutateURI(new nsStandardURL::Mutator())
+        .Apply(&nsIFileURLMutator::MarkFileURL)
+        .Apply(&nsIStandardURLMutator::Init,
+               nsIStandardURL::URLTYPE_NO_AUTHORITY, -1, buf, aCharset,
+               aBaseURI, nullptr)
+        .Finalize(aURI);
+  }
+
+  if (scheme.EqualsLiteral("data")) {
+    return nsDataHandler::CreateNewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("moz-safe-about") ||
+      scheme.EqualsLiteral("page-icon") || scheme.EqualsLiteral("moz") ||
+      scheme.EqualsLiteral("moz-anno")) {
+    return NS_MutateURI(new nsSimpleURI::Mutator())
+        .SetSpec(aSpec)
+        .Finalize(aURI);
+  }
+
+  if (scheme.EqualsLiteral("chrome")) {
+    return nsChromeProtocolHandler::CreateNewURI(aSpec, aCharset, aBaseURI,
+                                                 aURI);
+  }
+
+  if (scheme.EqualsLiteral("javascript")) {
+    return nsJSProtocolHandler::CreateNewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("blob")) {
+    return BlobURLProtocolHandler::CreateNewURI(aSpec, aCharset, aBaseURI,
+                                                aURI);
+  }
+
+  if (scheme.EqualsLiteral("view-source")) {
+    return nsViewSourceHandler::CreateNewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("resource")) {
+    RefPtr<nsResProtocolHandler> handler = nsResProtocolHandler::GetSingleton();
+    if (!handler) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+    return handler->NewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("indexeddb") || scheme.EqualsLiteral("uuid")) {
+    return NS_MutateURI(new nsStandardURL::Mutator())
+        .Apply(&nsIStandardURLMutator::Init, nsIStandardURL::URLTYPE_AUTHORITY,
+               0, aSpec, aCharset, aBaseURI, nullptr)
+        .Finalize(aURI);
+  }
+
+  if (scheme.EqualsLiteral("moz-extension")) {
+    RefPtr<mozilla::net::ExtensionProtocolHandler> handler =
+        mozilla::net::ExtensionProtocolHandler::GetSingleton();
+    if (!handler) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+    return handler->NewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("moz-page-thumb")) {
+    // The moz-page-thumb service runs JS to resolve a URI to a
+    // storage location, so this should only ever run on the main
+    // thread.
+    if (!NS_IsMainThread()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    RefPtr<mozilla::net::PageThumbProtocolHandler> handler =
+        mozilla::net::PageThumbProtocolHandler::GetSingleton();
+    if (!handler) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+    return handler->NewURI(aSpec, aCharset, aBaseURI, aURI);
+  }
+
+  if (scheme.EqualsLiteral("about")) {
+    return nsAboutProtocolHandler::CreateNewURI(aSpec, aCharset, aBaseURI,
+                                                aURI);
+  }
+
+  if (scheme.EqualsLiteral("jar")) {
+    return NS_MutateURI(new nsJARURI::Mutator())
+        .Apply(&nsIJARURIMutator::SetSpecBaseCharset, aSpec, aBaseURI, aCharset)
+        .Finalize(aURI);
+  }
+
+  if (scheme.EqualsLiteral("moz-icon")) {
+    return NS_MutateURI(new nsMozIconURI::Mutator())
+        .SetSpec(aSpec)
+        .Finalize(aURI);
+  }
+
+#ifdef MOZ_WIDGET_GTK
+  if (scheme.EqualsLiteral("smb") || scheme.EqualsLiteral("sftp")) {
+    return NS_MutateURI(new nsStandardURL::Mutator())
+        .Apply(&nsIStandardURLMutator::Init, nsIStandardURL::URLTYPE_STANDARD,
+               -1, aSpec, aCharset, aBaseURI, nullptr)
+        .Finalize(aURI);
+  }
+#endif
+
+  if (scheme.EqualsLiteral("android")) {
+    return NS_MutateURI(NS_STANDARDURLMUTATOR_CONTRACTID)
+        .Apply(&nsIStandardURLMutator::Init, nsIStandardURL::URLTYPE_STANDARD,
+               -1, aSpec, aCharset, aBaseURI, nullptr)
+        .Finalize(aURI);
+  }
+
+  // web-extensions can add custom protocol implementations with standard URLs
+  // that have notion of hostname, authority and relative URLs. Below we
+  // manually check agains set of known protocols schemes until more general
+  // solution is in place (See Bug 1569733)
+  if (!StaticPrefs::network_url_useDefaultURI()) {
+    if (scheme.EqualsLiteral("dweb") || scheme.EqualsLiteral("dat") ||
+        scheme.EqualsLiteral("ipfs") || scheme.EqualsLiteral("ipns") ||
+        scheme.EqualsLiteral("ssb") || scheme.EqualsLiteral("wtp")) {
+      return NewStandardURI(aSpec, aCharset, aBaseURI, -1, aURI);
+    }
+  }
+
+#if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
+  rv = NS_NewMailnewsURI(aURI, aSpec, aCharset, aBaseURI);
+  if (rv != NS_ERROR_UNKNOWN_PROTOCOL) {
+    return rv;
+  }
+#endif
+
+  if (aBaseURI) {
+    nsAutoCString newSpec;
+    rv = aBaseURI->Resolve(aSpec, newSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString newScheme;
+    rv = net_ExtractURLScheme(newSpec, newScheme);
+    if (NS_SUCCEEDED(rv)) {
+      // The scheme shouldn't really change at this point.
+      MOZ_DIAGNOSTIC_ASSERT(newScheme == scheme);
+    }
+
+    if (StaticPrefs::network_url_useDefaultURI()) {
+      return NS_MutateURI(new DefaultURI::Mutator())
+          .SetSpec(newSpec)
+          .Finalize(aURI);
+    }
+
+    return NS_MutateURI(new nsSimpleURI::Mutator())
+        .SetSpec(newSpec)
+        .Finalize(aURI);
+  }
+
+  if (StaticPrefs::network_url_useDefaultURI()) {
+    return NS_MutateURI(new DefaultURI::Mutator())
+        .SetSpec(aSpec)
+        .Finalize(aURI);
+  }
+
+  // Falls back to external protocol handler.
+  return NS_MutateURI(new nsSimpleURI::Mutator()).SetSpec(aSpec).Finalize(aURI);
+}
+
+nsresult NS_GetSanitizedURIStringFromURI(nsIURI* aUri,
+                                         nsAString& aSanitizedSpec) {
+  aSanitizedSpec.Truncate();
+
+  nsCOMPtr<nsISensitiveInfoHiddenURI> safeUri = do_QueryInterface(aUri);
+  nsAutoCString cSpec;
+  nsresult rv;
+  if (safeUri) {
+    rv = safeUri->GetSensitiveInfoHiddenSpec(cSpec);
+  } else {
+    rv = aUri->GetSpec(cSpec);
+  }
+
+  if (NS_SUCCEEDED(rv)) {
+    aSanitizedSpec.Assign(NS_ConvertUTF8toUTF16(cSpec));
+  }
+  return rv;
+}
+
+nsresult NS_LoadPersistentPropertiesFromURISpec(
+    nsIPersistentProperties** outResult, const nsACString& aSpec) {
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = NS_NewChannel(getter_AddRefs(channel), uri,
+                     nsContentUtils::GetSystemPrincipal(),
+                     nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                     nsIContentPolicy::TYPE_OTHER);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIInputStream> in;
+  rv = channel->Open(getter_AddRefs(in));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIPersistentProperties> properties = new nsPersistentProperties();
+  rv = properties->Load(in);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  properties.swap(*outResult);
+  return NS_OK;
+}
+
+bool NS_UsePrivateBrowsing(nsIChannel* channel) {
+  OriginAttributes attrs;
+  bool result = StoragePrincipalHelper::GetOriginAttributes(
+      channel, attrs, StoragePrincipalHelper::eRegularPrincipal);
+  NS_ENSURE_TRUE(result, result);
+  return attrs.mPrivateBrowsingId > 0;
+}
+
+bool NS_HasBeenCrossOrigin(nsIChannel* aChannel, bool aReport) {
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+  // TYPE_DOCUMENT loads have a null LoadingPrincipal and can not be cross
+  // origin.
+  if (!loadInfo->GetLoadingPrincipal()) {
+    return false;
+  }
+
+  // Always treat tainted channels as cross-origin.
+  if (loadInfo->GetTainting() != LoadTainting::Basic) {
+    return true;
+  }
+
+  nsCOMPtr<nsIPrincipal> loadingPrincipal = loadInfo->GetLoadingPrincipal();
+  uint32_t mode = loadInfo->GetSecurityMode();
+  bool dataInherits =
+      mode == nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_INHERITS_SEC_CONTEXT ||
+      mode == nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_INHERITS_SEC_CONTEXT ||
+      mode == nsILoadInfo::SEC_REQUIRE_CORS_INHERITS_SEC_CONTEXT;
+
+  bool aboutBlankInherits = dataInherits && loadInfo->GetAboutBlankInherits();
+
+  uint64_t innerWindowID = loadInfo->GetInnerWindowID();
+
+  for (nsIRedirectHistoryEntry* redirectHistoryEntry :
+       loadInfo->RedirectChain()) {
+    nsCOMPtr<nsIPrincipal> principal;
+    redirectHistoryEntry->GetPrincipal(getter_AddRefs(principal));
+    if (!principal) {
+      return true;
+    }
+
+    nsCOMPtr<nsIURI> uri;
+    auto* basePrin = BasePrincipal::Cast(principal);
+    basePrin->GetURI(getter_AddRefs(uri));
+    if (!uri) {
+      return true;
+    }
+
+    if (aboutBlankInherits && NS_IsAboutBlank(uri)) {
+      continue;
+    }
+
+    nsresult res;
+    if (aReport) {
+      res = loadingPrincipal->CheckMayLoadWithReporting(uri, dataInherits,
+                                                        innerWindowID);
+    } else {
+      res = loadingPrincipal->CheckMayLoad(uri, dataInherits);
+    }
+    if (NS_FAILED(res)) {
+      return true;
+    }
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
+  if (!uri) {
+    return true;
+  }
+
+  if (aboutBlankInherits && NS_IsAboutBlank(uri)) {
+    return false;
+  }
+
+  nsresult res;
+  if (aReport) {
+    res = loadingPrincipal->CheckMayLoadWithReporting(uri, dataInherits,
+                                                      innerWindowID);
+  } else {
+    res = loadingPrincipal->CheckMayLoad(uri, dataInherits);
+  }
+
+  return NS_FAILED(res);
+}
+
+bool NS_IsSafeMethodNav(nsIChannel* aChannel) {
+  RefPtr<HttpBaseChannel> baseChan = do_QueryObject(aChannel);
+  if (!baseChan) {
+    return false;
+  }
+  nsHttpRequestHead* requestHead = baseChan->GetRequestHead();
+  if (!requestHead) {
+    return false;
+  }
+  return requestHead->IsSafeMethod();
+}
+
+void NS_WrapAuthPrompt(nsIAuthPrompt* aAuthPrompt,
+                       nsIAuthPrompt2** aAuthPrompt2) {
+  nsCOMPtr<nsIAuthPromptAdapterFactory> factory =
+      do_GetService(NS_AUTHPROMPT_ADAPTER_FACTORY_CONTRACTID);
+  if (!factory) return;
+
+  NS_WARNING("Using deprecated nsIAuthPrompt");
+  factory->CreateAdapter(aAuthPrompt, aAuthPrompt2);
+}
+
+void NS_QueryAuthPrompt2(nsIInterfaceRequestor* aCallbacks,
+                         nsIAuthPrompt2** aAuthPrompt) {
+  CallGetInterface(aCallbacks, aAuthPrompt);
+  if (*aAuthPrompt) return;
+
+  // Maybe only nsIAuthPrompt is provided and we have to wrap it.
+  nsCOMPtr<nsIAuthPrompt> prompt(do_GetInterface(aCallbacks));
+  if (!prompt) return;
+
+  NS_WrapAuthPrompt(prompt, aAuthPrompt);
+}
+
+void NS_QueryAuthPrompt2(nsIChannel* aChannel, nsIAuthPrompt2** aAuthPrompt) {
+  *aAuthPrompt = nullptr;
+
+  // We want to use any auth prompt we can find on the channel's callbacks,
+  // and if that fails use the loadgroup's prompt (if any)
+  // Therefore, we can't just use NS_QueryNotificationCallbacks, because
+  // that would prefer a loadgroup's nsIAuthPrompt2 over a channel's
+  // nsIAuthPrompt.
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+  aChannel->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (callbacks) {
+    NS_QueryAuthPrompt2(callbacks, aAuthPrompt);
+    if (*aAuthPrompt) return;
+  }
+
+  nsCOMPtr<nsILoadGroup> group;
+  aChannel->GetLoadGroup(getter_AddRefs(group));
+  if (!group) return;
+
+  group->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  if (!callbacks) return;
+  NS_QueryAuthPrompt2(callbacks, aAuthPrompt);
+}
+
+nsresult NS_NewNotificationCallbacksAggregation(
+    nsIInterfaceRequestor* callbacks, nsILoadGroup* loadGroup,
+    nsIEventTarget* target, nsIInterfaceRequestor** result) {
+  nsCOMPtr<nsIInterfaceRequestor> cbs;
+  if (loadGroup) loadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));
+  return NS_NewInterfaceRequestorAggregation(callbacks, cbs, target, result);
+}
+
+nsresult NS_NewNotificationCallbacksAggregation(
+    nsIInterfaceRequestor* callbacks, nsILoadGroup* loadGroup,
+    nsIInterfaceRequestor** result) {
+  return NS_NewNotificationCallbacksAggregation(callbacks, loadGroup, nullptr,
+                                                result);
+}
+
+nsresult NS_DoImplGetInnermostURI(nsINestedURI* nestedURI, nsIURI** result) {
+  MOZ_ASSERT(nestedURI, "Must have a nested URI!");
+  MOZ_ASSERT(!*result, "Must have null *result");
+
+  nsCOMPtr<nsIURI> inner;
+  nsresult rv = nestedURI->GetInnerURI(getter_AddRefs(inner));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // We may need to loop here until we reach the innermost
+  // URI.
+  nsCOMPtr<nsINestedURI> nestedInner(do_QueryInterface(inner));
+  while (nestedInner) {
+    rv = nestedInner->GetInnerURI(getter_AddRefs(inner));
+    NS_ENSURE_SUCCESS(rv, rv);
+    nestedInner = do_QueryInterface(inner);
+  }
+
+  // Found the innermost one if we reach here.
+  inner.swap(*result);
+
+  return rv;
+}
+
+nsresult NS_ImplGetInnermostURI(nsINestedURI* nestedURI, nsIURI** result) {
+  // Make it safe to use swap()
+  *result = nullptr;
+
+  return NS_DoImplGetInnermostURI(nestedURI, result);
+}
+
+already_AddRefed<nsIURI> NS_GetInnermostURI(nsIURI* aURI) {
+  MOZ_ASSERT(aURI, "Must have URI");
+
+  nsCOMPtr<nsIURI> uri = aURI;
+
+  nsCOMPtr<nsINestedURI> nestedURI(do_QueryInterface(uri));
+  if (!nestedURI) {
+    return uri.forget();
+  }
+
+  nsresult rv = nestedURI->GetInnermostURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  return uri.forget();
+}
+
+nsresult NS_GetFinalChannelURI(nsIChannel* channel, nsIURI** uri) {
+  *uri = nullptr;
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  nsCOMPtr<nsIURI> resultPrincipalURI;
+  loadInfo->GetResultPrincipalURI(getter_AddRefs(resultPrincipalURI));
+  if (resultPrincipalURI) {
+    resultPrincipalURI.forget(uri);
+    return NS_OK;
+  }
+  return channel->GetOriginalURI(uri);
+}
+
+nsresult NS_URIChainHasFlags(nsIURI* uri, uint32_t flags, bool* result) {
+  nsresult rv;
+  nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return util->URIChainHasFlags(uri, flags, result);
+}
+
+uint32_t NS_SecurityHashURI(nsIURI* aURI) {
+  nsCOMPtr<nsIURI> baseURI = NS_GetInnermostURI(aURI);
+
+  nsAutoCString scheme;
+  uint32_t schemeHash = 0;
+  if (NS_SUCCEEDED(baseURI->GetScheme(scheme))) {
+    schemeHash = mozilla::HashString(scheme);
+  }
+
+  // TODO figure out how to hash file:// URIs
+  if (scheme.EqualsLiteral("file")) return schemeHash;  // sad face
+
+#if IS_ORIGIN_IS_FULL_SPEC_DEFINED
+  bool hasFlag;
+  if (NS_FAILED(NS_URIChainHasFlags(
+          baseURI, nsIProtocolHandler::ORIGIN_IS_FULL_SPEC, &hasFlag)) ||
+      hasFlag) {
+    nsAutoCString spec;
+    uint32_t specHash;
+    nsresult res = baseURI->GetSpec(spec);
+    if (NS_SUCCEEDED(res))
+      specHash = mozilla::HashString(spec);
+    else
+      specHash = static_cast<uint32_t>(res);
+    return specHash;
+  }
+#endif
+
+  nsAutoCString host;
+  uint32_t hostHash = 0;
+  if (NS_SUCCEEDED(baseURI->GetAsciiHost(host))) {
+    hostHash = mozilla::HashString(host);
+  }
+
+  return mozilla::AddToHash(schemeHash, hostHash, NS_GetRealPort(baseURI));
+}
+
+bool NS_SecurityCompareURIs(nsIURI* aSourceURI, nsIURI* aTargetURI,
+                            bool aStrictFileOriginPolicy) {
+  nsresult rv;
+
+  // Note that this is not an Equals() test on purpose -- for URIs that don't
+  // support host/port, we want equality to basically be object identity, for
+  // security purposes.  Otherwise, for example, two javascript: URIs that
+  // are otherwise unrelated could end up "same origin", which would be
+  // unfortunate.
+  if (aSourceURI && aSourceURI == aTargetURI) {
+    return true;
+  }
+
+  if (!aTargetURI || !aSourceURI) {
+    return false;
+  }
+
+  // If either URI is a nested URI, get the base URI
+  nsCOMPtr<nsIURI> sourceBaseURI = NS_GetInnermostURI(aSourceURI);
+  nsCOMPtr<nsIURI> targetBaseURI = NS_GetInnermostURI(aTargetURI);
+
+#if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
+  // Check if either URI has a special origin.
+  nsCOMPtr<nsIURI> origin;
+  nsCOMPtr<nsIURIWithSpecialOrigin> uriWithSpecialOrigin =
+      do_QueryInterface(sourceBaseURI);
+  if (uriWithSpecialOrigin) {
+    rv = uriWithSpecialOrigin->GetOrigin(getter_AddRefs(origin));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return false;
+    }
+    MOZ_ASSERT(origin);
+    sourceBaseURI = origin;
+  }
+  uriWithSpecialOrigin = do_QueryInterface(targetBaseURI);
+  if (uriWithSpecialOrigin) {
+    rv = uriWithSpecialOrigin->GetOrigin(getter_AddRefs(origin));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return false;
+    }
+    MOZ_ASSERT(origin);
+    targetBaseURI = origin;
+  }
+#endif
+
+  nsCOMPtr<nsIPrincipal> sourceBlobPrincipal;
+  if (BlobURLProtocolHandler::GetBlobURLPrincipal(
+          sourceBaseURI, getter_AddRefs(sourceBlobPrincipal))) {
+    nsCOMPtr<nsIURI> sourceBlobOwnerURI;
+    auto* basePrin = BasePrincipal::Cast(sourceBlobPrincipal);
+    rv = basePrin->GetURI(getter_AddRefs(sourceBlobOwnerURI));
+    if (NS_SUCCEEDED(rv)) {
+      sourceBaseURI = sourceBlobOwnerURI;
+    }
+  }
+
+  nsCOMPtr<nsIPrincipal> targetBlobPrincipal;
+  if (BlobURLProtocolHandler::GetBlobURLPrincipal(
+          targetBaseURI, getter_AddRefs(targetBlobPrincipal))) {
+    nsCOMPtr<nsIURI> targetBlobOwnerURI;
+    auto* basePrin = BasePrincipal::Cast(targetBlobPrincipal);
+    rv = basePrin->GetURI(getter_AddRefs(targetBlobOwnerURI));
+    if (NS_SUCCEEDED(rv)) {
+      targetBaseURI = targetBlobOwnerURI;
+    }
+  }
+
+  if (!sourceBaseURI || !targetBaseURI) return false;
+
+  // Compare schemes
+  nsAutoCString targetScheme;
+  bool sameScheme = false;
+  if (NS_FAILED(targetBaseURI->GetScheme(targetScheme)) ||
+      NS_FAILED(sourceBaseURI->SchemeIs(targetScheme.get(), &sameScheme)) ||
+      !sameScheme) {
+    // Not same-origin if schemes differ
+    return false;
+  }
+
+  // For file scheme, reject unless the files are identical. See
+  // NS_RelaxStrictFileOriginPolicy for enforcing file same-origin checking
+  if (targetScheme.EqualsLiteral("file")) {
+    // in traditional unsafe behavior all files are the same origin
+    if (!aStrictFileOriginPolicy) return true;
+
+    nsCOMPtr<nsIFileURL> sourceFileURL(do_QueryInterface(sourceBaseURI));
+    nsCOMPtr<nsIFileURL> targetFileURL(do_QueryInterface(targetBaseURI));
+
+    if (!sourceFileURL || !targetFileURL) return false;
+
+    nsCOMPtr<nsIFile> sourceFile, targetFile;
+
+    sourceFileURL->GetFile(getter_AddRefs(sourceFile));
+    targetFileURL->GetFile(getter_AddRefs(targetFile));
+
+    if (!sourceFile || !targetFile) return false;
+
+    // Otherwise they had better match
+    bool filesAreEqual = false;
+    rv = sourceFile->Equals(targetFile, &filesAreEqual);
+    return NS_SUCCEEDED(rv) && filesAreEqual;
+  }
+
+#if IS_ORIGIN_IS_FULL_SPEC_DEFINED
+  bool hasFlag;
+  if (NS_FAILED(NS_URIChainHasFlags(
+          targetBaseURI, nsIProtocolHandler::ORIGIN_IS_FULL_SPEC, &hasFlag)) ||
+      hasFlag) {
+    // URIs with this flag have the whole spec as a distinct trust
+    // domain; use the whole spec for comparison
+    nsAutoCString targetSpec;
+    nsAutoCString sourceSpec;
+    return (NS_SUCCEEDED(targetBaseURI->GetSpec(targetSpec)) &&
+            NS_SUCCEEDED(sourceBaseURI->GetSpec(sourceSpec)) &&
+            targetSpec.Equals(sourceSpec));
+  }
+#endif
+
+  // Compare hosts
+  nsAutoCString targetHost;
+  nsAutoCString sourceHost;
+  if (NS_FAILED(targetBaseURI->GetAsciiHost(targetHost)) ||
+      NS_FAILED(sourceBaseURI->GetAsciiHost(sourceHost))) {
+    return false;
+  }
+
+  nsCOMPtr<nsIStandardURL> targetURL(do_QueryInterface(targetBaseURI));
+  nsCOMPtr<nsIStandardURL> sourceURL(do_QueryInterface(sourceBaseURI));
+  if (!targetURL || !sourceURL) {
+    return false;
+  }
+
+  if (!targetHost.Equals(sourceHost, nsCaseInsensitiveCStringComparator)) {
+    return false;
+  }
+
+  return NS_GetRealPort(targetBaseURI) == NS_GetRealPort(sourceBaseURI);
+}
+
+bool NS_URIIsLocalFile(nsIURI* aURI) {
+  nsCOMPtr<nsINetUtil> util = do_GetNetUtil();
+
+  bool isFile;
+  return util &&
+         NS_SUCCEEDED(util->ProtocolHasFlags(
+             aURI, nsIProtocolHandler::URI_IS_LOCAL_FILE, &isFile)) &&
+         isFile;
+}
+
+bool NS_RelaxStrictFileOriginPolicy(nsIURI* aTargetURI, nsIURI* aSourceURI,
+                                    bool aAllowDirectoryTarget /* = false */) {
+  if (!NS_URIIsLocalFile(aTargetURI)) {
+    // This is probably not what the caller intended
+    MOZ_ASSERT_UNREACHABLE(
+        "NS_RelaxStrictFileOriginPolicy called with non-file URI");
+    return false;
+  }
+
+  if (!NS_URIIsLocalFile(aSourceURI)) {
+    // If the source is not also a file: uri then forget it
+    // (don't want resource: principals in a file: doc)
+    //
+    // note: we're not de-nesting jar: uris here, we want to
+    // keep archive content bottled up in its own little island
+    return false;
+  }
+
+  //
+  // pull out the internal files
+  //
+  nsCOMPtr<nsIFileURL> targetFileURL(do_QueryInterface(aTargetURI));
+  nsCOMPtr<nsIFileURL> sourceFileURL(do_QueryInterface(aSourceURI));
+  nsCOMPtr<nsIFile> targetFile;
+  nsCOMPtr<nsIFile> sourceFile;
+  bool targetIsDir;
+
+  // Make sure targetFile is not a directory (bug 209234)
+  // and that it exists w/out unescaping (bug 395343)
+  if (!sourceFileURL || !targetFileURL ||
+      NS_FAILED(targetFileURL->GetFile(getter_AddRefs(targetFile))) ||
+      NS_FAILED(sourceFileURL->GetFile(getter_AddRefs(sourceFile))) ||
+      !targetFile || !sourceFile || NS_FAILED(targetFile->Normalize()) ||
+#ifndef MOZ_WIDGET_ANDROID
+      NS_FAILED(sourceFile->Normalize()) ||
+#endif
+      (!aAllowDirectoryTarget &&
+       (NS_FAILED(targetFile->IsDirectory(&targetIsDir)) || targetIsDir))) {
+    return false;
+  }
+
+  return false;
+}
+
+bool NS_IsInternalSameURIRedirect(nsIChannel* aOldChannel,
+                                  nsIChannel* aNewChannel, uint32_t aFlags) {
+  if (!(aFlags & nsIChannelEventSink::REDIRECT_INTERNAL)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> oldURI, newURI;
+  aOldChannel->GetURI(getter_AddRefs(oldURI));
+  aNewChannel->GetURI(getter_AddRefs(newURI));
+
+  if (!oldURI || !newURI) {
+    return false;
+  }
+
+  bool res;
+  return NS_SUCCEEDED(oldURI->Equals(newURI, &res)) && res;
+}
+
+bool NS_IsHSTSUpgradeRedirect(nsIChannel* aOldChannel, nsIChannel* aNewChannel,
+                              uint32_t aFlags) {
+  if (!(aFlags & nsIChannelEventSink::REDIRECT_STS_UPGRADE)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> oldURI, newURI;
+  aOldChannel->GetURI(getter_AddRefs(oldURI));
+  aNewChannel->GetURI(getter_AddRefs(newURI));
+
+  if (!oldURI || !newURI) {
+    return false;
+  }
+
+  if (!oldURI->SchemeIs("http")) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> upgradedURI;
+  nsresult rv = NS_GetSecureUpgradedURI(oldURI, getter_AddRefs(upgradedURI));
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  bool res;
+  return NS_SUCCEEDED(upgradedURI->Equals(newURI, &res)) && res;
+}
+
+bool NS_ShouldRemoveAuthHeaderOnRedirect(nsIChannel* aOldChannel,
+                                         nsIChannel* aNewChannel,
+                                         uint32_t aFlags) {
+  // we need to strip Authentication headers for external cross-origin redirects
+  // Howerver, we should NOT strip auth headers for
+  // - internal redirects/HSTS upgrades
+  // - same origin redirects
+  // Ref: https://fetch.spec.whatwg.org/#http-redirect-fetch
+  if ((aFlags & (nsIChannelEventSink::REDIRECT_STS_UPGRADE |
+                 nsIChannelEventSink::REDIRECT_INTERNAL))) {
+    // this is an internal redirect do not strip auth header
+    return false;
+  }
+  nsCOMPtr<nsIURI> oldUri;
+  MOZ_ALWAYS_SUCCEEDS(
+      NS_GetFinalChannelURI(aOldChannel, getter_AddRefs(oldUri)));
+
+  nsCOMPtr<nsIURI> newUri;
+  MOZ_ALWAYS_SUCCEEDS(
+      NS_GetFinalChannelURI(aNewChannel, getter_AddRefs(newUri)));
+
+  nsresult rv = nsContentUtils::GetSecurityManager()->CheckSameOriginURI(
+      newUri, oldUri, false, false);
+
+  return NS_FAILED(rv);
+}
+
+nsresult NS_LinkRedirectChannels(uint64_t channelId,
+                                 nsIParentChannel* parentChannel,
+                                 nsIChannel** _result) {
+  nsCOMPtr<nsIRedirectChannelRegistrar> registrar =
+      RedirectChannelRegistrar::GetOrCreate();
+  MOZ_ASSERT(registrar);
+
+  return registrar->LinkChannels(channelId, parentChannel, _result);
+}
+
+nsILoadInfo::CrossOriginEmbedderPolicy
+NS_GetCrossOriginEmbedderPolicyFromHeader(
+    const nsACString& aHeader, bool aIsOriginTrialCoepCredentiallessEnabled) {
+  nsCOMPtr<nsISFVService> sfv = GetSFVService();
+
+  nsCOMPtr<nsISFVItem> item;
+  nsresult rv = sfv->ParseItem(aHeader, getter_AddRefs(item));
+  if (NS_FAILED(rv)) {
+    return nsILoadInfo::EMBEDDER_POLICY_NULL;
+  }
+
+  nsCOMPtr<nsISFVBareItem> value;
+  rv = item->GetValue(getter_AddRefs(value));
+  if (NS_FAILED(rv)) {
+    return nsILoadInfo::EMBEDDER_POLICY_NULL;
+  }
+
+  nsCOMPtr<nsISFVToken> token = do_QueryInterface(value);
+  if (!token) {
+    return nsILoadInfo::EMBEDDER_POLICY_NULL;
+  }
+
+  nsAutoCString embedderPolicy;
+  rv = token->GetValue(embedderPolicy);
+  if (NS_FAILED(rv)) {
+    return nsILoadInfo::EMBEDDER_POLICY_NULL;
+  }
+
+  if (embedderPolicy.EqualsLiteral("require-corp")) {
+    return nsILoadInfo::EMBEDDER_POLICY_REQUIRE_CORP;
+  } else if (embedderPolicy.EqualsLiteral("credentialless") &&
+             IsCoepCredentiallessEnabled(
+                 aIsOriginTrialCoepCredentiallessEnabled)) {
+    return nsILoadInfo::EMBEDDER_POLICY_CREDENTIALLESS;
+  }
+
+  return nsILoadInfo::EMBEDDER_POLICY_NULL;
+}
+
+/** Given the first (disposition) token from a Content-Disposition header,
+ * tell whether it indicates the content is inline or attachment
+ * @param aDispToken the disposition token from the content-disposition header
+ */
+uint32_t NS_GetContentDispositionFromToken(const nsAString& aDispToken) {
+  // RFC 2183, section 2.8 says that an unknown disposition
+  // value should be treated as "attachment"
+  // If all of these tests eval to false, then we have a content-disposition of
+  // "attachment" or unknown
+  if (aDispToken.IsEmpty() || aDispToken.LowerCaseEqualsLiteral("inline") ||
+      // Broken sites just send
+      // Content-Disposition: filename="file"
+      // without a disposition token... screen those out.
+      StringHead(aDispToken, 8).LowerCaseEqualsLiteral("filename")) {
+    return nsIChannel::DISPOSITION_INLINE;
+  }
+
+  return nsIChannel::DISPOSITION_ATTACHMENT;
+}
+
+uint32_t NS_GetContentDispositionFromHeader(const nsACString& aHeader,
+                                            nsIChannel* aChan /* = nullptr */) {
+  nsresult rv;
+  nsCOMPtr<nsIMIMEHeaderParam> mimehdrpar =
+      do_GetService(NS_MIMEHEADERPARAM_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return nsIChannel::DISPOSITION_ATTACHMENT;
+
+  nsAutoString dispToken;
+  rv = mimehdrpar->GetParameterHTTP(aHeader, "", ""_ns, true, nullptr,
+                                    dispToken);
+
+  if (NS_FAILED(rv)) {
+    // special case (see bug 272541): empty disposition type handled as "inline"
+    if (rv == NS_ERROR_FIRST_HEADER_FIELD_COMPONENT_EMPTY) {
+      return nsIChannel::DISPOSITION_INLINE;
+    }
+    return nsIChannel::DISPOSITION_ATTACHMENT;
+  }
+
+  return NS_GetContentDispositionFromToken(dispToken);
+}
+
+nsresult NS_GetFilenameFromDisposition(nsAString& aFilename,
+                                       const nsACString& aDisposition) {
+  aFilename.Truncate();
+
+  nsresult rv;
+  nsCOMPtr<nsIMIMEHeaderParam> mimehdrpar =
+      do_GetService(NS_MIMEHEADERPARAM_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  // Get the value of 'filename' parameter
+  rv = mimehdrpar->GetParameterHTTP(aDisposition, "filename", ""_ns, true,
+                                    nullptr, aFilename);
+
+  if (NS_FAILED(rv)) {
+    aFilename.Truncate();
+    return rv;
+  }
+
+  if (aFilename.IsEmpty()) return NS_ERROR_NOT_AVAILABLE;
+
+  // Filename may still be percent-encoded. Fix:
+  if (aFilename.FindChar('%') != -1) {
+    nsCOMPtr<nsITextToSubURI> textToSubURI =
+        do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
+    if (NS_SUCCEEDED(rv)) {
+      nsAutoString unescaped;
+      textToSubURI->UnEscapeURIForUI(NS_ConvertUTF16toUTF8(aFilename),
+                                     /* dontEscape = */ true, unescaped);
+      aFilename.Assign(unescaped);
+    }
+  }
+
+  return NS_OK;
+}
+
+void net_EnsurePSMInit() {
+  if (XRE_IsSocketProcess()) {
+    EnsureNSSInitializedChromeOrContent();
+    return;
+  }
+
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(NS_IsMainThread());
+
+  DebugOnly<bool> rv = EnsureNSSInitializedChromeOrContent();
+  MOZ_ASSERT(rv);
+}
+
+bool NS_IsAboutBlank(nsIURI* uri) {
+  // GetSpec can be expensive for some URIs, so check the scheme first.
+  if (!uri->SchemeIs("about")) {
+    return false;
+  }
+
+  nsAutoCString spec;
+  if (NS_FAILED(uri->GetSpec(spec))) {
+    return false;
+  }
+
+  return spec.EqualsLiteral("about:blank");
+}
+
+bool NS_IsAboutSrcdoc(nsIURI* uri) {
+  // GetSpec can be expensive for some URIs, so check the scheme first.
+  if (!uri->SchemeIs("about")) {
+    return false;
+  }
+
+  nsAutoCString spec;
+  if (NS_FAILED(uri->GetSpec(spec))) {
+    return false;
+  }
+
+  return spec.EqualsLiteral("about:srcdoc");
+}
+
+nsresult NS_GenerateHostPort(const nsCString& host, int32_t port,
+                             nsACString& hostLine) {
+  if (strchr(host.get(), ':')) {
+    // host is an IPv6 address literal and must be encapsulated in []'s
+    hostLine.Assign('[');
+    // scope id is not needed for Host header.
+    int scopeIdPos = host.FindChar('%');
+    if (scopeIdPos == -1) {
+      hostLine.Append(host);
+    } else if (scopeIdPos > 0) {
+      hostLine.Append(Substring(host, 0, scopeIdPos));
+    } else {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    hostLine.Append(']');
+  } else {
+    hostLine.Assign(host);
+  }
+  if (port != -1) {
+    hostLine.Append(':');
+    hostLine.AppendInt(port);
+  }
+  return NS_OK;
+}
+
+void NS_SniffContent(const char* aSnifferType, nsIRequest* aRequest,
+                     const uint8_t* aData, uint32_t aLength,
+                     nsACString& aSniffedType) {
+  using ContentSnifferCache = nsCategoryCache<nsIContentSniffer>;
+  extern ContentSnifferCache* gNetSniffers;
+  extern ContentSnifferCache* gDataSniffers;
+  extern ContentSnifferCache* gORBSniffers;
+  extern ContentSnifferCache* gNetAndORBSniffers;
+  ContentSnifferCache* cache = nullptr;
+  if (!strcmp(aSnifferType, NS_CONTENT_SNIFFER_CATEGORY)) {
+    if (!gNetSniffers) {
+      gNetSniffers = new ContentSnifferCache(NS_CONTENT_SNIFFER_CATEGORY);
+    }
+    cache = gNetSniffers;
+  } else if (!strcmp(aSnifferType, NS_DATA_SNIFFER_CATEGORY)) {
+    if (!gDataSniffers) {
+      gDataSniffers = new ContentSnifferCache(NS_DATA_SNIFFER_CATEGORY);
+    }
+    cache = gDataSniffers;
+  } else if (!strcmp(aSnifferType, NS_ORB_SNIFFER_CATEGORY)) {
+    if (!gORBSniffers) {
+      gORBSniffers = new ContentSnifferCache(NS_ORB_SNIFFER_CATEGORY);
+    }
+    cache = gORBSniffers;
+  } else if (!strcmp(aSnifferType, NS_CONTENT_AND_ORB_SNIFFER_CATEGORY)) {
+    if (!gNetAndORBSniffers) {
+      gNetAndORBSniffers =
+          new ContentSnifferCache(NS_CONTENT_AND_ORB_SNIFFER_CATEGORY);
+    }
+    cache = gNetAndORBSniffers;
+  } else {
+    // Invalid content sniffer type was requested
+    MOZ_ASSERT(false);
+    return;
+  }
+
+  // In case XCTO nosniff was present, we could just skip sniffing here
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
+  if (channel) {
+    nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+    if (loadInfo->GetSkipContentSniffing()) {
+      /* Bug 1571742
+       * We cannot skip snffing if the current MIME-Type might be a JSON.
+       * The JSON-Viewer relies on its own sniffer to determine, if it can
+       * render the page, so we need to make an exception if the Server provides
+       * a application/ mime, as it might be json.
+       */
+      nsAutoCString currentContentType;
+      channel->GetContentType(currentContentType);
+      if (!StringBeginsWith(currentContentType, "application/"_ns)) {
+        return;
+      }
+    }
+  }
+  nsCOMArray<nsIContentSniffer> sniffers;
+  cache->GetEntries(sniffers);
+  for (int32_t i = 0; i < sniffers.Count(); ++i) {
+    nsresult rv = sniffers[i]->GetMIMETypeFromContent(aRequest, aData, aLength,
+                                                      aSniffedType);
+    if (NS_SUCCEEDED(rv) && !aSniffedType.IsEmpty()) {
+      return;
+    }
+  }
+
+  aSniffedType.Truncate();
+}
+
+bool NS_IsSrcdocChannel(nsIChannel* aChannel) {
+  bool isSrcdoc;
+  nsCOMPtr<nsIInputStreamChannel> isr = do_QueryInterface(aChannel);
+  if (isr) {
+    isr->GetIsSrcdocChannel(&isSrcdoc);
+    return isSrcdoc;
+  }
+  nsCOMPtr<nsIViewSourceChannel> vsc = do_QueryInterface(aChannel);
+  if (vsc) {
+    nsresult rv = vsc->GetIsSrcdocChannel(&isSrcdoc);
+    if (NS_SUCCEEDED(rv)) {
+      return isSrcdoc;
+    }
+  }
+  return false;
+}
+
+// helper function for NS_ShouldSecureUpgrade for checking HSTS
+bool handleResultFunc(bool aAllowSTS, bool aIsStsHost) {
+  if (aIsStsHost) {
+    LOG(("nsHttpChannel::Connect() STS permissions found\n"));
+    if (aAllowSTS) {
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::STS);
+      return true;
+    }
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::PrefBlockedSTS);
+  } else {
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::NoReasonToUpgrade);
+  }
+  return false;
+};
+// That function is a helper function of NS_ShouldSecureUpgrade to check if
+// CSP upgrade-insecure-requests, Mixed content auto upgrading or HTTPs-Only/-
+// First should upgrade the given request.
+static bool ShouldSecureUpgradeNoHSTS(nsIURI* aURI, nsILoadInfo* aLoadInfo) {
+  // 2. CSP upgrade-insecure-requests
+  if (aLoadInfo->GetUpgradeInsecureRequests()) {
+    // let's log a message to the console that we are upgrading a request
+    nsAutoCString scheme;
+    aURI->GetScheme(scheme);
+    // append the additional 's' for security to the scheme :-)
+    scheme.AppendLiteral("s");
+    NS_ConvertUTF8toUTF16 reportSpec(aURI->GetSpecOrDefault());
+    NS_ConvertUTF8toUTF16 reportScheme(scheme);
+    AutoTArray<nsString, 2> params = {reportSpec, reportScheme};
+    uint64_t innerWindowId = aLoadInfo->GetInnerWindowID();
+    CSP_LogLocalizedStr("upgradeInsecureRequest", params,
+                        u""_ns,  // aSourceFile
+                        u""_ns,  // aScriptSample
+                        0,       // aLineNumber
+                        0,       // aColumnNumber
+                        nsIScriptError::warningFlag,
+                        "upgradeInsecureRequest"_ns, innerWindowId,
+                        !!aLoadInfo->GetOriginAttributes().mPrivateBrowsingId);
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::CSP);
+    return true;
+  }
+  // 3. Mixed content auto upgrading
+  if (aLoadInfo->GetBrowserUpgradeInsecureRequests()) {
+    // let's log a message to the console that we are upgrading a request
+    nsAutoCString scheme;
+    aURI->GetScheme(scheme);
+    // append the additional 's' for security to the scheme :-)
+    scheme.AppendLiteral("s");
+    NS_ConvertUTF8toUTF16 reportSpec(aURI->GetSpecOrDefault());
+    NS_ConvertUTF8toUTF16 reportScheme(scheme);
+    AutoTArray<nsString, 2> params = {reportSpec, reportScheme};
+
+    nsAutoString localizedMsg;
+    nsContentUtils::FormatLocalizedString(nsContentUtils::eSECURITY_PROPERTIES,
+                                          "MixedContentAutoUpgrade", params,
+                                          localizedMsg);
+
+    // Prepending ixed Content to the outgoing console message
+    nsString message;
+    message.AppendLiteral(u"Mixed Content: ");
+    message.Append(localizedMsg);
+
+    uint64_t innerWindowId = aLoadInfo->GetInnerWindowID();
+    nsContentUtils::ReportToConsoleByWindowID(
+        message, nsIScriptError::warningFlag, "Mixed Content Message"_ns,
+        innerWindowId, aURI);
+
+    // Set this flag so we know we'll upgrade because of
+    // 'security.mixed_content.upgrade_display_content'.
+    aLoadInfo->SetBrowserDidUpgradeInsecureRequests(true);
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::BrowserDisplay);
+
+    return true;
+  }
+
+  // 4. Https-Only
+  if (nsHTTPSOnlyUtils::ShouldUpgradeRequest(aURI, aLoadInfo)) {
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::HTTPSOnly);
+    return true;
+  }
+  // 4.a Https-First
+  if (nsHTTPSOnlyUtils::ShouldUpgradeHttpsFirstRequest(aURI, aLoadInfo)) {
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::HTTPSFirst);
+    return true;
+  }
+  return false;
+}
+
+// Check if channel should be upgraded. check in the following order:
+// 1. HSTS
+// 2. CSP upgrade-insecure-requests
+// 3. Mixed content auto upgrading
+// 4. Https-Only / first
+// (5. Https RR - will be checked in nsHttpChannel)
+nsresult NS_ShouldSecureUpgrade(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo, nsIPrincipal* aChannelResultPrincipal,
+    bool aAllowSTS, const OriginAttributes& aOriginAttributes,
+    bool& aShouldUpgrade, std::function<void(bool, nsresult)>&& aResultCallback,
+    bool& aWillCallback) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  aWillCallback = false;
+  aShouldUpgrade = false;
+
+  // Even if we're in private browsing mode, we still enforce existing STS
+  // data (it is read-only).
+  // if the connection is not using SSL and either the exact host matches or
+  // a superdomain wants to force HTTPS, do it.
+  bool isHttps = aURI->SchemeIs("https");
+
+  // If request is https, then there is nothing to do here.
+  if (isHttps) {
+    Telemetry::AccumulateCategorical(
+        Telemetry::LABELS_HTTP_SCHEME_UPGRADE_TYPE::AlreadyHTTPS);
+    aShouldUpgrade = false;
+    return NS_OK;
+  }
+  // If it is a mixed content trustworthy loopback, then we shouldn't upgrade
+  // it.
+  if (nsMixedContentBlocker::IsPotentiallyTrustworthyLoopbackURL(aURI)) {
+    aShouldUpgrade = false;
+    return NS_OK;
+  }
+  // If no loadInfo exist there is nothing to upgrade here.
+  if (!aLoadInfo) {
+    aShouldUpgrade = false;
+    return NS_OK;
+  }
+  MOZ_ASSERT(!aURI->SchemeIs("https"));
+
+  // enforce Strict-Transport-Security
+  nsISiteSecurityService* sss = gHttpHandler->GetSSService();
+  NS_ENSURE_TRUE(sss, NS_ERROR_OUT_OF_MEMORY);
+
+  bool isStsHost = false;
+  // Calling |IsSecureURI| before the storage is ready to read will
+  // block the main thread. Once the storage is ready, we can call it
+  // from main thread.
+  static Atomic<bool, Relaxed> storageReady(false);
+  if (!storageReady && gSocketTransportService && aResultCallback) {
+    nsCOMPtr<nsILoadInfo> loadInfo = aLoadInfo;
+    nsCOMPtr<nsIURI> uri = aURI;
+    auto callbackWrapper = [resultCallback{std::move(aResultCallback)}, uri,
+                            loadInfo](bool aShouldUpgrade, nsresult aStatus) {
+      MOZ_ASSERT(NS_IsMainThread());
+
+      // 1. HSTS upgrade
+      if (aShouldUpgrade || NS_FAILED(aStatus)) {
+        resultCallback(aShouldUpgrade, aStatus);
+        return;
+      }
+      // Check if we need to upgrade because of other reasons.
+      // 2. CSP upgrade-insecure-requests
+      // 3. Mixed content auto upgrading
+      // 4. Https-Only / first
+      bool shouldUpgrade = ShouldSecureUpgradeNoHSTS(uri, loadInfo);
+      resultCallback(shouldUpgrade, aStatus);
+    };
+    nsCOMPtr<nsISiteSecurityService> service = sss;
+    nsresult rv = gSocketTransportService->Dispatch(
+        NS_NewRunnableFunction(
+            "net::NS_ShouldSecureUpgrade",
+            [service{std::move(service)}, uri{std::move(uri)},
+             originAttributes(aOriginAttributes),
+             handleResultFunc{std::move(handleResultFunc)},
+             callbackWrapper{std::move(callbackWrapper)},
+             allowSTS{std::move(aAllowSTS)}]() mutable {
+              bool isStsHost = false;
+              nsresult rv =
+                  service->IsSecureURI(uri, originAttributes, &isStsHost);
+
+              // Successfully get the result from |IsSecureURI| implies that
+              // the storage is ready to read.
+              storageReady = NS_SUCCEEDED(rv);
+              bool shouldUpgrade = handleResultFunc(allowSTS, isStsHost);
+              // Check if request should be upgraded.
+              NS_DispatchToMainThread(NS_NewRunnableFunction(
+                  "net::NS_ShouldSecureUpgrade::ResultCallback",
+                  [rv, shouldUpgrade,
+                   callbackWrapper{std::move(callbackWrapper)}]() {
+                    callbackWrapper(shouldUpgrade, rv);
+                  }));
+            }),
+        NS_DISPATCH_NORMAL);
+    aWillCallback = NS_SUCCEEDED(rv);
+    return rv;
+  }
+
+  nsresult rv = sss->IsSecureURI(aURI, aOriginAttributes, &isStsHost);
+
+  // if the SSS check fails, it's likely because this load is on a
+  // malformed URI or something else in the setup is wrong, so any error
+  // should be reported.
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aShouldUpgrade = handleResultFunc(aAllowSTS, isStsHost);
+  if (!aShouldUpgrade) {
+    // Check for CSP upgrade-insecure-requests, Mixed content auto upgrading
+    // and Https-Only / -First.
+    aShouldUpgrade = ShouldSecureUpgradeNoHSTS(aURI, aLoadInfo);
+  }
+  return rv;
+}
+
+nsresult NS_GetSecureUpgradedURI(nsIURI* aURI, nsIURI** aUpgradedURI) {
+  NS_MutateURI mutator(aURI);
+  mutator.SetScheme("https"_ns);  // Change the scheme to HTTPS:
+
+  // Change the default port to 443:
+  nsCOMPtr<nsIStandardURL> stdURL = do_QueryInterface(aURI);
+  if (stdURL) {
+    mutator.Apply(&nsIStandardURLMutator::SetDefaultPort, 443, nullptr);
+  } else {
+    // If we don't have a nsStandardURL, fall back to using GetPort/SetPort.
+    // XXXdholbert Is this function even called with a non-nsStandardURL arg,
+    // in practice?
+    NS_WARNING("Calling NS_GetSecureUpgradedURI for non nsStandardURL");
+    int32_t oldPort = -1;
+    nsresult rv = aURI->GetPort(&oldPort);
+    if (NS_FAILED(rv)) return rv;
+
+    // Keep any nonstandard ports so only the scheme is changed.
+    // For example:
+    //  http://foo.com:80 -> https://foo.com:443
+    //  http://foo.com:81 -> https://foo.com:81
+
+    if (oldPort == 80 || oldPort == -1) {
+      mutator.SetPort(-1);
+    } else {
+      mutator.SetPort(oldPort);
+    }
+  }
+
+  return mutator.Finalize(aUpgradedURI);
+}
+
+nsresult NS_CompareLoadInfoAndLoadContext(nsIChannel* aChannel) {
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+
+  nsCOMPtr<nsILoadContext> loadContext;
+  NS_QueryNotificationCallbacks(aChannel, loadContext);
+  if (!loadContext) {
+    return NS_OK;
+  }
+
+  // We try to skip about:newtab.
+  // about:newtab will use SystemPrincipal to download thumbnails through
+  // https:// and blob URLs.
+  bool isAboutPage = false;
+  nsINode* node = loadInfo->LoadingNode();
+  if (node) {
+    nsIURI* uri = node->OwnerDoc()->GetDocumentURI();
+    isAboutPage = uri->SchemeIs("about");
+  }
+
+  if (isAboutPage) {
+    return NS_OK;
+  }
+
+  // We skip the favicon loading here. The favicon loading might be
+  // triggered by the XUL image. For that case, the loadContext will have
+  // default originAttributes since the XUL image uses SystemPrincipal, but
+  // the loadInfo will use originAttributes from the content. Thus, the
+  // originAttributes between loadInfo and loadContext will be different.
+  // That's why we have to skip the comparison for the favicon loading.
+  if (loadInfo->GetLoadingPrincipal() &&
+      loadInfo->GetLoadingPrincipal()->IsSystemPrincipal() &&
+      loadInfo->InternalContentPolicyType() ==
+          nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON) {
+    return NS_OK;
+  }
+
+  OriginAttributes originAttrsLoadInfo = loadInfo->GetOriginAttributes();
+  OriginAttributes originAttrsLoadContext;
+  loadContext->GetOriginAttributes(originAttrsLoadContext);
+
+  LOG(
+      ("NS_CompareLoadInfoAndLoadContext - loadInfo: %d, %d; "
+       "loadContext: %d, %d. [channel=%p]",
+       originAttrsLoadInfo.mUserContextId,
+       originAttrsLoadInfo.mPrivateBrowsingId,
+       originAttrsLoadContext.mUserContextId,
+       originAttrsLoadContext.mPrivateBrowsingId, aChannel));
+
+  MOZ_ASSERT(originAttrsLoadInfo.mUserContextId ==
+                 originAttrsLoadContext.mUserContextId,
+             "The value of mUserContextId in the loadContext and in the "
+             "loadInfo are not the same!");
+
+  MOZ_ASSERT(originAttrsLoadInfo.mPrivateBrowsingId ==
+                 originAttrsLoadContext.mPrivateBrowsingId,
+             "The value of mPrivateBrowsingId in the loadContext and in the "
+             "loadInfo are not the same!");
+
+  return NS_OK;
+}
+
+nsresult NS_SetRequestBlockingReason(nsIChannel* channel, uint32_t reason) {
+  NS_ENSURE_ARG(channel);
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+  return NS_SetRequestBlockingReason(loadInfo, reason);
+}
+
+nsresult NS_SetRequestBlockingReason(nsILoadInfo* loadInfo, uint32_t reason) {
+  NS_ENSURE_ARG(loadInfo);
+
+  return loadInfo->SetRequestBlockingReason(reason);
+}
+
+nsresult NS_SetRequestBlockingReasonIfNull(nsILoadInfo* loadInfo,
+                                           uint32_t reason) {
+  NS_ENSURE_ARG(loadInfo);
+
+  uint32_t existingReason;
+  if (NS_SUCCEEDED(loadInfo->GetRequestBlockingReason(&existingReason)) &&
+      existingReason != nsILoadInfo::BLOCKING_REASON_NONE) {
+    return NS_OK;
+  }
+
+  return loadInfo->SetRequestBlockingReason(reason);
+}
+
+bool NS_IsOffline() {
+  bool offline = true;
+  bool connectivity = true;
+  nsCOMPtr<nsIIOService> ios = do_GetIOService();
+  if (ios) {
+    ios->GetOffline(&offline);
+    ios->GetConnectivity(&connectivity);
+  }
+  return offline || !connectivity;
+}
+
+/**
+ * This function returns true if this channel should be classified by
+ * the URL Classifier, false otherwise.
+ *
+ * The idea of the algorithm to determine if a channel should be
+ * classified is based on:
+ * 1. Channels created by non-privileged code should be classified.
+ * 2. Top-level document’s channels, if loaded by privileged code
+ *    (system principal), should be classified.
+ * 3. Any other channel, created by privileged code, is considered safe.
+ *
+ * A bad/hacked/corrupted safebrowsing database, plus a mistakenly
+ * classified critical channel (this may result from a bug in the exemption
+ * rules or incorrect information being passed into) can cause serious
+ * problems. For example, if the updater channel is classified and blocked
+ * by the Safe Browsing, Firefox can't update itself, and there is no way to
+ * recover from that.
+ *
+ * So two safeguards are added to ensure critical channels are never
+ * automatically classified either because there is a bug in the algorithm
+ * or the data in loadinfo is wrong.
+ * 1. beConservative, this is set by ServiceRequest and we treat
+ *    channel created for ServiceRequest as critical channels.
+ * 2. nsIChannel::LOAD_BYPASS_URL_CLASSIFIER, channel's opener can use this
+ *    flag to enforce bypassing the URL classifier check.
+ */
+bool NS_ShouldClassifyChannel(nsIChannel* aChannel) {
+  nsLoadFlags loadFlags;
+  Unused << aChannel->GetLoadFlags(&loadFlags);
+  //  If our load flags dictate that we must let this channel through without
+  //  URL classification, obey that here without performing more checks.
+  if (loadFlags & nsIChannel::LOAD_BYPASS_URL_CLASSIFIER) {
+    return false;
+  }
+
+  nsCOMPtr<nsIHttpChannelInternal> httpChannel(do_QueryInterface(aChannel));
+  if (httpChannel) {
+    bool beConservative;
+    nsresult rv = httpChannel->GetBeConservative(&beConservative);
+
+    // beConservative flag, set by ServiceRequest to ensure channels that
+    // fetch update use conservative TLS setting, are used here to identify
+    // channels are critical to bypass classification. for channels don't
+    // support beConservative, continue to apply the exemption rules.
+    if (NS_SUCCEEDED(rv) && beConservative) {
+      return false;
+    }
+  }
+
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+  ExtContentPolicyType type = loadInfo->GetExternalContentPolicyType();
+  // Skip classifying channel triggered by system unless it is a top-level
+  // load.
+  return !(loadInfo->TriggeringPrincipal()->IsSystemPrincipal() &&
+           ExtContentPolicy::TYPE_DOCUMENT != type);
+}
+
+namespace mozilla {
+namespace net {
+
+bool InScriptableRange(int64_t val) {
+  return (val <= kJS_MAX_SAFE_INTEGER) && (val >= kJS_MIN_SAFE_INTEGER);
+}
+
+bool InScriptableRange(uint64_t val) { return val <= kJS_MAX_SAFE_UINTEGER; }
+
+nsresult GetParameterHTTP(const nsACString& aHeaderVal, const char* aParamName,
+                          nsAString& aResult) {
+  return nsMIMEHeaderParamImpl::GetParameterHTTP(aHeaderVal, aParamName,
+                                                 aResult);
+}
+
+bool ChannelIsPost(nsIChannel* aChannel) {
+  if (nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel)) {
+    nsAutoCString method;
+    Unused << httpChannel->GetRequestMethod(method);
+    return method.EqualsLiteral("POST");
+  }
+  return false;
+}
+
+bool SchemeIsHTTP(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("http");
+}
+
+bool SchemeIsHTTPS(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("https");
+}
+
+bool SchemeIsJavascript(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("javascript");
+}
+
+bool SchemeIsChrome(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("chrome");
+}
+
+bool SchemeIsAbout(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("about");
+}
+
+bool SchemeIsBlob(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("blob");
+}
+
+bool SchemeIsFile(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("file");
+}
+
+bool SchemeIsData(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("data");
+}
+
+bool SchemeIsViewSource(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("view-source");
+}
+
+bool SchemeIsResource(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("resource");
+}
+
+bool SchemeIsFTP(nsIURI* aURI) {
+  MOZ_ASSERT(aURI);
+  return aURI->SchemeIs("ftp");
+}
+
+// Decode a parameter value using the encoding defined in RFC 5987 (in place)
+//
+//   charset  "'" [ language ] "'" value-chars
+//
+// returns true when decoding happened successfully (otherwise leaves
+// passed value alone)
+static bool Decode5987Format(nsAString& aEncoded) {
+  nsresult rv;
+  nsCOMPtr<nsIMIMEHeaderParam> mimehdrpar =
+      do_GetService(NS_MIMEHEADERPARAM_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return false;
+
+  nsAutoCString asciiValue;
+
+  const char16_t* encstart = aEncoded.BeginReading();
+  const char16_t* encend = aEncoded.EndReading();
+
+  // create a plain ASCII string, aborting if we can't do that
+  // converted form is always shorter than input
+  while (encstart != encend) {
+    if (*encstart > 0 && *encstart < 128) {
+      asciiValue.Append((char)*encstart);
+    } else {
+      return false;
+    }
+    encstart++;
+  }
+
+  nsAutoString decoded;
+  nsAutoCString language;
+
+  rv = mimehdrpar->DecodeRFC5987Param(asciiValue, language, decoded);
+  if (NS_FAILED(rv)) return false;
+
+  aEncoded = decoded;
+  return true;
+}
+
+LinkHeader::LinkHeader() { mCrossOrigin.SetIsVoid(true); }
+
+void LinkHeader::Reset() {
+  mHref.Truncate();
+  mRel.Truncate();
+  mTitle.Truncate();
+  mIntegrity.Truncate();
+  mSrcset.Truncate();
+  mSizes.Truncate();
+  mType.Truncate();
+  mMedia.Truncate();
+  mAnchor.Truncate();
+  mCrossOrigin.Truncate();
+  mReferrerPolicy.Truncate();
+  mAs.Truncate();
+  mCrossOrigin.SetIsVoid(true);
+}
+
+nsresult LinkHeader::NewResolveHref(nsIURI** aOutURI, nsIURI* aBaseURI) const {
+  if (mAnchor.IsEmpty()) {
+    // use the base uri
+    return NS_NewURI(aOutURI, mHref, nullptr, aBaseURI);
+  }
+
+  // compute the anchored URI
+  nsCOMPtr<nsIURI> anchoredURI;
+  nsresult rv =
+      NS_NewURI(getter_AddRefs(anchoredURI), mAnchor, nullptr, aBaseURI);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_NewURI(aOutURI, mHref, nullptr, anchoredURI);
+}
+
+bool LinkHeader::operator==(const LinkHeader& rhs) const {
+  return mHref == rhs.mHref && mRel == rhs.mRel && mTitle == rhs.mTitle &&
+         mIntegrity == rhs.mIntegrity && mSrcset == rhs.mSrcset &&
+         mSizes == rhs.mSizes && mType == rhs.mType && mMedia == rhs.mMedia &&
+         mAnchor == rhs.mAnchor && mCrossOrigin == rhs.mCrossOrigin &&
+         mReferrerPolicy == rhs.mReferrerPolicy && mAs == rhs.mAs;
+}
+
+nsTArray<LinkHeader> ParseLinkHeader(const nsAString& aLinkData) {
+  nsTArray<LinkHeader> linkHeaders;
+
+  // keep track where we are within the header field
+  bool seenParameters = false;
+
+  // parse link content and add to array
+  LinkHeader header;
+  nsAutoString titleStar;
+
+  // copy to work buffer
+  nsAutoString stringList(aLinkData);
+
+  // put an extra null at the end
+  stringList.Append(kNullCh);
+
+  char16_t* start = stringList.BeginWriting();
+
+  while (*start != kNullCh) {
+    // parse link content and call process style link
+
+    // skip leading space
+    while ((*start != kNullCh) && nsCRT::IsAsciiSpace(*start)) {
+      ++start;
+    }
+
+    char16_t* end = start;
+    char16_t* last = end - 1;
+
+    bool wasQuotedString = false;
+
+    // look for semicolon or comma
+    while (*end != kNullCh && *end != kSemicolon && *end != kComma) {
+      char16_t ch = *end;
+
+      if (ch == kQuote || ch == kLessThan) {
+        // quoted string
+
+        char16_t quote = ch;
+        if (quote == kLessThan) {
+          quote = kGreaterThan;
+        }
+
+        wasQuotedString = (ch == kQuote);
+
+        char16_t* closeQuote = (end + 1);
+
+        // seek closing quote
+        while (*closeQuote != kNullCh && quote != *closeQuote) {
+          // in quoted-string, "\" is an escape character
+          if (wasQuotedString && *closeQuote == kBackSlash &&
+              *(closeQuote + 1) != kNullCh) {
+            ++closeQuote;
+          }
+
+          ++closeQuote;
+        }
+
+        if (quote == *closeQuote) {
+          // found closer
+
+          // skip to close quote
+          end = closeQuote;
+
+          last = end - 1;
+
+          ch = *(end + 1);
+
+          if (ch != kNullCh && ch != kSemicolon && ch != kComma) {
+            // end string here
+            *(++end) = kNullCh;
+
+            ch = *(end + 1);
+
+            // keep going until semi or comma
+            while (ch != kNullCh && ch != kSemicolon && ch != kComma) {
+              ++end;
+
+              ch = *(end + 1);
+            }
+          }
+        }
+      }
+
+      ++end;
+      ++last;
+    }
+
+    char16_t endCh = *end;
+
+    // end string here
+    *end = kNullCh;
+
+    if (start < end) {
+      if ((*start == kLessThan) && (*last == kGreaterThan)) {
+        *last = kNullCh;
+
+        // first instance of <...> wins
+        // also, do not allow hrefs after the first param was seen
+        if (header.mHref.IsEmpty() && !seenParameters) {
+          header.mHref = (start + 1);
+          header.mHref.StripWhitespace();
+        }
+      } else {
+        char16_t* equals = start;
+        seenParameters = true;
+
+        while ((*equals != kNullCh) && (*equals != kEqual)) {
+          equals++;
+        }
+
+        const bool hadEquals = *equals != kNullCh;
+        *equals = kNullCh;
+        nsAutoString attr(start);
+        attr.StripWhitespace();
+
+        char16_t* value = hadEquals ? ++equals : equals;
+        while (nsCRT::IsAsciiSpace(*value)) {
+          value++;
+        }
+
+        if ((*value == kQuote) && (*value == *last)) {
+          *last = kNullCh;
+          value++;
+        }
+
+        if (wasQuotedString) {
+          // unescape in-place
+          char16_t* unescaped = value;
+          char16_t* src = value;
+
+          while (*src != kNullCh) {
+            if (*src == kBackSlash && *(src + 1) != kNullCh) {
+              src++;
+            }
+            *unescaped++ = *src++;
+          }
+
+          *unescaped = kNullCh;
+        }
+
+        if (attr.LowerCaseEqualsLiteral("rel")) {
+          if (header.mRel.IsEmpty()) {
+            header.mRel = value;
+            header.mRel.CompressWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("title")) {
+          if (header.mTitle.IsEmpty()) {
+            header.mTitle = value;
+            header.mTitle.CompressWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("title*")) {
+          if (titleStar.IsEmpty() && !wasQuotedString) {
+            // RFC 5987 encoding; uses token format only, so skip if we get
+            // here with a quoted-string
+            nsAutoString tmp;
+            tmp = value;
+            if (Decode5987Format(tmp)) {
+              titleStar = tmp;
+              titleStar.CompressWhitespace();
+            } else {
+              // header value did not parse, throw it away
+              titleStar.Truncate();
+            }
+          }
+        } else if (attr.LowerCaseEqualsLiteral("type")) {
+          if (header.mType.IsEmpty()) {
+            header.mType = value;
+            header.mType.StripWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("media")) {
+          if (header.mMedia.IsEmpty()) {
+            header.mMedia = value;
+
+            // The HTML5 spec is formulated in terms of the CSS3 spec,
+            // which specifies that media queries are case insensitive.
+            nsContentUtils::ASCIIToLower(header.mMedia);
+          }
+        } else if (attr.LowerCaseEqualsLiteral("anchor")) {
+          if (header.mAnchor.IsEmpty()) {
+            header.mAnchor = value;
+            header.mAnchor.StripWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("crossorigin")) {
+          if (header.mCrossOrigin.IsVoid()) {
+            header.mCrossOrigin.SetIsVoid(false);
+            header.mCrossOrigin = value;
+            header.mCrossOrigin.StripWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("as")) {
+          if (header.mAs.IsEmpty()) {
+            header.mAs = value;
+            header.mAs.CompressWhitespace();
+          }
+        } else if (attr.LowerCaseEqualsLiteral("referrerpolicy")) {
+          // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#referrer-policy-attribute
+          // Specs says referrer policy attribute is an enumerated attribute,
+          // case insensitive and includes the empty string
+          // We will parse the value with AttributeReferrerPolicyFromString
+          // later, which will handle parsing it as an enumerated attribute.
+          if (header.mReferrerPolicy.IsEmpty()) {
+            header.mReferrerPolicy = value;
+          }
+        } else if (attr.LowerCaseEqualsLiteral("integrity")) {
+          if (header.mIntegrity.IsEmpty()) {
+            header.mIntegrity = value;
+          }
+        } else if (attr.LowerCaseEqualsLiteral("imagesrcset")) {
+          if (header.mSrcset.IsEmpty()) {
+            header.mSrcset = value;
+          }
+        } else if (attr.LowerCaseEqualsLiteral("imagesizes")) {
+          if (header.mSizes.IsEmpty()) {
+            header.mSizes = value;
+          }
+        }
+      }
+    }
+
+    if (endCh == kComma) {
+      // hit a comma, process what we've got so far
+
+      header.mHref.Trim(" \t\n\r\f");  // trim HTML5 whitespace
+      if (!header.mHref.IsEmpty() && !header.mRel.IsEmpty()) {
+        if (!titleStar.IsEmpty()) {
+          // prefer RFC 5987 variant over non-I18zed version
+          header.mTitle = titleStar;
+        }
+        linkHeaders.AppendElement(header);
+      }
+
+      titleStar.Truncate();
+      header.Reset();
+
+      seenParameters = false;
+    }
+
+    start = ++end;
+  }
+
+  header.mHref.Trim(" \t\n\r\f");  // trim HTML5 whitespace
+  if (!header.mHref.IsEmpty() && !header.mRel.IsEmpty()) {
+    if (!titleStar.IsEmpty()) {
+      // prefer RFC 5987 variant over non-I18zed version
+      header.mTitle = titleStar;
+    }
+    linkHeaders.AppendElement(header);
+  }
+
+  return linkHeaders;
+}
+
+// We will use official mime-types from:
+// https://www.iana.org/assignments/media-types/media-types.xhtml#font
+// We do not support old deprecated mime-types for preload feature.
+// (We currectly do not support font/collection)
+static uint32_t StyleLinkElementFontMimeTypesNum = 5;
+static const char* StyleLinkElementFontMimeTypes[] = {
+    "font/otf", "font/sfnt", "font/ttf", "font/woff", "font/woff2"};
+
+bool IsFontMimeType(const nsAString& aType) {
+  if (aType.IsEmpty()) {
+    return true;
+  }
+  for (uint32_t i = 0; i < StyleLinkElementFontMimeTypesNum; i++) {
+    if (aType.EqualsASCII(StyleLinkElementFontMimeTypes[i])) {
+      return true;
+    }
+  }
+  return false;
+}
+
+static const nsAttrValue::EnumTable kAsAttributeTable[] = {
+    {"", DESTINATION_INVALID},      {"audio", DESTINATION_AUDIO},
+    {"font", DESTINATION_FONT},     {"image", DESTINATION_IMAGE},
+    {"script", DESTINATION_SCRIPT}, {"style", DESTINATION_STYLE},
+    {"track", DESTINATION_TRACK},   {"video", DESTINATION_VIDEO},
+    {"fetch", DESTINATION_FETCH},   {nullptr, 0}};
+
+void ParseAsValue(const nsAString& aValue, nsAttrValue& aResult) {
+  DebugOnly<bool> success =
+      aResult.ParseEnumValue(aValue, kAsAttributeTable, false,
+                             // default value is a empty string
+                             // if aValue is not a value we
+                             // understand
+                             &kAsAttributeTable[0]);
+  MOZ_ASSERT(success);
+}
+
+nsContentPolicyType AsValueToContentPolicy(const nsAttrValue& aValue) {
+  switch (aValue.GetEnumValue()) {
+    case DESTINATION_INVALID:
+      return nsIContentPolicy::TYPE_INVALID;
+    case DESTINATION_AUDIO:
+      return nsIContentPolicy::TYPE_INTERNAL_AUDIO;
+    case DESTINATION_TRACK:
+      return nsIContentPolicy::TYPE_INTERNAL_TRACK;
+    case DESTINATION_VIDEO:
+      return nsIContentPolicy::TYPE_INTERNAL_VIDEO;
+    case DESTINATION_FONT:
+      return nsIContentPolicy::TYPE_FONT;
+    case DESTINATION_IMAGE:
+      return nsIContentPolicy::TYPE_IMAGE;
+    case DESTINATION_SCRIPT:
+      return nsIContentPolicy::TYPE_SCRIPT;
+    case DESTINATION_STYLE:
+      return nsIContentPolicy::TYPE_STYLESHEET;
+    case DESTINATION_FETCH:
+      return nsIContentPolicy::TYPE_INTERNAL_FETCH_PRELOAD;
+  }
+  return nsIContentPolicy::TYPE_INVALID;
+}
+
+// TODO: implement this using nsAttrValue's destination enums when support for
+// the new destinations is added; see this diff for a possible start:
+// https://phabricator.services.mozilla.com/D172368?vs=705114&id=708720
+bool IsScriptLikeOrInvalid(const nsAString& aAs) {
+  return !(
+      aAs.LowerCaseEqualsASCII("fetch") || aAs.LowerCaseEqualsASCII("audio") ||
+      aAs.LowerCaseEqualsASCII("document") ||
+      aAs.LowerCaseEqualsASCII("embed") || aAs.LowerCaseEqualsASCII("font") ||
+      aAs.LowerCaseEqualsASCII("frame") || aAs.LowerCaseEqualsASCII("iframe") ||
+      aAs.LowerCaseEqualsASCII("image") ||
+      aAs.LowerCaseEqualsASCII("manifest") ||
+      aAs.LowerCaseEqualsASCII("object") ||
+      aAs.LowerCaseEqualsASCII("report") || aAs.LowerCaseEqualsASCII("style") ||
+      aAs.LowerCaseEqualsASCII("track") || aAs.LowerCaseEqualsASCII("video") ||
+      aAs.LowerCaseEqualsASCII("webidentity") ||
+      aAs.LowerCaseEqualsASCII("xslt"));
+}
+
+bool CheckPreloadAttrs(const nsAttrValue& aAs, const nsAString& aType,
+                       const nsAString& aMedia,
+                       mozilla::dom::Document* aDocument) {
+  nsContentPolicyType policyType = AsValueToContentPolicy(aAs);
+  if (policyType == nsIContentPolicy::TYPE_INVALID) {
+    return false;
+  }
+
+  // Check if media attribute is valid.
+  if (!aMedia.IsEmpty()) {
+    RefPtr<mozilla::dom::MediaList> mediaList =
+        mozilla::dom::MediaList::Create(NS_ConvertUTF16toUTF8(aMedia));
+    if (!mediaList->Matches(*aDocument)) {
+      return false;
+    }
+  }
+
+  if (aType.IsEmpty()) {
+    return true;
+  }
+
+  if (policyType == nsIContentPolicy::TYPE_INTERNAL_FETCH_PRELOAD) {
+    return true;
+  }
+
+  nsAutoString type(aType);
+  ToLowerCase(type);
+  if (policyType == nsIContentPolicy::TYPE_MEDIA) {
+    if (aAs.GetEnumValue() == DESTINATION_TRACK) {
+      return type.EqualsASCII("text/vtt");
+    }
+    Maybe<MediaContainerType> mimeType = MakeMediaContainerType(aType);
+    if (!mimeType) {
+      return false;
+    }
+    DecoderDoctorDiagnostics diagnostics;
+    CanPlayStatus status =
+        DecoderTraits::CanHandleContainerType(*mimeType, &diagnostics);
+    // Preload if this return CANPLAY_YES and CANPLAY_MAYBE.
+    return status != CANPLAY_NO;
+  }
+  if (policyType == nsIContentPolicy::TYPE_FONT) {
+    return IsFontMimeType(type);
+  }
+  if (policyType == nsIContentPolicy::TYPE_IMAGE) {
+    return imgLoader::SupportImageWithMimeType(
+        NS_ConvertUTF16toUTF8(type), AcceptedMimeTypes::IMAGES_AND_DOCUMENTS);
+  }
+  if (policyType == nsIContentPolicy::TYPE_SCRIPT) {
+    return nsContentUtils::IsJavascriptMIMEType(type);
+  }
+  if (policyType == nsIContentPolicy::TYPE_STYLESHEET) {
+    return type.EqualsASCII("text/css");
+  }
+  return false;
+}
+
+void WarnIgnoredPreload(const mozilla::dom::Document& aDoc, nsIURI& aURI) {
+  AutoTArray<nsString, 1> params;
+  {
+    nsCString uri = nsContentUtils::TruncatedURLForDisplay(&aURI);
+    AppendUTF8toUTF16(uri, *params.AppendElement());
+  }
+  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag, "DOM"_ns, &aDoc,
+                                  nsContentUtils::eDOM_PROPERTIES,
+                                  "PreloadIgnoredInvalidAttr", params);
+}
+
+nsresult HasRootDomain(const nsACString& aInput, const nsACString& aHost,
+                       bool* aResult) {
+  if (NS_WARN_IF(!aResult)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aResult = false;
+
+  // If the strings are the same, we obviously have a match.
+  if (aInput == aHost) {
+    *aResult = true;
+    return NS_OK;
+  }
+
+  // If aHost is not found, we know we do not have it as a root domain.
+  int32_t index = nsAutoCString(aInput).Find(aHost);
+  if (index == kNotFound) {
+    return NS_OK;
+  }
+
+  // Otherwise, we have aHost as our root domain iff the index of aHost is
+  // aHost.length subtracted from our length and (since we do not have an
+  // exact match) the character before the index is a dot or slash.
+  *aResult = index > 0 && (uint32_t)index == aInput.Length() - aHost.Length() &&
+             (aInput[index - 1] == '.' || aInput[index - 1] == '/');
+  return NS_OK;
+}
+
+void CheckForBrokenChromeURL(nsILoadInfo* aLoadInfo, nsIURI* aURI) {
+  if (!aURI) {
+    return;
+  }
+  nsAutoCString scheme;
+  aURI->GetScheme(scheme);
+  if (!scheme.EqualsLiteral("chrome") && !scheme.EqualsLiteral("resource")) {
+    return;
+  }
+  nsAutoCString host;
+  aURI->GetHost(host);
+  // Ignore test hits.
+  if (host.EqualsLiteral("mochitests") || host.EqualsLiteral("reftest")) {
+    return;
+  }
+
+  nsAutoCString filePath;
+  aURI->GetFilePath(filePath);
+  // Fluent likes checking for files everywhere and expects failure.
+  if (StringEndsWith(filePath, ".ftl"_ns)) {
+    return;
+  }
+
+  // Ignore fetches/xhrs, as they are frequently used in a way where
+  // non-existence is OK (ie with fallbacks). This risks false negatives (ie
+  // files that *should* be there but aren't) - which we accept for now.
+  ExtContentPolicy policy = aLoadInfo
+                                ? aLoadInfo->GetExternalContentPolicyType()
+                                : ExtContentPolicy::TYPE_OTHER;
+  if (policy == ExtContentPolicy::TYPE_FETCH ||
+      policy == ExtContentPolicy::TYPE_XMLHTTPREQUEST) {
+    return;
+  }
+
+  if (aLoadInfo) {
+    bool shouldSkipCheckForBrokenURLOrZeroSized;
+    MOZ_ALWAYS_SUCCEEDS(aLoadInfo->GetShouldSkipCheckForBrokenURLOrZeroSized(
+        &shouldSkipCheckForBrokenURLOrZeroSized));
+    if (shouldSkipCheckForBrokenURLOrZeroSized) {
+      return;
+    }
+  }
+
+  nsCString spec;
+  aURI->GetSpec(spec);
+
+#ifdef ANDROID
+  // Various toolkit files use this and are shipped on android, but
+  // info-pages.css and aboutLicense.css are not - bug 1808987
+  if (StringEndsWith(spec, "info-pages.css"_ns) ||
+      StringEndsWith(spec, "aboutLicense.css"_ns) ||
+      // Error page CSS is also missing: bug 1810039
+      StringEndsWith(spec, "aboutNetError.css"_ns) ||
+      StringEndsWith(spec, "aboutHttpsOnlyError.css"_ns) ||
+      StringEndsWith(spec, "error-pages.css"_ns) ||
+      // popup.css is used in a single mochitest: bug 1810577
+      StringEndsWith(spec, "/popup.css"_ns) ||
+      // Used by an extension installation test - bug 1809650
+      StringBeginsWith(spec, "resource://android/assets/web_extensions/"_ns)) {
+    return;
+  }
+#endif
+
+  // DTD files from gre may not exist when requested by tests.
+  if (StringBeginsWith(spec, "resource://gre/res/dtd/"_ns)) {
+    return;
+  }
+
+  // The background task machinery allows the caller to specify a JSM on the
+  // command line, which is then looked up in both app-specific and toolkit-wide
+  // locations.
+  if (spec.Find("backgroundtasks") != kNotFound) {
+    return;
+  }
+
+  if (xpc::IsInAutomation()) {
+#ifdef DEBUG
+    if (NS_IsMainThread()) {
+      nsCOMPtr<nsIXPConnect> xpc = nsIXPConnect::XPConnect();
+      Unused << xpc->DebugDumpJSStack(false, false, false);
+    }
+#endif
+    MOZ_CRASH_UNSAFE_PRINTF("Missing chrome or resource URLs: %s", spec.get());
+  } else {
+    printf_stderr("Missing chrome or resource URL: %s\n", spec.get());
+  }
+}
+
+bool IsCoepCredentiallessEnabled(bool aIsOriginTrialCoepCredentiallessEnabled) {
+  return StaticPrefs::
+             browser_tabs_remote_coep_credentialless_DoNotUseDirectly() ||
+         aIsOriginTrialCoepCredentiallessEnabled;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsNetUtil.h b/netwerk/base/nsNetUtil.h
new file mode 100644
index 0000000000..cc036fd697
--- /dev/null
+++ b/netwerk/base/nsNetUtil.h
@@ -0,0 +1,1068 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 sts=2 et cin: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsNetUtil_h__
+#define nsNetUtil_h__
+
+#include <functional>
+#include "mozilla/Maybe.h"
+#include "mozilla/ResultExtensions.h"
+#include "nsAttrValue.h"
+#include "nsCOMPtr.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsILoadGroup.h"
+#include "nsINestedURI.h"
+#include "nsINetUtil.h"
+#include "nsIRequest.h"
+#include "nsILoadInfo.h"
+#include "nsIIOService.h"
+#include "nsIURI.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/Services.h"
+#include "mozilla/Unused.h"
+#include "nsNetCID.h"
+#include "nsReadableUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+class nsIPrincipal;
+class nsIAsyncStreamCopier;
+class nsIAuthPrompt;
+class nsIAuthPrompt2;
+class nsIChannel;
+class nsIChannelPolicy;
+class nsICookieJarSettings;
+class nsIDownloadObserver;
+class nsIEventTarget;
+class nsIFileProtocolHandler;
+class nsIFileRandomAccessStream;
+class nsIHttpChannel;
+class nsIInputStream;
+class nsIInputStreamPump;
+class nsIInterfaceRequestor;
+class nsIOutputStream;
+class nsIParentChannel;
+class nsIPersistentProperties;
+class nsIProxyInfo;
+class nsIRandomAccessStream;
+class nsIRequestObserver;
+class nsISerialEventTarget;
+class nsIStreamListener;
+class nsIStreamLoader;
+class nsIStreamLoaderObserver;
+class nsIIncrementalStreamLoader;
+class nsIIncrementalStreamLoaderObserver;
+
+namespace mozilla {
+class Encoding;
+class OriginAttributes;
+class OriginTrials;
+namespace dom {
+class ClientInfo;
+class PerformanceStorage;
+class ServiceWorkerDescriptor;
+}  // namespace dom
+
+namespace ipc {
+class FileDescriptor;
+}  // namespace ipc
+
+}  // namespace mozilla
+
+template <class>
+class nsCOMPtr;
+template <typename>
+struct already_AddRefed;
+
+already_AddRefed<nsIIOService> do_GetIOService(nsresult* error = nullptr);
+
+already_AddRefed<nsINetUtil> do_GetNetUtil(nsresult* error = nullptr);
+
+// private little helper function... don't call this directly!
+nsresult net_EnsureIOService(nsIIOService** ios, nsCOMPtr<nsIIOService>& grip);
+
+nsresult NS_NewURI(nsIURI** aURI, const nsACString& spec,
+                   const char* charset = nullptr, nsIURI* baseURI = nullptr);
+
+nsresult NS_NewURI(nsIURI** result, const nsACString& spec,
+                   mozilla::NotNull<const mozilla::Encoding*> encoding,
+                   nsIURI* baseURI = nullptr);
+
+nsresult NS_NewURI(nsIURI** result, const nsAString& spec,
+                   const char* charset = nullptr, nsIURI* baseURI = nullptr);
+
+nsresult NS_NewURI(nsIURI** result, const nsAString& spec,
+                   mozilla::NotNull<const mozilla::Encoding*> encoding,
+                   nsIURI* baseURI = nullptr);
+
+nsresult NS_NewURI(nsIURI** result, const char* spec,
+                   nsIURI* baseURI = nullptr);
+
+nsresult NS_NewFileURI(
+    nsIURI** result, nsIFile* spec,
+    nsIIOService* ioService =
+        nullptr);  // pass in nsIIOService to optimize callers
+
+// Functions for adding additional encoding to a URL for compatibility with
+// Apple's NSURL class URLWithString method.
+//
+// @param aResult
+//        Out parameter for the encoded URL spec
+// @param aSpec
+//        The spec for the URL to be encoded
+nsresult NS_GetSpecWithNSURLEncoding(nsACString& aResult,
+                                     const nsACString& aSpec);
+// @param aResult
+//        Out parameter for the encoded URI
+// @param aSpec
+//        The spec for the URL to be encoded
+nsresult NS_NewURIWithNSURLEncoding(nsIURI** aResult, const nsACString& aSpec);
+
+// These methods will only mutate the URI if the ref of aInput doesn't already
+// match the ref we are trying to set.
+// If aInput has no ref, and we are calling NS_GetURIWithoutRef, or
+// NS_GetURIWithNewRef with an empty string, then aOutput will be the same
+// as aInput. The same is true if aRef is already equal to the ref of aInput.
+// This is OK because URIs are immutable and threadsafe.
+// If the URI doesn't support ref fragments aOutput will be the same as aInput.
+nsresult NS_GetURIWithNewRef(nsIURI* aInput, const nsACString& aRef,
+                             nsIURI** aOutput);
+nsresult NS_GetURIWithoutRef(nsIURI* aInput, nsIURI** aOutput);
+
+nsresult NS_GetSanitizedURIStringFromURI(nsIURI* aUri,
+                                         nsAString& aSanitizedSpec);
+
+/*
+ * How to create a new Channel, using NS_NewChannel,
+ * NS_NewChannelWithTriggeringPrincipal,
+ * NS_NewInputStreamChannel, NS_NewChannelInternal
+ * and it's variations:
+ *
+ * What specific API function to use:
+ * * The NS_NewChannelInternal functions should almost never be directly
+ *   called outside of necko code.
+ * * If possible, use NS_NewChannel() providing a loading *nsINode*
+ * * If no loading *nsINode* is available, try calling NS_NewChannel() providing
+ *   a loading *ClientInfo*.
+ * * If no loading *nsINode* or *ClientInfo* are available, call NS_NewChannel()
+ *   providing a loading *nsIPrincipal*.
+ * * Call NS_NewChannelWithTriggeringPrincipal if the triggeringPrincipal
+ *   is different from the loadingPrincipal.
+ * * Call NS_NewChannelInternal() providing aLoadInfo object in cases where
+ *   you already have loadInfo object, e.g in case of a channel redirect.
+ *
+ * @param aURI
+ *        nsIURI from which to make a channel
+ * @param aLoadingNode
+ * @param aLoadingPrincipal
+ * @param aTriggeringPrincipal
+ * @param aSecurityFlags
+ * @param aContentPolicyType
+ *        These will be used as values for the nsILoadInfo object on the
+ *        created channel. For details, see nsILoadInfo in nsILoadInfo.idl
+ *
+ * Please note, if you provide both a loadingNode and a loadingPrincipal,
+ * then loadingPrincipal must be equal to loadingNode->NodePrincipal().
+ * But less error prone is to just supply a loadingNode.
+ *
+ * Note, if you provide a loading ClientInfo its principal must match the
+ * loading principal.  Currently you must pass both as the loading principal
+ * may have additional mutable values like CSP on it.  In the future these
+ * will be removed from nsIPrincipal and the API can be changed to take just
+ * the loading ClientInfo.
+ *
+ * Keep in mind that URIs coming from a webpage should *never* use the
+ * systemPrincipal as the loadingPrincipal.
+ */
+nsresult NS_NewChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    const mozilla::Maybe<mozilla::dom::ClientInfo>& aLoadingClientInfo,
+    const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings = nullptr,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr, uint32_t aSandboxFlags = 0,
+    bool aSkipCheckForBrokenURLOrZeroSized = false);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, nsILoadInfo* aLoadInfo,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult /*NS_NewChannelWithNodeAndTriggeringPrincipal */
+NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsINode* aLoadingNode,
+    nsIPrincipal* aTriggeringPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings = nullptr,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannelWithTriggeringPrincipal(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    nsIPrincipal* aTriggeringPrincipal,
+    const mozilla::dom::ClientInfo& aLoadingClientInfo,
+    const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings = nullptr,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannel(
+    nsIChannel** outChannel, nsIURI* aUri, nsINode* aLoadingNode,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr, uint32_t aSandboxFlags = 0,
+    bool aSkipCheckForBrokenURLOrZeroSized = false);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannel(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings = nullptr,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr, uint32_t aSandboxFlags = 0,
+    bool aSkipCheckForBrokenURLOrZeroSized = false);
+
+// See NS_NewChannelInternal for usage and argument description
+nsresult NS_NewChannel(
+    nsIChannel** outChannel, nsIURI* aUri, nsIPrincipal* aLoadingPrincipal,
+    const mozilla::dom::ClientInfo& aLoadingClientInfo,
+    const mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor>& aController,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    nsICookieJarSettings* aCookieJarSettings = nullptr,
+    mozilla::dom::PerformanceStorage* aPerformanceStorage = nullptr,
+    nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL,
+    nsIIOService* aIoService = nullptr, uint32_t aSandboxFlags = 0,
+    bool aSkipCheckForBrokenURLOrZeroSized = false);
+
+nsresult NS_GetIsDocumentChannel(nsIChannel* aChannel, bool* aIsDocument);
+
+nsresult NS_MakeAbsoluteURI(nsACString& result, const nsACString& spec,
+                            nsIURI* baseURI);
+
+nsresult NS_MakeAbsoluteURI(char** result, const char* spec, nsIURI* baseURI);
+
+nsresult NS_MakeAbsoluteURI(nsAString& result, const nsAString& spec,
+                            nsIURI* baseURI);
+
+/**
+ * This function is a helper function to get a scheme's default port.
+ */
+int32_t NS_GetDefaultPort(const char* scheme,
+                          nsIIOService* ioService = nullptr);
+
+/**
+ * This function is a helper function to apply the ToAscii conversion
+ * to a string
+ */
+bool NS_StringToACE(const nsACString& idn, nsACString& result);
+
+/**
+ * This function is a helper function to get a protocol's default port if the
+ * URI does not specify a port explicitly. Returns -1 if this protocol has no
+ * concept of ports or if there was an error getting the port.
+ */
+int32_t NS_GetRealPort(nsIURI* aURI);
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri,
+    already_AddRefed<nsIInputStream> aStream, const nsACString& aContentType,
+    const nsACString& aContentCharset, nsILoadInfo* aLoadInfo);
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri,
+    already_AddRefed<nsIInputStream> aStream, const nsACString& aContentType,
+    const nsACString& aContentCharset, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType);
+
+nsresult NS_NewInputStreamChannel(nsIChannel** outChannel, nsIURI* aUri,
+                                  already_AddRefed<nsIInputStream> aStream,
+                                  nsIPrincipal* aLoadingPrincipal,
+                                  nsSecurityFlags aSecurityFlags,
+                                  nsContentPolicyType aContentPolicyType,
+                                  const nsACString& aContentType = ""_ns,
+                                  const nsACString& aContentCharset = ""_ns);
+
+nsresult NS_NewInputStreamChannelInternal(
+    nsIChannel** outChannel, nsIURI* aUri, const nsAString& aData,
+    const nsACString& aContentType, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsIPrincipal* aTriggeringPrincipal,
+    nsSecurityFlags aSecurityFlags, nsContentPolicyType aContentPolicyType,
+    bool aIsSrcdocChannel = false);
+
+nsresult NS_NewInputStreamChannelInternal(nsIChannel** outChannel, nsIURI* aUri,
+                                          const nsAString& aData,
+                                          const nsACString& aContentType,
+                                          nsILoadInfo* aLoadInfo,
+                                          bool aIsSrcdocChannel = false);
+
+nsresult NS_NewInputStreamChannel(nsIChannel** outChannel, nsIURI* aUri,
+                                  const nsAString& aData,
+                                  const nsACString& aContentType,
+                                  nsIPrincipal* aLoadingPrincipal,
+                                  nsSecurityFlags aSecurityFlags,
+                                  nsContentPolicyType aContentPolicyType,
+                                  bool aIsSrcdocChannel = false);
+
+nsresult NS_NewInputStreamPump(
+    nsIInputStreamPump** aResult, already_AddRefed<nsIInputStream> aStream,
+    uint32_t aSegsize = 0, uint32_t aSegcount = 0, bool aCloseWhenDone = false,
+    nsISerialEventTarget* aMainThreadTarget = nullptr);
+
+nsresult NS_NewLoadGroup(nsILoadGroup** result, nsIRequestObserver* obs);
+
+// Create a new nsILoadGroup that will match the given principal.
+nsresult NS_NewLoadGroup(nsILoadGroup** aResult, nsIPrincipal* aPrincipal);
+
+// Determine if the given loadGroup/principal pair will produce a principal
+// with similar permissions when passed to NS_NewChannel().  This checks for
+// things like making sure the browser element flag matches.  Without
+// an appropriate load group these values can be lost when getting the result
+// principal back out of the channel.  Null principals are also always allowed
+// as they do not have permissions to actually use the load group.
+bool NS_LoadGroupMatchesPrincipal(nsILoadGroup* aLoadGroup,
+                                  nsIPrincipal* aPrincipal);
+
+nsresult NS_NewDownloader(nsIStreamListener** result,
+                          nsIDownloadObserver* observer,
+                          nsIFile* downloadLocation = nullptr);
+
+nsresult NS_NewStreamLoader(nsIStreamLoader** result,
+                            nsIStreamLoaderObserver* observer,
+                            nsIRequestObserver* requestObserver = nullptr);
+
+nsresult NS_NewIncrementalStreamLoader(
+    nsIIncrementalStreamLoader** result,
+    nsIIncrementalStreamLoaderObserver* observer);
+
+nsresult NS_NewStreamLoaderInternal(
+    nsIStreamLoader** outStream, nsIURI* aUri,
+    nsIStreamLoaderObserver* aObserver, nsINode* aLoadingNode,
+    nsIPrincipal* aLoadingPrincipal, nsSecurityFlags aSecurityFlags,
+    nsContentPolicyType aContentPolicyType, nsILoadGroup* aLoadGroup = nullptr,
+    nsIInterfaceRequestor* aCallbacks = nullptr,
+    nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL);
+
+nsresult NS_NewStreamLoader(nsIStreamLoader** outStream, nsIURI* aUri,
+                            nsIStreamLoaderObserver* aObserver,
+                            nsINode* aLoadingNode,
+                            nsSecurityFlags aSecurityFlags,
+                            nsContentPolicyType aContentPolicyType,
+                            nsILoadGroup* aLoadGroup = nullptr,
+                            nsIInterfaceRequestor* aCallbacks = nullptr,
+                            nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL);
+
+nsresult NS_NewStreamLoader(nsIStreamLoader** outStream, nsIURI* aUri,
+                            nsIStreamLoaderObserver* aObserver,
+                            nsIPrincipal* aLoadingPrincipal,
+                            nsSecurityFlags aSecurityFlags,
+                            nsContentPolicyType aContentPolicyType,
+                            nsILoadGroup* aLoadGroup = nullptr,
+                            nsIInterfaceRequestor* aCallbacks = nullptr,
+                            nsLoadFlags aLoadFlags = nsIRequest::LOAD_NORMAL);
+
+nsresult NS_NewSyncStreamListener(nsIStreamListener** result,
+                                  nsIInputStream** stream);
+
+/**
+ * Implement the nsIChannel::Open(nsIInputStream**) method using the channel's
+ * AsyncOpen method.
+ *
+ * NOTE: Reading from the returned nsIInputStream may spin the current
+ * thread's event queue, which could result in any event being processed.
+ */
+nsresult NS_ImplementChannelOpen(nsIChannel* channel, nsIInputStream** result);
+
+nsresult NS_NewRequestObserverProxy(nsIRequestObserver** result,
+                                    nsIRequestObserver* observer,
+                                    nsISupports* context);
+
+nsresult NS_NewSimpleStreamListener(nsIStreamListener** result,
+                                    nsIOutputStream* sink,
+                                    nsIRequestObserver* observer = nullptr);
+
+nsresult NS_CheckPortSafety(int32_t port, const char* scheme,
+                            nsIIOService* ioService = nullptr);
+
+// Determine if this URI is using a safe port.
+nsresult NS_CheckPortSafety(nsIURI* uri);
+
+nsresult NS_NewProxyInfo(const nsACString& type, const nsACString& host,
+                         int32_t port, uint32_t flags, nsIProxyInfo** result);
+
+nsresult NS_GetFileProtocolHandler(nsIFileProtocolHandler** result,
+                                   nsIIOService* ioService = nullptr);
+
+nsresult NS_GetFileFromURLSpec(const nsACString& inURL, nsIFile** result,
+                               nsIIOService* ioService = nullptr);
+
+nsresult NS_GetURLSpecFromFile(nsIFile* file, nsACString& url,
+                               nsIIOService* ioService = nullptr);
+
+/**
+ * Converts the nsIFile to the corresponding URL string.
+ * Should only be called on files which are not directories,
+ * is otherwise identical to NS_GetURLSpecFromFile, but is
+ * usually more efficient.
+ * Warning: this restriction may not be enforced at runtime!
+ */
+nsresult NS_GetURLSpecFromActualFile(nsIFile* file, nsACString& url,
+                                     nsIIOService* ioService = nullptr);
+
+/**
+ * Converts the nsIFile to the corresponding URL string.
+ * Should only be called on files which are directories,
+ * is otherwise identical to NS_GetURLSpecFromFile, but is
+ * usually more efficient.
+ * Warning: this restriction may not be enforced at runtime!
+ */
+nsresult NS_GetURLSpecFromDir(nsIFile* file, nsACString& url,
+                              nsIIOService* ioService = nullptr);
+
+/**
+ * Obtains the referrer for a given channel.  This first tries to obtain the
+ * referrer from the property docshell.internalReferrer, and if that doesn't
+ * work and the channel is an nsIHTTPChannel, we check it's referrer property.
+ *
+ */
+void NS_GetReferrerFromChannel(nsIChannel* channel, nsIURI** referrer);
+
+nsresult NS_ParseRequestContentType(const nsACString& rawContentType,
+                                    nsCString& contentType,
+                                    nsCString& contentCharset);
+
+nsresult NS_ParseResponseContentType(const nsACString& rawContentType,
+                                     nsCString& contentType,
+                                     nsCString& contentCharset);
+
+nsresult NS_ExtractCharsetFromContentType(const nsACString& rawContentType,
+                                          nsCString& contentCharset,
+                                          bool* hadCharset,
+                                          int32_t* charsetStart,
+                                          int32_t* charsetEnd);
+
+nsresult NS_NewLocalFileInputStream(nsIInputStream** result, nsIFile* file,
+                                    int32_t ioFlags = -1, int32_t perm = -1,
+                                    int32_t behaviorFlags = 0);
+
+mozilla::Result<nsCOMPtr<nsIInputStream>, nsresult> NS_NewLocalFileInputStream(
+    nsIFile* file, int32_t ioFlags = -1, int32_t perm = -1,
+    int32_t behaviorFlags = 0);
+
+nsresult NS_NewLocalFileOutputStream(nsIOutputStream** result, nsIFile* file,
+                                     int32_t ioFlags = -1, int32_t perm = -1,
+                                     int32_t behaviorFlags = 0);
+
+mozilla::Result<nsCOMPtr<nsIOutputStream>, nsresult>
+NS_NewLocalFileOutputStream(nsIFile* file, int32_t ioFlags = -1,
+                            int32_t perm = -1, int32_t behaviorFlags = 0);
+
+nsresult NS_NewLocalFileOutputStream(nsIOutputStream** result,
+                                     const mozilla::ipc::FileDescriptor& fd);
+
+// returns a file output stream which can be QI'ed to nsISafeOutputStream.
+nsresult NS_NewAtomicFileOutputStream(nsIOutputStream** result, nsIFile* file,
+                                      int32_t ioFlags = -1, int32_t perm = -1,
+                                      int32_t behaviorFlags = 0);
+
+// returns a file output stream which can be QI'ed to nsISafeOutputStream.
+nsresult NS_NewSafeLocalFileOutputStream(nsIOutputStream** result,
+                                         nsIFile* file, int32_t ioFlags = -1,
+                                         int32_t perm = -1,
+                                         int32_t behaviorFlags = 0);
+
+nsresult NS_NewLocalFileRandomAccessStream(nsIRandomAccessStream** result,
+                                           nsIFile* file, int32_t ioFlags = -1,
+                                           int32_t perm = -1,
+                                           int32_t behaviorFlags = 0);
+
+mozilla::Result<nsCOMPtr<nsIRandomAccessStream>, nsresult>
+NS_NewLocalFileRandomAccessStream(nsIFile* file, int32_t ioFlags = -1,
+                                  int32_t perm = -1, int32_t behaviorFlags = 0);
+
+[[nodiscard]] nsresult NS_NewBufferedInputStream(
+    nsIInputStream** aResult, already_AddRefed<nsIInputStream> aInputStream,
+    uint32_t aBufferSize);
+
+mozilla::Result<nsCOMPtr<nsIInputStream>, nsresult> NS_NewBufferedInputStream(
+    already_AddRefed<nsIInputStream> aInputStream, uint32_t aBufferSize);
+
+// note: the resulting stream can be QI'ed to nsISafeOutputStream iff the
+// provided stream supports it.
+nsresult NS_NewBufferedOutputStream(
+    nsIOutputStream** aResult, already_AddRefed<nsIOutputStream> aOutputStream,
+    uint32_t aBufferSize);
+
+/**
+ * This function reads an inputStream and stores its content into a buffer. In
+ * general, you should avoid using this function because, it blocks the current
+ * thread until the operation is done.
+ * If the inputStream is async, the reading happens on an I/O thread.
+ *
+ * @param aInputStream the inputStream.
+ * @param aDest the destination buffer. if *aDest is null, it will be allocated
+ *              with the size of the written data. if aDest is not null, aCount
+ *              must greater than 0.
+ * @param aCount the amount of data to read. Use -1 if you want that all the
+ *               stream is read.
+ * @param aWritten this pointer will be used to store the number of data
+ *                 written in the buffer. If you don't need, pass nullptr.
+ */
+nsresult NS_ReadInputStreamToBuffer(nsIInputStream* aInputStream, void** aDest,
+                                    int64_t aCount,
+                                    uint64_t* aWritten = nullptr);
+
+/**
+ * See the comment for NS_ReadInputStreamToBuffer
+ */
+nsresult NS_ReadInputStreamToString(nsIInputStream* aInputStream,
+                                    nsACString& aDest, int64_t aCount,
+                                    uint64_t* aWritten = nullptr);
+
+nsresult NS_LoadPersistentPropertiesFromURISpec(
+    nsIPersistentProperties** outResult, const nsACString& aSpec);
+
+/**
+ * NS_QueryNotificationCallbacks implements the canonical algorithm for
+ * querying interfaces from a channel's notification callbacks.  It first
+ * searches the channel's notificationCallbacks attribute, and if the interface
+ * is not found there, then it inspects the notificationCallbacks attribute of
+ * the channel's loadGroup.
+ *
+ * Note: templatized only because nsIWebSocketChannel is currently not an
+ * nsIChannel.
+ */
+template <class T>
+inline void NS_QueryNotificationCallbacks(T* channel, const nsIID& iid,
+                                          void** result) {
+  MOZ_ASSERT(channel, "null channel");
+  *result = nullptr;
+
+  nsCOMPtr<nsIInterfaceRequestor> cbs;
+  mozilla::Unused << channel->GetNotificationCallbacks(getter_AddRefs(cbs));
+  if (cbs) cbs->GetInterface(iid, result);
+  if (!*result) {
+    // try load group's notification callbacks...
+    nsCOMPtr<nsILoadGroup> loadGroup;
+    mozilla::Unused << channel->GetLoadGroup(getter_AddRefs(loadGroup));
+    if (loadGroup) {
+      loadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));
+      if (cbs) cbs->GetInterface(iid, result);
+    }
+  }
+}
+
+// template helper:
+// Note: "class C" templatized only because nsIWebSocketChannel is currently not
+// an nsIChannel.
+
+template <class C, class T>
+inline void NS_QueryNotificationCallbacks(C* channel, nsCOMPtr<T>& result) {
+  NS_QueryNotificationCallbacks(channel, NS_GET_TEMPLATE_IID(T),
+                                getter_AddRefs(result));
+}
+
+/**
+ * Alternate form of NS_QueryNotificationCallbacks designed for use by
+ * nsIChannel implementations.
+ */
+inline void NS_QueryNotificationCallbacks(nsIInterfaceRequestor* callbacks,
+                                          nsILoadGroup* loadGroup,
+                                          const nsIID& iid, void** result) {
+  *result = nullptr;
+
+  if (callbacks) callbacks->GetInterface(iid, result);
+  if (!*result) {
+    // try load group's notification callbacks...
+    if (loadGroup) {
+      nsCOMPtr<nsIInterfaceRequestor> cbs;
+      loadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));
+      if (cbs) cbs->GetInterface(iid, result);
+    }
+  }
+}
+
+/**
+ * Returns true if channel is using Private Browsing, or false if not.
+ * Returns false if channel's callbacks don't implement nsILoadContext.
+ */
+bool NS_UsePrivateBrowsing(nsIChannel* channel);
+
+/**
+ * Returns true if the channel has visited any cross-origin URLs on any
+ * URLs that it was redirected through.
+ */
+bool NS_HasBeenCrossOrigin(nsIChannel* aChannel, bool aReport = false);
+
+/**
+ * Returns true if the channel has a safe method.
+ */
+bool NS_IsSafeMethodNav(nsIChannel* aChannel);
+
+// Unique first-party domain for separating the safebrowsing cookie.
+// Note if this value is changed, code in test_cookiejars_safebrowsing.js and
+// nsUrlClassifierHashCompleter.js should also be changed.
+#define NECKO_SAFEBROWSING_FIRST_PARTY_DOMAIN \
+  "safebrowsing.86868755-6b82-4842-b301-72671a0db32e.mozilla"
+
+// Unique first-party domain for separating about uri.
+#define ABOUT_URI_FIRST_PARTY_DOMAIN \
+  "about.ef2a7dd5-93bc-417f-a698-142c3116864f.mozilla"
+
+/**
+ * Wraps an nsIAuthPrompt so that it can be used as an nsIAuthPrompt2. This
+ * method is provided mainly for use by other methods in this file.
+ *
+ * *aAuthPrompt2 should be set to null before calling this function.
+ */
+void NS_WrapAuthPrompt(nsIAuthPrompt* aAuthPrompt,
+                       nsIAuthPrompt2** aAuthPrompt2);
+
+/**
+ * Gets an auth prompt from an interface requestor. This takes care of wrapping
+ * an nsIAuthPrompt so that it can be used as an nsIAuthPrompt2.
+ */
+void NS_QueryAuthPrompt2(nsIInterfaceRequestor* aCallbacks,
+                         nsIAuthPrompt2** aAuthPrompt);
+
+/**
+ * Gets an nsIAuthPrompt2 from a channel. Use this instead of
+ * NS_QueryNotificationCallbacks for better backwards compatibility.
+ */
+void NS_QueryAuthPrompt2(nsIChannel* aChannel, nsIAuthPrompt2** aAuthPrompt);
+
+/* template helper */
+template <class T>
+inline void NS_QueryNotificationCallbacks(nsIInterfaceRequestor* callbacks,
+                                          nsILoadGroup* loadGroup,
+                                          nsCOMPtr<T>& result) {
+  NS_QueryNotificationCallbacks(callbacks, loadGroup, NS_GET_TEMPLATE_IID(T),
+                                getter_AddRefs(result));
+}
+
+/* template helper */
+template <class T>
+inline void NS_QueryNotificationCallbacks(
+    const nsCOMPtr<nsIInterfaceRequestor>& aCallbacks,
+    const nsCOMPtr<nsILoadGroup>& aLoadGroup, nsCOMPtr<T>& aResult) {
+  NS_QueryNotificationCallbacks(aCallbacks.get(), aLoadGroup.get(), aResult);
+}
+
+/* template helper */
+template <class T>
+inline void NS_QueryNotificationCallbacks(const nsCOMPtr<nsIChannel>& aChannel,
+                                          nsCOMPtr<T>& aResult) {
+  NS_QueryNotificationCallbacks(aChannel.get(), aResult);
+}
+
+/**
+ * This function returns a nsIInterfaceRequestor instance that returns the
+ * same result as NS_QueryNotificationCallbacks when queried.  It is useful
+ * as the value for nsISocketTransport::securityCallbacks.
+ */
+nsresult NS_NewNotificationCallbacksAggregation(
+    nsIInterfaceRequestor* callbacks, nsILoadGroup* loadGroup,
+    nsIEventTarget* target, nsIInterfaceRequestor** result);
+
+nsresult NS_NewNotificationCallbacksAggregation(
+    nsIInterfaceRequestor* callbacks, nsILoadGroup* loadGroup,
+    nsIInterfaceRequestor** result);
+
+/**
+ * Helper function for testing online/offline state of the browser.
+ */
+bool NS_IsOffline();
+
+/**
+ * Helper functions for implementing nsINestedURI::innermostURI.
+ *
+ * Note that NS_DoImplGetInnermostURI is "private" -- call
+ * NS_ImplGetInnermostURI instead.
+ */
+nsresult NS_DoImplGetInnermostURI(nsINestedURI* nestedURI, nsIURI** result);
+
+nsresult NS_ImplGetInnermostURI(nsINestedURI* nestedURI, nsIURI** result);
+
+/**
+ * Helper function for testing whether the given URI, or any of its
+ * inner URIs, has all the given protocol flags.
+ */
+nsresult NS_URIChainHasFlags(nsIURI* uri, uint32_t flags, bool* result);
+
+/**
+ * Helper function for getting the innermost URI for a given URI.  The return
+ * value could be just the object passed in if it's not a nested URI.
+ */
+already_AddRefed<nsIURI> NS_GetInnermostURI(nsIURI* aURI);
+
+/**
+ * Helper function for getting the host name of the innermost URI for a given
+ * URI.  The return value could be the host name of the URI passed in if it's
+ * not a nested URI.
+ */
+inline nsresult NS_GetInnermostURIHost(nsIURI* aURI, nsACString& aHost) {
+  aHost.Truncate();
+
+  // This block is optimized in order to avoid the overhead of calling
+  // NS_GetInnermostURI() which incurs a lot of overhead in terms of
+  // AddRef/Release calls.
+  nsCOMPtr<nsINestedURI> nestedURI = do_QueryInterface(aURI);
+  if (nestedURI) {
+    // We have a nested URI!
+    nsCOMPtr<nsIURI> uri;
+    nsresult rv = nestedURI->GetInnermostURI(getter_AddRefs(uri));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    rv = uri->GetAsciiHost(aHost);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  } else {
+    // We have a non-nested URI!
+    nsresult rv = aURI->GetAsciiHost(aHost);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  return NS_OK;
+}
+
+/**
+ * Get the "final" URI for a channel.  This is either channel's load info
+ * resultPrincipalURI, if set, or GetOriginalURI.  In most cases (but not all)
+ * load info resultPrincipalURI, if set, corresponds to URI of the channel if
+ * it's required to represent the actual principal for the channel.
+ */
+nsresult NS_GetFinalChannelURI(nsIChannel* channel, nsIURI** uri);
+
+// NS_SecurityHashURI must return the same hash value for any two URIs that
+// compare equal according to NS_SecurityCompareURIs.  Unfortunately, in the
+// case of files, it's not clear we can do anything better than returning
+// the schemeHash, so hashing files degenerates to storing them in a list.
+uint32_t NS_SecurityHashURI(nsIURI* aURI);
+
+bool NS_SecurityCompareURIs(nsIURI* aSourceURI, nsIURI* aTargetURI,
+                            bool aStrictFileOriginPolicy);
+
+bool NS_URIIsLocalFile(nsIURI* aURI);
+
+// When strict file origin policy is enabled, SecurityCompareURIs will fail for
+// file URIs that do not point to the same local file. This call provides an
+// alternate file-specific origin check that allows target files that are
+// contained in the same directory as the source.
+//
+// https://developer.mozilla.org/en-US/docs/Same-origin_policy_for_file:_URIs
+bool NS_RelaxStrictFileOriginPolicy(nsIURI* aTargetURI, nsIURI* aSourceURI,
+                                    bool aAllowDirectoryTarget = false);
+
+bool NS_IsInternalSameURIRedirect(nsIChannel* aOldChannel,
+                                  nsIChannel* aNewChannel, uint32_t aFlags);
+
+bool NS_IsHSTSUpgradeRedirect(nsIChannel* aOldChannel, nsIChannel* aNewChannel,
+                              uint32_t aFlags);
+
+bool NS_ShouldRemoveAuthHeaderOnRedirect(nsIChannel* aOldChannel,
+                                         nsIChannel* aNewChannel,
+                                         uint32_t aFlags);
+
+nsresult NS_LinkRedirectChannels(uint64_t channelId,
+                                 nsIParentChannel* parentChannel,
+                                 nsIChannel** _result);
+
+/**
+ * Returns nsILoadInfo::EMBEDDER_POLICY_REQUIRE_CORP if `aHeader` is
+ * "require-corp" and nsILoadInfo::EMBEDDER_POLICY_NULL otherwise.
+ *
+ * See: https://mikewest.github.io/corpp/#parsing
+ */
+nsILoadInfo::CrossOriginEmbedderPolicy
+NS_GetCrossOriginEmbedderPolicyFromHeader(
+    const nsACString& aHeader, bool aIsOriginTrialCoepCredentiallessEnabled);
+
+/** Given the first (disposition) token from a Content-Disposition header,
+ * tell whether it indicates the content is inline or attachment
+ * @param aDispToken the disposition token from the content-disposition header
+ */
+uint32_t NS_GetContentDispositionFromToken(const nsAString& aDispToken);
+
+/** Determine the disposition (inline/attachment) of the content based on the
+ * Content-Disposition header
+ * @param aHeader the content-disposition header (full value)
+ * @param aChan the channel the header came from
+ */
+uint32_t NS_GetContentDispositionFromHeader(const nsACString& aHeader,
+                                            nsIChannel* aChan = nullptr);
+
+/** Extracts the filename out of a content-disposition header
+ * @param aFilename [out] The filename. Can be empty on error.
+ * @param aDisposition Value of a Content-Disposition header
+
+ */
+nsresult NS_GetFilenameFromDisposition(nsAString& aFilename,
+                                       const nsACString& aDisposition);
+
+/**
+ * Make sure Personal Security Manager is initialized
+ */
+void net_EnsurePSMInit();
+
+/**
+ * Test whether a URI is "about:blank".  |uri| must not be null
+ */
+bool NS_IsAboutBlank(nsIURI* uri);
+
+/**
+ * Test whether a URI is "about:srcdoc".  |uri| must not be null
+ */
+bool NS_IsAboutSrcdoc(nsIURI* uri);
+
+nsresult NS_GenerateHostPort(const nsCString& host, int32_t port,
+                             nsACString& hostLine);
+
+/**
+ * Sniff the content type for a given request or a given buffer.
+ *
+ * aSnifferType can be either NS_CONTENT_SNIFFER_CATEGORY or
+ * NS_DATA_SNIFFER_CATEGORY.  The function returns the sniffed content type
+ * in the aSniffedType argument.  This argument will not be modified if the
+ * content type could not be sniffed.
+ */
+void NS_SniffContent(const char* aSnifferType, nsIRequest* aRequest,
+                     const uint8_t* aData, uint32_t aLength,
+                     nsACString& aSniffedType);
+
+/**
+ * Whether the channel was created to load a srcdoc document.
+ * Note that view-source:about:srcdoc is classified as a srcdoc document by
+ * this function, which may not be applicable everywhere.
+ */
+bool NS_IsSrcdocChannel(nsIChannel* aChannel);
+
+/**
+ * Return true if the given string is a reasonable HTTP header value given the
+ * definition in RFC 2616 section 4.2.  Currently we don't pay the cost to do
+ * full, sctrict validation here since it would require fulling parsing the
+ * value.
+ */
+bool NS_IsReasonableHTTPHeaderValue(const nsACString& aValue);
+
+/**
+ * Return true if the given string is a valid HTTP token per RFC 2616 section
+ * 2.2.
+ */
+bool NS_IsValidHTTPToken(const nsACString& aToken);
+
+/**
+ * Strip the leading or trailing HTTP whitespace per fetch spec section 2.2.
+ */
+void NS_TrimHTTPWhitespace(const nsACString& aSource, nsACString& aDest);
+
+/**
+ * Return true if the given request must be upgraded to HTTPS.
+ * If |aResultCallback| is provided and the storage is not ready to read, the
+ * result will be sent back through the callback and |aWillCallback| will be
+ * true. Otherwiew, the result will be set to |aShouldUpgrade| and
+ * |aWillCallback| is false.
+ */
+nsresult NS_ShouldSecureUpgrade(
+    nsIURI* aURI, nsILoadInfo* aLoadInfo, nsIPrincipal* aChannelResultPrincipal,
+    bool aAllowSTS, const mozilla::OriginAttributes& aOriginAttributes,
+    bool& aShouldUpgrade, std::function<void(bool, nsresult)>&& aResultCallback,
+    bool& aWillCallback);
+
+/**
+ * Returns an https URI for channels that need to go through secure upgrades.
+ */
+nsresult NS_GetSecureUpgradedURI(nsIURI* aURI, nsIURI** aUpgradedURI);
+
+nsresult NS_CompareLoadInfoAndLoadContext(nsIChannel* aChannel);
+
+/**
+ * Return true if this channel should be classified by the URL classifier.
+ */
+bool NS_ShouldClassifyChannel(nsIChannel* aChannel);
+
+/**
+ * Helper to set the blocking reason on loadinfo of the channel.
+ */
+nsresult NS_SetRequestBlockingReason(nsIChannel* channel, uint32_t reason);
+nsresult NS_SetRequestBlockingReason(nsILoadInfo* loadInfo, uint32_t reason);
+nsresult NS_SetRequestBlockingReasonIfNull(nsILoadInfo* loadInfo,
+                                           uint32_t reason);
+
+namespace mozilla {
+namespace net {
+
+const static uint64_t kJS_MAX_SAFE_UINTEGER = +9007199254740991ULL;
+const static int64_t kJS_MIN_SAFE_INTEGER = -9007199254740991LL;
+const static int64_t kJS_MAX_SAFE_INTEGER = +9007199254740991LL;
+
+// Make sure a 64bit value can be captured by JS MAX_SAFE_INTEGER
+bool InScriptableRange(int64_t val);
+
+// Make sure a 64bit value can be captured by JS MAX_SAFE_INTEGER
+bool InScriptableRange(uint64_t val);
+
+/**
+ * Given the value of a single header field  (such as
+ * Content-Disposition and Content-Type) and the name of a parameter
+ * (e.g. filename, name, charset), returns the value of the parameter.
+ * See nsIMIMEHeaderParam.idl for more information.
+ *
+ * @param  aHeaderVal        a header string to get the value of a parameter
+ *                           from.
+ * @param  aParamName        the name of a MIME header parameter (e.g.
+ *                           filename, name, charset). If empty or nullptr,
+ *                           returns the first (possibly) _unnamed_ 'parameter'.
+ * @return the value of <code>aParamName</code> in Unichar(UTF-16).
+ */
+nsresult GetParameterHTTP(const nsACString& aHeaderVal, const char* aParamName,
+                          nsAString& aResult);
+
+/**
+ * Helper function that determines if channel is an HTTP POST.
+ *
+ * @param aChannel
+ *        The channel to test
+ *
+ * @return True if channel is an HTTP post.
+ */
+bool ChannelIsPost(nsIChannel* aChannel);
+
+/**
+ * Convenience functions for verifying nsIURI schemes. These functions simply
+ * wrap aURI->SchemeIs(), but specify the protocol as part of the function name.
+ */
+
+bool SchemeIsHTTP(nsIURI* aURI);
+bool SchemeIsHTTPS(nsIURI* aURI);
+bool SchemeIsJavascript(nsIURI* aURI);
+bool SchemeIsChrome(nsIURI* aURI);
+bool SchemeIsAbout(nsIURI* aURI);
+bool SchemeIsBlob(nsIURI* aURI);
+bool SchemeIsFile(nsIURI* aURI);
+bool SchemeIsData(nsIURI* aURI);
+bool SchemeIsViewSource(nsIURI* aURI);
+bool SchemeIsResource(nsIURI* aURI);
+bool SchemeIsFTP(nsIURI* aURI);
+
+struct LinkHeader {
+  nsString mHref;
+  nsString mRel;
+  nsString mTitle;
+  nsString mIntegrity;
+  nsString mSrcset;
+  nsString mSizes;
+  nsString mType;
+  nsString mMedia;
+  nsString mAnchor;
+  nsString mCrossOrigin;
+  nsString mReferrerPolicy;
+  nsString mAs;
+
+  LinkHeader();
+  void Reset();
+
+  nsresult NewResolveHref(nsIURI** aOutURI, nsIURI* aBaseURI) const;
+
+  bool operator==(const LinkHeader& rhs) const;
+};
+
+nsTArray<LinkHeader> ParseLinkHeader(const nsAString& aLinkData);
+
+enum ASDestination : uint8_t {
+  DESTINATION_INVALID,
+  DESTINATION_AUDIO,
+  DESTINATION_DOCUMENT,
+  DESTINATION_EMBED,
+  DESTINATION_FONT,
+  DESTINATION_IMAGE,
+  DESTINATION_MANIFEST,
+  DESTINATION_OBJECT,
+  DESTINATION_REPORT,
+  DESTINATION_SCRIPT,
+  DESTINATION_SERVICEWORKER,
+  DESTINATION_SHAREDWORKER,
+  DESTINATION_STYLE,
+  DESTINATION_TRACK,
+  DESTINATION_VIDEO,
+  DESTINATION_WORKER,
+  DESTINATION_XSLT,
+  DESTINATION_FETCH
+};
+
+void ParseAsValue(const nsAString& aValue, nsAttrValue& aResult);
+nsContentPolicyType AsValueToContentPolicy(const nsAttrValue& aValue);
+bool IsScriptLikeOrInvalid(const nsAString& aAs);
+
+bool CheckPreloadAttrs(const nsAttrValue& aAs, const nsAString& aType,
+                       const nsAString& aMedia,
+                       mozilla::dom::Document* aDocument);
+void WarnIgnoredPreload(const mozilla::dom::Document&, nsIURI&);
+
+/**
+ * Returns true if the |aInput| in is part of the root domain of |aHost|.
+ * For example, if |aInput| is "www.mozilla.org", and we pass in
+ * "mozilla.org" as |aHost|, this will return true.  It would return false
+ * the other way around.
+ *
+ * @param aInput The host to be analyzed.
+ * @param aHost  The host to compare to.
+ */
+nsresult HasRootDomain(const nsACString& aInput, const nsACString& aHost,
+                       bool* aResult);
+
+void CheckForBrokenChromeURL(nsILoadInfo* aLoadInfo, nsIURI* aURI);
+
+bool IsCoepCredentiallessEnabled(bool aIsOriginTrialCoepCredentiallessEnabled);
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // !nsNetUtil_h__
diff --git a/netwerk/base/nsNetworkInfoService.cpp b/netwerk/base/nsNetworkInfoService.cpp
new file mode 100644
index 0000000000..91354a80bb
--- /dev/null
+++ b/netwerk/base/nsNetworkInfoService.cpp
@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#if defined(XP_MACOSX) || defined(XP_LINUX)
+#  include <unistd.h>
+#elif defined(XP_WIN)
+#  include <winsock2.h>
+#endif
+
+#include "nsNetworkInfoService.h"
+
+#if defined(XP_MACOSX) || defined(XP_WIN) || defined(XP_LINUX)
+#  include "NetworkInfoServiceImpl.h"
+#else
+#  error "Unsupported platform for nsNetworkInfoService!  Check moz.build"
+#endif
+
+namespace mozilla::net {
+
+NS_IMPL_ISUPPORTS(nsNetworkInfoService, nsINetworkInfoService)
+
+nsNetworkInfoService::nsNetworkInfoService() = default;
+
+nsresult nsNetworkInfoService::Init() { return NS_OK; }
+
+nsresult nsNetworkInfoService::ListNetworkAddresses(
+    nsIListNetworkAddressesListener* aListener) {
+  nsresult rv;
+
+  AddrMapType addrMap;
+  rv = DoListAddresses(addrMap);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aListener->OnListNetworkAddressesFailed();
+    return NS_OK;
+  }
+
+  uint32_t addrCount = addrMap.Count();
+  nsTArray<nsCString> addrStrings;
+  if (!addrStrings.SetCapacity(addrCount, fallible)) {
+    aListener->OnListNetworkAddressesFailed();
+    return NS_OK;
+  }
+
+  for (const auto& data : addrMap.Values()) {
+    addrStrings.AppendElement(data);
+  }
+  aListener->OnListedNetworkAddresses(addrStrings);
+  return NS_OK;
+}
+
+// TODO: Bug 1275373: https://bugzilla.mozilla.org/show_bug.cgi?id=1275373
+// Use platform-specific implementation of DoGetHostname on Cocoa and Windows.
+static nsresult DoGetHostname(nsACString& aHostname) {
+  char hostnameBuf[256];
+  int result = gethostname(hostnameBuf, 256);
+  if (result == -1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Ensure that there is always a terminating NUL byte.
+  hostnameBuf[255] = '\0';
+
+  // Find the first '.', terminate string there.
+  char* dotLocation = strchr(hostnameBuf, '.');
+  if (dotLocation) {
+    *dotLocation = '\0';
+  }
+
+  if (strlen(hostnameBuf) == 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  aHostname.AssignASCII(hostnameBuf);
+  return NS_OK;
+}
+
+nsresult nsNetworkInfoService::GetHostname(nsIGetHostnameListener* aListener) {
+  nsresult rv;
+  nsCString hostnameStr;
+  rv = DoGetHostname(hostnameStr);
+  if (NS_FAILED(rv)) {
+    aListener->OnGetHostnameFailed();
+    return NS_OK;
+  }
+
+  aListener->OnGotHostname(hostnameStr);
+
+  return NS_OK;
+}
+
+}  // namespace mozilla::net
diff --git a/netwerk/base/nsNetworkInfoService.h b/netwerk/base/nsNetworkInfoService.h
new file mode 100644
index 0000000000..d7b449b96f
--- /dev/null
+++ b/netwerk/base/nsNetworkInfoService.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_nsNetworkInfoService_h
+#define mozilla_net_nsNetworkInfoService_h
+
+#include "nsISupportsImpl.h"
+
+#include "nsINetworkInfoService.h"
+
+#define NETWORKINFOSERVICE_CID                       \
+  {                                                  \
+    0x296d0900, 0xf8ef, 0x4df0, {                    \
+      0x9c, 0x35, 0xdb, 0x58, 0x62, 0xab, 0xc5, 0x8d \
+    }                                                \
+  }
+
+namespace mozilla {
+namespace net {
+
+class nsNetworkInfoService final : public nsINetworkInfoService {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSINETWORKINFOSERVICE
+
+  nsresult Init();
+
+  explicit nsNetworkInfoService();
+
+ private:
+  virtual ~nsNetworkInfoService() = default;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // mozilla_dom_nsNetworkInfoService_h
diff --git a/netwerk/base/nsPACMan.cpp b/netwerk/base/nsPACMan.cpp
new file mode 100644
index 0000000000..ccd5ef45a8
--- /dev/null
+++ b/netwerk/base/nsPACMan.cpp
@@ -0,0 +1,1009 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsPACMan.h"
+
+#include "mozilla/Preferences.h"
+#include "nsContentUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsIAuthPrompt.h"
+#include "nsIDHCPClient.h"
+#include "nsIHttpChannel.h"
+#include "nsIPrefBranch.h"
+#include "nsIPromptFactory.h"
+#include "nsIProtocolProxyService.h"
+#include "nsISystemProxySettings.h"
+#include "nsIOService.h"
+#include "nsNetUtil.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Result.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Telemetry.h"
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gProxyLog("proxy");
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gProxyLog, LogLevel::Debug, args)
+#define MOZ_WPAD_URL "http://wpad/wpad.dat"
+#define MOZ_DHCP_WPAD_OPTION 252
+
+// These pointers are declared in nsProtocolProxyService.cpp
+extern const char kProxyType_HTTPS[];
+extern const char kProxyType_DIRECT[];
+
+// The PAC thread does evaluations of both PAC files and
+// nsISystemProxySettings because they can both block the calling thread and we
+// don't want that on the main thread
+
+// Check to see if the underlying request was not an error page in the case of
+// a HTTP request.  For other types of channels, just return true.
+static bool HttpRequestSucceeded(nsIStreamLoader* loader) {
+  nsCOMPtr<nsIRequest> request;
+  loader->GetRequest(getter_AddRefs(request));
+
+  bool result = true;  // default to assuming success
+
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(request);
+  if (httpChannel) {
+    // failsafe
+    Unused << httpChannel->GetRequestSucceeded(&result);
+  }
+
+  return result;
+}
+
+// Read preference setting of extra JavaScript context heap size.
+// PrefService tends to be run on main thread, where ProxyAutoConfig runs on
+// ProxyResolution thread, so it's read here and passed to ProxyAutoConfig.
+static uint32_t GetExtraJSContextHeapSize() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  static int32_t extraSize = -1;
+
+  if (extraSize < 0) {
+    nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+    int32_t value;
+
+    if (prefs &&
+        NS_SUCCEEDED(prefs->GetIntPref(
+            "network.proxy.autoconfig_extra_jscontext_heap_size", &value))) {
+      LOG(("autoconfig_extra_jscontext_heap_size: %d\n", value));
+
+      extraSize = value;
+    }
+  }
+
+  return extraSize < 0 ? 0 : extraSize;
+}
+
+// Read network proxy type from preference
+// Used to verify that the preference is WPAD in nsPACMan::ConfigureWPAD
+nsresult GetNetworkProxyTypeFromPref(int32_t* type) {
+  *type = 0;
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+
+  if (!prefs) {
+    LOG(("Failed to get a preference service object"));
+    return NS_ERROR_FACTORY_NOT_REGISTERED;
+  }
+  nsresult rv = prefs->GetIntPref("network.proxy.type", type);
+  if (NS_FAILED(rv)) {
+    LOG(("Failed to retrieve network.proxy.type from prefs"));
+    return rv;
+  }
+  LOG(("network.proxy.type pref retrieved: %d\n", *type));
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+// The ExecuteCallback runnable is triggered by
+// nsPACManCallback::OnQueryComplete on the Main thread when its completion is
+// discovered on the pac thread
+
+class ExecuteCallback final : public Runnable {
+ public:
+  ExecuteCallback(nsPACManCallback* aCallback, nsresult status)
+      : Runnable("net::ExecuteCallback"),
+        mCallback(aCallback),
+        mStatus(status) {}
+
+  void SetPACString(const nsACString& pacString) { mPACString = pacString; }
+
+  void SetPACURL(const nsACString& pacURL) { mPACURL = pacURL; }
+
+  NS_IMETHOD Run() override {
+    mCallback->OnQueryComplete(mStatus, mPACString, mPACURL);
+    mCallback = nullptr;
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACManCallback> mCallback;
+  nsresult mStatus;
+  nsCString mPACString;
+  nsCString mPACURL;
+};
+
+//-----------------------------------------------------------------------------
+
+// The PAC thread must be deleted from the main thread, this class
+// acts as a proxy to do that, as the PACMan is reference counted
+// and might be destroyed on either thread
+
+class ShutdownThread final : public Runnable {
+ public:
+  explicit ShutdownThread(nsIThread* thread)
+      : Runnable("net::ShutdownThread"), mThread(thread) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    mThread->Shutdown();
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIThread> mThread;
+};
+
+// Dispatch this to wait until the PAC thread shuts down.
+
+class WaitForThreadShutdown final : public Runnable {
+ public:
+  explicit WaitForThreadShutdown(nsPACMan* aPACMan)
+      : Runnable("net::WaitForThreadShutdown"), mPACMan(aPACMan) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    if (mPACMan->mPACThread) {
+      mPACMan->mPACThread->Shutdown();
+      mPACMan->mPACThread = nullptr;
+    }
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+};
+
+//-----------------------------------------------------------------------------
+
+// PACLoadComplete allows the PAC thread to tell the main thread that
+// the javascript PAC file has been installed (perhaps unsuccessfully)
+// and that there is no reason to queue executions anymore
+
+class PACLoadComplete final : public Runnable {
+ public:
+  explicit PACLoadComplete(nsPACMan* aPACMan)
+      : Runnable("net::PACLoadComplete"), mPACMan(aPACMan) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    {
+      auto loader = mPACMan->mLoader.Lock();
+      loader.ref() = nullptr;
+    }
+    mPACMan->PostProcessPendingQ();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+};
+
+//-----------------------------------------------------------------------------
+
+// ConfigureWPADComplete allows the PAC thread to tell the main thread that
+// the URL for the PAC file has been found
+class ConfigureWPADComplete final : public Runnable {
+ public:
+  ConfigureWPADComplete(nsPACMan* aPACMan, const nsACString& aPACURISpec)
+      : Runnable("net::ConfigureWPADComplete"),
+        mPACMan(aPACMan),
+        mPACURISpec(aPACURISpec) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    mPACMan->AssignPACURISpec(mPACURISpec);
+    mPACMan->ContinueLoadingAfterPACUriKnown();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+  nsCString mPACURISpec;
+};
+
+//-----------------------------------------------------------------------------
+
+// ExecutePACThreadAction is used to proxy actions from the main
+// thread onto the PAC thread. There are 4 options: process the queue,
+// cancel the queue, query DHCP for the PAC option
+// and setup the javascript context with a new PAC file
+
+class ExecutePACThreadAction final : public Runnable {
+ public:
+  // by default we just process the queue
+  explicit ExecutePACThreadAction(nsPACMan* aPACMan)
+      : Runnable("net::ExecutePACThreadAction"),
+        mPACMan(aPACMan),
+        mCancel(false),
+        mCancelStatus(NS_OK),
+        mSetupPAC(false),
+        mExtraHeapSize(0),
+        mConfigureWPAD(false),
+        mShutdown(false) {}
+
+  void CancelQueue(nsresult status, bool aShutdown) {
+    mCancel = true;
+    mCancelStatus = status;
+    mShutdown = aShutdown;
+  }
+
+  void SetupPAC(const char* data, uint32_t dataLen, const nsACString& pacURI,
+                uint32_t extraHeapSize) {
+    mSetupPAC = true;
+    mSetupPACData.Assign(data, dataLen);
+    mSetupPACURI = pacURI;
+    mExtraHeapSize = extraHeapSize;
+  }
+
+  void ConfigureWPAD() { mConfigureWPAD = true; }
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+    if (mCancel) {
+      mPACMan->CancelPendingQ(mCancelStatus, mShutdown);
+      mCancel = false;
+      return NS_OK;
+    }
+
+    if (mSetupPAC) {
+      mSetupPAC = false;
+
+      nsCOMPtr<nsISerialEventTarget> target = mPACMan->GetNeckoTarget();
+      mPACMan->mPAC->ConfigurePAC(mSetupPACURI, mSetupPACData,
+                                  mPACMan->mIncludePath, mExtraHeapSize,
+                                  target);
+
+      RefPtr<PACLoadComplete> runnable = new PACLoadComplete(mPACMan);
+      mPACMan->Dispatch(runnable.forget());
+      return NS_OK;
+    }
+
+    if (mConfigureWPAD) {
+      nsAutoCString spec;
+      mConfigureWPAD = false;
+      mPACMan->ConfigureWPAD(spec);
+      RefPtr<ConfigureWPADComplete> runnable =
+          new ConfigureWPADComplete(mPACMan, spec);
+      mPACMan->Dispatch(runnable.forget());
+      return NS_OK;
+    }
+
+    mPACMan->ProcessPendingQ();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+
+  bool mCancel;
+  nsresult mCancelStatus;
+
+  bool mSetupPAC;
+  uint32_t mExtraHeapSize;
+  nsCString mSetupPACData;
+  nsCString mSetupPACURI;
+  bool mConfigureWPAD;
+  bool mShutdown;
+};
+
+//-----------------------------------------------------------------------------
+
+PendingPACQuery::PendingPACQuery(nsPACMan* pacMan, nsIURI* uri,
+                                 nsPACManCallback* callback, uint32_t flags,
+                                 bool mainThreadResponse)
+    : Runnable("net::PendingPACQuery"),
+      mPort(0),
+      mFlags(flags),
+      mPACMan(pacMan),
+      mCallback(callback),
+      mOnMainThreadOnly(mainThreadResponse) {
+  uri->GetAsciiSpec(mSpec);
+  uri->GetAsciiHost(mHost);
+  uri->GetScheme(mScheme);
+  uri->GetPort(&mPort);
+}
+
+void PendingPACQuery::Complete(nsresult status, const nsACString& pacString) {
+  if (!mCallback) return;
+  RefPtr<ExecuteCallback> runnable = new ExecuteCallback(mCallback, status);
+  runnable->SetPACString(pacString);
+  if (mOnMainThreadOnly) {
+    mPACMan->Dispatch(runnable.forget());
+  } else {
+    runnable->Run();
+  }
+}
+
+void PendingPACQuery::UseAlternatePACFile(const nsACString& pacURL) {
+  if (!mCallback) return;
+
+  RefPtr<ExecuteCallback> runnable = new ExecuteCallback(mCallback, NS_OK);
+  runnable->SetPACURL(pacURL);
+  if (mOnMainThreadOnly) {
+    mPACMan->Dispatch(runnable.forget());
+  } else {
+    runnable->Run();
+  }
+}
+
+NS_IMETHODIMP
+PendingPACQuery::Run() {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  mPACMan->PostQuery(this);
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+static bool sThreadLocalSetup = false;
+static uint32_t sThreadLocalIndex = 0xdeadbeef;  // out of range
+
+static const char* kPACIncludePath =
+    "network.proxy.autoconfig_url.include_path";
+
+nsPACMan::nsPACMan(nsISerialEventTarget* mainThreadEventTarget)
+    : NeckoTargetHolder(mainThreadEventTarget),
+      mLoader("nsPACMan::mLoader"),
+      mLoadPending(false),
+      mShutdown(false),
+      mLoadFailureCount(0),
+      mInProgress(false),
+      mAutoDetect(false),
+      mWPADOverDHCPEnabled(false),
+      mProxyConfigType(0) {
+  MOZ_ASSERT(NS_IsMainThread(), "pacman must be created on main thread");
+  mIncludePath = Preferences::GetBool(kPACIncludePath, false);
+  if (StaticPrefs::network_proxy_parse_pac_on_socket_process() &&
+      gIOService->SocketProcessReady()) {
+    mPAC = MakeUnique<RemoteProxyAutoConfig>();
+  } else {
+    mPAC = MakeUnique<ProxyAutoConfig>();
+    if (!sThreadLocalSetup) {
+      sThreadLocalSetup = true;
+      PR_NewThreadPrivateIndex(&sThreadLocalIndex, nullptr);
+    }
+    mPAC->SetThreadLocalIndex(sThreadLocalIndex);
+  }
+}
+
+nsPACMan::~nsPACMan() {
+  MOZ_ASSERT(mShutdown, "Shutdown must be called before dtor.");
+
+  if (mPACThread) {
+    if (NS_IsMainThread()) {
+      mPACThread->Shutdown();
+      mPACThread = nullptr;
+    } else {
+      RefPtr<ShutdownThread> runnable = new ShutdownThread(mPACThread);
+      Dispatch(runnable.forget());
+    }
+  }
+
+#ifdef DEBUG
+  {
+    auto loader = mLoader.Lock();
+    NS_ASSERTION(loader.ref() == nullptr, "pac man not shutdown properly");
+  }
+#endif
+
+  NS_ASSERTION(mPendingQ.isEmpty(), "pac man not shutdown properly");
+}
+
+void nsPACMan::Shutdown() {
+  MOZ_ASSERT(NS_IsMainThread(), "pacman must be shutdown on main thread");
+  if (mShutdown) {
+    return;
+  }
+
+  CancelExistingLoad();
+
+  if (mPACThread) {
+    PostCancelPendingQ(NS_ERROR_ABORT, /*aShutdown =*/true);
+
+    // Shutdown is initiated from an observer. We don't want to block the
+    // observer service on thread shutdown so we post a shutdown runnable that
+    // will run after we return instead.
+    RefPtr<WaitForThreadShutdown> runnable = new WaitForThreadShutdown(this);
+    Dispatch(runnable.forget());
+  }
+
+  mShutdown = true;
+}
+
+nsresult nsPACMan::DispatchToPAC(already_AddRefed<nsIRunnable> aEvent,
+                                 bool aSync) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsCOMPtr<nsIRunnable> e(aEvent);
+
+  if (mShutdown) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Lazily create the PAC thread. This method is main-thread only so we don't
+  // have to worry about threading issues here.
+  if (!mPACThread) {
+    MOZ_TRY(NS_NewNamedThread("ProxyResolution", getter_AddRefs(mPACThread)));
+    nsresult rv = mPAC->Init(mPACThread);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  if (aSync) {
+    return NS_DispatchAndSpinEventLoopUntilComplete(
+        "nsPACMan::DispatchToPAC"_ns, mPACThread, e.forget());
+  } else {
+    return mPACThread->Dispatch(e.forget());
+  }
+}
+
+nsresult nsPACMan::AsyncGetProxyForURI(nsIURI* uri, nsPACManCallback* callback,
+                                       uint32_t flags,
+                                       bool mainThreadResponse) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  if (mShutdown) return NS_ERROR_NOT_AVAILABLE;
+
+  // Maybe Reload PAC
+  if (!mPACURISpec.IsEmpty() && !mScheduledReload.IsNull() &&
+      TimeStamp::Now() > mScheduledReload) {
+    LOG(("nsPACMan::AsyncGetProxyForURI reload as scheduled\n"));
+
+    LoadPACFromURI(mAutoDetect ? ""_ns : mPACURISpec, false);
+  }
+
+  RefPtr<PendingPACQuery> query =
+      new PendingPACQuery(this, uri, callback, flags, mainThreadResponse);
+
+  if (IsPACURI(uri)) {
+    // deal with this directly instead of queueing it
+    query->Complete(NS_OK, ""_ns);
+    return NS_OK;
+  }
+
+  return DispatchToPAC(query.forget());
+}
+
+nsresult nsPACMan::PostQuery(PendingPACQuery* query) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+
+  if (mShutdown) {
+    query->Complete(NS_ERROR_NOT_AVAILABLE, ""_ns);
+    return NS_OK;
+  }
+
+  // add a reference to the query while it is in the pending list
+  RefPtr<PendingPACQuery> addref(query);
+  mPendingQ.insertBack(addref.forget().take());
+  ProcessPendingQ();
+  return NS_OK;
+}
+
+nsresult nsPACMan::LoadPACFromURI(const nsACString& aSpec) {
+  return LoadPACFromURI(aSpec, true);
+}
+
+nsresult nsPACMan::LoadPACFromURI(const nsACString& aSpec,
+                                  bool aResetLoadFailureCount) {
+  NS_ENSURE_STATE(!mShutdown);
+
+  nsCOMPtr<nsIStreamLoader> loader =
+      do_CreateInstance(NS_STREAMLOADER_CONTRACTID);
+  NS_ENSURE_STATE(loader);
+
+  LOG(("nsPACMan::LoadPACFromURI aSpec: %s, aResetLoadFailureCount: %s\n",
+       aSpec.BeginReading(), aResetLoadFailureCount ? "true" : "false"));
+
+  CancelExistingLoad();
+
+  {
+    auto locked = mLoader.Lock();
+    locked.ref() = loader.forget();
+  }
+  mPACURIRedirectSpec.Truncate();
+  mNormalPACURISpec.Truncate();  // set at load time
+  if (aResetLoadFailureCount) {
+    mLoadFailureCount = 0;
+  }
+  mAutoDetect = aSpec.IsEmpty();
+  mPACURISpec.Assign(aSpec);
+
+  // reset to Null
+  mScheduledReload = TimeStamp();
+
+  // if we're on the main thread here so we can get hold of prefs,
+  // we check that we have WPAD preffed on if we're auto-detecting
+  if (mAutoDetect && NS_IsMainThread()) {
+    nsresult rv = GetNetworkProxyTypeFromPref(&mProxyConfigType);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    if (mProxyConfigType != nsIProtocolProxyService::PROXYCONFIG_WPAD) {
+      LOG(
+          ("LoadPACFromURI - Aborting WPAD autodetection because the pref "
+           "doesn't match anymore"));
+      return NS_BINDING_ABORTED;
+    }
+  }
+  // Since we might get called from nsProtocolProxyService::Init, we need to
+  // post an event back to the main thread before we try to use the IO service.
+  //
+  // But, we need to flag ourselves as loading, so that we queue up any PAC
+  // queries the enter between now and when we actually load the PAC file.
+
+  if (!mLoadPending) {
+    nsCOMPtr<nsIRunnable> runnable = NewRunnableMethod(
+        "nsPACMan::StartLoading", this, &nsPACMan::StartLoading);
+    nsresult rv =
+        NS_IsMainThread()
+            ? Dispatch(runnable.forget())
+            : GetCurrentSerialEventTarget()->Dispatch(runnable.forget());
+    if (NS_FAILED(rv)) return rv;
+    mLoadPending = true;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsPACMan::GetPACFromDHCP(nsACString& aSpec) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  if (!mDHCPClient) {
+    LOG(
+        ("nsPACMan::GetPACFromDHCP DHCP option %d query failed because there "
+         "is no DHCP client available\n",
+         MOZ_DHCP_WPAD_OPTION));
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+  nsresult rv;
+  rv = mDHCPClient->GetOption(MOZ_DHCP_WPAD_OPTION, aSpec);
+  if (NS_FAILED(rv)) {
+    LOG((
+        "nsPACMan::GetPACFromDHCP DHCP option %d query failed with result %d\n",
+        MOZ_DHCP_WPAD_OPTION, (uint32_t)rv));
+  } else {
+    LOG(
+        ("nsPACMan::GetPACFromDHCP DHCP option %d query succeeded, finding PAC "
+         "URL %s\n",
+         MOZ_DHCP_WPAD_OPTION, aSpec.BeginReading()));
+  }
+  return rv;
+}
+
+nsresult nsPACMan::ConfigureWPAD(nsACString& aSpec) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+
+  if (mProxyConfigType != nsIProtocolProxyService::PROXYCONFIG_WPAD) {
+    LOG(
+        ("ConfigureWPAD - Aborting WPAD autodetection because the pref "
+         "doesn't match anymore"));
+    return NS_BINDING_ABORTED;
+  }
+
+  aSpec.Truncate();
+  if (mWPADOverDHCPEnabled) {
+    GetPACFromDHCP(aSpec);
+  }
+
+  if (aSpec.IsEmpty()) {
+    // We diverge from the WPAD spec here in that we don't walk the
+    // hosts's FQDN, stripping components until we hit a TLD.  Doing so
+    // is dangerous in the face of an incomplete list of TLDs, and TLDs
+    // get added over time.  We could consider doing only a single
+    // substitution of the first component, if that proves to help
+    // compatibility.
+    aSpec.AssignLiteral(MOZ_WPAD_URL);
+  }
+  return NS_OK;
+}
+
+void nsPACMan::AssignPACURISpec(const nsACString& aSpec) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  mPACURISpec.Assign(aSpec);
+}
+
+void nsPACMan::StartLoading() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  mLoadPending = false;
+
+  {
+    // CancelExistingLoad was called...
+    nsCOMPtr<nsIStreamLoader> loader;
+    {
+      auto locked = mLoader.Lock();
+      loader = locked.ref();
+    }
+    if (!loader) {
+      PostCancelPendingQ(NS_ERROR_ABORT);
+      return;
+    }
+  }
+
+  if (mAutoDetect) {
+    nsresult rv = GetNetworkProxyTypeFromPref(&mProxyConfigType);
+    if (NS_FAILED(rv)) {
+      NS_WARNING(
+          "Could not retrieve Network Proxy Type pref when auto-detecting "
+          "proxy. Halting.");
+      return;
+    }
+    RefPtr<ExecutePACThreadAction> wpadConfigurer =
+        new ExecutePACThreadAction(this);
+    wpadConfigurer->ConfigureWPAD();
+    DispatchToPAC(wpadConfigurer.forget());
+  } else {
+    ContinueLoadingAfterPACUriKnown();
+  }
+}
+
+void nsPACMan::ContinueLoadingAfterPACUriKnown() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsCOMPtr<nsIStreamLoader> loader;
+  {
+    auto locked = mLoader.Lock();
+    loader = locked.ref();
+  }
+
+  // CancelExistingLoad was called...
+  if (!loader) {
+    PostCancelPendingQ(NS_ERROR_ABORT);
+    return;
+  }
+  if (NS_SUCCEEDED(loader->Init(this, nullptr))) {
+    // Always hit the origin server when loading PAC.
+    nsCOMPtr<nsIIOService> ios = do_GetIOService();
+    if (ios) {
+      nsCOMPtr<nsIChannel> channel;
+      nsCOMPtr<nsIURI> pacURI;
+      NS_NewURI(getter_AddRefs(pacURI), mPACURISpec);
+
+      // NOTE: This results in GetProxyForURI being called
+      if (pacURI) {
+        nsresult rv = pacURI->GetSpec(mNormalPACURISpec);
+        MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+        NS_NewChannel(getter_AddRefs(channel), pacURI,
+                      nsContentUtils::GetSystemPrincipal(),
+                      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                      nsIContentPolicy::TYPE_OTHER,
+                      nullptr,  // nsICookieJarSettings
+                      nullptr,  // PerformanceStorage
+                      nullptr,  // aLoadGroup
+                      nullptr,  // aCallbacks
+                      nsIRequest::LOAD_NORMAL, ios);
+      } else {
+        LOG(("nsPACMan::StartLoading Failed pacspec uri conversion %s\n",
+             mPACURISpec.get()));
+      }
+
+      if (channel) {
+        // allow deprecated HTTP request from SystemPrincipal
+        nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+        loadInfo->SetAllowDeprecatedSystemRequests(true);
+        loadInfo->SetHttpsOnlyStatus(nsILoadInfo::HTTPS_ONLY_EXEMPT);
+
+        channel->SetLoadFlags(nsIRequest::LOAD_BYPASS_CACHE);
+        channel->SetNotificationCallbacks(this);
+        if (NS_SUCCEEDED(channel->AsyncOpen(loader))) return;
+      }
+    }
+  }
+
+  CancelExistingLoad();
+  PostCancelPendingQ(NS_ERROR_UNEXPECTED);
+}
+
+void nsPACMan::OnLoadFailure() {
+  int32_t minInterval = 5;    // 5 seconds
+  int32_t maxInterval = 300;  // 5 minutes
+
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (prefs) {
+    prefs->GetIntPref("network.proxy.autoconfig_retry_interval_min",
+                      &minInterval);
+    prefs->GetIntPref("network.proxy.autoconfig_retry_interval_max",
+                      &maxInterval);
+  }
+
+  int32_t interval = minInterval << mLoadFailureCount++;  // seconds
+  if (!interval || interval > maxInterval) interval = maxInterval;
+
+  mScheduledReload = TimeStamp::Now() + TimeDuration::FromSeconds(interval);
+
+  LOG(("OnLoadFailure: retry in %d seconds (%d fails)\n", interval,
+       (uint32_t)mLoadFailureCount));
+
+  // while we wait for the retry queued members should try direct
+  // even if that means fast failure.
+  PostCancelPendingQ(NS_ERROR_NOT_AVAILABLE);
+}
+
+void nsPACMan::CancelExistingLoad() {
+  nsCOMPtr<nsIStreamLoader> loader;
+  {
+    auto locked = mLoader.Lock();
+    loader.swap(*locked);
+  }
+  if (loader) {
+    nsCOMPtr<nsIRequest> request;
+    loader->GetRequest(getter_AddRefs(request));
+    if (request) {
+      request->Cancel(NS_ERROR_ABORT);
+    }
+  }
+}
+
+void nsPACMan::PostProcessPendingQ() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+  DispatchToPAC(pending.forget());
+}
+
+void nsPACMan::PostCancelPendingQ(nsresult status, bool aShutdown) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+  pending->CancelQueue(status, aShutdown);
+  DispatchToPAC(pending.forget());
+}
+
+void nsPACMan::CancelPendingQ(nsresult status, bool aShutdown) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  RefPtr<PendingPACQuery> query;
+
+  while (!mPendingQ.isEmpty()) {
+    query = dont_AddRef(mPendingQ.popLast());
+    query->Complete(status, ""_ns);
+  }
+
+  if (aShutdown) {
+    mPAC->Shutdown();
+  }
+}
+
+void nsPACMan::ProcessPendingQ() {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  while (ProcessPending()) {
+    ;
+  }
+
+  if (mShutdown) {
+    mPAC->Shutdown();
+  } else {
+    // do GC while the thread has nothing pending
+    mPAC->GC();
+  }
+}
+
+// returns true if progress was made by shortening the queue
+bool nsPACMan::ProcessPending() {
+  if (mPendingQ.isEmpty()) return false;
+
+  // queue during normal load, but if we are retrying a failed load then
+  // fast fail the queries
+  if (mInProgress || (IsLoading() && !mLoadFailureCount)) return false;
+
+  RefPtr<PendingPACQuery> query(dont_AddRef(mPendingQ.popFirst()));
+
+  // Having |mLoadFailureCount > 0| means we haven't had a sucessful PAC load
+  // yet. We should use DIRECT instead.
+  if (mShutdown || IsLoading() || mLoadFailureCount > 0) {
+    query->Complete(NS_ERROR_NOT_AVAILABLE, ""_ns);
+    return true;
+  }
+
+  nsAutoCString pacString;
+  bool completed = false;
+  mInProgress = true;
+  nsAutoCString PACURI;
+
+  // first we need to consider the system proxy changing the pac url
+  if (mSystemProxySettings &&
+      NS_SUCCEEDED(mSystemProxySettings->GetPACURI(PACURI)) &&
+      !PACURI.IsEmpty() && !PACURI.Equals(mPACURISpec)) {
+    query->UseAlternatePACFile(PACURI);
+    LOG(("Use PAC from system settings: %s\n", PACURI.get()));
+    completed = true;
+  }
+
+  // now try the system proxy settings for this particular url if
+  // PAC was not specified
+  if (!completed && mSystemProxySettings && PACURI.IsEmpty() &&
+      NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(
+          query->mSpec, query->mScheme, query->mHost, query->mPort,
+          pacString))) {
+    if (query->mFlags & nsIProtocolProxyService::RESOLVE_PREFER_SOCKS_PROXY &&
+        query->mFlags & nsIProtocolProxyService::RESOLVE_PREFER_HTTPS_PROXY) {
+      if (StringBeginsWith(pacString, nsDependentCString(kProxyType_DIRECT),
+                           nsCaseInsensitiveUTF8StringComparator)) {
+        // DIRECT indicates that system proxy settings are not configured to use
+        // SOCKS proxy. Try https proxy as a secondary preferrable proxy. This
+        // is mainly for websocket whose precedence is SOCKS > HTTPS > DIRECT.
+        NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(
+            query->mSpec, nsDependentCString(kProxyType_HTTPS), query->mHost,
+            query->mPort, pacString));
+      }
+    }
+    LOG(("Use proxy from system settings: %s\n", pacString.get()));
+    query->Complete(NS_OK, pacString);
+    completed = true;
+  }
+
+  // the systemproxysettings didn't complete the resolution. try via PAC
+  if (!completed) {
+    auto callback = [query(query)](nsresult aStatus,
+                                   const nsACString& aResult) {
+      LOG(("Use proxy from PAC: %s\n", PromiseFlatCString(aResult).get()));
+      query->Complete(aStatus, aResult);
+    };
+    mPAC->GetProxyForURIWithCallback(query->mSpec, query->mHost,
+                                     std::move(callback));
+  }
+
+  mInProgress = false;
+  return true;
+}
+
+NS_IMPL_ISUPPORTS(nsPACMan, nsIStreamLoaderObserver, nsIInterfaceRequestor,
+                  nsIChannelEventSink)
+
+NS_IMETHODIMP
+nsPACMan::OnStreamComplete(nsIStreamLoader* loader, nsISupports* context,
+                           nsresult status, uint32_t dataLen,
+                           const uint8_t* data) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  bool loadSucceeded = NS_SUCCEEDED(status) && HttpRequestSucceeded(loader);
+  {
+    auto locked = mLoader.Lock();
+    if (locked.ref() != loader) {
+      // If this happens, then it means that LoadPACFromURI was called more
+      // than once before the initial call completed.  In this case, status
+      // should be NS_ERROR_ABORT, and if so, then we know that we can and
+      // should delay any processing.
+      LOG(("OnStreamComplete: called more than once\n"));
+      if (status == NS_ERROR_ABORT) {
+        return NS_OK;
+      }
+    } else if (!loadSucceeded) {
+      // We have to clear the loader to indicate that we are not loading PAC
+      // currently.
+      // Note that we can only clear the loader when |loader| and |mLoader| are
+      // the same one.
+      locked.ref() = nullptr;
+    }
+  }
+
+  LOG(("OnStreamComplete: entry\n"));
+
+  if (loadSucceeded) {
+    // Get the URI spec used to load this PAC script.
+    nsAutoCString pacURI;
+    {
+      nsCOMPtr<nsIRequest> request;
+      loader->GetRequest(getter_AddRefs(request));
+      nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+      if (channel) {
+        nsCOMPtr<nsIURI> uri;
+        channel->GetURI(getter_AddRefs(uri));
+        if (uri) uri->GetAsciiSpec(pacURI);
+      }
+    }
+
+    nsCOMPtr<nsIProtocolProxyService> pps =
+        do_GetService(NS_PROTOCOLPROXYSERVICE_CONTRACTID);
+    MOZ_ASSERT(pps);
+    if (pps) {
+      pps->NotifyProxyConfigChangedInternal();
+    }
+
+    // We succeeded in loading the pac file using a bunch of interfaces that are
+    // main thread only.  Unfortunately, we have to initialize the instance of
+    // the PAC evaluator (NS_PROXYAUTOCONFIG_CONTRACTID) on the PAC thread,
+    // because that's where it will be used.
+    RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+    pending->SetupPAC(reinterpret_cast<const char*>(data), dataLen, pacURI,
+                      GetExtraJSContextHeapSize());
+    DispatchToPAC(pending.forget());
+
+    LOG(("OnStreamComplete: process the PAC contents\n"));
+
+    // Even if the PAC file could not be parsed, we did succeed in loading the
+    // data for it.
+    mLoadFailureCount = 0;
+  } else {
+    // We were unable to load the PAC file (presumably because of a network
+    // failure).  Try again a little later.
+    LOG(("OnStreamComplete: unable to load PAC, retry later\n"));
+    OnLoadFailure();
+  }
+
+  if (NS_SUCCEEDED(status)) {
+    PostProcessPendingQ();
+  } else {
+    PostCancelPendingQ(status);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPACMan::GetInterface(const nsIID& iid, void** result) {
+  // In case loading the PAC file requires authentication.
+  if (iid.Equals(NS_GET_IID(nsIAuthPrompt))) {
+    nsCOMPtr<nsIPromptFactory> promptFac =
+        do_GetService("@mozilla.org/prompter;1");
+    NS_ENSURE_TRUE(promptFac, NS_ERROR_NO_INTERFACE);
+    nsresult rv =
+        promptFac->GetPrompt(nullptr, iid, reinterpret_cast<void**>(result));
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_NO_INTERFACE;
+    }
+    return NS_OK;
+  }
+
+  // In case loading the PAC file results in a redirect.
+  if (iid.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    NS_ADDREF_THIS();
+    *result = static_cast<nsIChannelEventSink*>(this);
+    return NS_OK;
+  }
+
+  return NS_ERROR_NO_INTERFACE;
+}
+
+NS_IMETHODIMP
+nsPACMan::AsyncOnChannelRedirect(nsIChannel* oldChannel, nsIChannel* newChannel,
+                                 uint32_t flags,
+                                 nsIAsyncVerifyRedirectCallback* callback) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIURI> pacURI;
+  if (NS_FAILED((rv = newChannel->GetURI(getter_AddRefs(pacURI))))) return rv;
+
+  rv = pacURI->GetSpec(mPACURIRedirectSpec);
+  if (NS_FAILED(rv)) return rv;
+
+  LOG(("nsPACMan redirect from original %s to redirected %s\n",
+       mPACURISpec.get(), mPACURIRedirectSpec.get()));
+
+  // do not update mPACURISpec - that needs to stay as the
+  // configured URI so that we can determine when the config changes.
+  // However do track the most recent URI in the redirect change
+  // as mPACURIRedirectSpec so that URI can be allowed to bypass
+  // the proxy and actually fetch the pac file.
+
+  callback->OnRedirectVerifyCallback(NS_OK);
+  return NS_OK;
+}
+
+nsresult nsPACMan::Init(nsISystemProxySettings* systemProxySettings) {
+  mSystemProxySettings = systemProxySettings;
+  mDHCPClient = do_GetService(NS_DHCPCLIENT_CONTRACTID);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsPACMan.h b/netwerk/base/nsPACMan.h
new file mode 100644
index 0000000000..dd7d6edb8c
--- /dev/null
+++ b/netwerk/base/nsPACMan.h
@@ -0,0 +1,295 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsPACMan_h__
+#define nsPACMan_h__
+
+#include "mozilla/Atomics.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/DataMutex.h"
+#include "mozilla/LinkedList.h"
+#include "mozilla/Logging.h"
+#include "mozilla/net/NeckoTargetHolder.h"
+#include "mozilla/TimeStamp.h"
+#include "nsCOMPtr.h"
+#include "nsIChannelEventSink.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIStreamLoader.h"
+#include "nsThreadUtils.h"
+#include "nsIURI.h"
+#include "nsString.h"
+#include "ProxyAutoConfig.h"
+
+class nsISystemProxySettings;
+class nsIDHCPClient;
+class nsIThread;
+
+namespace mozilla {
+namespace net {
+
+class nsPACMan;
+class WaitForThreadShutdown;
+
+/**
+ * This class defines a callback interface used by AsyncGetProxyForURI.
+ */
+class NS_NO_VTABLE nsPACManCallback : public nsISupports {
+ public:
+  /**
+   * This method is invoked on the same thread that called AsyncGetProxyForURI.
+   *
+   * @param status
+   *        This parameter indicates whether or not the PAC query succeeded.
+   * @param pacString
+   *        This parameter holds the value of the PAC string.  It is empty when
+   *        status is a failure code.
+   * @param newPACURL
+   *        This parameter holds the URL of a new PAC file that should be loaded
+   *        before the query is evaluated again. At least one of pacString and
+   *        newPACURL should be 0 length.
+   */
+  virtual void OnQueryComplete(nsresult status, const nsACString& pacString,
+                               const nsACString& newPACURL) = 0;
+};
+
+class PendingPACQuery final : public Runnable,
+                              public LinkedListElement<PendingPACQuery> {
+ public:
+  PendingPACQuery(nsPACMan* pacMan, nsIURI* uri, nsPACManCallback* callback,
+                  uint32_t flags, bool mainThreadResponse);
+
+  // can be called from either thread
+  void Complete(nsresult status, const nsACString& pacString);
+  void UseAlternatePACFile(const nsACString& pacURL);
+
+  nsCString mSpec;
+  nsCString mScheme;
+  nsCString mHost;
+  int32_t mPort;
+  uint32_t mFlags;
+
+  NS_IMETHOD Run(void) override; /* Runnable */
+
+ private:
+  nsPACMan* mPACMan;  // weak reference
+
+ private:
+  RefPtr<nsPACManCallback> mCallback;
+  bool mOnMainThreadOnly;
+};
+
+/**
+ * This class provides an abstraction layer above the PAC thread.  The methods
+ * defined on this class are intended to be called on the main thread only.
+ */
+
+class nsPACMan final : public nsIStreamLoaderObserver,
+                       public nsIInterfaceRequestor,
+                       public nsIChannelEventSink,
+                       public NeckoTargetHolder {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  explicit nsPACMan(nsISerialEventTarget* mainThreadEventTarget);
+
+  /**
+   * This method may be called to shutdown the PAC manager.  Any async queries
+   * that have not yet completed will either finish normally or be canceled by
+   * the time this method returns.
+   */
+  void Shutdown();
+
+  /**
+   * This method queries a PAC result asynchronously.  The callback runs on the
+   * calling thread.  If the PAC file has not yet been loaded, then this method
+   * will queue up the request, and complete it once the PAC file has been
+   * loaded.
+   *
+   * @param uri
+   *        The URI to query.
+   * @param callback
+   *        The callback to run once the PAC result is available.
+   * @param flags
+   *        A bit-wise combination of the RESOLVE_ flags defined above.  Pass
+   *        0 to specify the default behavior.
+   * @param mustCallbackOnMainThread
+   *        If set to false the callback can be made from the PAC thread
+   */
+  nsresult AsyncGetProxyForURI(nsIURI* uri, nsPACManCallback* callback,
+                               uint32_t flags, bool mainThreadResponse);
+
+  /**
+   * This method may be called to reload the PAC file.  While we are loading
+   * the PAC file, any asynchronous PAC queries will be queued up to be
+   * processed once the PAC file finishes loading.
+   *
+   * @param aSpec
+   *        The non normalized uri spec of this URI used for comparison with
+   *        system proxy settings to determine if the PAC uri has changed.
+   */
+  nsresult LoadPACFromURI(const nsACString& aSpec);
+
+  /**
+   * Returns true if we are currently loading the PAC file.
+   */
+  bool IsLoading() {
+    auto loader = mLoader.Lock();
+    return loader.ref() != nullptr;
+  }
+
+  /**
+   * Returns true if the given URI matches the URI of our PAC file or the
+   * URI it has been redirected to. In the case of a chain of redirections
+   * only the current one being followed and the original are considered
+   * becuase this information is used, respectively, to determine if we
+   * should bypass the proxy (to fetch the pac file) or if the pac
+   * configuration has changed (and we should reload the pac file)
+   */
+  bool IsPACURI(const nsACString& spec) {
+    return mPACURISpec.Equals(spec) || mPACURIRedirectSpec.Equals(spec) ||
+           mNormalPACURISpec.Equals(spec);
+  }
+
+  bool IsPACURI(nsIURI* uri) {
+    if (mPACURISpec.IsEmpty() && mPACURIRedirectSpec.IsEmpty()) {
+      return false;
+    }
+
+    nsAutoCString tmp;
+    nsresult rv = uri->GetSpec(tmp);
+    if (NS_FAILED(rv)) {
+      return false;
+    }
+
+    return IsPACURI(tmp);
+  }
+
+  bool IsUsingWPAD() { return mAutoDetect; }
+
+  nsresult Init(nsISystemProxySettings*);
+  static nsPACMan* sInstance;
+
+  // PAC thread operations only
+  void ProcessPendingQ();
+  void CancelPendingQ(nsresult, bool aShutdown);
+
+  void SetWPADOverDHCPEnabled(bool aValue) { mWPADOverDHCPEnabled = aValue; }
+
+ private:
+  NS_DECL_NSISTREAMLOADEROBSERVER
+  NS_DECL_NSIINTERFACEREQUESTOR
+  NS_DECL_NSICHANNELEVENTSINK
+
+  friend class PendingPACQuery;
+  friend class PACLoadComplete;
+  friend class ConfigureWPADComplete;
+  friend class ExecutePACThreadAction;
+  friend class WaitForThreadShutdown;
+  friend class TestPACMan;
+
+  ~nsPACMan();
+
+  /**
+   * Cancel any existing load if any.
+   */
+  void CancelExistingLoad();
+
+  /**
+   * Start loading the PAC file.
+   */
+  void StartLoading();
+
+  /**
+   * Continue loading the PAC file.
+   */
+  void ContinueLoadingAfterPACUriKnown();
+
+  /**
+   * This method may be called to reload the PAC file.  While we are loading
+   * the PAC file, any asynchronous PAC queries will be queued up to be
+   * processed once the PAC file finishes loading.
+   *
+   * @param aSpec
+   *        The non normalized uri spec of this URI used for comparison with
+   *        system proxy settings to determine if the PAC uri has changed.
+   * @param aResetLoadFailureCount
+   *        A flag saying whether the exponential back-off for attempting to
+   * reload the PAC should be reset.
+   */
+  nsresult LoadPACFromURI(const nsACString& aSpec, bool aResetLoadFailureCount);
+
+  /**
+   * Reload the PAC file if there is reason to.
+   */
+  void MaybeReloadPAC();
+
+  /**
+   * Called when we fail to load the PAC file.
+   */
+  void OnLoadFailure();
+
+  /**
+   * PostQuery() only runs on the PAC thread and it is used to
+   * place a pendingPACQuery into the queue and potentially
+   * execute the queue if it was otherwise empty
+   */
+  nsresult PostQuery(PendingPACQuery* query);
+
+  // Having found the PAC URI on the PAC thread, copy it to a string which
+  // can be altered on the main thread.
+  void AssignPACURISpec(const nsACString& aSpec);
+
+  // PAC thread operations only
+  void PostProcessPendingQ();
+  void PostCancelPendingQ(nsresult, bool aShutdown = false);
+  bool ProcessPending();
+  nsresult GetPACFromDHCP(nsACString& aSpec);
+  nsresult ConfigureWPAD(nsACString& aSpec);
+
+ private:
+  /**
+   * Dispatches a runnable to the PAC processing thread. Handles lazy
+   * instantiation of the thread.
+   *
+   * @param aEvent The event to disptach.
+   * @param aSync Whether or not this should be synchronous dispatch.
+   */
+  nsresult DispatchToPAC(already_AddRefed<nsIRunnable> aEvent,
+                         bool aSync = false);
+
+  UniquePtr<ProxyAutoConfigBase> mPAC;
+  nsCOMPtr<nsIThread> mPACThread;
+  nsCOMPtr<nsISystemProxySettings> mSystemProxySettings;
+  nsCOMPtr<nsIDHCPClient> mDHCPClient;
+
+  LinkedList<PendingPACQuery> mPendingQ; /* pac thread only */
+
+  // These specs are not nsIURI so that they can be used off the main thread.
+  // The non-normalized versions are directly from the configuration, the
+  // normalized version has been extracted from an nsIURI
+  nsCString mPACURISpec;
+  nsCString mPACURIRedirectSpec;
+  nsCString mNormalPACURISpec;
+
+  DataMutex<nsCOMPtr<nsIStreamLoader>> mLoader;
+  bool mLoadPending;
+  Atomic<bool, Relaxed> mShutdown;
+  TimeStamp mScheduledReload;
+  Atomic<uint32_t, Relaxed> mLoadFailureCount;
+
+  bool mInProgress;
+  bool mIncludePath;
+  bool mAutoDetect;
+  bool mWPADOverDHCPEnabled;
+  int32_t mProxyConfigType;
+};
+
+extern LazyLogModule gProxyLog;
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsPACMan_h__
diff --git a/netwerk/base/nsPISocketTransportService.idl b/netwerk/base/nsPISocketTransportService.idl
new file mode 100644
index 0000000000..e7c8ac5a60
--- /dev/null
+++ b/netwerk/base/nsPISocketTransportService.idl
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISocketTransportService.idl"
+
+/**
+ * This is a private interface used by the internals of the networking library.
+ * It will never be frozen.  Do not use it in external code.
+ */
+[builtinclass, scriptable, uuid(18f73bf1-b35b-4b7b-aa9a-11bcbdbc389c)]
+interface nsPISocketTransportService : nsIRoutedSocketTransportService
+{
+  /**
+   * init/shutdown routines.
+   */
+  void init();
+  void shutdown(in bool aXpcomShutdown);
+
+  /**
+   * controls the TCP sender window clamp
+   */
+  readonly attribute long sendBufferSize;
+
+  /**
+   * Controls whether the socket transport service is offline.
+   * Setting it offline will cause non-local socket detachment.
+   */
+  attribute boolean offline;
+
+  /**
+   * Controls the default timeout (in seconds) for sending keepalive probes.
+   */
+  readonly attribute long keepaliveIdleTime;
+
+  /**
+   * Controls the default interval (in seconds) between retrying keepalive probes.
+   */
+  readonly attribute long keepaliveRetryInterval;
+
+  /**
+   * Controls the default retransmission count for keepalive probes.
+   */
+  readonly attribute long keepaliveProbeCount;
+};
+
+%{C++
+/*
+ * I/O activity observer topic. Sends out information about the
+ * amount of data we're sending/receiving via sockets and disk files.
+ *
+ * Activated via the "io.activity.enabled" preference.
+ */
+#define NS_IO_ACTIVITY "io-activity"
+
+
+%}
diff --git a/netwerk/base/nsPreloadedStream.cpp b/netwerk/base/nsPreloadedStream.cpp
new file mode 100644
index 0000000000..cd7a7e79d2
--- /dev/null
+++ b/netwerk/base/nsPreloadedStream.cpp
@@ -0,0 +1,148 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsPreloadedStream.h"
+#include "nsIRunnable.h"
+
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsPreloadedStream, nsIInputStream, nsIAsyncInputStream,
+                  nsIInputStreamCallback)
+
+nsPreloadedStream::nsPreloadedStream(nsIAsyncInputStream* aStream,
+                                     const char* data, uint32_t datalen)
+    : mStream(aStream),
+      mOffset(0),
+      mLen(datalen),
+      mCallback("nsPreloadedStream") {
+  mBuf = (char*)moz_xmalloc(datalen);
+  memcpy(mBuf, data, datalen);
+}
+
+nsPreloadedStream::~nsPreloadedStream() { free(mBuf); }
+
+NS_IMETHODIMP
+nsPreloadedStream::Close() {
+  mLen = 0;
+  return mStream->Close();
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::Available(uint64_t* _retval) {
+  uint64_t avail = 0;
+
+  nsresult rv = mStream->Available(&avail);
+  if (NS_FAILED(rv)) return rv;
+  *_retval = avail + mLen;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::StreamStatus() { return mStream->StreamStatus(); }
+
+NS_IMETHODIMP
+nsPreloadedStream::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  if (!mLen) return mStream->Read(aBuf, aCount, _retval);
+
+  uint32_t toRead = std::min(mLen, aCount);
+  memcpy(aBuf, mBuf + mOffset, toRead);
+  mOffset += toRead;
+  mLen -= toRead;
+  *_retval = toRead;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                                uint32_t aCount, uint32_t* result) {
+  if (!mLen) return mStream->ReadSegments(aWriter, aClosure, aCount, result);
+
+  *result = 0;
+  while (mLen > 0 && aCount > 0) {
+    uint32_t toRead = std::min(mLen, aCount);
+    uint32_t didRead = 0;
+    nsresult rv;
+
+    rv = aWriter(this, aClosure, mBuf + mOffset, *result, toRead, &didRead);
+
+    if (NS_FAILED(rv)) return NS_OK;
+
+    *result += didRead;
+    mOffset += didRead;
+    mLen -= didRead;
+    aCount -= didRead;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::IsNonBlocking(bool* _retval) {
+  return mStream->IsNonBlocking(_retval);
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::CloseWithStatus(nsresult aStatus) {
+  mLen = 0;
+  return mStream->CloseWithStatus(aStatus);
+}
+
+class RunOnThread : public Runnable {
+ public:
+  RunOnThread(nsIAsyncInputStream* aStream, nsIInputStreamCallback* aCallback)
+      : Runnable("net::RunOnThread"), mStream(aStream), mCallback(aCallback) {}
+
+  virtual ~RunOnThread() = default;
+
+  NS_IMETHOD Run() override {
+    mCallback->OnInputStreamReady(mStream);
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIAsyncInputStream> mStream;
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+};
+
+NS_IMETHODIMP
+nsPreloadedStream::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
+                             uint32_t aRequestedCount,
+                             nsIEventTarget* aEventTarget) {
+  if (!mLen) {
+    {
+      auto lock = mCallback.Lock();
+      *lock = aCallback;
+    }
+    return mStream->AsyncWait(aCallback ? this : nullptr, aFlags,
+                              aRequestedCount, aEventTarget);
+  }
+
+  if (!aCallback) return NS_OK;
+
+  if (!aEventTarget) return aCallback->OnInputStreamReady(this);
+
+  nsCOMPtr<nsIRunnable> event = new RunOnThread(this, aCallback);
+  return aEventTarget->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+nsPreloadedStream::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  {
+    auto lock = mCallback.Lock();
+    callback = lock->forget();
+  }
+  if (callback) {
+    return callback->OnInputStreamReady(this);
+  }
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsPreloadedStream.h b/netwerk/base/nsPreloadedStream.h
new file mode 100644
index 0000000000..5c550b43e7
--- /dev/null
+++ b/netwerk/base/nsPreloadedStream.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This class allows you to prefix an existing nsIAsyncInputStream
+ * with a preloaded block of data known at construction time by wrapping the
+ * two data sources into a new nsIAsyncInputStream. Readers of the new
+ * stream initially see the preloaded data and when that has been exhausted
+ * they automatically read from the wrapped stream.
+ *
+ * It is used by nsHttpConnection when it has over buffered while reading from
+ * the HTTP input socket and accidentally consumed data that belongs to
+ * a different protocol via the HTTP Upgrade mechanism. That over-buffered
+ * data is preloaded together with the input socket to form the new input socket
+ * given to the new protocol handler.
+ */
+
+#ifndef nsPreloadedStream_h__
+#define nsPreloadedStream_h__
+
+#include "nsIAsyncInputStream.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/DataMutex.h"
+
+namespace mozilla {
+namespace net {
+
+class nsPreloadedStream final : public nsIAsyncInputStream,
+                                public nsIInputStreamCallback {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+
+  nsPreloadedStream(nsIAsyncInputStream* aStream, const char* data,
+                    uint32_t datalen);
+
+ private:
+  ~nsPreloadedStream();
+
+  nsCOMPtr<nsIAsyncInputStream> mStream;
+
+  char* mBuf;
+  uint32_t mOffset;
+  uint32_t mLen;
+
+  DataMutex<nsCOMPtr<nsIInputStreamCallback>> mCallback;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/nsProtocolProxyService.cpp b/netwerk/base/nsProtocolProxyService.cpp
new file mode 100644
index 0000000000..07a752a94f
--- /dev/null
+++ b/netwerk/base/nsProtocolProxyService.cpp
@@ -0,0 +1,2458 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 sts=2 et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/AutoRestore.h"
+
+#include "nsProtocolProxyService.h"
+#include "nsProxyInfo.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIIOService.h"
+#include "nsIObserverService.h"
+#include "nsIProtocolHandler.h"
+#include "nsIProtocolProxyCallback.h"
+#include "nsIChannel.h"
+#include "nsICancelable.h"
+#include "nsDNSService2.h"
+#include "nsPIDNSService.h"
+#include "nsIPrefBranch.h"
+#include "nsIPrefService.h"
+#include "nsContentUtils.h"
+#include "nsCRT.h"
+#include "nsThreadUtils.h"
+#include "nsQueryObject.h"
+#include "nsSOCKSIOLayer.h"
+#include "nsString.h"
+#include "nsNetUtil.h"
+#include "nsNetCID.h"
+#include "prnetdb.h"
+#include "nsPACMan.h"
+#include "nsProxyRelease.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/CondVar.h"
+#include "nsISystemProxySettings.h"
+#include "nsINetworkLinkService.h"
+#include "nsIHttpChannelInternal.h"
+#include "mozilla/dom/nsMixedContentBlocker.h"
+#include "mozilla/Logging.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Tokenizer.h"
+#include "mozilla/Unused.h"
+
+//----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+extern const char kProxyType_HTTP[];
+extern const char kProxyType_HTTPS[];
+extern const char kProxyType_SOCKS[];
+extern const char kProxyType_SOCKS4[];
+extern const char kProxyType_SOCKS5[];
+extern const char kProxyType_DIRECT[];
+extern const char kProxyType_PROXY[];
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gProxyLog, LogLevel::Debug, args)
+
+//----------------------------------------------------------------------------
+
+#define PROXY_PREF_BRANCH "network.proxy"
+#define PROXY_PREF(x) PROXY_PREF_BRANCH "." x
+
+//----------------------------------------------------------------------------
+
+// This structure is intended to be allocated on the stack
+struct nsProtocolInfo {
+  nsAutoCString scheme;
+  uint32_t flags = 0;
+  int32_t defaultPort = 0;
+};
+
+//----------------------------------------------------------------------------
+
+// Return the channel's proxy URI, or if it doesn't exist, the
+// channel's main URI.
+static nsresult GetProxyURI(nsIChannel* channel, nsIURI** aOut) {
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIURI> proxyURI;
+  nsCOMPtr<nsIHttpChannelInternal> httpChannel(do_QueryInterface(channel));
+  if (httpChannel) {
+    rv = httpChannel->GetProxyURI(getter_AddRefs(proxyURI));
+  }
+  if (!proxyURI) {
+    rv = channel->GetURI(getter_AddRefs(proxyURI));
+  }
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  proxyURI.forget(aOut);
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+nsProtocolProxyService::FilterLink::FilterLink(uint32_t p,
+                                               nsIProtocolProxyFilter* f)
+    : position(p), filter(f), channelFilter(nullptr) {
+  LOG(("nsProtocolProxyService::FilterLink::FilterLink %p, filter=%p", this,
+       f));
+}
+nsProtocolProxyService::FilterLink::FilterLink(
+    uint32_t p, nsIProtocolProxyChannelFilter* cf)
+    : position(p), filter(nullptr), channelFilter(cf) {
+  LOG(("nsProtocolProxyService::FilterLink::FilterLink %p, channel-filter=%p",
+       this, cf));
+}
+
+nsProtocolProxyService::FilterLink::~FilterLink() {
+  LOG(("nsProtocolProxyService::FilterLink::~FilterLink %p", this));
+}
+
+//-----------------------------------------------------------------------------
+
+// The nsPACManCallback portion of this implementation should be run
+// on the main thread - so call nsPACMan::AsyncGetProxyForURI() with
+// a true mainThreadResponse parameter.
+class nsAsyncResolveRequest final : public nsIRunnable,
+                                    public nsPACManCallback,
+                                    public nsICancelable {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  nsAsyncResolveRequest(nsProtocolProxyService* pps, nsIChannel* channel,
+                        uint32_t aResolveFlags,
+                        nsIProtocolProxyCallback* callback)
+      : mResolveFlags(aResolveFlags),
+        mPPS(pps),
+        mXPComPPS(pps),
+        mChannel(channel),
+        mCallback(callback) {
+    NS_ASSERTION(mCallback, "null callback");
+  }
+
+ private:
+  ~nsAsyncResolveRequest() {
+    if (!NS_IsMainThread()) {
+      // these xpcom pointers might need to be proxied back to the
+      // main thread to delete safely, but if this request had its
+      // callbacks called normally they will all be null and this is a nop
+
+      if (mChannel) {
+        NS_ReleaseOnMainThread("nsAsyncResolveRequest::mChannel",
+                               mChannel.forget());
+      }
+
+      if (mCallback) {
+        NS_ReleaseOnMainThread("nsAsyncResolveRequest::mCallback",
+                               mCallback.forget());
+      }
+
+      if (mProxyInfo) {
+        NS_ReleaseOnMainThread("nsAsyncResolveRequest::mProxyInfo",
+                               mProxyInfo.forget());
+      }
+
+      if (mXPComPPS) {
+        NS_ReleaseOnMainThread("nsAsyncResolveRequest::mXPComPPS",
+                               mXPComPPS.forget());
+      }
+    }
+  }
+
+  // Helper class to loop over all registered asynchronous filters.
+  // There is a cycle between nsAsyncResolveRequest and this class that
+  // is broken after the last filter has called back on this object.
+  class AsyncApplyFilters final : public nsIProxyProtocolFilterResult,
+                                  public nsIRunnable,
+                                  public nsICancelable {
+    // The reference counter is thread-safe, but the processing logic is
+    // considered single thread only.  We want the counter be thread safe,
+    // since this class can be released on a background thread.
+    NS_DECL_THREADSAFE_ISUPPORTS
+    NS_DECL_NSIPROXYPROTOCOLFILTERRESULT
+    NS_DECL_NSIRUNNABLE
+    NS_DECL_NSICANCELABLE
+
+    using Callback =
+        std::function<nsresult(nsAsyncResolveRequest*, nsIProxyInfo*, bool)>;
+
+    explicit AsyncApplyFilters(nsProtocolInfo& aInfo,
+                               Callback const& aCallback);
+    // This method starts the processing or filters.  If all of them
+    // answer synchronously (call back from within applyFilters) this method
+    // will return immediately and the returning result will carry return
+    // result of the callback given in constructor.
+    // This method is looping the registered filters (that have been copied
+    // locally) as long as an answer from a filter is obtained synchronously.
+    // Note that filters are processed serially to let them build a list
+    // of proxy info.
+    nsresult AsyncProcess(nsAsyncResolveRequest* aRequest);
+
+   private:
+    using FilterLink = nsProtocolProxyService::FilterLink;
+
+    virtual ~AsyncApplyFilters();
+    // Processes the next filter and loops until a filter is successfully
+    // called on or it has called back to us.
+    nsresult ProcessNextFilter();
+    // Called after the last filter has been processed (=called back or failed
+    // to be called on)
+    nsresult Finish();
+
+    nsProtocolInfo mInfo;
+    // This is nullified before we call back on the request or when
+    // Cancel() on this object has been called to break the cycle
+    // and signal to stop.
+    RefPtr<nsAsyncResolveRequest> mRequest;
+    Callback mCallback;
+    // A shallow snapshot of filters as they were registered at the moment
+    // we started to process filters for the given resolve request.
+    nsTArray<RefPtr<FilterLink>> mFiltersCopy;
+
+    nsTArray<RefPtr<FilterLink>>::index_type mNextFilterIndex;
+    // true when we are calling ProcessNextFilter() from inside AsyncProcess(),
+    // false otherwise.
+    bool mProcessingInLoop;
+    // true after a filter called back to us with a result, dropped to false
+    // just before we call a filter.
+    bool mFilterCalledBack;
+
+    // This keeps the initial value we pass to the first filter in line and also
+    // collects the result from each filter call.
+    nsCOMPtr<nsIProxyInfo> mProxyInfo;
+
+    // The logic is written as non-thread safe, assert single-thread usage.
+    nsCOMPtr<nsISerialEventTarget> mProcessingThread;
+  };
+
+  void EnsureResolveFlagsMatch() {
+    nsCOMPtr<nsProxyInfo> pi = do_QueryInterface(mProxyInfo);
+    if (!pi || pi->ResolveFlags() == mResolveFlags) {
+      return;
+    }
+
+    nsCOMPtr<nsIProxyInfo> proxyInfo =
+        pi->CloneProxyInfoWithNewResolveFlags(mResolveFlags);
+    mProxyInfo.swap(proxyInfo);
+  }
+
+ public:
+  nsresult ProcessLocally(nsProtocolInfo& info, nsIProxyInfo* pi,
+                          bool isSyncOK) {
+    SetResult(NS_OK, pi);
+
+    auto consumeFiltersResult = [isSyncOK](nsAsyncResolveRequest* ctx,
+                                           nsIProxyInfo* pi,
+                                           bool aCalledAsync) -> nsresult {
+      ctx->SetResult(NS_OK, pi);
+      if (isSyncOK || aCalledAsync) {
+        ctx->Run();
+        return NS_OK;
+      }
+
+      return ctx->DispatchCallback();
+    };
+
+    mAsyncFilterApplier = new AsyncApplyFilters(info, consumeFiltersResult);
+    // may call consumeFiltersResult() directly
+    return mAsyncFilterApplier->AsyncProcess(this);
+  }
+
+  void SetResult(nsresult status, nsIProxyInfo* pi) {
+    mStatus = status;
+    mProxyInfo = pi;
+  }
+
+  NS_IMETHOD Run() override {
+    if (mCallback) DoCallback();
+    return NS_OK;
+  }
+
+  NS_IMETHOD Cancel(nsresult reason) override {
+    NS_ENSURE_ARG(NS_FAILED(reason));
+
+    if (mAsyncFilterApplier) {
+      mAsyncFilterApplier->Cancel(reason);
+    }
+
+    // If we've already called DoCallback then, nothing more to do.
+    if (!mCallback) return NS_OK;
+
+    SetResult(reason, nullptr);
+    return DispatchCallback();
+  }
+
+  nsresult DispatchCallback() {
+    if (mDispatched) {  // Only need to dispatch once
+      return NS_OK;
+    }
+
+    nsresult rv = NS_DispatchToCurrentThread(this);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("unable to dispatch callback event");
+    } else {
+      mDispatched = true;
+      return NS_OK;
+    }
+
+    mCallback = nullptr;  // break possible reference cycle
+    return rv;
+  }
+
+ private:
+  // Called asynchronously, so we do not need to post another PLEvent
+  // before calling DoCallback.
+  void OnQueryComplete(nsresult status, const nsACString& pacString,
+                       const nsACString& newPACURL) override {
+    // If we've already called DoCallback then, nothing more to do.
+    if (!mCallback) return;
+
+    // Provided we haven't been canceled...
+    if (mStatus == NS_OK) {
+      mStatus = status;
+      mPACString = pacString;
+      mPACURL = newPACURL;
+    }
+
+    // In the cancelation case, we may still have another PLEvent in
+    // the queue that wants to call DoCallback.  No need to wait for
+    // it, just run the callback now.
+    DoCallback();
+  }
+
+  void DoCallback() {
+    bool pacAvailable = true;
+    if (mStatus == NS_ERROR_NOT_AVAILABLE && !mProxyInfo) {
+      // If the PAC service is not avail (e.g. failed pac load
+      // or shutdown) then we will be going direct. Make that
+      // mapping now so that any filters are still applied.
+      mPACString = "DIRECT;"_ns;
+      mStatus = NS_OK;
+
+      LOG(("pac not available, use DIRECT\n"));
+      pacAvailable = false;
+    }
+
+    // Generate proxy info from the PAC string if appropriate
+    if (NS_SUCCEEDED(mStatus) && !mProxyInfo && !mPACString.IsEmpty()) {
+      mPPS->ProcessPACString(mPACString, mResolveFlags,
+                             getter_AddRefs(mProxyInfo));
+      nsCOMPtr<nsIURI> proxyURI;
+      GetProxyURI(mChannel, getter_AddRefs(proxyURI));
+
+      // Now apply proxy filters
+      nsProtocolInfo info;
+      mStatus = mPPS->GetProtocolInfo(proxyURI, &info);
+
+      auto consumeFiltersResult = [pacAvailable](nsAsyncResolveRequest* self,
+                                                 nsIProxyInfo* pi,
+                                                 bool async) -> nsresult {
+        LOG(("DoCallback::consumeFiltersResult this=%p, pi=%p, async=%d", self,
+             pi, async));
+
+        self->mProxyInfo = pi;
+
+        if (pacAvailable) {
+          // if !pacAvailable, it was already logged above
+          LOG(("pac thread callback %s\n", self->mPACString.get()));
+        }
+
+        if (NS_SUCCEEDED(self->mStatus)) {
+          self->mPPS->MaybeDisableDNSPrefetch(self->mProxyInfo);
+        }
+
+        self->EnsureResolveFlagsMatch();
+        self->mCallback->OnProxyAvailable(self, self->mChannel,
+                                          self->mProxyInfo, self->mStatus);
+
+        return NS_OK;
+      };
+
+      if (NS_SUCCEEDED(mStatus)) {
+        mAsyncFilterApplier = new AsyncApplyFilters(info, consumeFiltersResult);
+        // This may call consumeFiltersResult() directly.
+        mAsyncFilterApplier->AsyncProcess(this);
+        return;
+      }
+
+      consumeFiltersResult(this, nullptr, false);
+    } else if (NS_SUCCEEDED(mStatus) && !mPACURL.IsEmpty()) {
+      LOG(("pac thread callback indicates new pac file load\n"));
+
+      nsCOMPtr<nsIURI> proxyURI;
+      GetProxyURI(mChannel, getter_AddRefs(proxyURI));
+
+      // trigger load of new pac url
+      nsresult rv = mPPS->ConfigureFromPAC(mPACURL, false);
+      if (NS_SUCCEEDED(rv)) {
+        // now that the load is triggered, we can resubmit the query
+        RefPtr<nsAsyncResolveRequest> newRequest =
+            new nsAsyncResolveRequest(mPPS, mChannel, mResolveFlags, mCallback);
+        rv = mPPS->mPACMan->AsyncGetProxyForURI(proxyURI, newRequest,
+                                                mResolveFlags, true);
+      }
+
+      if (NS_FAILED(rv)) {
+        mCallback->OnProxyAvailable(this, mChannel, nullptr, rv);
+      }
+
+      // do not call onproxyavailable() in SUCCESS case - the newRequest will
+      // take care of that
+    } else {
+      LOG(("pac thread callback did not provide information %" PRIX32 "\n",
+           static_cast<uint32_t>(mStatus)));
+      if (NS_SUCCEEDED(mStatus)) mPPS->MaybeDisableDNSPrefetch(mProxyInfo);
+      EnsureResolveFlagsMatch();
+      mCallback->OnProxyAvailable(this, mChannel, mProxyInfo, mStatus);
+    }
+
+    // We are on the main thread now and don't need these any more so
+    // release them to avoid having to proxy them back to the main thread
+    // in the dtor
+    mCallback = nullptr;  // in case the callback holds an owning ref to us
+    mPPS = nullptr;
+    mXPComPPS = nullptr;
+    mChannel = nullptr;
+    mProxyInfo = nullptr;
+  }
+
+ private:
+  nsresult mStatus{NS_OK};
+  nsCString mPACString;
+  nsCString mPACURL;
+  bool mDispatched{false};
+  uint32_t mResolveFlags;
+
+  nsProtocolProxyService* mPPS;
+  nsCOMPtr<nsIProtocolProxyService> mXPComPPS;
+  nsCOMPtr<nsIChannel> mChannel;
+  nsCOMPtr<nsIProtocolProxyCallback> mCallback;
+  nsCOMPtr<nsIProxyInfo> mProxyInfo;
+
+  RefPtr<AsyncApplyFilters> mAsyncFilterApplier;
+};
+
+NS_IMPL_ISUPPORTS(nsAsyncResolveRequest, nsICancelable, nsIRunnable)
+
+NS_IMPL_ISUPPORTS(nsAsyncResolveRequest::AsyncApplyFilters,
+                  nsIProxyProtocolFilterResult, nsICancelable, nsIRunnable)
+
+nsAsyncResolveRequest::AsyncApplyFilters::AsyncApplyFilters(
+    nsProtocolInfo& aInfo, Callback const& aCallback)
+    : mInfo(aInfo),
+      mCallback(aCallback),
+      mNextFilterIndex(0),
+      mProcessingInLoop(false),
+      mFilterCalledBack(false) {
+  LOG(("AsyncApplyFilters %p", this));
+}
+
+nsAsyncResolveRequest::AsyncApplyFilters::~AsyncApplyFilters() {
+  LOG(("~AsyncApplyFilters %p", this));
+
+  MOZ_ASSERT(!mRequest);
+  MOZ_ASSERT(!mProxyInfo);
+  MOZ_ASSERT(!mFiltersCopy.Length());
+}
+
+nsresult nsAsyncResolveRequest::AsyncApplyFilters::AsyncProcess(
+    nsAsyncResolveRequest* aRequest) {
+  LOG(("AsyncApplyFilters::AsyncProcess %p for req %p", this, aRequest));
+
+  MOZ_ASSERT(!mRequest, "AsyncApplyFilters started more than once!");
+
+  if (!(mInfo.flags & nsIProtocolHandler::ALLOWS_PROXY)) {
+    // Calling the callback directly (not via Finish()) since we
+    // don't want to prune.
+    return mCallback(aRequest, aRequest->mProxyInfo, false);
+  }
+
+  mProcessingThread = NS_GetCurrentThread();
+
+  mRequest = aRequest;
+  mProxyInfo = aRequest->mProxyInfo;
+
+  aRequest->mPPS->CopyFilters(mFiltersCopy);
+
+  // We want to give filters a chance to process in a single loop to prevent
+  // any current-thread dispatch delays when those are not needed.
+  // This code is rather "loopy" than "recursive" to prevent long stack traces.
+  do {
+    MOZ_ASSERT(!mProcessingInLoop);
+
+    mozilla::AutoRestore<bool> restore(mProcessingInLoop);
+    mProcessingInLoop = true;
+
+    nsresult rv = ProcessNextFilter();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  } while (mFilterCalledBack);
+
+  return NS_OK;
+}
+
+nsresult nsAsyncResolveRequest::AsyncApplyFilters::ProcessNextFilter() {
+  LOG(("AsyncApplyFilters::ProcessNextFilter %p ENTER pi=%p", this,
+       mProxyInfo.get()));
+
+  RefPtr<FilterLink> filter;
+  do {
+    mFilterCalledBack = false;
+
+    if (!mRequest) {
+      // We got canceled
+      LOG(("  canceled"));
+      return NS_OK;  // should we let the consumer know?
+    }
+
+    if (mNextFilterIndex == mFiltersCopy.Length()) {
+      return Finish();
+    }
+
+    filter = mFiltersCopy[mNextFilterIndex++];
+
+    // Loop until a call to a filter succeeded.  Other option is to recurse
+    // but that would waste stack trace when a number of filters gets registered
+    // and all from some reason tend to fail.
+    // The !mFilterCalledBack part of the condition is there to protect us from
+    // calling on another filter when the current one managed to call back and
+    // then threw. We already have the result so take it and use it since
+    // the next filter will be processed by the root loop or a call to
+    // ProcessNextFilter has already been dispatched to this thread.
+    LOG(("  calling filter %p pi=%p", filter.get(), mProxyInfo.get()));
+  } while (!mRequest->mPPS->ApplyFilter(filter, mRequest->mChannel, mInfo,
+                                        mProxyInfo, this) &&
+           !mFilterCalledBack);
+
+  LOG(("AsyncApplyFilters::ProcessNextFilter %p LEAVE pi=%p", this,
+       mProxyInfo.get()));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncResolveRequest::AsyncApplyFilters::OnProxyFilterResult(
+    nsIProxyInfo* aProxyInfo) {
+  LOG(("AsyncApplyFilters::OnProxyFilterResult %p pi=%p", this, aProxyInfo));
+
+  MOZ_ASSERT(mProcessingThread && mProcessingThread->IsOnCurrentThread());
+  MOZ_ASSERT(!mFilterCalledBack);
+
+  if (mFilterCalledBack) {
+    LOG(("  duplicate notification?"));
+    return NS_OK;
+  }
+
+  mFilterCalledBack = true;
+
+  if (!mRequest) {
+    // We got canceled
+    LOG(("  canceled"));
+    return NS_OK;
+  }
+
+  mProxyInfo = aProxyInfo;
+
+  if (mProcessingInLoop) {
+    // No need to call/dispatch ProcessNextFilter(), we are in a control
+    // loop that will do this for us and save recursion/dispatching.
+    LOG(("  in a root loop"));
+    return NS_OK;
+  }
+
+  if (mNextFilterIndex == mFiltersCopy.Length()) {
+    // We are done, all filters have been called on!
+    Finish();
+    return NS_OK;
+  }
+
+  // Redispatch, since we don't want long stacks when filters respond
+  // synchronously.
+  LOG(("  redispatching"));
+  NS_DispatchToCurrentThread(this);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAsyncResolveRequest::AsyncApplyFilters::Run() {
+  LOG(("AsyncApplyFilters::Run %p", this));
+
+  MOZ_ASSERT(mProcessingThread && mProcessingThread->IsOnCurrentThread());
+
+  ProcessNextFilter();
+  return NS_OK;
+}
+
+nsresult nsAsyncResolveRequest::AsyncApplyFilters::Finish() {
+  LOG(("AsyncApplyFilters::Finish %p pi=%p", this, mProxyInfo.get()));
+
+  MOZ_ASSERT(mRequest);
+
+  mFiltersCopy.Clear();
+
+  RefPtr<nsAsyncResolveRequest> request;
+  request.swap(mRequest);
+
+  nsCOMPtr<nsIProxyInfo> pi;
+  pi.swap(mProxyInfo);
+
+  request->mPPS->PruneProxyInfo(mInfo, pi);
+  return mCallback(request, pi, !mProcessingInLoop);
+}
+
+NS_IMETHODIMP
+nsAsyncResolveRequest::AsyncApplyFilters::Cancel(nsresult reason) {
+  LOG(("AsyncApplyFilters::Cancel %p", this));
+
+  MOZ_ASSERT(mProcessingThread && mProcessingThread->IsOnCurrentThread());
+
+  // This will be called only from inside the request, so don't call
+  // its's callback.  Dropping the members means we simply break the cycle.
+  mFiltersCopy.Clear();
+  mProxyInfo = nullptr;
+  mRequest = nullptr;
+
+  return NS_OK;
+}
+
+// Bug 1366133: make GetPACURI off-main-thread since it may hang on Windows
+// platform
+class AsyncGetPACURIRequest final : public nsIRunnable {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  using CallbackFunc = nsresult (nsProtocolProxyService::*)(bool, bool,
+                                                            nsresult,
+                                                            const nsACString&);
+
+  AsyncGetPACURIRequest(nsProtocolProxyService* aService,
+                        CallbackFunc aCallback,
+                        nsISystemProxySettings* aSystemProxySettings,
+                        bool aMainThreadOnly, bool aForceReload,
+                        bool aResetPACThread)
+      : mIsMainThreadOnly(aMainThreadOnly),
+        mService(aService),
+        mServiceHolder(do_QueryObject(aService)),
+        mCallback(aCallback),
+        mSystemProxySettings(aSystemProxySettings),
+        mForceReload(aForceReload),
+        mResetPACThread(aResetPACThread) {
+    MOZ_ASSERT(NS_IsMainThread());
+    Unused << mIsMainThreadOnly;
+  }
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread() == mIsMainThreadOnly);
+
+    nsCString pacUri;
+    nsresult rv = mSystemProxySettings->GetPACURI(pacUri);
+
+    nsCOMPtr<nsIRunnable> event =
+        NewNonOwningCancelableRunnableMethod<bool, bool, nsresult, nsCString>(
+            "AsyncGetPACURIRequestCallback", mService, mCallback, mForceReload,
+            mResetPACThread, rv, pacUri);
+
+    return NS_DispatchToMainThread(event);
+  }
+
+ private:
+  ~AsyncGetPACURIRequest() {
+    NS_ReleaseOnMainThread("AsyncGetPACURIRequest::mServiceHolder",
+                           mServiceHolder.forget());
+  }
+
+  bool mIsMainThreadOnly;
+
+  nsProtocolProxyService* mService;  // ref-count is hold by mServiceHolder
+  nsCOMPtr<nsIProtocolProxyService2> mServiceHolder;
+  CallbackFunc mCallback;
+  nsCOMPtr<nsISystemProxySettings> mSystemProxySettings;
+
+  bool mForceReload;
+  bool mResetPACThread;
+};
+
+NS_IMPL_ISUPPORTS(AsyncGetPACURIRequest, nsIRunnable)
+
+//----------------------------------------------------------------------------
+
+//
+// apply mask to address (zeros out excluded bits).
+//
+// NOTE: we do the byte swapping here to minimize overall swapping.
+//
+static void proxy_MaskIPv6Addr(PRIPv6Addr& addr, uint16_t mask_len) {
+  if (mask_len == 128) return;
+
+  if (mask_len > 96) {
+    addr.pr_s6_addr32[3] =
+        PR_htonl(PR_ntohl(addr.pr_s6_addr32[3]) & (~0uL << (128 - mask_len)));
+  } else if (mask_len > 64) {
+    addr.pr_s6_addr32[3] = 0;
+    addr.pr_s6_addr32[2] =
+        PR_htonl(PR_ntohl(addr.pr_s6_addr32[2]) & (~0uL << (96 - mask_len)));
+  } else if (mask_len > 32) {
+    addr.pr_s6_addr32[3] = 0;
+    addr.pr_s6_addr32[2] = 0;
+    addr.pr_s6_addr32[1] =
+        PR_htonl(PR_ntohl(addr.pr_s6_addr32[1]) & (~0uL << (64 - mask_len)));
+  } else {
+    addr.pr_s6_addr32[3] = 0;
+    addr.pr_s6_addr32[2] = 0;
+    addr.pr_s6_addr32[1] = 0;
+    addr.pr_s6_addr32[0] =
+        PR_htonl(PR_ntohl(addr.pr_s6_addr32[0]) & (~0uL << (32 - mask_len)));
+  }
+}
+
+static void proxy_GetStringPref(nsIPrefBranch* aPrefBranch, const char* aPref,
+                                nsCString& aResult) {
+  nsAutoCString temp;
+  nsresult rv = aPrefBranch->GetCharPref(aPref, temp);
+  if (NS_FAILED(rv)) {
+    aResult.Truncate();
+  } else {
+    aResult.Assign(temp);
+    // all of our string prefs are hostnames, so we should remove any
+    // whitespace characters that the user might have unknowingly entered.
+    aResult.StripWhitespace();
+  }
+}
+
+static void proxy_GetIntPref(nsIPrefBranch* aPrefBranch, const char* aPref,
+                             int32_t& aResult) {
+  int32_t temp;
+  nsresult rv = aPrefBranch->GetIntPref(aPref, &temp);
+  if (NS_FAILED(rv)) {
+    aResult = -1;
+  } else {
+    aResult = temp;
+  }
+}
+
+static void proxy_GetBoolPref(nsIPrefBranch* aPrefBranch, const char* aPref,
+                              bool& aResult) {
+  bool temp;
+  nsresult rv = aPrefBranch->GetBoolPref(aPref, &temp);
+  if (NS_FAILED(rv)) {
+    aResult = false;
+  } else {
+    aResult = temp;
+  }
+}
+
+//----------------------------------------------------------------------------
+
+static const int32_t PROXYCONFIG_DIRECT4X = 3;
+static const int32_t PROXYCONFIG_COUNT = 6;
+
+NS_IMPL_ADDREF(nsProtocolProxyService)
+NS_IMPL_RELEASE(nsProtocolProxyService)
+NS_IMPL_CLASSINFO(nsProtocolProxyService, nullptr, nsIClassInfo::SINGLETON,
+                  NS_PROTOCOLPROXYSERVICE_CID)
+
+// NS_IMPL_QUERY_INTERFACE_CI with the nsProtocolProxyService QI change
+NS_INTERFACE_MAP_BEGIN(nsProtocolProxyService)
+  NS_INTERFACE_MAP_ENTRY(nsIProtocolProxyService)
+  NS_INTERFACE_MAP_ENTRY(nsIProtocolProxyService2)
+  NS_INTERFACE_MAP_ENTRY(nsIObserver)
+  NS_INTERFACE_MAP_ENTRY(nsITimerCallback)
+  NS_INTERFACE_MAP_ENTRY(nsINamed)
+  NS_INTERFACE_MAP_ENTRY_CONCRETE(nsProtocolProxyService)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIProtocolProxyService)
+  NS_IMPL_QUERY_CLASSINFO(nsProtocolProxyService)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CI_INTERFACE_GETTER(nsProtocolProxyService, nsIProtocolProxyService,
+                            nsIProtocolProxyService2)
+
+nsProtocolProxyService::nsProtocolProxyService() : mSessionStart(PR_Now()) {}
+
+nsProtocolProxyService::~nsProtocolProxyService() {
+  // These should have been cleaned up in our Observe method.
+  NS_ASSERTION(mHostFiltersArray.Length() == 0 && mFilters.Length() == 0 &&
+                   mPACMan == nullptr,
+               "what happened to xpcom-shutdown?");
+}
+
+// nsProtocolProxyService methods
+nsresult nsProtocolProxyService::Init() {
+  // failure to access prefs is non-fatal
+  nsCOMPtr<nsIPrefBranch> prefBranch = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (prefBranch) {
+    // monitor proxy prefs
+    prefBranch->AddObserver(PROXY_PREF_BRANCH, this, false);
+
+    // read all prefs
+    PrefsChanged(prefBranch, nullptr);
+  }
+
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  if (obs) {
+    // register for shutdown notification so we can clean ourselves up
+    // properly.
+    obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
+    obs->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
+  }
+
+  return NS_OK;
+}
+
+// ReloadNetworkPAC() checks if there's a non-networked PAC in use then avoids
+// to call ReloadPAC()
+nsresult nsProtocolProxyService::ReloadNetworkPAC() {
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (!prefs) {
+    return NS_OK;
+  }
+
+  int32_t type;
+  nsresult rv = prefs->GetIntPref(PROXY_PREF("type"), &type);
+  if (NS_FAILED(rv)) {
+    return NS_OK;
+  }
+
+  if (type == PROXYCONFIG_PAC) {
+    nsAutoCString pacSpec;
+    prefs->GetCharPref(PROXY_PREF("autoconfig_url"), pacSpec);
+    if (!pacSpec.IsEmpty()) {
+      nsCOMPtr<nsIURI> pacURI;
+      rv = NS_NewURI(getter_AddRefs(pacURI), pacSpec);
+      if (!NS_SUCCEEDED(rv)) {
+        return rv;
+      }
+
+      nsProtocolInfo pac;
+      rv = GetProtocolInfo(pacURI, &pac);
+      if (!NS_SUCCEEDED(rv)) {
+        return rv;
+      }
+
+      if (!pac.scheme.EqualsLiteral("file") &&
+          !pac.scheme.EqualsLiteral("data")) {
+        LOG((": received network changed event, reload PAC"));
+        ReloadPAC();
+      }
+    }
+  } else if ((type == PROXYCONFIG_WPAD) || (type == PROXYCONFIG_SYSTEM)) {
+    ReloadPAC();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsProtocolProxyService::AsyncConfigureFromPAC(bool aForceReload,
+                                                       bool aResetPACThread) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  bool mainThreadOnly;
+  nsresult rv = mSystemProxySettings->GetMainThreadOnly(&mainThreadOnly);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIRunnable> req = new AsyncGetPACURIRequest(
+      this, &nsProtocolProxyService::OnAsyncGetPACURI, mSystemProxySettings,
+      mainThreadOnly, aForceReload, aResetPACThread);
+
+  if (mainThreadOnly) {
+    return req->Run();
+  }
+
+  return NS_DispatchBackgroundTask(req.forget(),
+                                   nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult nsProtocolProxyService::OnAsyncGetPACURI(bool aForceReload,
+                                                  bool aResetPACThread,
+                                                  nsresult aResult,
+                                                  const nsACString& aUri) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (aResetPACThread) {
+    ResetPACThread();
+  }
+
+  if (NS_SUCCEEDED(aResult) && !aUri.IsEmpty()) {
+    ConfigureFromPAC(PromiseFlatCString(aUri), aForceReload);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::Observe(nsISupports* aSubject, const char* aTopic,
+                                const char16_t* aData) {
+  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
+    mIsShutdown = true;
+    // cleanup
+    mHostFiltersArray.Clear();
+    mFilters.Clear();
+
+    if (mPACMan) {
+      mPACMan->Shutdown();
+      mPACMan = nullptr;
+    }
+
+    if (mReloadPACTimer) {
+      mReloadPACTimer->Cancel();
+      mReloadPACTimer = nullptr;
+    }
+
+    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+    if (obs) {
+      obs->RemoveObserver(this, NS_NETWORK_LINK_TOPIC);
+      obs->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
+    }
+
+  } else if (strcmp(aTopic, NS_NETWORK_LINK_TOPIC) == 0) {
+    nsCString converted = NS_ConvertUTF16toUTF8(aData);
+    const char* state = converted.get();
+    if (!strcmp(state, NS_NETWORK_LINK_DATA_CHANGED)) {
+      uint32_t delay = StaticPrefs::network_proxy_reload_pac_delay();
+      LOG(("nsProtocolProxyService::Observe call ReloadNetworkPAC() delay=%u",
+           delay));
+
+      if (delay) {
+        if (mReloadPACTimer) {
+          mReloadPACTimer->Cancel();
+          mReloadPACTimer = nullptr;
+        }
+        NS_NewTimerWithCallback(getter_AddRefs(mReloadPACTimer), this, delay,
+                                nsITimer::TYPE_ONE_SHOT);
+      } else {
+        ReloadNetworkPAC();
+      }
+    }
+  } else {
+    NS_ASSERTION(strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0,
+                 "what is this random observer event?");
+    nsCOMPtr<nsIPrefBranch> prefs = do_QueryInterface(aSubject);
+    if (prefs) PrefsChanged(prefs, NS_LossyConvertUTF16toASCII(aData).get());
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::Notify(nsITimer* aTimer) {
+  MOZ_ASSERT(aTimer == mReloadPACTimer);
+  ReloadNetworkPAC();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::GetName(nsACString& aName) {
+  aName.AssignLiteral("nsProtocolProxyService");
+  return NS_OK;
+}
+
+void nsProtocolProxyService::PrefsChanged(nsIPrefBranch* prefBranch,
+                                          const char* pref) {
+  nsresult rv = NS_OK;
+  bool reloadPAC = false;
+  nsAutoCString tempString;
+  auto invokeCallback =
+      MakeScopeExit([&] { NotifyProxyConfigChangedInternal(); });
+
+  if (!pref || !strcmp(pref, PROXY_PREF("type"))) {
+    int32_t type = -1;
+    rv = prefBranch->GetIntPref(PROXY_PREF("type"), &type);
+    if (NS_SUCCEEDED(rv)) {
+      // bug 115720 - for ns4.x backwards compatibility
+      if (type == PROXYCONFIG_DIRECT4X) {
+        type = PROXYCONFIG_DIRECT;
+        // Reset the type so that the dialog looks correct, and we
+        // don't have to handle this case everywhere else
+        // I'm paranoid about a loop of some sort - only do this
+        // if we're enumerating all prefs, and ignore any error
+        if (!pref) prefBranch->SetIntPref(PROXY_PREF("type"), type);
+      } else if (type >= PROXYCONFIG_COUNT) {
+        LOG(("unknown proxy type: %" PRId32 "; assuming direct\n", type));
+        type = PROXYCONFIG_DIRECT;
+      }
+      mProxyConfig = type;
+      reloadPAC = true;
+    }
+
+    if (mProxyConfig == PROXYCONFIG_SYSTEM) {
+      mSystemProxySettings = do_GetService(NS_SYSTEMPROXYSETTINGS_CONTRACTID);
+      if (!mSystemProxySettings) mProxyConfig = PROXYCONFIG_DIRECT;
+      ResetPACThread();
+    } else {
+      if (mSystemProxySettings) {
+        mSystemProxySettings = nullptr;
+        ResetPACThread();
+      }
+    }
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("http"))) {
+    proxy_GetStringPref(prefBranch, PROXY_PREF("http"), mHTTPProxyHost);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("http_port"))) {
+    proxy_GetIntPref(prefBranch, PROXY_PREF("http_port"), mHTTPProxyPort);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("ssl"))) {
+    proxy_GetStringPref(prefBranch, PROXY_PREF("ssl"), mHTTPSProxyHost);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("ssl_port"))) {
+    proxy_GetIntPref(prefBranch, PROXY_PREF("ssl_port"), mHTTPSProxyPort);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("socks"))) {
+    proxy_GetStringPref(prefBranch, PROXY_PREF("socks"), mSOCKSProxyTarget);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("socks_port"))) {
+    proxy_GetIntPref(prefBranch, PROXY_PREF("socks_port"), mSOCKSProxyPort);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("socks_version"))) {
+    int32_t version;
+    proxy_GetIntPref(prefBranch, PROXY_PREF("socks_version"), version);
+    // make sure this preference value remains sane
+    if (version == 5) {
+      mSOCKSProxyVersion = 5;
+    } else {
+      mSOCKSProxyVersion = 4;
+    }
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("socks_remote_dns"))) {
+    proxy_GetBoolPref(prefBranch, PROXY_PREF("socks_remote_dns"),
+                      mSOCKSProxyRemoteDNS);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("proxy_over_tls"))) {
+    proxy_GetBoolPref(prefBranch, PROXY_PREF("proxy_over_tls"), mProxyOverTLS);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("enable_wpad_over_dhcp"))) {
+    proxy_GetBoolPref(prefBranch, PROXY_PREF("enable_wpad_over_dhcp"),
+                      mWPADOverDHCPEnabled);
+    reloadPAC = reloadPAC || mProxyConfig == PROXYCONFIG_WPAD;
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("failover_timeout"))) {
+    proxy_GetIntPref(prefBranch, PROXY_PREF("failover_timeout"),
+                     mFailedProxyTimeout);
+  }
+
+  if (!pref || !strcmp(pref, PROXY_PREF("no_proxies_on"))) {
+    rv = prefBranch->GetCharPref(PROXY_PREF("no_proxies_on"), tempString);
+    if (NS_SUCCEEDED(rv)) LoadHostFilters(tempString);
+  }
+
+  // We're done if not using something that could give us a PAC URL
+  // (PAC, WPAD or System)
+  if (mProxyConfig != PROXYCONFIG_PAC && mProxyConfig != PROXYCONFIG_WPAD &&
+      mProxyConfig != PROXYCONFIG_SYSTEM) {
+    return;
+  }
+
+  // OK, we need to reload the PAC file if:
+  //  1) network.proxy.type changed, or
+  //  2) network.proxy.autoconfig_url changed and PAC is configured
+
+  if (!pref || !strcmp(pref, PROXY_PREF("autoconfig_url"))) reloadPAC = true;
+
+  if (reloadPAC) {
+    tempString.Truncate();
+    if (mProxyConfig == PROXYCONFIG_PAC) {
+      prefBranch->GetCharPref(PROXY_PREF("autoconfig_url"), tempString);
+      if (mPACMan && !mPACMan->IsPACURI(tempString)) {
+        LOG(("PAC Thread URI Changed - Reset Pac Thread"));
+        ResetPACThread();
+      }
+    } else if (mProxyConfig == PROXYCONFIG_WPAD) {
+      LOG(("Auto-detecting proxy - Reset Pac Thread"));
+      ResetPACThread();
+    } else if (mSystemProxySettings) {
+      // Get System Proxy settings if available
+      AsyncConfigureFromPAC(false, false);
+    }
+    if (!tempString.IsEmpty() || mProxyConfig == PROXYCONFIG_WPAD) {
+      ConfigureFromPAC(tempString, false);
+    }
+  }
+}
+
+bool nsProtocolProxyService::CanUseProxy(nsIURI* aURI, int32_t defaultPort) {
+  int32_t port;
+  nsAutoCString host;
+
+  nsresult rv = aURI->GetAsciiHost(host);
+  if (NS_FAILED(rv) || host.IsEmpty()) return false;
+
+  rv = aURI->GetPort(&port);
+  if (NS_FAILED(rv)) return false;
+  if (port == -1) port = defaultPort;
+
+  PRNetAddr addr;
+  bool is_ipaddr = (PR_StringToNetAddr(host.get(), &addr) == PR_SUCCESS);
+
+  PRIPv6Addr ipv6;
+  if (is_ipaddr) {
+    // convert parsed address to IPv6
+    if (addr.raw.family == PR_AF_INET) {
+      // convert to IPv4-mapped address
+      PR_ConvertIPv4AddrToIPv6(addr.inet.ip, &ipv6);
+    } else if (addr.raw.family == PR_AF_INET6) {
+      // copy the address
+      memcpy(&ipv6, &addr.ipv6.ip, sizeof(PRIPv6Addr));
+    } else {
+      NS_WARNING("unknown address family");
+      return true;  // allow proxying
+    }
+  }
+
+  // Don't use proxy for local hosts (plain hostname, no dots)
+  if ((!is_ipaddr && mFilterLocalHosts && !host.Contains('.')) ||
+      // This method detects if we have network.proxy.allow_hijacking_localhost
+      // pref enabled. If it's true then this method will always return false
+      // otherwise it returns true if the host matches an address that's
+      // hardcoded to the loopback address.
+      (!StaticPrefs::network_proxy_allow_hijacking_localhost() &&
+       nsMixedContentBlocker::IsPotentiallyTrustworthyLoopbackHost(host))) {
+    LOG(("Not using proxy for this local host [%s]!\n", host.get()));
+    return false;  // don't allow proxying
+  }
+
+  int32_t index = -1;
+  while (++index < int32_t(mHostFiltersArray.Length())) {
+    const auto& hinfo = mHostFiltersArray[index];
+
+    if (is_ipaddr != hinfo->is_ipaddr) continue;
+    if (hinfo->port && hinfo->port != port) continue;
+
+    if (is_ipaddr) {
+      // generate masked version of target IPv6 address
+      PRIPv6Addr masked;
+      memcpy(&masked, &ipv6, sizeof(PRIPv6Addr));
+      proxy_MaskIPv6Addr(masked, hinfo->ip.mask_len);
+
+      // check for a match
+      if (memcmp(&masked, &hinfo->ip.addr, sizeof(PRIPv6Addr)) == 0) {
+        return false;  // proxy disallowed
+      }
+    } else {
+      uint32_t host_len = host.Length();
+      uint32_t filter_host_len = hinfo->name.host_len;
+
+      if (host_len >= filter_host_len) {
+        //
+        // compare last |filter_host_len| bytes of target hostname.
+        //
+        const char* host_tail = host.get() + host_len - filter_host_len;
+        if (!nsCRT::strncasecmp(host_tail, hinfo->name.host, filter_host_len)) {
+          // If the tail of the host string matches the filter
+
+          if (filter_host_len > 0 && hinfo->name.host[0] == '.') {
+            // If the filter was of the form .foo.bar.tld, all such
+            // matches are correct
+            return false;  // proxy disallowed
+          }
+
+          // abc-def.example.org should not match def.example.org
+          // however, *.def.example.org should match .def.example.org
+          // We check that the filter doesn't start with a `.`. If it does,
+          // then the strncasecmp above should suffice. If it doesn't,
+          // then we should only consider it a match if the strncasecmp happened
+          // at a subdomain boundary
+          if (host_len > filter_host_len && *(host_tail - 1) == '.') {
+            // If the host was something.foo.bar.tld and the filter
+            // was foo.bar.tld, it's still a match.
+            // the character right before the tail must be a
+            // `.` for this to work
+            return false;  // proxy disallowed
+          }
+
+          if (host_len == filter_host_len) {
+            // If the host and filter are of the same length,
+            // they should match
+            return false;  // proxy disallowed
+          }
+        }
+      }
+    }
+  }
+  return true;
+}
+
+// kProxyType\* may be referred to externally in
+// nsProxyInfo in order to compare by string pointer
+const char kProxyType_HTTP[] = "http";
+const char kProxyType_HTTPS[] = "https";
+const char kProxyType_PROXY[] = "proxy";
+const char kProxyType_SOCKS[] = "socks";
+const char kProxyType_SOCKS4[] = "socks4";
+const char kProxyType_SOCKS5[] = "socks5";
+const char kProxyType_DIRECT[] = "direct";
+
+const char* nsProtocolProxyService::ExtractProxyInfo(const char* start,
+                                                     uint32_t aResolveFlags,
+                                                     nsProxyInfo** result) {
+  *result = nullptr;
+  uint32_t flags = 0;
+
+  // see BNF in ProxyAutoConfig.h and notes in nsISystemProxySettings.idl
+
+  // find end of proxy info delimiter
+  const char* end = start;
+  while (*end && *end != ';') ++end;
+
+  // find end of proxy type delimiter
+  const char* sp = start;
+  while (sp < end && *sp != ' ' && *sp != '\t') ++sp;
+
+  uint32_t len = sp - start;
+  const char* type = nullptr;
+  switch (len) {
+    case 4:
+      if (nsCRT::strncasecmp(start, kProxyType_HTTP, 4) == 0) {
+        type = kProxyType_HTTP;
+      }
+      break;
+    case 5:
+      if (nsCRT::strncasecmp(start, kProxyType_PROXY, 5) == 0) {
+        type = kProxyType_HTTP;
+      } else if (nsCRT::strncasecmp(start, kProxyType_SOCKS, 5) == 0) {
+        type = kProxyType_SOCKS4;  // assume v4 for 4x compat
+        if (StaticPrefs::network_proxy_default_pac_script_socks_version() ==
+            5) {
+          type = kProxyType_SOCKS;
+        }
+      } else if (nsCRT::strncasecmp(start, kProxyType_HTTPS, 5) == 0) {
+        type = kProxyType_HTTPS;
+      }
+      break;
+    case 6:
+      if (nsCRT::strncasecmp(start, kProxyType_DIRECT, 6) == 0) {
+        type = kProxyType_DIRECT;
+      } else if (nsCRT::strncasecmp(start, kProxyType_SOCKS4, 6) == 0) {
+        type = kProxyType_SOCKS4;
+      } else if (nsCRT::strncasecmp(start, kProxyType_SOCKS5, 6) == 0) {
+        // map "SOCKS5" to "socks" to match contract-id of registered
+        // SOCKS-v5 socket provider.
+        type = kProxyType_SOCKS;
+      }
+      break;
+  }
+  if (type) {
+    int32_t port = -1;
+
+    // If it's a SOCKS5 proxy, do name resolution on the server side.
+    // We could use this with SOCKS4a servers too, but they might not
+    // support it.
+    if (type == kProxyType_SOCKS || mSOCKSProxyRemoteDNS) {
+      flags |= nsIProxyInfo::TRANSPARENT_PROXY_RESOLVES_HOST;
+    }
+
+    // extract host:port
+    start = sp;
+    while ((*start == ' ' || *start == '\t') && start < end) start++;
+
+    // port defaults
+    if (type == kProxyType_HTTP) {
+      port = 80;
+    } else if (type == kProxyType_HTTPS) {
+      port = 443;
+    } else {
+      port = 1080;
+    }
+
+    RefPtr<nsProxyInfo> pi = new nsProxyInfo();
+    pi->mType = type;
+    pi->mFlags = flags;
+    pi->mResolveFlags = aResolveFlags;
+    pi->mTimeout = mFailedProxyTimeout;
+
+    // www.foo.com:8080 and http://www.foo.com:8080
+    nsDependentCSubstring maybeURL(start, end - start);
+    nsCOMPtr<nsIURI> pacURI;
+
+    nsAutoCString urlHost;
+    // First assume the scheme is present, e.g. http://www.example.com:8080
+    if (NS_FAILED(NS_NewURI(getter_AddRefs(pacURI), maybeURL)) ||
+        NS_FAILED(pacURI->GetAsciiHost(urlHost)) || urlHost.IsEmpty()) {
+      // It isn't, assume www.example.com:8080
+      maybeURL.Insert("http://", 0);
+
+      if (NS_SUCCEEDED(NS_NewURI(getter_AddRefs(pacURI), maybeURL))) {
+        pacURI->GetAsciiHost(urlHost);
+      }
+    }
+
+    if (!urlHost.IsEmpty()) {
+      pi->mHost = urlHost;
+
+      int32_t tPort;
+      if (NS_SUCCEEDED(pacURI->GetPort(&tPort)) && tPort != -1) {
+        port = tPort;
+      }
+      pi->mPort = port;
+    }
+
+    pi.forget(result);
+  }
+
+  while (*end == ';' || *end == ' ' || *end == '\t') ++end;
+  return end;
+}
+
+void nsProtocolProxyService::GetProxyKey(nsProxyInfo* pi, nsCString& key) {
+  key.AssignASCII(pi->mType);
+  if (!pi->mHost.IsEmpty()) {
+    key.Append(' ');
+    key.Append(pi->mHost);
+    key.Append(':');
+    key.AppendInt(pi->mPort);
+  }
+}
+
+uint32_t nsProtocolProxyService::SecondsSinceSessionStart() {
+  PRTime now = PR_Now();
+
+  // get time elapsed since session start
+  int64_t diff = now - mSessionStart;
+
+  // convert microseconds to seconds
+  diff /= PR_USEC_PER_SEC;
+
+  // return converted 32 bit value
+  return uint32_t(diff);
+}
+
+void nsProtocolProxyService::EnableProxy(nsProxyInfo* pi) {
+  nsAutoCString key;
+  GetProxyKey(pi, key);
+  mFailedProxies.Remove(key);
+}
+
+void nsProtocolProxyService::DisableProxy(nsProxyInfo* pi) {
+  nsAutoCString key;
+  GetProxyKey(pi, key);
+
+  uint32_t dsec = SecondsSinceSessionStart();
+
+  // Add timeout to interval (this is the time when the proxy can
+  // be tried again).
+  dsec += pi->mTimeout;
+
+  // NOTE: The classic codebase would increase the timeout value
+  //       incrementally each time a subsequent failure occurred.
+  //       We could do the same, but it would require that we not
+  //       remove proxy entries in IsProxyDisabled or otherwise
+  //       change the way we are recording disabled proxies.
+  //       Simpler is probably better for now, and at least the
+  //       user can tune the timeout setting via preferences.
+
+  LOG(("DisableProxy %s %d\n", key.get(), dsec));
+
+  // If this fails, oh well... means we don't have enough memory
+  // to remember the failed proxy.
+  mFailedProxies.InsertOrUpdate(key, dsec);
+}
+
+bool nsProtocolProxyService::IsProxyDisabled(nsProxyInfo* pi) {
+  nsAutoCString key;
+  GetProxyKey(pi, key);
+
+  uint32_t val;
+  if (!mFailedProxies.Get(key, &val)) return false;
+
+  uint32_t dsec = SecondsSinceSessionStart();
+
+  // if time passed has exceeded interval, then try proxy again.
+  if (dsec > val) {
+    mFailedProxies.Remove(key);
+    return false;
+  }
+
+  return true;
+}
+
+nsresult nsProtocolProxyService::SetupPACThread(
+    nsISerialEventTarget* mainThreadEventTarget) {
+  if (mIsShutdown) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mPACMan) return NS_OK;
+
+  mPACMan = new nsPACMan(mainThreadEventTarget);
+
+  bool mainThreadOnly;
+  nsresult rv;
+  if (mSystemProxySettings &&
+      NS_SUCCEEDED(mSystemProxySettings->GetMainThreadOnly(&mainThreadOnly)) &&
+      !mainThreadOnly) {
+    rv = mPACMan->Init(mSystemProxySettings);
+  } else {
+    rv = mPACMan->Init(nullptr);
+  }
+  if (NS_FAILED(rv)) {
+    mPACMan->Shutdown();
+    mPACMan = nullptr;
+  }
+  return rv;
+}
+
+nsresult nsProtocolProxyService::ResetPACThread() {
+  if (!mPACMan) return NS_OK;
+
+  mPACMan->Shutdown();
+  mPACMan = nullptr;
+  return SetupPACThread();
+}
+
+nsresult nsProtocolProxyService::ConfigureFromPAC(const nsCString& spec,
+                                                  bool forceReload) {
+  nsresult rv = SetupPACThread();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool autodetect = spec.IsEmpty();
+  if (!forceReload && ((!autodetect && mPACMan->IsPACURI(spec)) ||
+                       (autodetect && mPACMan->IsUsingWPAD()))) {
+    return NS_OK;
+  }
+
+  mFailedProxies.Clear();
+
+  mPACMan->SetWPADOverDHCPEnabled(mWPADOverDHCPEnabled);
+  return mPACMan->LoadPACFromURI(spec);
+}
+
+void nsProtocolProxyService::ProcessPACString(const nsCString& pacString,
+                                              uint32_t aResolveFlags,
+                                              nsIProxyInfo** result) {
+  if (pacString.IsEmpty()) {
+    *result = nullptr;
+    return;
+  }
+
+  const char* proxies = pacString.get();
+
+  nsProxyInfo *pi = nullptr, *first = nullptr, *last = nullptr;
+  while (*proxies) {
+    proxies = ExtractProxyInfo(proxies, aResolveFlags, &pi);
+    if (pi && (pi->mType == kProxyType_HTTPS) && !mProxyOverTLS) {
+      delete pi;
+      pi = nullptr;
+    }
+
+    if (pi) {
+      if (last) {
+        NS_ASSERTION(last->mNext == nullptr, "leaking nsProxyInfo");
+        last->mNext = pi;
+      } else {
+        first = pi;
+      }
+      last = pi;
+    }
+  }
+  *result = first;
+}
+
+// nsIProtocolProxyService2
+NS_IMETHODIMP
+nsProtocolProxyService::ReloadPAC() {
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (!prefs) return NS_OK;
+
+  int32_t type;
+  nsresult rv = prefs->GetIntPref(PROXY_PREF("type"), &type);
+  if (NS_FAILED(rv)) return NS_OK;
+
+  nsAutoCString pacSpec;
+  if (type == PROXYCONFIG_PAC) {
+    prefs->GetCharPref(PROXY_PREF("autoconfig_url"), pacSpec);
+  } else if (type == PROXYCONFIG_SYSTEM) {
+    if (mSystemProxySettings) {
+      AsyncConfigureFromPAC(true, true);
+    } else {
+      ResetPACThread();
+    }
+  }
+
+  if (!pacSpec.IsEmpty() || type == PROXYCONFIG_WPAD) {
+    ConfigureFromPAC(pacSpec, true);
+  }
+  return NS_OK;
+}
+
+// When sync interface is removed this can go away too
+// The nsPACManCallback portion of this implementation should be run
+// off the main thread, because it uses a condvar for signaling and
+// the main thread is blocking on that condvar -
+//  so call nsPACMan::AsyncGetProxyForURI() with
+// a false mainThreadResponse parameter.
+class nsAsyncBridgeRequest final : public nsPACManCallback {
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  nsAsyncBridgeRequest()
+      : mMutex("nsDeprecatedCallback"),
+        mCondVar(mMutex, "nsDeprecatedCallback") {}
+
+  void OnQueryComplete(nsresult status, const nsACString& pacString,
+                       const nsACString& newPACURL) override {
+    MutexAutoLock lock(mMutex);
+    mCompleted = true;
+    mStatus = status;
+    mPACString = pacString;
+    mPACURL = newPACURL;
+    mCondVar.Notify();
+  }
+
+  void Lock() MOZ_CAPABILITY_ACQUIRE(mMutex) { mMutex.Lock(); }
+  void Unlock() MOZ_CAPABILITY_RELEASE(mMutex) { mMutex.Unlock(); }
+  void Wait() { mCondVar.Wait(TimeDuration::FromSeconds(3)); }
+
+ private:
+  ~nsAsyncBridgeRequest() = default;
+
+  friend class nsProtocolProxyService;
+
+  Mutex mMutex;
+  CondVar mCondVar;
+
+  nsresult mStatus MOZ_GUARDED_BY(mMutex){NS_OK};
+  nsCString mPACString MOZ_GUARDED_BY(mMutex);
+  nsCString mPACURL MOZ_GUARDED_BY(mMutex);
+  bool mCompleted MOZ_GUARDED_BY(mMutex){false};
+};
+NS_IMPL_ISUPPORTS0(nsAsyncBridgeRequest)
+
+nsresult nsProtocolProxyService::AsyncResolveInternal(
+    nsIChannel* channel, uint32_t flags, nsIProtocolProxyCallback* callback,
+    nsICancelable** result, bool isSyncOK,
+    nsISerialEventTarget* mainThreadEventTarget) {
+  NS_ENSURE_ARG_POINTER(channel);
+  NS_ENSURE_ARG_POINTER(callback);
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = GetProxyURI(channel, getter_AddRefs(uri));
+  if (NS_FAILED(rv)) return rv;
+
+  *result = nullptr;
+  RefPtr<nsAsyncResolveRequest> ctx =
+      new nsAsyncResolveRequest(this, channel, flags, callback);
+
+  nsProtocolInfo info;
+  rv = GetProtocolInfo(uri, &info);
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIProxyInfo> pi;
+  bool usePACThread;
+
+  // adapt to realtime changes in the system proxy service
+  if (mProxyConfig == PROXYCONFIG_SYSTEM) {
+    nsCOMPtr<nsISystemProxySettings> sp2 =
+        do_GetService(NS_SYSTEMPROXYSETTINGS_CONTRACTID);
+    if (sp2 != mSystemProxySettings) {
+      mSystemProxySettings = sp2;
+      ResetPACThread();
+    }
+  }
+
+  rv = SetupPACThread(mainThreadEventTarget);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // SystemProxySettings and PAC files can block the main thread
+  // but if neither of them are in use, we can just do the work
+  // right here and directly invoke the callback
+
+  rv =
+      Resolve_Internal(channel, info, flags, &usePACThread, getter_AddRefs(pi));
+  if (NS_FAILED(rv)) return rv;
+
+  if (!usePACThread || !mPACMan) {
+    // we can do it locally
+    rv = ctx->ProcessLocally(info, pi, isSyncOK);
+    if (NS_SUCCEEDED(rv) && !isSyncOK) {
+      ctx.forget(result);
+    }
+    return rv;
+  }
+
+  // else kick off a PAC thread query
+  rv = mPACMan->AsyncGetProxyForURI(uri, ctx, flags, true);
+  if (NS_SUCCEEDED(rv)) ctx.forget(result);
+  return rv;
+}
+
+// nsIProtocolProxyService
+NS_IMETHODIMP
+nsProtocolProxyService::AsyncResolve2(
+    nsIChannel* channel, uint32_t flags, nsIProtocolProxyCallback* callback,
+    nsISerialEventTarget* mainThreadEventTarget, nsICancelable** result) {
+  return AsyncResolveInternal(channel, flags, callback, result, true,
+                              mainThreadEventTarget);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::AsyncResolve(
+    nsISupports* channelOrURI, uint32_t flags,
+    nsIProtocolProxyCallback* callback,
+    nsISerialEventTarget* mainThreadEventTarget, nsICancelable** result) {
+  nsresult rv;
+  // Check if we got a channel:
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(channelOrURI);
+  if (!channel) {
+    nsCOMPtr<nsIURI> uri = do_QueryInterface(channelOrURI);
+    if (!uri) {
+      return NS_ERROR_NO_INTERFACE;
+    }
+
+    // creating a temporary channel from the URI which is not
+    // used to perform any network loads, hence its safe to
+    // use systemPrincipal as the loadingPrincipal.
+    rv = NS_NewChannel(getter_AddRefs(channel), uri,
+                       nsContentUtils::GetSystemPrincipal(),
+                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                       nsIContentPolicy::TYPE_OTHER);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return AsyncResolveInternal(channel, flags, callback, result, false,
+                              mainThreadEventTarget);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::NewProxyInfo(
+    const nsACString& aType, const nsACString& aHost, int32_t aPort,
+    const nsACString& aProxyAuthorizationHeader,
+    const nsACString& aConnectionIsolationKey, uint32_t aFlags,
+    uint32_t aFailoverTimeout, nsIProxyInfo* aFailoverProxy,
+    nsIProxyInfo** aResult) {
+  return NewProxyInfoWithAuth(aType, aHost, aPort, ""_ns, ""_ns,
+                              aProxyAuthorizationHeader,
+                              aConnectionIsolationKey, aFlags, aFailoverTimeout,
+                              aFailoverProxy, aResult);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::NewProxyInfoWithAuth(
+    const nsACString& aType, const nsACString& aHost, int32_t aPort,
+    const nsACString& aUsername, const nsACString& aPassword,
+    const nsACString& aProxyAuthorizationHeader,
+    const nsACString& aConnectionIsolationKey, uint32_t aFlags,
+    uint32_t aFailoverTimeout, nsIProxyInfo* aFailoverProxy,
+    nsIProxyInfo** aResult) {
+  static const char* types[] = {kProxyType_HTTP, kProxyType_HTTPS,
+                                kProxyType_SOCKS, kProxyType_SOCKS4,
+                                kProxyType_DIRECT};
+
+  // resolve type; this allows us to avoid copying the type string into each
+  // proxy info instance.  we just reference the string literals directly :)
+  const char* type = nullptr;
+  for (auto& t : types) {
+    if (aType.LowerCaseEqualsASCII(t)) {
+      type = t;
+      break;
+    }
+  }
+  NS_ENSURE_TRUE(type, NS_ERROR_INVALID_ARG);
+
+  // We have only implemented username/password for SOCKS proxies.
+  if ((!aUsername.IsEmpty() || !aPassword.IsEmpty()) &&
+      !aType.LowerCaseEqualsASCII(kProxyType_SOCKS) &&
+      !aType.LowerCaseEqualsASCII(kProxyType_SOCKS4)) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  return NewProxyInfo_Internal(type, aHost, aPort, aUsername, aPassword,
+                               aProxyAuthorizationHeader,
+                               aConnectionIsolationKey, aFlags,
+                               aFailoverTimeout, aFailoverProxy, 0, aResult);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::GetFailoverForProxy(nsIProxyInfo* aProxy, nsIURI* aURI,
+                                            nsresult aStatus,
+                                            nsIProxyInfo** aResult) {
+  // Failover is supported through a variety of methods including:
+  // * PAC scripts (PROXYCONFIG_PAC and PROXYCONFIG_WPAD)
+  // * System proxy
+  // * Extensions
+  // With extensions the mProxyConfig can be any type and the extension
+  // is still involved in the proxy filtering.  It may have also supplied
+  // any number of failover proxies.  We cannot determine what the mix is
+  // here, so we will attempt to get a failover regardless of the config
+  // type.  MANUAL configuration will not disable a proxy.
+
+  // Verify that |aProxy| is one of our nsProxyInfo objects.
+  nsCOMPtr<nsProxyInfo> pi = do_QueryInterface(aProxy);
+  NS_ENSURE_ARG(pi);
+  // OK, the QI checked out.  We can proceed.
+
+  // Remember that this proxy is down.  If the user has manually configured some
+  // proxies we do not want to disable them.
+  if (mProxyConfig != PROXYCONFIG_MANUAL) {
+    DisableProxy(pi);
+  }
+
+  // NOTE: At this point, we might want to prompt the user if we have
+  //       not already tried going DIRECT.  This is something that the
+  //       classic codebase supported; however, IE6 does not prompt.
+
+  if (!pi->mNext) return NS_ERROR_NOT_AVAILABLE;
+
+  LOG(("PAC failover from %s %s:%d to %s %s:%d\n", pi->mType, pi->mHost.get(),
+       pi->mPort, pi->mNext->mType, pi->mNext->mHost.get(), pi->mNext->mPort));
+
+  *aResult = do_AddRef(pi->mNext).take();
+  return NS_OK;
+}
+
+namespace {  // anon
+
+class ProxyFilterPositionComparator {
+  using FilterLinkRef = RefPtr<nsProtocolProxyService::FilterLink>;
+
+ public:
+  bool Equals(const FilterLinkRef& a, const FilterLinkRef& b) const {
+    return a->position == b->position;
+  }
+  bool LessThan(const FilterLinkRef& a, const FilterLinkRef& b) const {
+    return a->position < b->position;
+  }
+};
+
+class ProxyFilterObjectComparator {
+  using FilterLinkRef = RefPtr<nsProtocolProxyService::FilterLink>;
+
+ public:
+  bool Equals(const FilterLinkRef& link, const nsISupports* obj) const {
+    return obj == nsCOMPtr<nsISupports>(do_QueryInterface(link->filter)) ||
+           obj == nsCOMPtr<nsISupports>(do_QueryInterface(link->channelFilter));
+  }
+};
+
+}  // namespace
+
+nsresult nsProtocolProxyService::InsertFilterLink(RefPtr<FilterLink>&& link) {
+  LOG(("nsProtocolProxyService::InsertFilterLink filter=%p", link.get()));
+
+  if (mIsShutdown) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mFilters.AppendElement(link);
+  mFilters.Sort(ProxyFilterPositionComparator());
+
+  NotifyProxyConfigChangedInternal();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::RegisterFilter(nsIProtocolProxyFilter* filter,
+                                       uint32_t position) {
+  UnregisterFilter(filter);  // remove this filter if we already have it
+
+  RefPtr<FilterLink> link = new FilterLink(position, filter);
+  return InsertFilterLink(std::move(link));
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::RegisterChannelFilter(
+    nsIProtocolProxyChannelFilter* channelFilter, uint32_t position) {
+  UnregisterChannelFilter(
+      channelFilter);  // remove this filter if we already have it
+
+  RefPtr<FilterLink> link = new FilterLink(position, channelFilter);
+  return InsertFilterLink(std::move(link));
+}
+
+nsresult nsProtocolProxyService::RemoveFilterLink(nsISupports* givenObject) {
+  LOG(("nsProtocolProxyService::RemoveFilterLink target=%p", givenObject));
+
+  nsresult rv =
+      mFilters.RemoveElement(givenObject, ProxyFilterObjectComparator())
+          ? NS_OK
+          : NS_ERROR_UNEXPECTED;
+  if (NS_SUCCEEDED(rv)) {
+    NotifyProxyConfigChangedInternal();
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::UnregisterFilter(nsIProtocolProxyFilter* filter) {
+  // QI to nsISupports so we can safely test object identity.
+  nsCOMPtr<nsISupports> givenObject = do_QueryInterface(filter);
+  return RemoveFilterLink(givenObject);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::UnregisterChannelFilter(
+    nsIProtocolProxyChannelFilter* channelFilter) {
+  // QI to nsISupports so we can safely test object identity.
+  nsCOMPtr<nsISupports> givenObject = do_QueryInterface(channelFilter);
+  return RemoveFilterLink(givenObject);
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::GetProxyConfigType(uint32_t* aProxyConfigType) {
+  *aProxyConfigType = mProxyConfig;
+  return NS_OK;
+}
+
+void nsProtocolProxyService::LoadHostFilters(const nsACString& aFilters) {
+  if (mIsShutdown) {
+    return;
+  }
+
+  // check to see the owners flag? /!?/ TODO
+  if (mHostFiltersArray.Length() > 0) {
+    mHostFiltersArray.Clear();
+  }
+
+  // Reset mFilterLocalHosts - will be set to true if "<local>" is in pref
+  // string
+  mFilterLocalHosts = false;
+
+  if (aFilters.IsEmpty()) {
+    return;
+  }
+
+  //
+  // filter  = ( host | domain | ipaddr ["/" mask] ) [":" port]
+  // filters = filter *( "," LWS filter)
+  //
+  mozilla::Tokenizer t(aFilters);
+  mozilla::Tokenizer::Token token;
+  bool eof = false;
+  // while (*filters) {
+  while (!eof) {
+    // skip over spaces and ,
+    t.SkipWhites();
+    while (t.CheckChar(',')) {
+      t.SkipWhites();
+    }
+
+    nsAutoCString portStr;
+    nsAutoCString hostStr;
+    nsAutoCString maskStr;
+    t.Record();
+
+    bool parsingIPv6 = false;
+    bool parsingPort = false;
+    bool parsingMask = false;
+    while (t.Next(token)) {
+      if (token.Equals(mozilla::Tokenizer::Token::EndOfFile())) {
+        eof = true;
+        break;
+      }
+      if (token.Equals(mozilla::Tokenizer::Token::Char(',')) ||
+          token.Type() == mozilla::Tokenizer::TOKEN_WS) {
+        break;
+      }
+
+      if (token.Equals(mozilla::Tokenizer::Token::Char('['))) {
+        parsingIPv6 = true;
+        continue;
+      }
+
+      if (!parsingIPv6 && token.Equals(mozilla::Tokenizer::Token::Char(':'))) {
+        // Port is starting. Claim the previous as host.
+        if (parsingMask) {
+          t.Claim(maskStr);
+        } else {
+          t.Claim(hostStr);
+        }
+        t.Record();
+        parsingPort = true;
+        continue;
+      }
+
+      if (token.Equals(mozilla::Tokenizer::Token::Char('/'))) {
+        t.Claim(hostStr);
+        t.Record();
+        parsingMask = true;
+        continue;
+      }
+
+      if (token.Equals(mozilla::Tokenizer::Token::Char(']'))) {
+        parsingIPv6 = false;
+        continue;
+      }
+    }
+    if (!parsingPort && !parsingMask) {
+      t.Claim(hostStr);
+    } else if (parsingPort) {
+      t.Claim(portStr);
+    } else if (parsingMask) {
+      t.Claim(maskStr);
+    } else {
+      NS_WARNING("Could not parse this rule");
+      continue;
+    }
+
+    if (hostStr.IsEmpty()) {
+      continue;
+    }
+
+    // If the current host filter is "<local>", then all local (i.e.
+    // no dots in the hostname) hosts should bypass the proxy
+    if (hostStr.EqualsIgnoreCase("<local>")) {
+      mFilterLocalHosts = true;
+      LOG(
+          ("loaded filter for local hosts "
+           "(plain host names, no dots)\n"));
+      // Continue to next host filter;
+      continue;
+    }
+
+    // For all other host filters, create HostInfo object and add to list
+    HostInfo* hinfo = new HostInfo();
+    nsresult rv = NS_OK;
+
+    int32_t port = portStr.ToInteger(&rv);
+    if (NS_FAILED(rv)) {
+      port = 0;
+    }
+    hinfo->port = port;
+
+    int32_t maskLen = maskStr.ToInteger(&rv);
+    if (NS_FAILED(rv)) {
+      maskLen = 128;
+    }
+
+    // PR_StringToNetAddr can't parse brackets enclosed IPv6
+    nsAutoCString addrString = hostStr;
+    if (hostStr.First() == '[' && hostStr.Last() == ']') {
+      addrString = Substring(hostStr, 1, hostStr.Length() - 2);
+    }
+
+    PRNetAddr addr;
+    if (PR_StringToNetAddr(addrString.get(), &addr) == PR_SUCCESS) {
+      hinfo->is_ipaddr = true;
+      hinfo->ip.family = PR_AF_INET6;  // we always store address as IPv6
+      hinfo->ip.mask_len = maskLen;
+
+      if (hinfo->ip.mask_len == 0) {
+        NS_WARNING("invalid mask");
+        goto loser;
+      }
+
+      if (addr.raw.family == PR_AF_INET) {
+        // convert to IPv4-mapped address
+        PR_ConvertIPv4AddrToIPv6(addr.inet.ip, &hinfo->ip.addr);
+        // adjust mask_len accordingly
+        if (hinfo->ip.mask_len <= 32) hinfo->ip.mask_len += 96;
+      } else if (addr.raw.family == PR_AF_INET6) {
+        // copy the address
+        memcpy(&hinfo->ip.addr, &addr.ipv6.ip, sizeof(PRIPv6Addr));
+      } else {
+        NS_WARNING("unknown address family");
+        goto loser;
+      }
+
+      // apply mask to IPv6 address
+      proxy_MaskIPv6Addr(hinfo->ip.addr, hinfo->ip.mask_len);
+    } else {
+      nsAutoCString host;
+      if (hostStr.First() == '*') {
+        host = Substring(hostStr, 1);
+      } else {
+        host = hostStr;
+      }
+
+      if (host.IsEmpty()) {
+        hinfo->name.host = nullptr;
+        goto loser;
+      }
+
+      hinfo->name.host_len = host.Length();
+
+      hinfo->is_ipaddr = false;
+      hinfo->name.host = ToNewCString(host, mozilla::fallible);
+
+      if (!hinfo->name.host) goto loser;
+    }
+
+// #define DEBUG_DUMP_FILTERS
+#ifdef DEBUG_DUMP_FILTERS
+    printf("loaded filter[%zu]:\n", mHostFiltersArray.Length());
+    printf("  is_ipaddr = %u\n", hinfo->is_ipaddr);
+    printf("  port = %u\n", hinfo->port);
+    printf("  host = %s\n", hostStr.get());
+    if (hinfo->is_ipaddr) {
+      printf("  ip.family = %x\n", hinfo->ip.family);
+      printf("  ip.mask_len = %u\n", hinfo->ip.mask_len);
+
+      PRNetAddr netAddr;
+      PR_SetNetAddr(PR_IpAddrNull, PR_AF_INET6, 0, &netAddr);
+      memcpy(&netAddr.ipv6.ip, &hinfo->ip.addr, sizeof(hinfo->ip.addr));
+
+      char buf[256];
+      PR_NetAddrToString(&netAddr, buf, sizeof(buf));
+
+      printf("  ip.addr = %s\n", buf);
+    } else {
+      printf("  name.host = %s\n", hinfo->name.host);
+    }
+#endif
+
+    mHostFiltersArray.AppendElement(hinfo);
+    hinfo = nullptr;
+  loser:
+    delete hinfo;
+  }
+}
+
+nsresult nsProtocolProxyService::GetProtocolInfo(nsIURI* uri,
+                                                 nsProtocolInfo* info) {
+  AssertIsOnMainThread();
+  MOZ_ASSERT(uri, "URI is null");
+  MOZ_ASSERT(info, "info is null");
+
+  nsresult rv;
+
+  rv = uri->GetScheme(info->scheme);
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIIOService> ios = do_GetIOService(&rv);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = ios->GetDynamicProtocolFlags(uri, &info->flags);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = ios->GetDefaultPort(info->scheme.get(), &info->defaultPort);
+  return rv;
+}
+
+nsresult nsProtocolProxyService::NewProxyInfo_Internal(
+    const char* aType, const nsACString& aHost, int32_t aPort,
+    const nsACString& aUsername, const nsACString& aPassword,
+    const nsACString& aProxyAuthorizationHeader,
+    const nsACString& aConnectionIsolationKey, uint32_t aFlags,
+    uint32_t aFailoverTimeout, nsIProxyInfo* aFailoverProxy,
+    uint32_t aResolveFlags, nsIProxyInfo** aResult) {
+  if (aPort <= 0) aPort = -1;
+
+  nsCOMPtr<nsProxyInfo> failover;
+  if (aFailoverProxy) {
+    failover = do_QueryInterface(aFailoverProxy);
+    NS_ENSURE_ARG(failover);
+  }
+
+  RefPtr<nsProxyInfo> proxyInfo = new nsProxyInfo();
+
+  proxyInfo->mType = aType;
+  proxyInfo->mHost = aHost;
+  proxyInfo->mPort = aPort;
+  proxyInfo->mUsername = aUsername;
+  proxyInfo->mPassword = aPassword;
+  proxyInfo->mFlags = aFlags;
+  proxyInfo->mResolveFlags = aResolveFlags;
+  proxyInfo->mTimeout =
+      aFailoverTimeout == UINT32_MAX ? mFailedProxyTimeout : aFailoverTimeout;
+  proxyInfo->mProxyAuthorizationHeader = aProxyAuthorizationHeader;
+  proxyInfo->mConnectionIsolationKey = aConnectionIsolationKey;
+  failover.swap(proxyInfo->mNext);
+
+  proxyInfo.forget(aResult);
+  return NS_OK;
+}
+
+nsresult nsProtocolProxyService::Resolve_Internal(nsIChannel* channel,
+                                                  const nsProtocolInfo& info,
+                                                  uint32_t flags,
+                                                  bool* usePACThread,
+                                                  nsIProxyInfo** result) {
+  NS_ENSURE_ARG_POINTER(channel);
+
+  *usePACThread = false;
+  *result = nullptr;
+
+  if (!(info.flags & nsIProtocolHandler::ALLOWS_PROXY)) {
+    return NS_OK;  // Can't proxy this (filters may not override)
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = GetProxyURI(channel, getter_AddRefs(uri));
+  if (NS_FAILED(rv)) return rv;
+
+  // See bug #586908.
+  // Avoid endless loop if |uri| is the current PAC-URI. Returning OK
+  // here means that we will not use a proxy for this connection.
+  if (mPACMan && mPACMan->IsPACURI(uri)) return NS_OK;
+
+  // if proxies are enabled and this host:port combo is supposed to use a
+  // proxy, check for a proxy.
+  if ((mProxyConfig == PROXYCONFIG_DIRECT) ||
+      !CanUseProxy(uri, info.defaultPort)) {
+    return NS_OK;
+  }
+
+  bool mainThreadOnly;
+  if (mSystemProxySettings && mProxyConfig == PROXYCONFIG_SYSTEM &&
+      NS_SUCCEEDED(mSystemProxySettings->GetMainThreadOnly(&mainThreadOnly)) &&
+      !mainThreadOnly) {
+    *usePACThread = true;
+    return NS_OK;
+  }
+
+  if (mSystemProxySettings && mProxyConfig == PROXYCONFIG_SYSTEM) {
+    // If the system proxy setting implementation is not threadsafe (e.g
+    // linux gconf), we'll do it inline here. Such implementations promise
+    // not to block
+    // bug 1366133: this block uses GetPACURI & GetProxyForURI, which may
+    // hang on Windows platform. Fortunately, current implementation on
+    // Windows is not main thread only, so we are safe here.
+
+    nsAutoCString PACURI;
+    nsAutoCString pacString;
+
+    if (NS_SUCCEEDED(mSystemProxySettings->GetPACURI(PACURI)) &&
+        !PACURI.IsEmpty()) {
+      // There is a PAC URI configured. If it is unchanged, then
+      // just execute the PAC thread. If it is changed then load
+      // the new value
+
+      if (mPACMan && mPACMan->IsPACURI(PACURI)) {
+        // unchanged
+        *usePACThread = true;
+        return NS_OK;
+      }
+
+      ConfigureFromPAC(PACURI, false);
+      return NS_OK;
+    }
+
+    nsAutoCString spec;
+    nsAutoCString host;
+    nsAutoCString scheme;
+    int32_t port = -1;
+
+    uri->GetAsciiSpec(spec);
+    uri->GetAsciiHost(host);
+    uri->GetScheme(scheme);
+    uri->GetPort(&port);
+
+    if (flags & RESOLVE_PREFER_SOCKS_PROXY) {
+      LOG(("Ignoring RESOLVE_PREFER_SOCKS_PROXY for system proxy setting\n"));
+    } else if (flags & RESOLVE_PREFER_HTTPS_PROXY) {
+      scheme.AssignLiteral("https");
+    } else if (flags & RESOLVE_IGNORE_URI_SCHEME) {
+      scheme.AssignLiteral("http");
+    }
+
+    // now try the system proxy settings for this particular url
+    if (NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(spec, scheme, host,
+                                                          port, pacString))) {
+      nsCOMPtr<nsIProxyInfo> pi;
+      ProcessPACString(pacString, 0, getter_AddRefs(pi));
+
+      if (flags & RESOLVE_PREFER_SOCKS_PROXY &&
+          flags & RESOLVE_PREFER_HTTPS_PROXY) {
+        nsAutoCString type;
+        pi->GetType(type);
+        // DIRECT from ProcessPACString indicates that system proxy settings
+        // are not configured to use SOCKS proxy. Try https proxy as a
+        // secondary preferrable proxy. This is mainly for websocket whose
+        // proxy precedence is SOCKS > HTTPS > DIRECT.
+        if (type.EqualsLiteral(kProxyType_DIRECT)) {
+          scheme.AssignLiteral(kProxyType_HTTPS);
+          if (NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(
+                  spec, scheme, host, port, pacString))) {
+            ProcessPACString(pacString, 0, getter_AddRefs(pi));
+          }
+        }
+      }
+      pi.forget(result);
+      return NS_OK;
+    }
+  }
+
+  // if proxies are enabled and this host:port combo is supposed to use a
+  // proxy, check for a proxy.
+  if (mProxyConfig == PROXYCONFIG_DIRECT ||
+      (mProxyConfig == PROXYCONFIG_MANUAL &&
+       !CanUseProxy(uri, info.defaultPort))) {
+    return NS_OK;
+  }
+
+  // Proxy auto config magic...
+  if (mProxyConfig == PROXYCONFIG_PAC || mProxyConfig == PROXYCONFIG_WPAD) {
+    // Do not query PAC now.
+    *usePACThread = true;
+    return NS_OK;
+  }
+
+  // If we aren't in manual proxy configuration mode then we don't
+  // want to honor any manual specific prefs that might be still set
+  if (mProxyConfig != PROXYCONFIG_MANUAL) return NS_OK;
+
+  // proxy info values for manual configuration mode
+  const char* type = nullptr;
+  const nsACString* host = nullptr;
+  int32_t port = -1;
+
+  uint32_t proxyFlags = 0;
+
+  if ((flags & RESOLVE_PREFER_SOCKS_PROXY) && !mSOCKSProxyTarget.IsEmpty() &&
+      (IsHostLocalTarget(mSOCKSProxyTarget) || mSOCKSProxyPort > 0)) {
+    host = &mSOCKSProxyTarget;
+    if (mSOCKSProxyVersion == 4) {
+      type = kProxyType_SOCKS4;
+    } else {
+      type = kProxyType_SOCKS;
+    }
+    port = mSOCKSProxyPort;
+    if (mSOCKSProxyRemoteDNS) {
+      proxyFlags |= nsIProxyInfo::TRANSPARENT_PROXY_RESOLVES_HOST;
+    }
+  } else if ((flags & RESOLVE_PREFER_HTTPS_PROXY) &&
+             !mHTTPSProxyHost.IsEmpty() && mHTTPSProxyPort > 0) {
+    host = &mHTTPSProxyHost;
+    type = kProxyType_HTTP;
+    port = mHTTPSProxyPort;
+  } else if (!mHTTPProxyHost.IsEmpty() && mHTTPProxyPort > 0 &&
+             ((flags & RESOLVE_IGNORE_URI_SCHEME) ||
+              info.scheme.EqualsLiteral("http"))) {
+    host = &mHTTPProxyHost;
+    type = kProxyType_HTTP;
+    port = mHTTPProxyPort;
+  } else if (!mHTTPSProxyHost.IsEmpty() && mHTTPSProxyPort > 0 &&
+             !(flags & RESOLVE_IGNORE_URI_SCHEME) &&
+             info.scheme.EqualsLiteral("https")) {
+    host = &mHTTPSProxyHost;
+    type = kProxyType_HTTP;
+    port = mHTTPSProxyPort;
+  } else if (!mSOCKSProxyTarget.IsEmpty() &&
+             (IsHostLocalTarget(mSOCKSProxyTarget) || mSOCKSProxyPort > 0)) {
+    host = &mSOCKSProxyTarget;
+    if (mSOCKSProxyVersion == 4) {
+      type = kProxyType_SOCKS4;
+    } else {
+      type = kProxyType_SOCKS;
+    }
+    port = mSOCKSProxyPort;
+    if (mSOCKSProxyRemoteDNS) {
+      proxyFlags |= nsIProxyInfo::TRANSPARENT_PROXY_RESOLVES_HOST;
+    }
+  }
+
+  if (type) {
+    rv = NewProxyInfo_Internal(type, *host, port, ""_ns, ""_ns, ""_ns, ""_ns,
+                               proxyFlags, UINT32_MAX, nullptr, flags, result);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  return NS_OK;
+}
+
+void nsProtocolProxyService::MaybeDisableDNSPrefetch(nsIProxyInfo* aProxy) {
+  // Disable Prefetch in the DNS service if a proxy is in use.
+  if (!aProxy) return;
+
+  nsCOMPtr<nsProxyInfo> pi = do_QueryInterface(aProxy);
+  if (!pi || !pi->mType || pi->mType == kProxyType_DIRECT) return;
+
+  // To avoid getting DNS service recursively, we directly use
+  // GetXPCOMSingleton().
+  nsCOMPtr<nsIDNSService> dns = nsDNSService::GetXPCOMSingleton();
+  if (!dns) return;
+  nsCOMPtr<nsPIDNSService> pdns = do_QueryInterface(dns);
+  if (!pdns) return;
+
+  // We lose the prefetch optimization for the life of the dns service.
+  pdns->SetPrefetchEnabled(false);
+}
+
+void nsProtocolProxyService::CopyFilters(nsTArray<RefPtr<FilterLink>>& aCopy) {
+  MOZ_ASSERT(aCopy.Length() == 0);
+  aCopy.AppendElements(mFilters);
+}
+
+bool nsProtocolProxyService::ApplyFilter(
+    FilterLink const* filterLink, nsIChannel* channel,
+    const nsProtocolInfo& info, nsCOMPtr<nsIProxyInfo> list,
+    nsIProxyProtocolFilterResult* callback) {
+  nsresult rv;
+
+  // We prune the proxy list prior to invoking each filter.  This may be
+  // somewhat inefficient, but it seems like a good idea since we want each
+  // filter to "see" a valid proxy list.
+  PruneProxyInfo(info, list);
+
+  if (filterLink->filter) {
+    nsCOMPtr<nsIURI> uri;
+    Unused << GetProxyURI(channel, getter_AddRefs(uri));
+    if (!uri) {
+      return false;
+    }
+
+    rv = filterLink->filter->ApplyFilter(uri, list, callback);
+    return NS_SUCCEEDED(rv);
+  }
+
+  if (filterLink->channelFilter) {
+    rv = filterLink->channelFilter->ApplyFilter(channel, list, callback);
+    return NS_SUCCEEDED(rv);
+  }
+
+  return false;
+}
+
+void nsProtocolProxyService::PruneProxyInfo(const nsProtocolInfo& info,
+                                            nsIProxyInfo** list) {
+  if (!*list) return;
+
+  LOG(("nsProtocolProxyService::PruneProxyInfo ENTER list=%p", *list));
+
+  nsProxyInfo* head = nullptr;
+  CallQueryInterface(*list, &head);
+  if (!head) {
+    MOZ_ASSERT_UNREACHABLE("nsIProxyInfo must QI to nsProxyInfo");
+    return;
+  }
+  NS_RELEASE(*list);
+
+  // Pruning of disabled proxies works like this:
+  //   - If all proxies are disabled, return the full list
+  //   - Otherwise, remove the disabled proxies.
+  //
+  // Pruning of disallowed proxies works like this:
+  //   - If the protocol handler disallows the proxy, then we disallow it.
+
+  // Start by removing all disallowed proxies if required:
+  if (!(info.flags & nsIProtocolHandler::ALLOWS_PROXY_HTTP)) {
+    nsProxyInfo *last = nullptr, *iter = head;
+    while (iter) {
+      if ((iter->Type() == kProxyType_HTTP) ||
+          (iter->Type() == kProxyType_HTTPS)) {
+        // reject!
+        if (last) {
+          last->mNext = iter->mNext;
+        } else {
+          head = iter->mNext;
+        }
+        nsProxyInfo* next = iter->mNext;
+        iter->mNext = nullptr;
+        iter->Release();
+        iter = next;
+      } else {
+        last = iter;
+        iter = iter->mNext;
+      }
+    }
+    if (!head) {
+      return;
+    }
+  }
+
+  // Scan to see if all remaining non-direct proxies are disabled. If so, then
+  // we'll just bail and return them all.  Otherwise, we'll go and prune the
+  // disabled ones.
+
+  bool allNonDirectProxiesDisabled = true;
+
+  nsProxyInfo* iter;
+  for (iter = head; iter; iter = iter->mNext) {
+    if (!IsProxyDisabled(iter) && iter->mType != kProxyType_DIRECT) {
+      allNonDirectProxiesDisabled = false;
+      break;
+    }
+  }
+
+  if (allNonDirectProxiesDisabled &&
+      StaticPrefs::network_proxy_retry_failed_proxies()) {
+    LOG(("All proxies are disabled, so trying all again"));
+  } else {
+    // remove any disabled proxies.
+    nsProxyInfo* last = nullptr;
+    for (iter = head; iter;) {
+      if (IsProxyDisabled(iter)) {
+        // reject!
+        nsProxyInfo* reject = iter;
+
+        iter = iter->mNext;
+        if (last) {
+          last->mNext = iter;
+        } else {
+          head = iter;
+        }
+
+        reject->mNext = nullptr;
+        NS_RELEASE(reject);
+        continue;
+      }
+
+      // since we are about to use this proxy, make sure it is not on
+      // the disabled proxy list.  we'll add it back to that list if
+      // we have to (in GetFailoverForProxy).
+      //
+      // XXX(darin): It might be better to do this as a final pass.
+      //
+      EnableProxy(iter);
+
+      last = iter;
+      iter = iter->mNext;
+    }
+  }
+
+  // if only DIRECT was specified then return no proxy info, and we're done.
+  if (head && !head->mNext && head->mType == kProxyType_DIRECT) {
+    NS_RELEASE(head);
+  }
+
+  *list = head;  // Transfer ownership
+
+  LOG(("nsProtocolProxyService::PruneProxyInfo LEAVE list=%p", *list));
+}
+
+bool nsProtocolProxyService::GetIsPACLoading() {
+  return mPACMan && mPACMan->IsLoading();
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::AddProxyConfigCallback(
+    nsIProxyConfigChangedCallback* aCallback) {
+  MOZ_ASSERT(NS_IsMainThread());
+  if (!aCallback) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mProxyConfigChangedCallbacks.AppendElement(aCallback);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::RemoveProxyConfigCallback(
+    nsIProxyConfigChangedCallback* aCallback) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mProxyConfigChangedCallbacks.RemoveElement(aCallback);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProtocolProxyService::NotifyProxyConfigChangedInternal() {
+  LOG(("nsProtocolProxyService::NotifyProxyConfigChangedInternal"));
+  MOZ_ASSERT(NS_IsMainThread());
+
+  for (const auto& callback : mProxyConfigChangedCallbacks) {
+    callback->OnProxyConfigChanged();
+  }
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsProtocolProxyService.h b/netwerk/base/nsProtocolProxyService.h
new file mode 100644
index 0000000000..394450ca6e
--- /dev/null
+++ b/netwerk/base/nsProtocolProxyService.h
@@ -0,0 +1,420 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsProtocolProxyService_h__
+#define nsProtocolProxyService_h__
+
+#include "nsString.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+#include "nsIProtocolProxyService2.h"
+#include "nsIProtocolProxyFilter.h"
+#include "nsIProxyInfo.h"
+#include "nsIObserver.h"
+#include "nsTHashMap.h"
+#include "nsHashKeys.h"
+#include "nsITimer.h"
+#include "prio.h"
+#include "mozilla/Attributes.h"
+
+class nsIPrefBranch;
+class nsISystemProxySettings;
+
+namespace mozilla {
+namespace net {
+
+using nsFailedProxyTable = nsTHashMap<nsCStringHashKey, uint32_t>;
+
+class nsPACMan;
+class nsProxyInfo;
+struct nsProtocolInfo;
+
+// CID for the nsProtocolProxyService class
+// 091eedd8-8bae-4fe3-ad62-0c87351e640d
+#define NS_PROTOCOL_PROXY_SERVICE_IMPL_CID           \
+  {                                                  \
+    0x091eedd8, 0x8bae, 0x4fe3, {                    \
+      0xad, 0x62, 0x0c, 0x87, 0x35, 0x1e, 0x64, 0x0d \
+    }                                                \
+  }
+
+class nsProtocolProxyService final : public nsIProtocolProxyService2,
+                                     public nsIObserver,
+                                     public nsITimerCallback,
+                                     public nsINamed {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIPROTOCOLPROXYSERVICE2
+  NS_DECL_NSIPROTOCOLPROXYSERVICE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSINAMED
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_PROTOCOL_PROXY_SERVICE_IMPL_CID)
+
+  nsProtocolProxyService();
+
+  nsresult Init();
+
+ public:
+  // An instance of this struct is allocated for each registered
+  // nsIProtocolProxyFilter and each nsIProtocolProxyChannelFilter.
+  class FilterLink {
+   public:
+    NS_INLINE_DECL_REFCOUNTING(FilterLink)
+
+    uint32_t position;
+    nsCOMPtr<nsIProtocolProxyFilter> filter;
+    nsCOMPtr<nsIProtocolProxyChannelFilter> channelFilter;
+
+    FilterLink(uint32_t p, nsIProtocolProxyFilter* f);
+    FilterLink(uint32_t p, nsIProtocolProxyChannelFilter* cf);
+
+   private:
+    ~FilterLink();
+  };
+
+ protected:
+  friend class nsAsyncResolveRequest;
+  friend class TestProtocolProxyService_LoadHostFilters_Test;  // for gtest
+
+  ~nsProtocolProxyService();
+
+  /**
+   * This method is called whenever a preference may have changed or
+   * to initialize all preferences.
+   *
+   * @param prefs
+   *        This must be a pointer to the root pref branch.
+   * @param name
+   *        This can be the name of a fully-qualified preference, or it can
+   *        be null, in which case all preferences will be initialized.
+   */
+  void PrefsChanged(nsIPrefBranch* prefBranch, const char* pref);
+
+  /**
+   * This method is called to create a nsProxyInfo instance from the given
+   * PAC-style proxy string.  It parses up to the end of the string, or to
+   * the next ';' character.
+   *
+   * @param proxy
+   *        The PAC-style proxy string to parse.  This must not be null.
+   * @param aResolveFlags
+   *        The flags passed to Resolve or AsyncResolve that are stored in
+   *        proxyInfo.
+   * @param result
+   *        Upon return this points to a newly allocated nsProxyInfo or null
+   *        if the proxy string was invalid.
+   *
+   * @return A pointer beyond the parsed proxy string (never null).
+   */
+  const char* ExtractProxyInfo(const char* start, uint32_t aResolveFlags,
+                               nsProxyInfo** result);
+
+  /**
+   * Load the specified PAC file.
+   *
+   * @param pacURI
+   *        The URI spec of the PAC file to load.
+   */
+  nsresult ConfigureFromPAC(const nsCString& spec, bool forceReload);
+
+  /**
+   * This method builds a list of nsProxyInfo objects from the given PAC-
+   * style string.
+   *
+   * @param pacString
+   *        The PAC-style proxy string to parse.  This may be empty.
+   * @param aResolveFlags
+   *        The flags passed to Resolve or AsyncResolve that are stored in
+   *        proxyInfo.
+   * @param result
+   *        The resulting list of proxy info objects.
+   */
+  void ProcessPACString(const nsCString& pacString, uint32_t aResolveFlags,
+                        nsIProxyInfo** result);
+
+  /**
+   * This method generates a string valued identifier for the given
+   * nsProxyInfo object.
+   *
+   * @param pi
+   *        The nsProxyInfo object from which to generate the key.
+   * @param result
+   *        Upon return, this parameter holds the generated key.
+   */
+  void GetProxyKey(nsProxyInfo* pi, nsCString& key);
+
+  /**
+   * @return Seconds since start of session.
+   */
+  uint32_t SecondsSinceSessionStart();
+
+  /**
+   * This method removes the specified proxy from the disabled list.
+   *
+   * @param pi
+   *        The nsProxyInfo object identifying the proxy to enable.
+   */
+  void EnableProxy(nsProxyInfo* pi);
+
+  /**
+   * This method adds the specified proxy to the disabled list.
+   *
+   * @param pi
+   *        The nsProxyInfo object identifying the proxy to disable.
+   */
+  void DisableProxy(nsProxyInfo* pi);
+
+  /**
+   * This method tests to see if the given proxy is disabled.
+   *
+   * @param pi
+   *        The nsProxyInfo object identifying the proxy to test.
+   *
+   * @return True if the specified proxy is disabled.
+   */
+  bool IsProxyDisabled(nsProxyInfo* pi);
+
+  /**
+   * This method queries the protocol handler for the given scheme to check
+   * for the protocol flags and default port.
+   *
+   * @param uri
+   *        The URI to query.
+   * @param info
+   *        Holds information about the protocol upon return.  Pass address
+   *        of structure when you call this method.  This parameter must not
+   *        be null.
+   */
+  nsresult GetProtocolInfo(nsIURI* uri, nsProtocolInfo* info);
+
+  /**
+   * This method is an internal version nsIProtocolProxyService::newProxyInfo
+   * that expects a string literal for the type.
+   *
+   * @param type
+   *        The proxy type.
+   * @param host
+   *        The proxy host name (UTF-8 ok).
+   * @param port
+   *        The proxy port number.
+   * @param username
+   *        The username for the proxy (ASCII). May be "", but not null.
+   * @param password
+   *        The password for the proxy (ASCII). May be "", but not null.
+   * @param flags
+   *        The proxy flags (nsIProxyInfo::flags).
+   * @param timeout
+   *        The failover timeout for this proxy.
+   * @param next
+   *        The next proxy to try if this one fails.
+   * @param aResolveFlags
+   *        The flags passed to resolve (from nsIProtocolProxyService).
+   * @param result
+   *        The resulting nsIProxyInfo object.
+   */
+  nsresult NewProxyInfo_Internal(const char* type, const nsACString& host,
+                                 int32_t port, const nsACString& username,
+                                 const nsACString& password,
+                                 const nsACString& aProxyAuthorizationHeader,
+                                 const nsACString& aConnectionIsolationKey,
+                                 uint32_t flags, uint32_t timeout,
+                                 nsIProxyInfo* aFailoverProxy,
+                                 uint32_t aResolveFlags, nsIProxyInfo** result);
+
+  /**
+   * This method is an internal version of Resolve that does not query PAC.
+   * It performs all of the built-in processing, and reports back to the
+   * caller with either the proxy info result or a flag to instruct the
+   * caller to use PAC instead.
+   *
+   * @param channel
+   *        The channel to test.
+   * @param info
+   *        Information about the URI's protocol.
+   * @param flags
+   *        The flags passed to either the resolve or the asyncResolve method.
+   * @param usePAC
+   *        If this flag is set upon return, then PAC should be queried to
+   *        resolve the proxy info.
+   * @param result
+   *        The resulting proxy info or null.
+   */
+  nsresult Resolve_Internal(nsIChannel* channel, const nsProtocolInfo& info,
+                            uint32_t flags, bool* usePAC,
+                            nsIProxyInfo** result);
+
+  /**
+   * Shallow copy of the current list of registered filters so that
+   * we can safely let them asynchronously process a single proxy
+   * resolution request.
+   */
+  void CopyFilters(nsTArray<RefPtr<FilterLink>>& aCopy);
+
+  /**
+   * This method applies the provided filter to the given proxy info
+   * list, and expects |callback| be called on (synchronously or
+   * asynchronously) to provide the updated proxyinfo list.
+   */
+  bool ApplyFilter(FilterLink const* filterLink, nsIChannel* channel,
+                   const nsProtocolInfo& info, nsCOMPtr<nsIProxyInfo> list,
+                   nsIProxyProtocolFilterResult* callback);
+
+  /**
+   * This method prunes out disabled and disallowed proxies from a given
+   * proxy info list.
+   *
+   * @param info
+   *        Information about the URI's protocol.
+   * @param proxyInfo
+   *        The proxy info list to be modified.  This is an inout param.
+   */
+  void PruneProxyInfo(const nsProtocolInfo& info, nsIProxyInfo** list);
+
+  /**
+   * This method is a simple wrapper around PruneProxyInfo that takes the
+   * proxy info list inout param as a nsCOMPtr.
+   */
+  void PruneProxyInfo(const nsProtocolInfo& info,
+                      nsCOMPtr<nsIProxyInfo>& proxyInfo) {
+    nsIProxyInfo* pi = nullptr;
+    proxyInfo.swap(pi);
+    PruneProxyInfo(info, &pi);
+    proxyInfo.swap(pi);
+  }
+
+  /**
+   * This method populates mHostFiltersArray from the given string.
+   *
+   * @param hostFilters
+   *        A "no-proxy-for" exclusion list.
+   */
+  void LoadHostFilters(const nsACString& aFilters);
+
+  /**
+   * This method checks the given URI against mHostFiltersArray.
+   *
+   * @param uri
+   *        The URI to test.
+   * @param defaultPort
+   *        The default port for the given URI.
+   *
+   * @return True if the URI can use the specified proxy.
+   */
+  bool CanUseProxy(nsIURI* uri, int32_t defaultPort);
+
+  /**
+   * Disable Prefetch in the DNS service if a proxy is in use.
+   *
+   * @param aProxy
+   *        The proxy information
+   */
+  void MaybeDisableDNSPrefetch(nsIProxyInfo* aProxy);
+
+ private:
+  nsresult SetupPACThread(
+      nsISerialEventTarget* mainThreadEventTarget = nullptr);
+  nsresult ResetPACThread();
+  nsresult ReloadNetworkPAC();
+
+  nsresult AsyncConfigureFromPAC(bool aForceReload, bool aResetPACThread);
+  nsresult OnAsyncGetPACURI(bool aForceReload, bool aResetPACThread,
+                            nsresult aResult, const nsACString& aUri);
+
+ public:
+  // The Sun Forte compiler and others implement older versions of the
+  // C++ standard's rules on access and nested classes.  These structs
+  // need to be public in order to deal with those compilers.
+
+  struct HostInfoIP {
+    uint16_t family;
+    uint16_t mask_len;
+    PRIPv6Addr addr;  // possibly IPv4-mapped address
+  };
+
+  struct HostInfoName {
+    char* host;
+    uint32_t host_len;
+  };
+
+ protected:
+  // simplified array of filters defined by this struct
+  struct HostInfo {
+    bool is_ipaddr{false};
+    int32_t port{0};
+    // other members intentionally uninitialized
+    union {
+      HostInfoIP ip;
+      HostInfoName name;
+    };
+
+    HostInfo() = default;
+    ~HostInfo() {
+      if (!is_ipaddr && name.host) {
+        free(name.host);
+      }
+    }
+  };
+
+ private:
+  // Private methods to insert and remove FilterLinks from the FilterLink chain.
+  nsresult InsertFilterLink(RefPtr<FilterLink>&& link);
+  nsresult RemoveFilterLink(nsISupports* givenObject);
+
+ protected:
+  // Indicates if local hosts (plain hostnames, no dots) should use the proxy
+  bool mFilterLocalHosts{false};
+
+  // Holds an array of HostInfo objects
+  nsTArray<UniquePtr<HostInfo>> mHostFiltersArray;
+
+  // Filters, always sorted by the position.
+  nsTArray<RefPtr<FilterLink>> mFilters;
+
+  nsTArray<nsCOMPtr<nsIProxyConfigChangedCallback>>
+      mProxyConfigChangedCallbacks;
+
+  uint32_t mProxyConfig{PROXYCONFIG_DIRECT};
+
+  nsCString mHTTPProxyHost;
+  int32_t mHTTPProxyPort{-1};
+
+  nsCString mHTTPSProxyHost;
+  int32_t mHTTPSProxyPort{-1};
+
+  // mSOCKSProxyTarget could be a host, a domain socket path,
+  // or a named-pipe name.
+  nsCString mSOCKSProxyTarget;
+  int32_t mSOCKSProxyPort{-1};
+  int32_t mSOCKSProxyVersion{4};
+  bool mSOCKSProxyRemoteDNS{false};
+  bool mProxyOverTLS{true};
+  bool mWPADOverDHCPEnabled{false};
+
+  RefPtr<nsPACMan> mPACMan;  // non-null if we are using PAC
+  nsCOMPtr<nsISystemProxySettings> mSystemProxySettings;
+
+  PRTime mSessionStart;
+  nsFailedProxyTable mFailedProxies;
+  // 30 minute default
+  int32_t mFailedProxyTimeout{30 * 60};
+
+ private:
+  nsresult AsyncResolveInternal(nsIChannel* channel, uint32_t flags,
+                                nsIProtocolProxyCallback* callback,
+                                nsICancelable** result, bool isSyncOK,
+                                nsISerialEventTarget* mainThreadEventTarget);
+  bool mIsShutdown{false};
+  nsCOMPtr<nsITimer> mReloadPACTimer;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsProtocolProxyService,
+                              NS_PROTOCOL_PROXY_SERVICE_IMPL_CID)
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // !nsProtocolProxyService_h__
diff --git a/netwerk/base/nsProxyInfo.cpp b/netwerk/base/nsProxyInfo.cpp
new file mode 100644
index 0000000000..6859845739
--- /dev/null
+++ b/netwerk/base/nsProxyInfo.cpp
@@ -0,0 +1,216 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsProxyInfo.h"
+
+#include "mozilla/net/NeckoChannelParams.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla {
+namespace net {
+
+// Yes, we support QI to nsProxyInfo
+NS_IMPL_ISUPPORTS(nsProxyInfo, nsProxyInfo, nsIProxyInfo)
+
+// These pointers are declared in nsProtocolProxyService.cpp and
+// comparison of mType by string pointer is valid within necko
+extern const char kProxyType_HTTP[];
+extern const char kProxyType_HTTPS[];
+extern const char kProxyType_SOCKS[];
+extern const char kProxyType_SOCKS4[];
+extern const char kProxyType_SOCKS5[];
+extern const char kProxyType_DIRECT[];
+extern const char kProxyType_PROXY[];
+
+nsProxyInfo::nsProxyInfo(const nsACString& aType, const nsACString& aHost,
+                         int32_t aPort, const nsACString& aUsername,
+                         const nsACString& aPassword, uint32_t aFlags,
+                         uint32_t aTimeout, uint32_t aResolveFlags,
+                         const nsACString& aProxyAuthorizationHeader,
+                         const nsACString& aConnectionIsolationKey)
+    : mHost(aHost),
+      mUsername(aUsername),
+      mPassword(aPassword),
+      mProxyAuthorizationHeader(aProxyAuthorizationHeader),
+      mConnectionIsolationKey(aConnectionIsolationKey),
+      mPort(aPort),
+      mFlags(aFlags),
+      mResolveFlags(aResolveFlags),
+      mTimeout(aTimeout),
+      mNext(nullptr) {
+  if (aType.EqualsASCII(kProxyType_HTTP)) {
+    mType = kProxyType_HTTP;
+  } else if (aType.EqualsASCII(kProxyType_HTTPS)) {
+    mType = kProxyType_HTTPS;
+  } else if (aType.EqualsASCII(kProxyType_SOCKS)) {
+    mType = kProxyType_SOCKS;
+  } else if (aType.EqualsASCII(kProxyType_SOCKS4)) {
+    mType = kProxyType_SOCKS4;
+  } else if (aType.EqualsASCII(kProxyType_SOCKS5)) {
+    mType = kProxyType_SOCKS5;
+  } else if (aType.EqualsASCII(kProxyType_PROXY)) {
+    mType = kProxyType_PROXY;
+  } else {
+    mType = kProxyType_DIRECT;
+  }
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetHost(nsACString& result) {
+  result = mHost;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetPort(int32_t* result) {
+  *result = mPort;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetType(nsACString& result) {
+  result = mType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetFlags(uint32_t* result) {
+  *result = mFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetResolveFlags(uint32_t* result) {
+  *result = mResolveFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetUsername(nsACString& result) {
+  result = mUsername;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetPassword(nsACString& result) {
+  result = mPassword;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetProxyAuthorizationHeader(nsACString& result) {
+  result = mProxyAuthorizationHeader;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetConnectionIsolationKey(nsACString& result) {
+  result = mConnectionIsolationKey;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetFailoverTimeout(uint32_t* result) {
+  *result = mTimeout;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetFailoverProxy(nsIProxyInfo** result) {
+  NS_IF_ADDREF(*result = mNext);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::SetFailoverProxy(nsIProxyInfo* proxy) {
+  nsCOMPtr<nsProxyInfo> pi = do_QueryInterface(proxy);
+  NS_ENSURE_ARG(pi);
+
+  pi.swap(mNext);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::GetSourceId(nsACString& result) {
+  result = mSourceId;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsProxyInfo::SetSourceId(const nsACString& sourceId) {
+  mSourceId = sourceId;
+  return NS_OK;
+}
+
+bool nsProxyInfo::IsDirect() {
+  if (!mType) return true;
+  return mType == kProxyType_DIRECT;
+}
+
+bool nsProxyInfo::IsHTTP() { return mType == kProxyType_HTTP; }
+
+bool nsProxyInfo::IsHTTPS() { return mType == kProxyType_HTTPS; }
+
+bool nsProxyInfo::IsSOCKS() {
+  return mType == kProxyType_SOCKS || mType == kProxyType_SOCKS4 ||
+         mType == kProxyType_SOCKS5;
+}
+
+/* static */
+void nsProxyInfo::SerializeProxyInfo(nsProxyInfo* aProxyInfo,
+                                     nsTArray<ProxyInfoCloneArgs>& aResult) {
+  for (nsProxyInfo* iter = aProxyInfo; iter; iter = iter->mNext) {
+    ProxyInfoCloneArgs* arg = aResult.AppendElement();
+    arg->type() = nsCString(iter->Type());
+    arg->host() = iter->Host();
+    arg->port() = iter->Port();
+    arg->username() = iter->Username();
+    arg->password() = iter->Password();
+    arg->proxyAuthorizationHeader() = iter->ProxyAuthorizationHeader();
+    arg->connectionIsolationKey() = iter->ConnectionIsolationKey();
+    arg->flags() = iter->Flags();
+    arg->timeout() = iter->Timeout();
+    arg->resolveFlags() = iter->ResolveFlags();
+  }
+}
+
+/* static */
+nsProxyInfo* nsProxyInfo::DeserializeProxyInfo(
+    const nsTArray<ProxyInfoCloneArgs>& aArgs) {
+  nsProxyInfo *pi = nullptr, *first = nullptr, *last = nullptr;
+  for (const ProxyInfoCloneArgs& info : aArgs) {
+    pi = new nsProxyInfo(info.type(), info.host(), info.port(), info.username(),
+                         info.password(), info.flags(), info.timeout(),
+                         info.resolveFlags(), info.proxyAuthorizationHeader(),
+                         info.connectionIsolationKey());
+    if (last) {
+      last->mNext = pi;
+      // |mNext| will be released in |last|'s destructor.
+      NS_IF_ADDREF(last->mNext);
+    } else {
+      first = pi;
+    }
+    last = pi;
+  }
+
+  return first;
+}
+
+already_AddRefed<nsProxyInfo> nsProxyInfo::CloneProxyInfoWithNewResolveFlags(
+    uint32_t aResolveFlags) {
+  nsTArray<ProxyInfoCloneArgs> args;
+  SerializeProxyInfo(this, args);
+
+  for (auto& arg : args) {
+    arg.resolveFlags() = aResolveFlags;
+  }
+
+  RefPtr<nsProxyInfo> result = DeserializeProxyInfo(args);
+  return result.forget();
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsProxyInfo.h b/netwerk/base/nsProxyInfo.h
new file mode 100644
index 0000000000..ca8602edc0
--- /dev/null
+++ b/netwerk/base/nsProxyInfo.h
@@ -0,0 +1,100 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsProxyInfo_h__
+#define nsProxyInfo_h__
+
+#include "nsIProxyInfo.h"
+#include "nsString.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Attributes.h"
+
+// Use to support QI nsIProxyInfo to nsProxyInfo
+#define NS_PROXYINFO_IID                             \
+  { /* ed42f751-825e-4cc2-abeb-3670711a8b85 */       \
+    0xed42f751, 0x825e, 0x4cc2, {                    \
+      0xab, 0xeb, 0x36, 0x70, 0x71, 0x1a, 0x8b, 0x85 \
+    }                                                \
+  }
+
+namespace mozilla {
+namespace net {
+
+class ProxyInfoCloneArgs;
+
+// This class is exposed to other classes inside Necko for fast access
+// to the nsIProxyInfo attributes.
+class nsProxyInfo final : public nsIProxyInfo {
+ public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_PROXYINFO_IID)
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIPROXYINFO
+
+  // Cheap accessors for use within Necko
+  const nsCString& Host() const { return mHost; }
+  int32_t Port() const { return mPort; }
+  const char* Type() const { return mType; }
+  uint32_t Flags() const { return mFlags; }
+  const nsCString& Username() const { return mUsername; }
+  const nsCString& Password() const { return mPassword; }
+  uint32_t Timeout() { return mTimeout; }
+  uint32_t ResolveFlags() { return mResolveFlags; }
+  const nsCString& ProxyAuthorizationHeader() const {
+    return mProxyAuthorizationHeader;
+  }
+  const nsCString& ConnectionIsolationKey() const {
+    return mConnectionIsolationKey;
+  }
+
+  bool IsDirect();
+  bool IsHTTP();
+  bool IsHTTPS();
+  bool IsSOCKS();
+
+  static void SerializeProxyInfo(nsProxyInfo* aProxyInfo,
+                                 nsTArray<ProxyInfoCloneArgs>& aResult);
+  static nsProxyInfo* DeserializeProxyInfo(
+      const nsTArray<ProxyInfoCloneArgs>& aArgs);
+
+  already_AddRefed<nsProxyInfo> CloneProxyInfoWithNewResolveFlags(
+      uint32_t aResolveFlags);
+
+ private:
+  friend class nsProtocolProxyService;
+
+  explicit nsProxyInfo(const char* type = nullptr) : mType(type) {}
+
+  nsProxyInfo(const nsACString& aType, const nsACString& aHost, int32_t aPort,
+              const nsACString& aUsername, const nsACString& aPassword,
+              uint32_t aFlags, uint32_t aTimeout, uint32_t aResolveFlags,
+              const nsACString& aProxyAuthorizationHeader,
+              const nsACString& aConnectionIsolationKey);
+
+  ~nsProxyInfo() { NS_IF_RELEASE(mNext); }
+
+  const char* mType;  // pointer to statically allocated value
+  nsCString mHost;
+  nsCString mUsername;
+  nsCString mPassword;
+  nsCString mProxyAuthorizationHeader;
+  nsCString mConnectionIsolationKey;
+  nsCString mSourceId;
+  int32_t mPort{-1};
+  uint32_t mFlags{0};
+  // We need to read on multiple threads, but don't need to sync on anything
+  // else
+  Atomic<uint32_t, Relaxed> mResolveFlags{0};
+  uint32_t mTimeout{UINT32_MAX};
+  nsProxyInfo* mNext{nullptr};
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsProxyInfo, NS_PROXYINFO_IID)
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsProxyInfo_h__
diff --git a/netwerk/base/nsReadLine.h b/netwerk/base/nsReadLine.h
new file mode 100644
index 0000000000..f1e4693f92
--- /dev/null
+++ b/netwerk/base/nsReadLine.h
@@ -0,0 +1,131 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsReadLine_h__
+#define nsReadLine_h__
+
+#include "nsIInputStream.h"
+#include "mozilla/Likely.h"
+
+/**
+ * @file
+ * Functions to read complete lines from an input stream.
+ *
+ * To properly use the helper function in here (NS_ReadLine) the caller should
+ * create a nsLineBuffer<T> with new, and pass it to NS_ReadLine every time it
+ * wants a line out.
+ *
+ * When done, the object should be deleted.
+ */
+
+/**
+ * @internal
+ * Buffer size. This many bytes will be buffered. If a line is longer than this,
+ * the partial line will be appended to the out parameter of NS_ReadLine and the
+ * buffer will be emptied.
+ * Note: if you change this constant, please update the regression test in
+ * netwerk/test/unit/test_readline.js accordingly (bug 397850).
+ */
+#define kLineBufferSize 4096
+
+/**
+ * @internal
+ * Line buffer structure, buffers data from an input stream.
+ * The buffer is empty when |start| == |end|.
+ * Invariant: |start| <= |end|
+ */
+template <typename CharT>
+class nsLineBuffer {
+ public:
+  nsLineBuffer() : start(buf), end(buf) {}
+
+  CharT buf[kLineBufferSize + 1];
+  CharT* start;
+  CharT* end;
+};
+
+/**
+ * Read a line from an input stream. Lines are separated by '\r' (0x0D) or '\n'
+ * (0x0A), or "\r\n" or "\n\r".
+ *
+ * @param aStream
+ *        The stream to read from
+ * @param aBuffer
+ *        The line buffer to use.  A single line buffer must not be used with
+ *        different input streams.
+ * @param aLine [out]
+ *        The string where the line will be stored.
+ * @param more [out]
+ *        Whether more data is available in the buffer. If true, NS_ReadLine may
+ *        be called again to read further lines. Otherwise, further calls to
+ *        NS_ReadLine will return an error.
+ *
+ * @retval NS_OK
+ *         Read successful
+ * @retval error
+ *         Input stream returned an error upon read. See
+ *         nsIInputStream::read.
+ */
+template <typename CharT, class StreamType, class StringType>
+nsresult NS_ReadLine(StreamType* aStream, nsLineBuffer<CharT>* aBuffer,
+                     StringType& aLine, bool* more) {
+  CharT eolchar = 0;  // the first eol char or 1 after \r\n or \n\r is found
+
+  aLine.Truncate();
+
+  while (true) {  // will be returning out of this loop on eol or eof
+    if (aBuffer->start == aBuffer->end) {  // buffer is empty.  Read into it.
+      uint32_t bytesRead;
+      nsresult rv = aStream->Read(aBuffer->buf, kLineBufferSize, &bytesRead);
+      if (NS_FAILED(rv) || MOZ_UNLIKELY(bytesRead == 0)) {
+        *more = false;
+        return rv;
+      }
+      aBuffer->start = aBuffer->buf;
+      aBuffer->end = aBuffer->buf + bytesRead;
+      *(aBuffer->end) = '\0';
+    }
+
+    /*
+     * Walk the buffer looking for an end-of-line.
+     * There are 3 cases to consider:
+     *  1. the eol char is the last char in the buffer
+     *  2. the eol char + one more char at the end of the buffer
+     *  3. the eol char + two or more chars at the end of the buffer
+     * we need at least one char after the first eol char to determine if
+     * it's a \r\n or \n\r sequence (and skip over it), and we need one
+     * more char after the end-of-line to set |more| correctly.
+     */
+    CharT* current = aBuffer->start;
+    if (MOZ_LIKELY(eolchar == 0)) {
+      for (; current < aBuffer->end; ++current) {
+        if (*current == '\n' || *current == '\r') {
+          eolchar = *current;
+          *current++ = '\0';
+          aLine.Append(aBuffer->start);
+          break;
+        }
+      }
+    }
+    if (MOZ_LIKELY(eolchar != 0)) {
+      for (; current < aBuffer->end; ++current) {
+        if ((eolchar == '\r' && *current == '\n') ||
+            (eolchar == '\n' && *current == '\r')) {
+          eolchar = 1;
+          continue;
+        }
+        aBuffer->start = current;
+        *more = true;
+        return NS_OK;
+      }
+    }
+
+    if (eolchar == 0) aLine.Append(aBuffer->start);
+    aBuffer->start = aBuffer->end;  // mark the buffer empty
+  }
+}
+
+#endif  // nsReadLine_h__
diff --git a/netwerk/base/nsRedirectHistoryEntry.cpp b/netwerk/base/nsRedirectHistoryEntry.cpp
new file mode 100644
index 0000000000..da1a18cb95
--- /dev/null
+++ b/netwerk/base/nsRedirectHistoryEntry.cpp
@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsRedirectHistoryEntry.h"
+#include "nsCOMPtr.h"
+#include "nsIURI.h"
+#include "nsIPrincipal.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsRedirectHistoryEntry, nsIRedirectHistoryEntry)
+
+nsRedirectHistoryEntry::nsRedirectHistoryEntry(nsIPrincipal* aPrincipal,
+                                               nsIURI* aReferrer,
+                                               const nsACString& aRemoteAddress)
+    : mPrincipal(aPrincipal),
+      mReferrer(aReferrer),
+      mRemoteAddress(aRemoteAddress) {}
+
+NS_IMETHODIMP
+nsRedirectHistoryEntry::GetRemoteAddress(nsACString& result) {
+  result = mRemoteAddress;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsRedirectHistoryEntry::GetReferrerURI(nsIURI** referrer) {
+  *referrer = do_AddRef(mReferrer).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsRedirectHistoryEntry::GetPrincipal(nsIPrincipal** principal) {
+  *principal = do_AddRef(mPrincipal).take();
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsRedirectHistoryEntry.h b/netwerk/base/nsRedirectHistoryEntry.h
new file mode 100644
index 0000000000..bc916062a8
--- /dev/null
+++ b/netwerk/base/nsRedirectHistoryEntry.h
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsRedirectHistoryEntry_h__
+#define nsRedirectHistoryEntry_h__
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsIRedirectHistoryEntry.h"
+
+class nsIURI;
+class nsIPrincipal;
+
+namespace mozilla {
+namespace net {
+
+class nsRedirectHistoryEntry final : public nsIRedirectHistoryEntry {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREDIRECTHISTORYENTRY
+
+  nsRedirectHistoryEntry(nsIPrincipal* aPrincipal, nsIURI* aReferrer,
+                         const nsACString& aRemoteAddress);
+
+ private:
+  ~nsRedirectHistoryEntry() = default;
+
+  nsCOMPtr<nsIPrincipal> mPrincipal;
+  nsCOMPtr<nsIURI> mReferrer;
+  nsCString mRemoteAddress;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsRedirectHistoryEntry_h__
diff --git a/netwerk/base/nsRequestObserverProxy.cpp b/netwerk/base/nsRequestObserverProxy.cpp
new file mode 100644
index 0000000000..fda235488a
--- /dev/null
+++ b/netwerk/base/nsRequestObserverProxy.cpp
@@ -0,0 +1,175 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#include "nscore.h"
+#include "nsRequestObserverProxy.h"
+#include "nsIRequest.h"
+#include "mozilla/Logging.h"
+#include "mozilla/IntegerPrintfMacros.h"
+
+namespace mozilla {
+namespace net {
+
+static LazyLogModule gRequestObserverProxyLog("nsRequestObserverProxy");
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gRequestObserverProxyLog, LogLevel::Debug, args)
+
+//-----------------------------------------------------------------------------
+// nsARequestObserverEvent internal class...
+//-----------------------------------------------------------------------------
+
+nsARequestObserverEvent::nsARequestObserverEvent(nsIRequest* request)
+    : Runnable("net::nsARequestObserverEvent"), mRequest(request) {
+  MOZ_ASSERT(mRequest, "null pointer");
+}
+
+//-----------------------------------------------------------------------------
+// nsOnStartRequestEvent internal class...
+//-----------------------------------------------------------------------------
+
+class nsOnStartRequestEvent : public nsARequestObserverEvent {
+  RefPtr<nsRequestObserverProxy> mProxy;
+
+ public:
+  nsOnStartRequestEvent(nsRequestObserverProxy* proxy, nsIRequest* request)
+      : nsARequestObserverEvent(request), mProxy(proxy) {
+    MOZ_ASSERT(mProxy, "null pointer");
+  }
+
+  NS_IMETHOD Run() override {
+    LOG(("nsOnStartRequestEvent::HandleEvent [req=%p]\n", mRequest.get()));
+
+    if (!mProxy->mObserver) {
+      MOZ_ASSERT_UNREACHABLE(
+          "already handled onStopRequest event "
+          "(observer is null)");
+      return NS_OK;
+    }
+
+    LOG(("handle startevent=%p\n", this));
+    nsresult rv = mProxy->mObserver->OnStartRequest(mRequest);
+    if (NS_FAILED(rv)) {
+      LOG(("OnStartRequest failed [rv=%" PRIx32 "] canceling request!\n",
+           static_cast<uint32_t>(rv)));
+      rv = mRequest->Cancel(rv);
+      NS_ASSERTION(NS_SUCCEEDED(rv), "Cancel failed for request!");
+    }
+
+    return NS_OK;
+  }
+
+ private:
+  virtual ~nsOnStartRequestEvent() = default;
+};
+
+//-----------------------------------------------------------------------------
+// nsOnStopRequestEvent internal class...
+//-----------------------------------------------------------------------------
+
+class nsOnStopRequestEvent : public nsARequestObserverEvent {
+  RefPtr<nsRequestObserverProxy> mProxy;
+
+ public:
+  nsOnStopRequestEvent(nsRequestObserverProxy* proxy, nsIRequest* request)
+      : nsARequestObserverEvent(request), mProxy(proxy) {
+    MOZ_ASSERT(mProxy, "null pointer");
+  }
+
+  NS_IMETHOD Run() override {
+    LOG(("nsOnStopRequestEvent::HandleEvent [req=%p]\n", mRequest.get()));
+
+    nsMainThreadPtrHandle<nsIRequestObserver> observer = mProxy->mObserver;
+    if (!observer) {
+      MOZ_ASSERT_UNREACHABLE(
+          "already handled onStopRequest event "
+          "(observer is null)");
+      return NS_OK;
+    }
+    // Do not allow any more events to be handled after OnStopRequest
+    mProxy->mObserver = nullptr;
+
+    nsresult status = NS_OK;
+    DebugOnly<nsresult> rv = mRequest->GetStatus(&status);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "GetStatus failed for request!");
+
+    LOG(("handle stopevent=%p\n", this));
+    (void)observer->OnStopRequest(mRequest, status);
+
+    return NS_OK;
+  }
+
+ private:
+  virtual ~nsOnStopRequestEvent() = default;
+};
+
+//-----------------------------------------------------------------------------
+// nsRequestObserverProxy::nsISupports implementation...
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsRequestObserverProxy, nsIRequestObserver,
+                  nsIRequestObserverProxy)
+
+//-----------------------------------------------------------------------------
+// nsRequestObserverProxy::nsIRequestObserver implementation...
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsRequestObserverProxy::OnStartRequest(nsIRequest* request) {
+  LOG(("nsRequestObserverProxy::OnStartRequest [this=%p req=%p]\n", this,
+       request));
+
+  RefPtr<nsOnStartRequestEvent> ev = new nsOnStartRequestEvent(this, request);
+
+  LOG(("post startevent=%p\n", ev.get()));
+  return FireEvent(ev);
+}
+
+NS_IMETHODIMP
+nsRequestObserverProxy::OnStopRequest(nsIRequest* request, nsresult status) {
+  LOG(("nsRequestObserverProxy: OnStopRequest [this=%p req=%p status=%" PRIx32
+       "]\n",
+       this, request, static_cast<uint32_t>(status)));
+
+  // The status argument is ignored because, by the time the OnStopRequestEvent
+  // is actually processed, the status of the request may have changed :-(
+  // To make sure that an accurate status code is always used, GetStatus() is
+  // called when the OnStopRequestEvent is actually processed (see above).
+
+  RefPtr<nsOnStopRequestEvent> ev = new nsOnStopRequestEvent(this, request);
+
+  LOG(("post stopevent=%p\n", ev.get()));
+  return FireEvent(ev);
+}
+
+//-----------------------------------------------------------------------------
+// nsRequestObserverProxy::nsIRequestObserverProxy implementation...
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsRequestObserverProxy::Init(nsIRequestObserver* observer,
+                             nsISupports* context) {
+  NS_ENSURE_ARG_POINTER(observer);
+  mObserver = new nsMainThreadPtrHolder<nsIRequestObserver>(
+      "nsRequestObserverProxy::mObserver", observer);
+  mContext = new nsMainThreadPtrHolder<nsISupports>(
+      "nsRequestObserverProxy::mContext", context);
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsRequestObserverProxy implementation...
+//-----------------------------------------------------------------------------
+
+nsresult nsRequestObserverProxy::FireEvent(nsARequestObserverEvent* event) {
+  nsCOMPtr<nsIEventTarget> mainThread(GetMainThreadSerialEventTarget());
+  return mainThread->Dispatch(event, NS_DISPATCH_NORMAL);
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsRequestObserverProxy.h b/netwerk/base/nsRequestObserverProxy.h
new file mode 100644
index 0000000000..e1ccec0c4c
--- /dev/null
+++ b/netwerk/base/nsRequestObserverProxy.h
@@ -0,0 +1,56 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsRequestObserverProxy_h__
+#define nsRequestObserverProxy_h__
+
+#include "nsIRequestObserver.h"
+#include "nsIRequestObserverProxy.h"
+#include "nsIRequest.h"
+#include "nsThreadUtils.h"
+#include "nsCOMPtr.h"
+#include "nsProxyRelease.h"
+
+namespace mozilla {
+namespace net {
+
+class nsARequestObserverEvent;
+
+class nsRequestObserverProxy final : public nsIRequestObserverProxy {
+  ~nsRequestObserverProxy() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSIREQUESTOBSERVERPROXY
+
+  nsRequestObserverProxy() = default;
+
+  nsIRequestObserver* Observer() { return mObserver; }
+
+  nsresult FireEvent(nsARequestObserverEvent*);
+
+ protected:
+  nsMainThreadPtrHandle<nsIRequestObserver> mObserver;
+  nsMainThreadPtrHandle<nsISupports> mContext;
+
+  friend class nsOnStartRequestEvent;
+  friend class nsOnStopRequestEvent;
+};
+
+class nsARequestObserverEvent : public Runnable {
+ public:
+  explicit nsARequestObserverEvent(nsIRequest*);
+
+ protected:
+  virtual ~nsARequestObserverEvent() = default;
+
+  nsCOMPtr<nsIRequest> mRequest;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsRequestObserverProxy_h__
diff --git a/netwerk/base/nsSerializationHelper.cpp b/netwerk/base/nsSerializationHelper.cpp
new file mode 100644
index 0000000000..6e2efb7c57
--- /dev/null
+++ b/netwerk/base/nsSerializationHelper.cpp
@@ -0,0 +1,54 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsSerializationHelper.h"
+
+#include "mozilla/Base64.h"
+#include "nsISerializable.h"
+#include "nsIObjectOutputStream.h"
+#include "nsIObjectInputStream.h"
+#include "nsString.h"
+#include "nsBase64Encoder.h"
+#include "nsComponentManagerUtils.h"
+#include "nsStringStream.h"
+
+using namespace mozilla;
+
+nsresult NS_SerializeToString(nsISerializable* obj, nsACString& str) {
+  RefPtr<nsBase64Encoder> stream(new nsBase64Encoder());
+  if (!stream) return NS_ERROR_OUT_OF_MEMORY;
+
+  nsCOMPtr<nsIObjectOutputStream> objstream = NS_NewObjectOutputStream(stream);
+  nsresult rv =
+      objstream->WriteCompoundObject(obj, NS_GET_IID(nsISupports), true);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return stream->Finish(str);
+}
+
+nsresult NS_DeserializeObject(const nsACString& str, nsISupports** obj) {
+  nsCString decodedData;
+  nsresult rv = Base64Decode(str, decodedData);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIInputStream> stream;
+  rv = NS_NewCStringInputStream(getter_AddRefs(stream), std::move(decodedData));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIObjectInputStream> objstream = NS_NewObjectInputStream(stream);
+  return objstream->ReadObject(true, obj);
+}
+
+NS_IMPL_ISUPPORTS(nsSerializationHelper, nsISerializationHelper)
+
+NS_IMETHODIMP
+nsSerializationHelper::SerializeToString(nsISerializable* serializable,
+                                         nsACString& _retval) {
+  return NS_SerializeToString(serializable, _retval);
+}
+
+NS_IMETHODIMP
+nsSerializationHelper::DeserializeObject(const nsACString& input,
+                                         nsISupports** _retval) {
+  return NS_DeserializeObject(input, _retval);
+}
diff --git a/netwerk/base/nsSerializationHelper.h b/netwerk/base/nsSerializationHelper.h
new file mode 100644
index 0000000000..4e21a4c2df
--- /dev/null
+++ b/netwerk/base/nsSerializationHelper.h
@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/** @file
+ * Helper functions for (de)serializing objects to/from ASCII strings.
+ */
+
+#ifndef NSSERIALIZATIONHELPER_H_
+#define NSSERIALIZATIONHELPER_H_
+
+#include "nsStringFwd.h"
+#include "nsISerializationHelper.h"
+#include "mozilla/Attributes.h"
+
+class nsISerializable;
+
+/**
+ * Serialize an object to an ASCII string.
+ */
+nsresult NS_SerializeToString(nsISerializable* obj, nsACString& str);
+
+/**
+ * Deserialize an object.
+ */
+nsresult NS_DeserializeObject(const nsACString& str, nsISupports** obj);
+
+class nsSerializationHelper final : public nsISerializationHelper {
+  ~nsSerializationHelper() = default;
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSISERIALIZATIONHELPER
+};
+
+#endif
diff --git a/netwerk/base/nsServerSocket.cpp b/netwerk/base/nsServerSocket.cpp
new file mode 100644
index 0000000000..cf8fc7b619
--- /dev/null
+++ b/netwerk/base/nsServerSocket.cpp
@@ -0,0 +1,582 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsSocketTransport2.h"
+#include "nsServerSocket.h"
+#include "nsProxyRelease.h"
+#include "nsError.h"
+#include "nsNetCID.h"
+#include "prnetdb.h"
+#include "prio.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/Unused.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIFile.h"
+#if defined(XP_WIN)
+#  include "private/pprio.h"
+#  include <winsock2.h>
+#  include <mstcpip.h>
+
+#  ifndef IPV6_V6ONLY
+#    define IPV6_V6ONLY 27
+#  endif
+
+#endif
+
+namespace mozilla {
+namespace net {
+
+//-----------------------------------------------------------------------------
+
+using nsServerSocketFunc = void (nsServerSocket::*)();
+
+static nsresult PostEvent(nsServerSocket* s, nsServerSocketFunc func) {
+  nsCOMPtr<nsIRunnable> ev = NewRunnableMethod("net::PostEvent", s, func);
+  if (!gSocketTransportService) return NS_ERROR_FAILURE;
+
+  return gSocketTransportService->Dispatch(ev, NS_DISPATCH_NORMAL);
+}
+
+//-----------------------------------------------------------------------------
+// nsServerSocket
+//-----------------------------------------------------------------------------
+
+nsServerSocket::nsServerSocket() {
+  // we want to be able to access the STS directly, and it may not have been
+  // constructed yet.  the STS constructor sets gSocketTransportService.
+  if (!gSocketTransportService) {
+    // This call can fail if we're offline, for example.
+    nsCOMPtr<nsISocketTransportService> sts =
+        do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID);
+  }
+  // make sure the STS sticks around as long as we do
+  NS_IF_ADDREF(gSocketTransportService);
+}
+
+nsServerSocket::~nsServerSocket() {
+  Close();  // just in case :)
+
+  // release our reference to the STS
+  nsSocketTransportService* serv = gSocketTransportService;
+  NS_IF_RELEASE(serv);
+}
+
+void nsServerSocket::OnMsgClose() {
+  SOCKET_LOG(("nsServerSocket::OnMsgClose [this=%p]\n", this));
+
+  if (NS_FAILED(mCondition)) return;
+
+  // tear down socket.  this signals the STS to detach our socket handler.
+  mCondition = NS_BINDING_ABORTED;
+
+  // if we are attached, then we'll close the socket in our OnSocketDetached.
+  // otherwise, call OnSocketDetached from here.
+  if (!mAttached) OnSocketDetached(mFD);
+}
+
+void nsServerSocket::OnMsgAttach() {
+  SOCKET_LOG(("nsServerSocket::OnMsgAttach [this=%p]\n", this));
+
+  if (NS_FAILED(mCondition)) return;
+
+  mCondition = TryAttach();
+
+  // if we hit an error while trying to attach then bail...
+  if (NS_FAILED(mCondition)) {
+    NS_ASSERTION(!mAttached, "should not be attached already");
+    OnSocketDetached(mFD);
+  }
+}
+
+nsresult nsServerSocket::TryAttach() {
+  nsresult rv;
+
+  if (!gSocketTransportService) return NS_ERROR_FAILURE;
+
+  //
+  // find out if it is going to be ok to attach another socket to the STS.
+  // if not then we have to wait for the STS to tell us that it is ok.
+  // the notification is asynchronous, which means that when we could be
+  // in a race to call AttachSocket once notified.  for this reason, when
+  // we get notified, we just re-enter this function.  as a result, we are
+  // sure to ask again before calling AttachSocket.  in this way we deal
+  // with the race condition.  though it isn't the most elegant solution,
+  // it is far simpler than trying to build a system that would guarantee
+  // FIFO ordering (which wouldn't even be that valuable IMO).  see bug
+  // 194402 for more info.
+  //
+  if (!gSocketTransportService->CanAttachSocket()) {
+    nsCOMPtr<nsIRunnable> event = NewRunnableMethod(
+        "net::nsServerSocket::OnMsgAttach", this, &nsServerSocket::OnMsgAttach);
+    if (!event) return NS_ERROR_OUT_OF_MEMORY;
+
+    nsresult rv = gSocketTransportService->NotifyWhenCanAttachSocket(event);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  //
+  // ok, we can now attach our socket to the STS for polling
+  //
+  rv = gSocketTransportService->AttachSocket(mFD, this);
+  if (NS_FAILED(rv)) return rv;
+
+  mAttached = true;
+
+  //
+  // now, configure our poll flags for listening...
+  //
+  mPollFlags = (PR_POLL_READ | PR_POLL_EXCEPT);
+  return NS_OK;
+}
+
+void nsServerSocket::CreateClientTransport(PRFileDesc* aClientFD,
+                                           const NetAddr& aClientAddr) {
+  RefPtr<nsSocketTransport> trans = new nsSocketTransport;
+  if (NS_WARN_IF(!trans)) {
+    mCondition = NS_ERROR_OUT_OF_MEMORY;
+    return;
+  }
+
+  nsresult rv = trans->InitWithConnectedSocket(aClientFD, &aClientAddr);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    mCondition = rv;
+    return;
+  }
+
+  mListener->OnSocketAccepted(this, trans);
+}
+
+//-----------------------------------------------------------------------------
+// nsServerSocket::nsASocketHandler
+//-----------------------------------------------------------------------------
+
+void nsServerSocket::OnSocketReady(PRFileDesc* fd, int16_t outFlags) {
+  NS_ASSERTION(NS_SUCCEEDED(mCondition), "oops");
+  NS_ASSERTION(mFD == fd, "wrong file descriptor");
+  NS_ASSERTION(outFlags != -1, "unexpected timeout condition reached");
+
+  if (outFlags & (PR_POLL_ERR | PR_POLL_HUP | PR_POLL_NVAL)) {
+    NS_WARNING("error polling on listening socket");
+    mCondition = NS_ERROR_UNEXPECTED;
+    return;
+  }
+
+  PRFileDesc* clientFD;
+  PRNetAddr prClientAddr;
+
+  // NSPR doesn't tell us the peer address's length (as provided by the
+  // 'accept' system call), so we can't distinguish between named,
+  // unnamed, and abstract peer addresses. Clear prClientAddr first, so
+  // that the path will at least be reliably empty for unnamed and
+  // abstract addresses, and not garbage when the peer is unnamed.
+  memset(&prClientAddr, 0, sizeof(prClientAddr));
+
+  clientFD = PR_Accept(mFD, &prClientAddr, PR_INTERVAL_NO_WAIT);
+  if (!clientFD) {
+    NS_WARNING("PR_Accept failed");
+    mCondition = NS_ERROR_UNEXPECTED;
+    return;
+  }
+  PR_SetFDInheritable(clientFD, false);
+
+  NetAddr clientAddr(&prClientAddr);
+  // Accept succeeded, create socket transport and notify consumer
+  CreateClientTransport(clientFD, clientAddr);
+}
+
+void nsServerSocket::OnSocketDetached(PRFileDesc* fd) {
+  // force a failure condition if none set; maybe the STS is shutting down :-/
+  if (NS_SUCCEEDED(mCondition)) mCondition = NS_ERROR_ABORT;
+
+  if (mFD) {
+    NS_ASSERTION(mFD == fd, "wrong file descriptor");
+    PR_Close(mFD);
+    mFD = nullptr;
+  }
+
+  if (mListener) {
+    mListener->OnStopListening(this, mCondition);
+
+    // need to atomically clear mListener.  see our Close() method.
+    RefPtr<nsIServerSocketListener> listener = nullptr;
+    {
+      MutexAutoLock lock(mLock);
+      listener = ToRefPtr(std::move(mListener));
+    }
+
+    // XXX we need to proxy the release to the listener's target thread to work
+    // around bug 337492.
+    if (listener) {
+      NS_ProxyRelease("nsServerSocket::mListener", mListenerTarget,
+                      listener.forget());
+    }
+  }
+}
+
+void nsServerSocket::IsLocal(bool* aIsLocal) {
+#if defined(XP_UNIX)
+  // Unix-domain sockets are always local.
+  if (mAddr.raw.family == PR_AF_LOCAL) {
+    *aIsLocal = true;
+    return;
+  }
+#endif
+
+  // If bound to loopback, this server socket only accepts local connections.
+  *aIsLocal = PR_IsNetAddrType(&mAddr, PR_IpAddrLoopback);
+}
+
+void nsServerSocket::KeepWhenOffline(bool* aKeepWhenOffline) {
+  *aKeepWhenOffline = mKeepWhenOffline;
+}
+
+//-----------------------------------------------------------------------------
+// nsServerSocket::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsServerSocket, nsIServerSocket)
+
+//-----------------------------------------------------------------------------
+// nsServerSocket::nsIServerSocket
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsServerSocket::Init(int32_t aPort, bool aLoopbackOnly, int32_t aBackLog) {
+  return InitSpecialConnection(aPort, aLoopbackOnly ? LoopbackOnly : 0,
+                               aBackLog);
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitIPv6(int32_t aPort, bool aLoopbackOnly, int32_t aBackLog) {
+  PRNetAddrValue val;
+  PRNetAddr addr;
+
+  if (aPort < 0) {
+    aPort = 0;
+  }
+  if (aLoopbackOnly) {
+    val = PR_IpAddrLoopback;
+  } else {
+    val = PR_IpAddrAny;
+  }
+  PR_SetNetAddr(val, PR_AF_INET6, aPort, &addr);
+
+  mKeepWhenOffline = false;
+  return InitWithAddress(&addr, aBackLog);
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitDualStack(int32_t aPort, int32_t aBackLog) {
+  if (aPort < 0) {
+    aPort = 0;
+  }
+  PRNetAddr addr;
+  PR_SetNetAddr(PR_IpAddrAny, PR_AF_INET6, aPort, &addr);
+  return InitWithAddressInternal(&addr, aBackLog, true);
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitWithFilename(nsIFile* aPath, uint32_t aPermissions,
+                                 int32_t aBacklog) {
+#if defined(XP_UNIX)
+  nsresult rv;
+
+  nsAutoCString path;
+  rv = aPath->GetNativePath(path);
+  if (NS_FAILED(rv)) return rv;
+
+  // Create a Unix domain PRNetAddr referring to the given path.
+  PRNetAddr addr;
+  if (path.Length() > sizeof(addr.local.path) - 1) {
+    return NS_ERROR_FILE_NAME_TOO_LONG;
+  }
+  addr.local.family = PR_AF_LOCAL;
+  memcpy(addr.local.path, path.get(), path.Length());
+  addr.local.path[path.Length()] = '\0';
+
+  rv = InitWithAddress(&addr, aBacklog);
+  if (NS_FAILED(rv)) return rv;
+
+  return aPath->SetPermissions(aPermissions);
+#else
+  return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitWithAbstractAddress(const nsACString& aName,
+                                        int32_t aBacklog) {
+  // Abstract socket address is supported on Linux and Android only.
+  // If not Linux, we should return error.
+#if defined(XP_LINUX)
+  // Create an abstract socket address PRNetAddr referring to the name
+  PRNetAddr addr;
+  if (aName.Length() > sizeof(addr.local.path) - 2) {
+    return NS_ERROR_FILE_NAME_TOO_LONG;
+  }
+  addr.local.family = PR_AF_LOCAL;
+  addr.local.path[0] = 0;
+  memcpy(addr.local.path + 1, aName.BeginReading(), aName.Length());
+  addr.local.path[aName.Length() + 1] = 0;
+
+  return InitWithAddress(&addr, aBacklog);
+#else
+  return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitSpecialConnection(int32_t aPort, nsServerSocketFlag aFlags,
+                                      int32_t aBackLog) {
+  PRNetAddrValue val;
+  PRNetAddr addr;
+
+  if (aPort < 0) aPort = 0;
+  if (aFlags & nsIServerSocket::LoopbackOnly) {
+    val = PR_IpAddrLoopback;
+  } else {
+    val = PR_IpAddrAny;
+  }
+  PR_SetNetAddr(val, PR_AF_INET, aPort, &addr);
+
+  mKeepWhenOffline = ((aFlags & nsIServerSocket::KeepWhenOffline) != 0);
+  return InitWithAddress(&addr, aBackLog);
+}
+
+NS_IMETHODIMP
+nsServerSocket::InitWithAddress(const PRNetAddr* aAddr, int32_t aBackLog) {
+  return InitWithAddressInternal(aAddr, aBackLog);
+}
+
+nsresult nsServerSocket::InitWithAddressInternal(const PRNetAddr* aAddr,
+                                                 int32_t aBackLog,
+                                                 bool aDualStack) {
+  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
+  nsresult rv;
+
+  //
+  // configure listening socket...
+  //
+
+  mFD = PR_OpenTCPSocket(aAddr->raw.family);
+  if (!mFD) {
+    NS_WARNING("unable to create server socket");
+    return ErrorAccordingToNSPR(PR_GetError());
+  }
+
+#if defined(XP_WIN)
+  // https://docs.microsoft.com/en-us/windows/win32/winsock/dual-stack-sockets
+  // To create a Dual-Stack Socket, we have to disable IPV6_V6ONLY.
+  if (aDualStack) {
+    PROsfd osfd = PR_FileDesc2NativeHandle(mFD);
+    if (osfd != -1) {
+      int disable = 0;
+      setsockopt(osfd, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&disable,
+                 sizeof(disable));
+    }
+  }
+#else
+  mozilla::Unused << aDualStack;
+#endif
+
+  PR_SetFDInheritable(mFD, false);
+
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_Reuseaddr;
+  opt.value.reuse_addr = true;
+  PR_SetSocketOption(mFD, &opt);
+
+  opt.option = PR_SockOpt_Nonblocking;
+  opt.value.non_blocking = true;
+  PR_SetSocketOption(mFD, &opt);
+
+  if (PR_Bind(mFD, aAddr) != PR_SUCCESS) {
+    NS_WARNING("failed to bind socket");
+    goto fail;
+  }
+
+  if (aBackLog < 0) aBackLog = 5;  // seems like a reasonable default
+
+  if (PR_Listen(mFD, aBackLog) != PR_SUCCESS) {
+    NS_WARNING("cannot listen on socket");
+    goto fail;
+  }
+
+  // get the resulting socket address, which may be different than what
+  // we passed to bind.
+  if (PR_GetSockName(mFD, &mAddr) != PR_SUCCESS) {
+    NS_WARNING("cannot get socket name");
+    goto fail;
+  }
+
+  // Set any additional socket defaults needed by child classes
+  rv = SetSocketDefaults();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    goto fail;
+  }
+
+  // wait until AsyncListen is called before polling the socket for
+  // client connections.
+  return NS_OK;
+
+fail:
+  rv = ErrorAccordingToNSPR(PR_GetError());
+  Close();
+  return rv;
+}
+
+NS_IMETHODIMP
+nsServerSocket::Close() {
+  {
+    MutexAutoLock lock(mLock);
+    // we want to proxy the close operation to the socket thread if a listener
+    // has been set.  otherwise, we should just close the socket here...
+    if (!mListener) {
+      if (mFD) {
+        PR_Close(mFD);
+        mFD = nullptr;
+      }
+      return NS_OK;
+    }
+  }
+  return PostEvent(this, &nsServerSocket::OnMsgClose);
+}
+
+namespace {
+
+class ServerSocketListenerProxy final : public nsIServerSocketListener {
+  ~ServerSocketListenerProxy() = default;
+
+ public:
+  explicit ServerSocketListenerProxy(nsIServerSocketListener* aListener)
+      : mListener(new nsMainThreadPtrHolder<nsIServerSocketListener>(
+            "ServerSocketListenerProxy::mListener", aListener)),
+        mTarget(GetCurrentSerialEventTarget()) {}
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISERVERSOCKETLISTENER
+
+  class OnSocketAcceptedRunnable : public Runnable {
+   public:
+    OnSocketAcceptedRunnable(
+        const nsMainThreadPtrHandle<nsIServerSocketListener>& aListener,
+        nsIServerSocket* aServ, nsISocketTransport* aTransport)
+        : Runnable("net::ServerSocketListenerProxy::OnSocketAcceptedRunnable"),
+          mListener(aListener),
+          mServ(aServ),
+          mTransport(aTransport) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
+    nsCOMPtr<nsIServerSocket> mServ;
+    nsCOMPtr<nsISocketTransport> mTransport;
+  };
+
+  class OnStopListeningRunnable : public Runnable {
+   public:
+    OnStopListeningRunnable(
+        const nsMainThreadPtrHandle<nsIServerSocketListener>& aListener,
+        nsIServerSocket* aServ, nsresult aStatus)
+        : Runnable("net::ServerSocketListenerProxy::OnStopListeningRunnable"),
+          mListener(aListener),
+          mServ(aServ),
+          mStatus(aStatus) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
+    nsCOMPtr<nsIServerSocket> mServ;
+    nsresult mStatus;
+  };
+
+ private:
+  nsMainThreadPtrHandle<nsIServerSocketListener> mListener;
+  nsCOMPtr<nsIEventTarget> mTarget;
+};
+
+NS_IMPL_ISUPPORTS(ServerSocketListenerProxy, nsIServerSocketListener)
+
+NS_IMETHODIMP
+ServerSocketListenerProxy::OnSocketAccepted(nsIServerSocket* aServ,
+                                            nsISocketTransport* aTransport) {
+  RefPtr<OnSocketAcceptedRunnable> r =
+      new OnSocketAcceptedRunnable(mListener, aServ, aTransport);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+ServerSocketListenerProxy::OnStopListening(nsIServerSocket* aServ,
+                                           nsresult aStatus) {
+  RefPtr<OnStopListeningRunnable> r =
+      new OnStopListeningRunnable(mListener, aServ, aStatus);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+ServerSocketListenerProxy::OnSocketAcceptedRunnable::Run() {
+  mListener->OnSocketAccepted(mServ, mTransport);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ServerSocketListenerProxy::OnStopListeningRunnable::Run() {
+  mListener->OnStopListening(mServ, mStatus);
+  return NS_OK;
+}
+
+}  // namespace
+
+NS_IMETHODIMP
+nsServerSocket::AsyncListen(nsIServerSocketListener* aListener) {
+  // ensuring mFD implies ensuring mLock
+  NS_ENSURE_TRUE(mFD, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mListener == nullptr, NS_ERROR_IN_PROGRESS);
+  {
+    MutexAutoLock lock(mLock);
+    mListener = new ServerSocketListenerProxy(aListener);
+    mListenerTarget = GetCurrentSerialEventTarget();
+  }
+
+  // Child classes may need to do additional setup just before listening begins
+  nsresult rv = OnSocketListen();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return PostEvent(this, &nsServerSocket::OnMsgAttach);
+}
+
+NS_IMETHODIMP
+nsServerSocket::GetPort(int32_t* aResult) {
+  // no need to enter the lock here
+  uint16_t port;
+  if (mAddr.raw.family == PR_AF_INET) {
+    port = mAddr.inet.port;
+  } else if (mAddr.raw.family == PR_AF_INET6) {
+    port = mAddr.ipv6.port;
+  } else {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aResult = static_cast<int32_t>(NetworkEndian::readUint16(&port));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsServerSocket::GetAddress(PRNetAddr* aResult) {
+  // no need to enter the lock here
+  memcpy(aResult, &mAddr, sizeof(mAddr));
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsServerSocket.h b/netwerk/base/nsServerSocket.h
new file mode 100644
index 0000000000..76908697fe
--- /dev/null
+++ b/netwerk/base/nsServerSocket.h
@@ -0,0 +1,70 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsServerSocket_h__
+#define nsServerSocket_h__
+
+#include "prio.h"
+#include "nsASocketHandler.h"
+#include "nsCOMPtr.h"
+#include "nsIServerSocket.h"
+#include "mozilla/Mutex.h"
+
+//-----------------------------------------------------------------------------
+
+class nsIEventTarget;
+namespace mozilla {
+namespace net {
+union NetAddr;
+
+class nsServerSocket : public nsASocketHandler, public nsIServerSocket {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISERVERSOCKET
+
+  // nsASocketHandler methods:
+  virtual void OnSocketReady(PRFileDesc* fd, int16_t outFlags) override;
+  virtual void OnSocketDetached(PRFileDesc* fd) override;
+  virtual void IsLocal(bool* aIsLocal) override;
+  virtual void KeepWhenOffline(bool* aKeepWhenOffline) override;
+
+  virtual uint64_t ByteCountSent() override { return 0; }
+  virtual uint64_t ByteCountReceived() override { return 0; }
+  nsServerSocket();
+
+  virtual void CreateClientTransport(PRFileDesc* clientFD,
+                                     const mozilla::net::NetAddr& clientAddr);
+  virtual nsresult SetSocketDefaults() { return NS_OK; }
+  virtual nsresult OnSocketListen() { return NS_OK; }
+
+ protected:
+  virtual ~nsServerSocket();
+  PRFileDesc* mFD{nullptr};
+  nsCOMPtr<nsIServerSocketListener> mListener;
+
+ private:
+  void OnMsgClose();
+  void OnMsgAttach();
+
+  // try attaching our socket (mFD) to the STS's poll list.
+  nsresult TryAttach();
+
+  nsresult InitWithAddressInternal(const PRNetAddr* aAddr, int32_t aBackLog,
+                                   bool aDualStack = false);
+
+  // lock protects access to mListener; so it is not cleared while being used.
+  mozilla::Mutex mLock MOZ_UNANNOTATED{"nsServerSocket.mLock"};
+  PRNetAddr mAddr = {.raw = {0, {0}}};
+  nsCOMPtr<nsIEventTarget> mListenerTarget;
+  bool mAttached{false};
+  bool mKeepWhenOffline{false};
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+//-----------------------------------------------------------------------------
+
+#endif  // nsServerSocket_h__
diff --git a/netwerk/base/nsSimpleNestedURI.cpp b/netwerk/base/nsSimpleNestedURI.cpp
new file mode 100644
index 0000000000..54f57b4625
--- /dev/null
+++ b/netwerk/base/nsSimpleNestedURI.cpp
@@ -0,0 +1,228 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "base/basictypes.h"
+
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsIClassInfoImpl.h"
+#include "nsSimpleNestedURI.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+
+#include "mozilla/ipc/URIUtils.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_CLASSINFO(nsSimpleNestedURI, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_SIMPLENESTEDURI_CID)
+// Empty CI getter. We only need nsIClassInfo for Serialization
+NS_IMPL_CI_INTERFACE_GETTER0(nsSimpleNestedURI)
+
+NS_IMPL_ADDREF_INHERITED(nsSimpleNestedURI, nsSimpleURI)
+NS_IMPL_RELEASE_INHERITED(nsSimpleNestedURI, nsSimpleURI)
+NS_IMPL_QUERY_INTERFACE_CI_INHERITED(nsSimpleNestedURI, nsSimpleURI,
+                                     nsINestedURI)
+
+nsSimpleNestedURI::nsSimpleNestedURI(nsIURI* innerURI) : mInnerURI(innerURI) {
+  NS_ASSERTION(innerURI, "Must have inner URI");
+}
+
+nsresult nsSimpleNestedURI::SetPathQueryRef(const nsACString& aPathQueryRef) {
+  NS_ENSURE_TRUE(mInnerURI, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIURI> inner;
+  nsresult rv =
+      NS_MutateURI(mInnerURI).SetPathQueryRef(aPathQueryRef).Finalize(inner);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = nsSimpleURI::SetPathQueryRef(aPathQueryRef);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // If the regular SetPathQueryRef worked, also set it on the inner URI
+  mInnerURI = inner;
+  return NS_OK;
+}
+
+nsresult nsSimpleNestedURI::SetQuery(const nsACString& aQuery) {
+  NS_ENSURE_TRUE(mInnerURI, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIURI> inner;
+  nsresult rv = NS_MutateURI(mInnerURI).SetQuery(aQuery).Finalize(inner);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = nsSimpleURI::SetQuery(aQuery);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // If the regular SetQuery worked, also set it on the inner URI
+  mInnerURI = inner;
+  return NS_OK;
+}
+
+nsresult nsSimpleNestedURI::SetRef(const nsACString& aRef) {
+  NS_ENSURE_TRUE(mInnerURI, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIURI> inner;
+  nsresult rv = NS_MutateURI(mInnerURI).SetRef(aRef).Finalize(inner);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = nsSimpleURI::SetRef(aRef);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // If the regular SetRef worked, also set it on the inner URI
+  mInnerURI = inner;
+  return NS_OK;
+}
+
+// nsISerializable
+
+NS_IMETHODIMP
+nsSimpleNestedURI::Read(nsIObjectInputStream* aStream) {
+  MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsSimpleNestedURI::ReadPrivate(nsIObjectInputStream* aStream) {
+  nsresult rv = nsSimpleURI::ReadPrivate(aStream);
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsISupports> supports;
+  rv = aStream->ReadObject(true, getter_AddRefs(supports));
+  if (NS_FAILED(rv)) return rv;
+
+  mInnerURI = do_QueryInterface(supports, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSimpleNestedURI::Write(nsIObjectOutputStream* aStream) {
+  nsCOMPtr<nsISerializable> serializable = do_QueryInterface(mInnerURI);
+  if (!serializable) {
+    // We can't serialize ourselves
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsresult rv = nsSimpleURI::Write(aStream);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = aStream->WriteCompoundObject(mInnerURI, NS_GET_IID(nsIURI), true);
+  return rv;
+}
+
+NS_IMETHODIMP_(void)
+nsSimpleNestedURI::Serialize(mozilla::ipc::URIParams& aParams) {
+  using namespace mozilla::ipc;
+
+  SimpleNestedURIParams params;
+  URIParams simpleParams;
+
+  nsSimpleURI::Serialize(simpleParams);
+  params.simpleParams() = simpleParams;
+
+  SerializeURI(mInnerURI, params.innerURI());
+
+  aParams = params;
+}
+
+bool nsSimpleNestedURI::Deserialize(const mozilla::ipc::URIParams& aParams) {
+  using namespace mozilla::ipc;
+
+  if (aParams.type() != URIParams::TSimpleNestedURIParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const SimpleNestedURIParams& params = aParams.get_SimpleNestedURIParams();
+  if (!nsSimpleURI::Deserialize(params.simpleParams())) return false;
+
+  mInnerURI = DeserializeURI(params.innerURI());
+  return true;
+}
+
+// nsINestedURI
+
+NS_IMETHODIMP
+nsSimpleNestedURI::GetInnerURI(nsIURI** aURI) {
+  NS_ENSURE_TRUE(mInnerURI, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIURI> uri = mInnerURI;
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleNestedURI::GetInnermostURI(nsIURI** uri) {
+  return NS_ImplGetInnermostURI(this, uri);
+}
+
+// nsSimpleURI overrides
+/* virtual */
+nsresult nsSimpleNestedURI::EqualsInternal(
+    nsIURI* other, nsSimpleURI::RefHandlingEnum refHandlingMode, bool* result) {
+  *result = false;
+  NS_ENSURE_TRUE(mInnerURI, NS_ERROR_NOT_INITIALIZED);
+
+  if (other) {
+    bool correctScheme;
+    nsresult rv = other->SchemeIs(mScheme.get(), &correctScheme);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (correctScheme) {
+      nsCOMPtr<nsINestedURI> nest = do_QueryInterface(other);
+      if (nest) {
+        nsCOMPtr<nsIURI> otherInner;
+        rv = nest->GetInnerURI(getter_AddRefs(otherInner));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        return (refHandlingMode == eHonorRef)
+                   ? otherInner->Equals(mInnerURI, result)
+                   : otherInner->EqualsExceptRef(mInnerURI, result);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+/* virtual */
+nsSimpleURI* nsSimpleNestedURI::StartClone(
+    nsSimpleURI::RefHandlingEnum refHandlingMode, const nsACString& newRef) {
+  NS_ENSURE_TRUE(mInnerURI, nullptr);
+
+  nsCOMPtr<nsIURI> innerClone;
+  nsresult rv = NS_OK;
+  if (refHandlingMode == eHonorRef) {
+    innerClone = mInnerURI;
+  } else if (refHandlingMode == eReplaceRef) {
+    rv = NS_GetURIWithNewRef(mInnerURI, newRef, getter_AddRefs(innerClone));
+  } else {
+    rv = NS_GetURIWithoutRef(mInnerURI, getter_AddRefs(innerClone));
+  }
+
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  nsSimpleNestedURI* url = new nsSimpleNestedURI(innerClone);
+  SetRefOnClone(url, refHandlingMode, newRef);
+
+  return url;
+}
+
+// Queries this list of interfaces. If none match, it queries mURI.
+NS_IMPL_NSIURIMUTATOR_ISUPPORTS(nsSimpleNestedURI::Mutator, nsIURISetters,
+                                nsIURIMutator, nsISerializable,
+                                nsINestedURIMutator)
+
+NS_IMETHODIMP
+nsSimpleNestedURI::Mutate(nsIURIMutator** aMutator) {
+  RefPtr<nsSimpleNestedURI::Mutator> mutator = new nsSimpleNestedURI::Mutator();
+  nsresult rv = mutator->InitFromURI(this);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mutator.forget(aMutator);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsSimpleNestedURI.h b/netwerk/base/nsSimpleNestedURI.h
new file mode 100644
index 0000000000..0887431421
--- /dev/null
+++ b/netwerk/base/nsSimpleNestedURI.h
@@ -0,0 +1,112 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * URI class to be used for cases when a simple URI actually resolves to some
+ * other sort of URI, with the latter being what's loaded when the load
+ * happens.
+ */
+
+#ifndef nsSimpleNestedURI_h__
+#define nsSimpleNestedURI_h__
+
+#include "nsCOMPtr.h"
+#include "nsSimpleURI.h"
+#include "nsINestedURI.h"
+#include "nsIURIMutator.h"
+
+namespace mozilla {
+namespace net {
+
+class nsSimpleNestedURI : public nsSimpleURI, public nsINestedURI {
+ protected:
+  nsSimpleNestedURI() = default;
+  explicit nsSimpleNestedURI(nsIURI* innerURI);
+
+  ~nsSimpleNestedURI() = default;
+
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSINESTEDURI
+
+  // Overrides for various methods nsSimpleURI implements follow.
+
+  // nsSimpleURI overrides
+  virtual nsresult EqualsInternal(nsIURI* other,
+                                  RefHandlingEnum refHandlingMode,
+                                  bool* result) override;
+  virtual nsSimpleURI* StartClone(RefHandlingEnum refHandlingMode,
+                                  const nsACString& newRef) override;
+  NS_IMETHOD Mutate(nsIURIMutator** _retval) override;
+  NS_IMETHOD_(void) Serialize(ipc::URIParams& aParams) override;
+
+  // nsISerializable overrides
+  NS_IMETHOD Read(nsIObjectInputStream* aStream) override;
+  NS_IMETHOD Write(nsIObjectOutputStream* aStream) override;
+
+ protected:
+  nsCOMPtr<nsIURI> mInnerURI;
+
+  nsresult SetPathQueryRef(const nsACString& aPathQueryRef) override;
+  nsresult SetQuery(const nsACString& aQuery) override;
+  nsresult SetRef(const nsACString& aRef) override;
+  bool Deserialize(const mozilla::ipc::URIParams&);
+  nsresult ReadPrivate(nsIObjectInputStream* stream);
+
+ public:
+  class Mutator final : public nsIURIMutator,
+                        public BaseURIMutator<nsSimpleNestedURI>,
+                        public nsISerializable,
+                        public nsINestedURIMutator {
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_SAFE_NSIURISETTERS_RET(mURI)
+
+    explicit Mutator() = default;
+
+   private:
+    virtual ~Mutator() = default;
+
+    [[nodiscard]] NS_IMETHOD Deserialize(
+        const mozilla::ipc::URIParams& aParams) override {
+      return InitFromIPCParams(aParams);
+    }
+
+    NS_IMETHOD
+    Write(nsIObjectOutputStream* aOutputStream) override {
+      return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    [[nodiscard]] NS_IMETHOD Read(nsIObjectInputStream* aStream) override {
+      return InitFromInputStream(aStream);
+    }
+
+    [[nodiscard]] NS_IMETHOD Finalize(nsIURI** aURI) override {
+      mURI.forget(aURI);
+      return NS_OK;
+    }
+
+    [[nodiscard]] NS_IMETHOD SetSpec(const nsACString& aSpec,
+                                     nsIURIMutator** aMutator) override {
+      if (aMutator) {
+        NS_ADDREF(*aMutator = this);
+      }
+      return InitFromSpec(aSpec);
+    }
+
+    [[nodiscard]] NS_IMETHOD Init(nsIURI* innerURI) override {
+      mURI = new nsSimpleNestedURI(innerURI);
+      return NS_OK;
+    }
+
+    friend class nsSimpleNestedURI;
+  };
+
+  friend BaseURIMutator<nsSimpleNestedURI>;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif /* nsSimpleNestedURI_h__ */
diff --git a/netwerk/base/nsSimpleStreamListener.cpp b/netwerk/base/nsSimpleStreamListener.cpp
new file mode 100644
index 0000000000..beed8a9f40
--- /dev/null
+++ b/netwerk/base/nsSimpleStreamListener.cpp
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsSimpleStreamListener.h"
+
+namespace mozilla {
+namespace net {
+
+//
+//----------------------------------------------------------------------------
+// nsISupports implementation...
+//----------------------------------------------------------------------------
+//
+NS_IMPL_ISUPPORTS(nsSimpleStreamListener, nsISimpleStreamListener,
+                  nsIStreamListener, nsIRequestObserver)
+
+//
+//----------------------------------------------------------------------------
+// nsIRequestObserver implementation...
+//----------------------------------------------------------------------------
+//
+NS_IMETHODIMP
+nsSimpleStreamListener::OnStartRequest(nsIRequest* aRequest) {
+  return mObserver ? mObserver->OnStartRequest(aRequest) : NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleStreamListener::OnStopRequest(nsIRequest* request, nsresult aStatus) {
+  return mObserver ? mObserver->OnStopRequest(request, aStatus) : NS_OK;
+}
+
+//
+//----------------------------------------------------------------------------
+// nsIStreamListener implementation...
+//----------------------------------------------------------------------------
+//
+NS_IMETHODIMP
+nsSimpleStreamListener::OnDataAvailable(nsIRequest* request,
+                                        nsIInputStream* aSource,
+                                        uint64_t aOffset, uint32_t aCount) {
+  uint32_t writeCount;
+  nsresult rv = mSink->WriteFrom(aSource, aCount, &writeCount);
+  //
+  // Equate zero bytes read and NS_SUCCEEDED to stopping the read.
+  //
+  if (NS_SUCCEEDED(rv) && (writeCount == 0)) return NS_BASE_STREAM_CLOSED;
+  return rv;
+}
+
+//
+//----------------------------------------------------------------------------
+// nsISimpleStreamListener implementation...
+//----------------------------------------------------------------------------
+//
+NS_IMETHODIMP
+nsSimpleStreamListener::Init(nsIOutputStream* aSink,
+                             nsIRequestObserver* aObserver) {
+  MOZ_ASSERT(aSink, "null output stream");
+
+  mSink = aSink;
+  mObserver = aObserver;
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsSimpleStreamListener.h b/netwerk/base/nsSimpleStreamListener.h
new file mode 100644
index 0000000000..890b49f61b
--- /dev/null
+++ b/netwerk/base/nsSimpleStreamListener.h
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsSimpleStreamListener_h__
+#define nsSimpleStreamListener_h__
+
+#include "nsISimpleStreamListener.h"
+#include "nsIOutputStream.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla {
+namespace net {
+
+class nsSimpleStreamListener : public nsISimpleStreamListener {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSISIMPLESTREAMLISTENER
+
+  nsSimpleStreamListener() = default;
+
+ protected:
+  virtual ~nsSimpleStreamListener() = default;
+
+  nsCOMPtr<nsIOutputStream> mSink;
+  nsCOMPtr<nsIRequestObserver> mObserver;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/nsSimpleURI.cpp b/netwerk/base/nsSimpleURI.cpp
new file mode 100644
index 0000000000..9775a96c41
--- /dev/null
+++ b/netwerk/base/nsSimpleURI.cpp
@@ -0,0 +1,782 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#undef LOG
+#include "ipc/IPCMessageUtils.h"
+
+#include "nsSimpleURI.h"
+#include "nscore.h"
+#include "nsCRT.h"
+#include "nsString.h"
+#include "nsURLHelper.h"
+#include "nsNetCID.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "nsEscape.h"
+#include "nsError.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/TextUtils.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIURIMutator.h"
+#include "mozilla/net/MozURL.h"
+#include "mozilla/StaticPrefs_network.h"
+
+using namespace mozilla::ipc;
+
+namespace mozilla {
+namespace net {
+
+static NS_DEFINE_CID(kThisSimpleURIImplementationCID,
+                     NS_THIS_SIMPLEURI_IMPLEMENTATION_CID);
+
+/* static */
+already_AddRefed<nsSimpleURI> nsSimpleURI::From(nsIURI* aURI) {
+  RefPtr<nsSimpleURI> uri;
+  nsresult rv = aURI->QueryInterface(kThisSimpleURIImplementationCID,
+                                     getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  return uri.forget();
+}
+
+NS_IMPL_CLASSINFO(nsSimpleURI, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_SIMPLEURI_CID)
+// Empty CI getter. We only need nsIClassInfo for Serialization
+NS_IMPL_CI_INTERFACE_GETTER0(nsSimpleURI)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsSimpleURI methods:
+
+NS_IMPL_ADDREF(nsSimpleURI)
+NS_IMPL_RELEASE(nsSimpleURI)
+NS_INTERFACE_TABLE_HEAD(nsSimpleURI)
+  NS_INTERFACE_TABLE(nsSimpleURI, nsIURI, nsISerializable)
+  NS_INTERFACE_TABLE_TO_MAP_SEGUE
+  NS_IMPL_QUERY_CLASSINFO(nsSimpleURI)
+  if (aIID.Equals(kThisSimpleURIImplementationCID)) {
+    foundInterface = static_cast<nsIURI*>(this);
+  } else
+    NS_INTERFACE_MAP_ENTRY(nsISizeOf)
+NS_INTERFACE_MAP_END
+
+////////////////////////////////////////////////////////////////////////////////
+// nsISerializable methods:
+
+NS_IMETHODIMP
+nsSimpleURI::Read(nsIObjectInputStream* aStream) {
+  MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsSimpleURI::ReadPrivate(nsIObjectInputStream* aStream) {
+  nsresult rv;
+
+  bool isMutable;
+  rv = aStream->ReadBoolean(&isMutable);
+  if (NS_FAILED(rv)) return rv;
+  Unused << isMutable;
+
+  rv = aStream->ReadCString(mScheme);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = aStream->ReadCString(mPath);
+  if (NS_FAILED(rv)) return rv;
+
+  bool isRefValid;
+  rv = aStream->ReadBoolean(&isRefValid);
+  if (NS_FAILED(rv)) return rv;
+  mIsRefValid = isRefValid;
+
+  if (isRefValid) {
+    rv = aStream->ReadCString(mRef);
+    if (NS_FAILED(rv)) return rv;
+  } else {
+    mRef.Truncate();  // invariant: mRef should be empty when it's not valid
+  }
+
+  bool isQueryValid;
+  rv = aStream->ReadBoolean(&isQueryValid);
+  if (NS_FAILED(rv)) return rv;
+  mIsQueryValid = isQueryValid;
+
+  if (isQueryValid) {
+    rv = aStream->ReadCString(mQuery);
+    if (NS_FAILED(rv)) return rv;
+  } else {
+    mQuery.Truncate();  // invariant: mQuery should be empty when it's not valid
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::Write(nsIObjectOutputStream* aStream) {
+  nsresult rv;
+
+  rv = aStream->WriteBoolean(false);  // former mMutable
+  if (NS_FAILED(rv)) return rv;
+
+  rv = aStream->WriteStringZ(mScheme.get());
+  if (NS_FAILED(rv)) return rv;
+
+  rv = aStream->WriteStringZ(mPath.get());
+  if (NS_FAILED(rv)) return rv;
+
+  rv = aStream->WriteBoolean(mIsRefValid);
+  if (NS_FAILED(rv)) return rv;
+
+  if (mIsRefValid) {
+    rv = aStream->WriteStringZ(mRef.get());
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  rv = aStream->WriteBoolean(mIsQueryValid);
+  if (NS_FAILED(rv)) return rv;
+
+  if (mIsQueryValid) {
+    rv = aStream->WriteStringZ(mQuery.get());
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  return NS_OK;
+}
+
+void nsSimpleURI::Serialize(URIParams& aParams) {
+  SimpleURIParams params;
+
+  params.scheme() = mScheme;
+  params.path() = mPath;
+
+  if (mIsRefValid) {
+    params.ref() = mRef;
+  } else {
+    params.ref().SetIsVoid(true);
+  }
+
+  if (mIsQueryValid) {
+    params.query() = mQuery;
+  } else {
+    params.query().SetIsVoid(true);
+  }
+
+  aParams = params;
+}
+
+bool nsSimpleURI::Deserialize(const URIParams& aParams) {
+  if (aParams.type() != URIParams::TSimpleURIParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  const SimpleURIParams& params = aParams.get_SimpleURIParams();
+
+  mScheme = params.scheme();
+  mPath = params.path();
+
+  if (params.ref().IsVoid()) {
+    mRef.Truncate();
+    mIsRefValid = false;
+  } else {
+    mRef = params.ref();
+    mIsRefValid = true;
+  }
+
+  if (params.query().IsVoid()) {
+    mQuery.Truncate();
+    mIsQueryValid = false;
+  } else {
+    mQuery = params.query();
+    mIsQueryValid = true;
+  }
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIURI methods:
+
+NS_IMETHODIMP
+nsSimpleURI::GetSpec(nsACString& result) {
+  if (!result.Assign(mScheme, fallible) || !result.Append(":"_ns, fallible) ||
+      !result.Append(mPath, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (mIsQueryValid) {
+    if (!result.Append("?"_ns, fallible) || !result.Append(mQuery, fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  } else {
+    MOZ_ASSERT(mQuery.IsEmpty(), "mIsQueryValid/mQuery invariant broken");
+  }
+
+  if (mIsRefValid) {
+    if (!result.Append("#"_ns, fallible) || !result.Append(mRef, fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  } else {
+    MOZ_ASSERT(mRef.IsEmpty(), "mIsRefValid/mRef invariant broken");
+  }
+
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsSimpleURI::GetSpecIgnoringRef(nsACString& result) {
+  result = mScheme + ":"_ns + mPath;
+  if (mIsQueryValid) {
+    result += "?"_ns + mQuery;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetDisplaySpec(nsACString& aUnicodeSpec) {
+  return GetSpec(aUnicodeSpec);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetDisplayHostPort(nsACString& aUnicodeHostPort) {
+  return GetHostPort(aUnicodeHostPort);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetDisplayHost(nsACString& aUnicodeHost) {
+  return GetHost(aUnicodeHost);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetDisplayPrePath(nsACString& aPrePath) {
+  return GetPrePath(aPrePath);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetHasRef(bool* result) {
+  *result = mIsRefValid;
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetSpecInternal(const nsACString& aSpec,
+                                      bool aStripWhitespace) {
+  if (StaticPrefs::network_url_max_length() &&
+      aSpec.Length() > StaticPrefs::network_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsresult rv = net_ExtractURLScheme(aSpec, mScheme);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsAutoCString spec;
+  rv = net_FilterAndEscapeURI(
+      aSpec, esc_OnlyNonASCII,
+      aStripWhitespace ? ASCIIMask::MaskWhitespace() : ASCIIMask::MaskCRLFTab(),
+      spec);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  int32_t colonPos = spec.FindChar(':');
+  MOZ_ASSERT(colonPos != kNotFound, "A colon should be in this string");
+  // This sets mPath, mQuery and mRef.
+  return SetPathQueryRefInternal(Substring(spec, colonPos + 1));
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetScheme(nsACString& result) {
+  result = mScheme;
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetScheme(const nsACString& input) {
+  // Strip tabs, newlines, carriage returns from input
+  nsAutoCString scheme(input);
+  scheme.StripTaggedASCII(ASCIIMask::MaskCRLFTab());
+
+  if (!net_IsValidScheme(scheme)) {
+    NS_WARNING("the given url scheme contains invalid characters");
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  mScheme = scheme;
+  ToLowerCase(mScheme);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetPrePath(nsACString& result) {
+  result = mScheme + ":"_ns;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetUserPass(nsACString& result) { return NS_ERROR_FAILURE; }
+
+nsresult nsSimpleURI::SetUserPass(const nsACString& userPass) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetUsername(nsACString& result) { return NS_ERROR_FAILURE; }
+
+nsresult nsSimpleURI::SetUsername(const nsACString& userName) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetPassword(nsACString& result) { return NS_ERROR_FAILURE; }
+
+nsresult nsSimpleURI::SetPassword(const nsACString& password) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetHostPort(nsACString& result) {
+  // Note: Audit all callers before changing this to return an empty
+  // string -- CAPS and UI code may depend on this throwing.
+  // Note: If this is changed, change GetAsciiHostPort as well.
+  return NS_ERROR_FAILURE;
+}
+
+nsresult nsSimpleURI::SetHostPort(const nsACString& result) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetHost(nsACString& result) {
+  // Note: Audit all callers before changing this to return an empty
+  // string -- CAPS and UI code depend on this throwing.
+  return NS_ERROR_FAILURE;
+}
+
+nsresult nsSimpleURI::SetHost(const nsACString& host) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetPort(int32_t* result) {
+  // Note: Audit all callers before changing this to return an empty
+  // string -- CAPS and UI code may depend on this throwing.
+  return NS_ERROR_FAILURE;
+}
+
+nsresult nsSimpleURI::SetPort(int32_t port) { return NS_ERROR_FAILURE; }
+
+NS_IMETHODIMP
+nsSimpleURI::GetPathQueryRef(nsACString& result) {
+  result = mPath;
+  if (mIsQueryValid) {
+    result += "?"_ns + mQuery;
+  }
+  if (mIsRefValid) {
+    result += "#"_ns + mRef;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetPathQueryRef(const nsACString& aPath) {
+  if (StaticPrefs::network_url_max_length() &&
+      aPath.Length() > StaticPrefs::network_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsAutoCString path;
+  nsresult rv = NS_EscapeURL(aPath, esc_OnlyNonASCII, path, fallible);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return SetPathQueryRefInternal(path);
+}
+
+nsresult nsSimpleURI::SetPathQueryRefInternal(const nsACString& aPath) {
+  nsresult rv;
+  const auto* start = aPath.BeginReading();
+  const auto* end = aPath.EndReading();
+
+  // Find the first instance of ? or # that marks the end of the path.
+  auto hashOrQueryFilter = [](char c) { return c == '?' || c == '#'; };
+  const auto* pathEnd = std::find_if(start, end, hashOrQueryFilter);
+
+  mIsQueryValid = false;
+  mQuery.Truncate();
+
+  mIsRefValid = false;
+  mRef.Truncate();
+
+  // The path
+  if (!mPath.Assign(Substring(start, pathEnd), fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (pathEnd == end) {
+    return NS_OK;
+  }
+
+  const auto* queryEnd =
+      std::find_if(pathEnd, end, [](char c) { return c == '#'; });
+
+  rv = SetQuery(Substring(pathEnd, queryEnd));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (queryEnd == end) {
+    return NS_OK;
+  }
+
+  return SetRef(Substring(queryEnd, end));
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetRef(nsACString& result) {
+  if (!mIsRefValid) {
+    MOZ_ASSERT(mRef.IsEmpty(), "mIsRefValid/mRef invariant broken");
+    result.Truncate();
+  } else {
+    result = mRef;
+  }
+
+  return NS_OK;
+}
+
+// NOTE: SetRef("") removes our ref, whereas SetRef("#") sets it to the empty
+// string (and will result in .spec and .path having a terminal #).
+nsresult nsSimpleURI::SetRef(const nsACString& aRef) {
+  if (StaticPrefs::network_url_max_length() &&
+      aRef.Length() > StaticPrefs::network_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsAutoCString ref;
+  nsresult rv =
+      NS_EscapeURL(aRef, esc_OnlyNonASCII | esc_Spaces, ref, fallible);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (ref.IsEmpty()) {
+    // Empty string means to remove ref completely.
+    mIsRefValid = false;
+    mRef.Truncate();  // invariant: mRef should be empty when it's not valid
+
+    // Trim trailing invalid chars when ref and query are removed
+    if (mScheme != "javascript" && mRef.IsEmpty() && mQuery.IsEmpty()) {
+      TrimTrailingCharactersFromPath();
+    }
+
+    return NS_OK;
+  }
+
+  mIsRefValid = true;
+
+  // Gracefully skip initial hash
+  if (ref[0] == '#') {
+    mRef = Substring(ref, 1);
+  } else {
+    mRef = ref;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::Equals(nsIURI* other, bool* result) {
+  return EqualsInternal(other, eHonorRef, result);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::EqualsExceptRef(nsIURI* other, bool* result) {
+  return EqualsInternal(other, eIgnoreRef, result);
+}
+
+/* virtual */
+nsresult nsSimpleURI::EqualsInternal(
+    nsIURI* other, nsSimpleURI::RefHandlingEnum refHandlingMode, bool* result) {
+  NS_ENSURE_ARG_POINTER(other);
+  MOZ_ASSERT(result, "null pointer");
+
+  RefPtr<nsSimpleURI> otherUri;
+  nsresult rv = other->QueryInterface(kThisSimpleURIImplementationCID,
+                                      getter_AddRefs(otherUri));
+  if (NS_FAILED(rv)) {
+    *result = false;
+    return NS_OK;
+  }
+
+  *result = EqualsInternal(otherUri, refHandlingMode);
+  return NS_OK;
+}
+
+bool nsSimpleURI::EqualsInternal(nsSimpleURI* otherUri,
+                                 RefHandlingEnum refHandlingMode) {
+  bool result = (mScheme == otherUri->mScheme && mPath == otherUri->mPath);
+
+  if (result) {
+    result = (mIsQueryValid == otherUri->mIsQueryValid &&
+              (!mIsQueryValid || mQuery == otherUri->mQuery));
+  }
+
+  if (result && refHandlingMode == eHonorRef) {
+    result = (mIsRefValid == otherUri->mIsRefValid &&
+              (!mIsRefValid || mRef == otherUri->mRef));
+  }
+
+  return result;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::SchemeIs(const char* i_Scheme, bool* o_Equals) {
+  MOZ_ASSERT(o_Equals, "null pointer");
+  if (!i_Scheme) {
+    *o_Equals = false;
+    return NS_OK;
+  }
+
+  const char* this_scheme = mScheme.get();
+
+  // mScheme is guaranteed to be lower case.
+  if (*i_Scheme == *this_scheme || *i_Scheme == (*this_scheme - ('a' - 'A'))) {
+    *o_Equals = nsCRT::strcasecmp(this_scheme, i_Scheme) == 0;
+  } else {
+    *o_Equals = false;
+  }
+
+  return NS_OK;
+}
+
+/* virtual */ nsSimpleURI* nsSimpleURI::StartClone(
+    nsSimpleURI::RefHandlingEnum refHandlingMode, const nsACString& newRef) {
+  nsSimpleURI* url = new nsSimpleURI();
+  SetRefOnClone(url, refHandlingMode, newRef);
+  return url;
+}
+
+/* virtual */
+void nsSimpleURI::SetRefOnClone(nsSimpleURI* url,
+                                nsSimpleURI::RefHandlingEnum refHandlingMode,
+                                const nsACString& newRef) {
+  if (refHandlingMode == eHonorRef) {
+    url->mRef = mRef;
+    url->mIsRefValid = mIsRefValid;
+  } else if (refHandlingMode == eReplaceRef) {
+    url->SetRef(newRef);
+  }
+}
+
+nsresult nsSimpleURI::Clone(nsIURI** result) {
+  return CloneInternal(eHonorRef, ""_ns, result);
+}
+
+nsresult nsSimpleURI::CloneInternal(
+    nsSimpleURI::RefHandlingEnum refHandlingMode, const nsACString& newRef,
+    nsIURI** result) {
+  RefPtr<nsSimpleURI> url = StartClone(refHandlingMode, newRef);
+  if (!url) return NS_ERROR_OUT_OF_MEMORY;
+
+  url->mScheme = mScheme;
+  url->mPath = mPath;
+
+  url->mIsQueryValid = mIsQueryValid;
+  if (url->mIsQueryValid) {
+    url->mQuery = mQuery;
+  }
+
+  url.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::Resolve(const nsACString& relativePath, nsACString& result) {
+  nsAutoCString scheme;
+  nsresult rv = net_ExtractURLScheme(relativePath, scheme);
+  if (NS_SUCCEEDED(rv)) {
+    result = relativePath;
+    return NS_OK;
+  }
+
+  nsAutoCString spec;
+  rv = GetAsciiSpec(spec);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    // If getting the spec fails for some reason, preserve behaviour and just
+    // return the relative path.
+    result = relativePath;
+    return NS_OK;
+  }
+
+  RefPtr<MozURL> url;
+  rv = MozURL::Init(getter_AddRefs(url), spec);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    // If parsing the current url fails, we revert to the previous behaviour
+    // and just return the relative path.
+    result = relativePath;
+    return NS_OK;
+  }
+
+  RefPtr<MozURL> url2;
+  rv = MozURL::Init(getter_AddRefs(url2), relativePath, url);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    // If parsing the relative url fails, we revert to the previous behaviour
+    // and just return the relative path.
+    result = relativePath;
+    return NS_OK;
+  }
+
+  result = url2->Spec();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetAsciiSpec(nsACString& aResult) {
+  nsresult rv = GetSpec(aResult);
+  if (NS_FAILED(rv)) return rv;
+  MOZ_ASSERT(IsAscii(aResult), "The spec should be ASCII");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetAsciiHostPort(nsACString& result) {
+  // XXX This behavior mimics GetHostPort.
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetAsciiHost(nsACString& result) {
+  result.Truncate();
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// nsSimpleURI::nsISizeOf
+//----------------------------------------------------------------------------
+
+size_t nsSimpleURI::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  return mScheme.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
+         mPath.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
+         mQuery.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
+         mRef.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+}
+
+size_t nsSimpleURI::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetFilePath(nsACString& aFilePath) {
+  aFilePath = mPath;
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetFilePath(const nsACString& aFilePath) {
+  if (mPath.IsEmpty() || mPath.First() != '/') {
+    // cannot-be-a-base
+    return NS_ERROR_MALFORMED_URI;
+  }
+  const char* current = aFilePath.BeginReading();
+  const char* end = aFilePath.EndReading();
+
+  // Only go up to the first ? or # symbol
+  for (; current < end; ++current) {
+    if (*current == '?' || *current == '#') {
+      break;
+    }
+  }
+  return SetPathQueryRef(
+      nsDependentCSubstring(aFilePath.BeginReading(), current));
+}
+
+NS_IMETHODIMP
+nsSimpleURI::GetQuery(nsACString& aQuery) {
+  if (!mIsQueryValid) {
+    MOZ_ASSERT(mQuery.IsEmpty(), "mIsQueryValid/mQuery invariant broken");
+    aQuery.Truncate();
+  } else {
+    aQuery = mQuery;
+  }
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetQuery(const nsACString& aQuery) {
+  if (StaticPrefs::network_url_max_length() &&
+      aQuery.Length() > StaticPrefs::network_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+  nsAutoCString query;
+  nsresult rv = NS_EscapeURL(aQuery, esc_OnlyNonASCII, query, fallible);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (query.IsEmpty()) {
+    // Empty string means to remove query completely.
+    mIsQueryValid = false;
+    mQuery.Truncate();  // invariant: mQuery should be empty when it's not valid
+
+    // Trim trailing invalid chars when ref and query are removed
+    if (mScheme != "javascript" && mRef.IsEmpty() && mQuery.IsEmpty()) {
+      TrimTrailingCharactersFromPath();
+    }
+
+    return NS_OK;
+  }
+
+  mIsQueryValid = true;
+
+  // Gracefully skip initial question mark
+  if (query[0] == '?') {
+    mQuery = Substring(query, 1);
+  } else {
+    mQuery = query;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsSimpleURI::SetQueryWithEncoding(const nsACString& aQuery,
+                                           const Encoding* aEncoding) {
+  return SetQuery(aQuery);
+}
+
+void nsSimpleURI::TrimTrailingCharactersFromPath() {
+  const auto* start = mPath.BeginReading();
+  const auto* end = mPath.EndReading();
+
+  auto charFilter = [](char c) { return static_cast<uint8_t>(c) > 0x20; };
+  const auto* newEnd =
+      std::find_if(std::reverse_iterator<decltype(end)>(end),
+                   std::reverse_iterator<decltype(start)>(start), charFilter)
+          .base();
+
+  auto trailCount = std::distance(newEnd, end);
+  if (trailCount) {
+    mPath.Truncate(mPath.Length() - trailCount);
+  }
+}
+
+// Queries this list of interfaces. If none match, it queries mURI.
+NS_IMPL_NSIURIMUTATOR_ISUPPORTS(nsSimpleURI::Mutator, nsIURISetters,
+                                nsIURIMutator, nsISerializable,
+                                nsISimpleURIMutator)
+
+NS_IMETHODIMP
+nsSimpleURI::Mutate(nsIURIMutator** aMutator) {
+  RefPtr<nsSimpleURI::Mutator> mutator = new nsSimpleURI::Mutator();
+  nsresult rv = mutator->InitFromURI(this);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mutator.forget(aMutator);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsSimpleURI.h b/netwerk/base/nsSimpleURI.h
new file mode 100644
index 0000000000..c3d3bdf270
--- /dev/null
+++ b/netwerk/base/nsSimpleURI.h
@@ -0,0 +1,164 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsSimpleURI_h__
+#define nsSimpleURI_h__
+
+#include "mozilla/MemoryReporting.h"
+#include "nsIURI.h"
+#include "nsISerializable.h"
+#include "nsString.h"
+#include "nsIClassInfo.h"
+#include "nsISizeOf.h"
+#include "nsIURIMutator.h"
+#include "nsISimpleURIMutator.h"
+
+namespace mozilla {
+namespace net {
+
+#define NS_THIS_SIMPLEURI_IMPLEMENTATION_CID         \
+  { /* 0b9bb0c2-fee6-470b-b9b9-9fd9462b5e19 */       \
+    0x0b9bb0c2, 0xfee6, 0x470b, {                    \
+      0xb9, 0xb9, 0x9f, 0xd9, 0x46, 0x2b, 0x5e, 0x19 \
+    }                                                \
+  }
+
+class nsSimpleURI : public nsIURI, public nsISerializable, public nsISizeOf {
+ protected:
+  nsSimpleURI() = default;
+  virtual ~nsSimpleURI() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIURI
+  NS_DECL_NSISERIALIZABLE
+
+  static already_AddRefed<nsSimpleURI> From(nsIURI* aURI);
+
+  // nsSimpleURI methods:
+
+  bool Equals(nsSimpleURI* aOther) { return EqualsInternal(aOther, eHonorRef); }
+
+  // nsISizeOf
+  // Among the sub-classes that inherit (directly or indirectly) from
+  // nsSimpleURI, measurement of the following members may be added later if
+  // DMD finds it is worthwhile:
+  // - nsJSURI: mBaseURI
+  // - nsSimpleNestedURI: mInnerURI
+  // - nsBlobURI: mPrincipal
+  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override;
+  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override;
+
+ protected:
+  // enum used in a few places to specify how .ref attribute should be handled
+  enum RefHandlingEnum { eIgnoreRef, eHonorRef, eReplaceRef };
+
+  virtual nsresult Clone(nsIURI** result);
+  virtual nsresult SetSpecInternal(const nsACString& aSpec,
+                                   bool aStripWhitespace = false);
+  virtual nsresult SetScheme(const nsACString& scheme);
+  virtual nsresult SetUserPass(const nsACString& input);
+  nsresult SetUsername(const nsACString& input);
+  virtual nsresult SetPassword(const nsACString& input);
+  virtual nsresult SetHostPort(const nsACString& aValue);
+  virtual nsresult SetHost(const nsACString& input);
+  virtual nsresult SetPort(int32_t port);
+  virtual nsresult SetPathQueryRef(const nsACString& aPath);
+  virtual nsresult SetRef(const nsACString& aRef);
+  virtual nsresult SetFilePath(const nsACString& aFilePath);
+  virtual nsresult SetQuery(const nsACString& aQuery);
+  virtual nsresult SetQueryWithEncoding(const nsACString& aQuery,
+                                        const Encoding* encoding);
+  nsresult ReadPrivate(nsIObjectInputStream* stream);
+
+  // Helper to share code between Equals methods.
+  virtual nsresult EqualsInternal(nsIURI* other,
+                                  RefHandlingEnum refHandlingMode,
+                                  bool* result);
+
+  // Helper to be used by inherited classes who want to test
+  // equality given an assumed nsSimpleURI.  This must NOT check
+  // the passed-in other for QI to our CID.
+  bool EqualsInternal(nsSimpleURI* otherUri, RefHandlingEnum refHandlingMode);
+
+  // Used by StartClone (and versions of StartClone in subclasses) to
+  // handle the ref in the right way for clones.
+  void SetRefOnClone(nsSimpleURI* url, RefHandlingEnum refHandlingMode,
+                     const nsACString& newRef);
+
+  // NOTE: This takes the refHandlingMode as an argument because
+  // nsSimpleNestedURI's specialized version needs to know how to clone
+  // its inner URI.
+  virtual nsSimpleURI* StartClone(RefHandlingEnum refHandlingMode,
+                                  const nsACString& newRef);
+
+  // Helper to share code between Clone methods.
+  virtual nsresult CloneInternal(RefHandlingEnum refHandlingMode,
+                                 const nsACString& newRef, nsIURI** result);
+
+  void TrimTrailingCharactersFromPath();
+  nsresult EscapeAndSetPathQueryRef(const nsACString& aPath);
+  nsresult SetPathQueryRefInternal(const nsACString& aPath);
+
+  bool Deserialize(const mozilla::ipc::URIParams&);
+
+  nsCString mScheme;
+  nsCString mPath;  // NOTE: mPath does not include ref, as an optimization
+  nsCString mRef;   // so that URIs with different refs can share string data.
+  nsCString
+      mQuery;  // so that URLs with different querys can share string data.
+  bool mIsRefValid{false};  // To distinguish between empty-ref and no-ref.
+  // To distinguish between empty-query and no-query.
+  bool mIsQueryValid{false};
+
+ public:
+  class Mutator final : public nsIURIMutator,
+                        public BaseURIMutator<nsSimpleURI>,
+                        public nsISimpleURIMutator,
+                        public nsISerializable {
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_SAFE_NSIURISETTERS_RET(mURI)
+    NS_DEFINE_NSIMUTATOR_COMMON
+
+    NS_IMETHOD
+    Write(nsIObjectOutputStream* aOutputStream) override {
+      return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    [[nodiscard]] NS_IMETHOD Read(nsIObjectInputStream* aStream) override {
+      return InitFromInputStream(aStream);
+    }
+
+    [[nodiscard]] NS_IMETHOD SetSpecAndFilterWhitespace(
+        const nsACString& aSpec, nsIURIMutator** aMutator) override {
+      if (aMutator) {
+        *aMutator = do_AddRef(this).take();
+      }
+
+      nsresult rv = NS_OK;
+      RefPtr<nsSimpleURI> uri = new nsSimpleURI();
+      rv = uri->SetSpecInternal(aSpec, /* filterWhitespace */ true);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      mURI = std::move(uri);
+      return NS_OK;
+    }
+
+    explicit Mutator() = default;
+
+   private:
+    virtual ~Mutator() = default;
+
+    friend class nsSimpleURI;
+  };
+
+  friend BaseURIMutator<nsSimpleURI>;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsSimpleURI_h__
diff --git a/netwerk/base/nsSocketTransport2.cpp b/netwerk/base/nsSocketTransport2.cpp
new file mode 100644
index 0000000000..b998ef886a
--- /dev/null
+++ b/netwerk/base/nsSocketTransport2.cpp
@@ -0,0 +1,3404 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <algorithm>
+
+#include "nsSocketTransport2.h"
+
+#include "IOActivityMonitor.h"
+#include "NSSErrorsService.h"
+#include "NetworkDataCountLayer.h"
+#include "QuicSocketControl.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/SyncRunnable.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/net/SSLTokensCache.h"
+#include "nsCOMPtr.h"
+#include "nsICancelable.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIDNSByTypeRecord.h"
+#include "nsIDNSRecord.h"
+#include "nsIDNSService.h"
+#include "nsIOService.h"
+#include "nsIPipe.h"
+#include "nsISocketProvider.h"
+#include "nsITLSSocketControl.h"
+#include "nsNetAddr.h"
+#include "nsNetCID.h"
+#include "nsNetSegmentUtils.h"
+#include "nsNetUtil.h"
+#include "nsPrintfCString.h"
+#include "nsProxyInfo.h"
+#include "nsSocketProviderService.h"
+#include "nsStreamUtils.h"
+#include "nsThreadUtils.h"
+#include "nsTransportUtils.h"
+#include "nsURLHelper.h"
+#include "prerr.h"
+#include "sslexp.h"
+#include "xpcpublic.h"
+
+#if defined(FUZZING)
+#  include "FuzzyLayer.h"
+#  include "FuzzySocketControl.h"
+#  include "mozilla/StaticPrefs_fuzzing.h"
+#endif
+
+#if defined(XP_WIN)
+#  include "ShutdownLayer.h"
+#endif
+
+/* Following inclusions required for keepalive config not supported by NSPR. */
+#include "private/pprio.h"
+#if defined(XP_WIN)
+#  include <winsock2.h>
+#  include <mstcpip.h>
+#elif defined(XP_UNIX)
+#  include <errno.h>
+#  include <netinet/tcp.h>
+#endif
+/* End keepalive config inclusions. */
+
+#define SUCCESSFUL_CONNECTING_TO_IPV4_ADDRESS 0
+#define UNSUCCESSFUL_CONNECTING_TO_IPV4_ADDRESS 1
+#define SUCCESSFUL_CONNECTING_TO_IPV6_ADDRESS 2
+#define UNSUCCESSFUL_CONNECTING_TO_IPV6_ADDRESS 3
+
+//-----------------------------------------------------------------------------
+
+static NS_DEFINE_CID(kDNSServiceCID, NS_DNSSERVICE_CID);
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+class nsSocketEvent : public Runnable {
+ public:
+  nsSocketEvent(nsSocketTransport* transport, uint32_t type,
+                nsresult status = NS_OK, nsISupports* param = nullptr,
+                std::function<void()>&& task = nullptr)
+      : Runnable("net::nsSocketEvent"),
+        mTransport(transport),
+        mType(type),
+        mStatus(status),
+        mParam(param),
+        mTask(std::move(task)) {}
+
+  NS_IMETHOD Run() override {
+    mTransport->OnSocketEvent(mType, mStatus, mParam, std::move(mTask));
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsSocketTransport> mTransport;
+
+  uint32_t mType;
+  nsresult mStatus;
+  nsCOMPtr<nsISupports> mParam;
+  std::function<void()> mTask;
+};
+
+//-----------------------------------------------------------------------------
+
+// #define TEST_CONNECT_ERRORS
+#ifdef TEST_CONNECT_ERRORS
+#  include <stdlib.h>
+static PRErrorCode RandomizeConnectError(PRErrorCode code) {
+  //
+  // To test out these errors, load http://www.yahoo.com/.  It should load
+  // correctly despite the random occurrence of these errors.
+  //
+  int n = rand();
+  if (n > RAND_MAX / 2) {
+    struct {
+      PRErrorCode err_code;
+      const char* err_name;
+    } errors[] = {
+        //
+        // These errors should be recoverable provided there is another
+        // IP address in mDNSRecord.
+        //
+        {PR_CONNECT_REFUSED_ERROR, "PR_CONNECT_REFUSED_ERROR"},
+        {PR_CONNECT_TIMEOUT_ERROR, "PR_CONNECT_TIMEOUT_ERROR"},
+        //
+        // This error will cause this socket transport to error out;
+        // however, if the consumer is HTTP, then the HTTP transaction
+        // should be restarted when this error occurs.
+        //
+        {PR_CONNECT_RESET_ERROR, "PR_CONNECT_RESET_ERROR"},
+    };
+    n = n % (sizeof(errors) / sizeof(errors[0]));
+    code = errors[n].err_code;
+    SOCKET_LOG(("simulating NSPR error %d [%s]\n", code, errors[n].err_name));
+  }
+  return code;
+}
+#endif
+
+//-----------------------------------------------------------------------------
+
+nsresult ErrorAccordingToNSPR(PRErrorCode errorCode) {
+  nsresult rv = NS_ERROR_FAILURE;
+  switch (errorCode) {
+    case PR_WOULD_BLOCK_ERROR:
+      rv = NS_BASE_STREAM_WOULD_BLOCK;
+      break;
+    case PR_CONNECT_ABORTED_ERROR:
+    case PR_CONNECT_RESET_ERROR:
+      rv = NS_ERROR_NET_RESET;
+      break;
+    case PR_END_OF_FILE_ERROR:  // XXX document this correlation
+      rv = NS_ERROR_NET_INTERRUPT;
+      break;
+    case PR_CONNECT_REFUSED_ERROR:
+    // We lump the following NSPR codes in with PR_CONNECT_REFUSED_ERROR. We
+    // could get better diagnostics by adding distinct XPCOM error codes for
+    // each of these, but there are a lot of places in Gecko that check
+    // specifically for NS_ERROR_CONNECTION_REFUSED, all of which would need to
+    // be checked.
+    case PR_NETWORK_UNREACHABLE_ERROR:
+    case PR_HOST_UNREACHABLE_ERROR:
+    case PR_ADDRESS_NOT_AVAILABLE_ERROR:
+    // Treat EACCES as a soft error since (at least on Linux) connect() returns
+    // EACCES when an IPv6 connection is blocked by a firewall. See bug 270784.
+    case PR_NO_ACCESS_RIGHTS_ERROR:
+      rv = NS_ERROR_CONNECTION_REFUSED;
+      break;
+    case PR_ADDRESS_NOT_SUPPORTED_ERROR:
+      rv = NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+      break;
+    case PR_IO_TIMEOUT_ERROR:
+    case PR_CONNECT_TIMEOUT_ERROR:
+      rv = NS_ERROR_NET_TIMEOUT;
+      break;
+    case PR_OUT_OF_MEMORY_ERROR:
+    // These really indicate that the descriptor table filled up, or that the
+    // kernel ran out of network buffers - but nobody really cares which part of
+    // the system ran out of memory.
+    case PR_PROC_DESC_TABLE_FULL_ERROR:
+    case PR_SYS_DESC_TABLE_FULL_ERROR:
+    case PR_INSUFFICIENT_RESOURCES_ERROR:
+      rv = NS_ERROR_OUT_OF_MEMORY;
+      break;
+    case PR_ADDRESS_IN_USE_ERROR:
+      rv = NS_ERROR_SOCKET_ADDRESS_IN_USE;
+      break;
+    // These filename-related errors can arise when using Unix-domain sockets.
+    case PR_FILE_NOT_FOUND_ERROR:
+      rv = NS_ERROR_FILE_NOT_FOUND;
+      break;
+    case PR_IS_DIRECTORY_ERROR:
+      rv = NS_ERROR_FILE_IS_DIRECTORY;
+      break;
+    case PR_LOOP_ERROR:
+      rv = NS_ERROR_FILE_UNRESOLVABLE_SYMLINK;
+      break;
+    case PR_NAME_TOO_LONG_ERROR:
+      rv = NS_ERROR_FILE_NAME_TOO_LONG;
+      break;
+    case PR_NO_DEVICE_SPACE_ERROR:
+      rv = NS_ERROR_FILE_NO_DEVICE_SPACE;
+      break;
+    case PR_NOT_DIRECTORY_ERROR:
+      rv = NS_ERROR_FILE_NOT_DIRECTORY;
+      break;
+    case PR_READ_ONLY_FILESYSTEM_ERROR:
+      rv = NS_ERROR_FILE_READ_ONLY;
+      break;
+    case PR_BAD_ADDRESS_ERROR:
+      rv = NS_ERROR_UNKNOWN_HOST;
+      break;
+    default:
+      if (psm::IsNSSErrorCode(errorCode)) {
+        rv = psm::GetXPCOMFromNSSError(errorCode);
+      }
+      break;
+
+      // NSPR's socket code can return these, but they're not worth breaking out
+      // into their own error codes, distinct from NS_ERROR_FAILURE:
+      //
+      // PR_BAD_DESCRIPTOR_ERROR
+      // PR_INVALID_ARGUMENT_ERROR
+      // PR_NOT_SOCKET_ERROR
+      // PR_NOT_TCP_SOCKET_ERROR
+      //   These would indicate a bug internal to the component.
+      //
+      // PR_PROTOCOL_NOT_SUPPORTED_ERROR
+      //   This means that we can't use the given "protocol" (like
+      //   IPPROTO_TCP or IPPROTO_UDP) with a socket of the given type. As
+      //   above, this indicates an internal bug.
+      //
+      // PR_IS_CONNECTED_ERROR
+      //   This indicates that we've applied a system call like 'bind' or
+      //   'connect' to a socket that is already connected. The socket
+      //   components manage each file descriptor's state, and in some cases
+      //   handle this error result internally. We shouldn't be returning
+      //   this to our callers.
+      //
+      // PR_IO_ERROR
+      //   This is so vague that NS_ERROR_FAILURE is just as good.
+  }
+  SOCKET_LOG(("ErrorAccordingToNSPR [in=%d out=%" PRIx32 "]\n", errorCode,
+              static_cast<uint32_t>(rv)));
+  return rv;
+}
+
+//-----------------------------------------------------------------------------
+// socket input stream impl
+//-----------------------------------------------------------------------------
+
+nsSocketInputStream::nsSocketInputStream(nsSocketTransport* trans)
+    : mTransport(trans) {}
+
+// called on the socket transport thread...
+//
+//   condition : failure code if socket has been closed
+//
+void nsSocketInputStream::OnSocketReady(nsresult condition) {
+  SOCKET_LOG(("nsSocketInputStream::OnSocketReady [this=%p cond=%" PRIx32 "]\n",
+              this, static_cast<uint32_t>(condition)));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    // update condition, but be careful not to erase an already
+    // existing error condition.
+    if (NS_SUCCEEDED(mCondition)) mCondition = condition;
+
+    // ignore event if only waiting for closure and not closed.
+    if (NS_FAILED(mCondition) || !(mCallbackFlags & WAIT_CLOSURE_ONLY)) {
+      callback = std::move(mCallback);
+      mCallbackFlags = 0;
+    }
+  }
+
+  if (callback) callback->OnInputStreamReady(this);
+}
+
+NS_IMPL_QUERY_INTERFACE(nsSocketInputStream, nsIInputStream,
+                        nsIAsyncInputStream)
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsSocketInputStream::AddRef() {
+  ++mReaderRefCnt;
+  return mTransport->AddRef();
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsSocketInputStream::Release() {
+  if (--mReaderRefCnt == 0) Close();
+  return mTransport->Release();
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::Close() { return CloseWithStatus(NS_BASE_STREAM_CLOSED); }
+
+NS_IMETHODIMP
+nsSocketInputStream::Available(uint64_t* avail) {
+  SOCKET_LOG(("nsSocketInputStream::Available [this=%p]\n", this));
+
+  *avail = 0;
+
+  PRFileDesc* fd;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (NS_FAILED(mCondition)) return mCondition;
+
+    fd = mTransport->GetFD_Locked();
+    if (!fd) return NS_OK;
+  }
+
+  // cannot hold lock while calling NSPR.  (worried about the fact that PSM
+  // synchronously proxies notifications over to the UI thread, which could
+  // mistakenly try to re-enter this code.)
+  int32_t n = PR_Available(fd);
+
+  // PSM does not implement PR_Available() so do a best approximation of it
+  // with MSG_PEEK
+  if ((n == -1) && (PR_GetError() == PR_NOT_IMPLEMENTED_ERROR)) {
+    char c;
+
+    n = PR_Recv(fd, &c, 1, PR_MSG_PEEK, 0);
+    SOCKET_LOG(
+        ("nsSocketInputStream::Available [this=%p] "
+         "using PEEK backup n=%d]\n",
+         this, n));
+  }
+
+  nsresult rv;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    mTransport->ReleaseFD_Locked(fd);
+
+    if (n >= 0) {
+      *avail = n;
+    } else {
+      PRErrorCode code = PR_GetError();
+      if (code == PR_WOULD_BLOCK_ERROR) return NS_OK;
+      mCondition = ErrorAccordingToNSPR(code);
+    }
+    rv = mCondition;
+  }
+  if (NS_FAILED(rv)) mTransport->OnInputClosed(rv);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::StreamStatus() {
+  SOCKET_LOG(("nsSocketInputStream::StreamStatus [this=%p]\n", this));
+
+  MutexAutoLock lock(mTransport->mLock);
+  return mCondition;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::Read(char* buf, uint32_t count, uint32_t* countRead) {
+  SOCKET_LOG(("nsSocketInputStream::Read [this=%p count=%u]\n", this, count));
+
+  *countRead = 0;
+
+  PRFileDesc* fd = nullptr;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (NS_FAILED(mCondition)) {
+      return (mCondition == NS_BASE_STREAM_CLOSED) ? NS_OK : mCondition;
+    }
+
+    fd = mTransport->GetFD_Locked();
+    if (!fd) return NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  SOCKET_LOG(("  calling PR_Read [count=%u]\n", count));
+
+  // cannot hold lock while calling NSPR.  (worried about the fact that PSM
+  // synchronously proxies notifications over to the UI thread, which could
+  // mistakenly try to re-enter this code.)
+  int32_t n = PR_Read(fd, buf, count);
+
+  SOCKET_LOG(("  PR_Read returned [n=%d]\n", n));
+
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+#ifdef ENABLE_SOCKET_TRACING
+    if (n > 0) mTransport->TraceInBuf(buf, n);
+#endif
+
+    mTransport->ReleaseFD_Locked(fd);
+
+    if (n > 0) {
+      mByteCount += (*countRead = n);
+    } else if (n < 0) {
+      PRErrorCode code = PR_GetError();
+      if (code == PR_WOULD_BLOCK_ERROR) return NS_BASE_STREAM_WOULD_BLOCK;
+      mCondition = ErrorAccordingToNSPR(code);
+    }
+    rv = mCondition;
+  }
+  if (NS_FAILED(rv)) mTransport->OnInputClosed(rv);
+
+  // only send this notification if we have indeed read some data.
+  // see bug 196827 for an example of why this is important.
+  if (n > 0) mTransport->SendStatus(NS_NET_STATUS_RECEIVING_FROM);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                  uint32_t count, uint32_t* countRead) {
+  // socket stream is unbuffered
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::IsNonBlocking(bool* nonblocking) {
+  *nonblocking = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::CloseWithStatus(nsresult reason) {
+  SOCKET_LOG(("nsSocketInputStream::CloseWithStatus [this=%p reason=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(reason)));
+
+  // may be called from any thread
+
+  nsresult rv;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (NS_SUCCEEDED(mCondition)) {
+      rv = mCondition = reason;
+    } else {
+      rv = NS_OK;
+    }
+  }
+  if (NS_FAILED(rv)) mTransport->OnInputClosed(rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketInputStream::AsyncWait(nsIInputStreamCallback* callback, uint32_t flags,
+                               uint32_t amount, nsIEventTarget* target) {
+  SOCKET_LOG(("nsSocketInputStream::AsyncWait [this=%p]\n", this));
+
+  bool hasError = false;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (callback && target) {
+      //
+      // build event proxy
+      //
+      mCallback = NS_NewInputStreamReadyEvent("nsSocketInputStream::AsyncWait",
+                                              callback, target);
+    } else {
+      mCallback = callback;
+    }
+    mCallbackFlags = flags;
+
+    hasError = NS_FAILED(mCondition);
+  }  // unlock mTransport->mLock
+
+  if (hasError) {
+    // OnSocketEvent will call OnInputStreamReady with an error code after
+    // going through the event loop. We do this because most socket callers
+    // do not expect AsyncWait() to synchronously execute the OnInputStreamReady
+    // callback.
+    mTransport->PostEvent(nsSocketTransport::MSG_INPUT_PENDING);
+  } else {
+    mTransport->OnInputPending();
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// socket output stream impl
+//-----------------------------------------------------------------------------
+
+nsSocketOutputStream::nsSocketOutputStream(nsSocketTransport* trans)
+    : mTransport(trans) {}
+
+// called on the socket transport thread...
+//
+//   condition : failure code if socket has been closed
+//
+void nsSocketOutputStream::OnSocketReady(nsresult condition) {
+  SOCKET_LOG(("nsSocketOutputStream::OnSocketReady [this=%p cond=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(condition)));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  nsCOMPtr<nsIOutputStreamCallback> callback;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    // update condition, but be careful not to erase an already
+    // existing error condition.
+    if (NS_SUCCEEDED(mCondition)) mCondition = condition;
+
+    // ignore event if only waiting for closure and not closed.
+    if (NS_FAILED(mCondition) || !(mCallbackFlags & WAIT_CLOSURE_ONLY)) {
+      callback = std::move(mCallback);
+      mCallbackFlags = 0;
+    }
+  }
+
+  if (callback) callback->OnOutputStreamReady(this);
+}
+
+NS_IMPL_QUERY_INTERFACE(nsSocketOutputStream, nsIOutputStream,
+                        nsIAsyncOutputStream)
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsSocketOutputStream::AddRef() {
+  ++mWriterRefCnt;
+  return mTransport->AddRef();
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsSocketOutputStream::Release() {
+  if (--mWriterRefCnt == 0) Close();
+  return mTransport->Release();
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::Close() { return CloseWithStatus(NS_BASE_STREAM_CLOSED); }
+
+NS_IMETHODIMP
+nsSocketOutputStream::Flush() { return NS_OK; }
+
+NS_IMETHODIMP
+nsSocketOutputStream::StreamStatus() {
+  MutexAutoLock lock(mTransport->mLock);
+  return mCondition;
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::Write(const char* buf, uint32_t count,
+                            uint32_t* countWritten) {
+  SOCKET_LOG(("nsSocketOutputStream::Write [this=%p count=%u]\n", this, count));
+
+  *countWritten = 0;
+
+  // A write of 0 bytes can be used to force the initial SSL handshake, so do
+  // not reject that.
+
+  PRFileDesc* fd = nullptr;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (NS_FAILED(mCondition)) return mCondition;
+
+    fd = mTransport->GetFD_Locked();
+    if (!fd) return NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  SOCKET_LOG(("  calling PR_Write [count=%u]\n", count));
+
+  // cannot hold lock while calling NSPR.  (worried about the fact that PSM
+  // synchronously proxies notifications over to the UI thread, which could
+  // mistakenly try to re-enter this code.)
+  int32_t n = PR_Write(fd, buf, count);
+
+  SOCKET_LOG(("  PR_Write returned [n=%d]\n", n));
+
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+#ifdef ENABLE_SOCKET_TRACING
+    if (n > 0) mTransport->TraceOutBuf(buf, n);
+#endif
+
+    mTransport->ReleaseFD_Locked(fd);
+
+    if (n > 0) {
+      mByteCount += (*countWritten = n);
+    } else if (n < 0) {
+      PRErrorCode code = PR_GetError();
+      if (code == PR_WOULD_BLOCK_ERROR) return NS_BASE_STREAM_WOULD_BLOCK;
+      mCondition = ErrorAccordingToNSPR(code);
+    }
+    rv = mCondition;
+  }
+  if (NS_FAILED(rv)) mTransport->OnOutputClosed(rv);
+
+  // only send this notification if we have indeed written some data.
+  // see bug 196827 for an example of why this is important.
+  if ((n > 0)) {
+    mTransport->SendStatus(NS_NET_STATUS_SENDING_TO);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::WriteSegments(nsReadSegmentFun reader, void* closure,
+                                    uint32_t count, uint32_t* countRead) {
+  // socket stream is unbuffered
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsSocketOutputStream::WriteFromSegments(
+    nsIInputStream* input, void* closure, const char* fromSegment,
+    uint32_t offset, uint32_t count, uint32_t* countRead) {
+  nsSocketOutputStream* self = (nsSocketOutputStream*)closure;
+  return self->Write(fromSegment, count, countRead);
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::WriteFrom(nsIInputStream* stream, uint32_t count,
+                                uint32_t* countRead) {
+  return stream->ReadSegments(WriteFromSegments, this, count, countRead);
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::IsNonBlocking(bool* nonblocking) {
+  *nonblocking = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::CloseWithStatus(nsresult reason) {
+  SOCKET_LOG(("nsSocketOutputStream::CloseWithStatus [this=%p reason=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(reason)));
+
+  // may be called from any thread
+
+  nsresult rv;
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (NS_SUCCEEDED(mCondition)) {
+      rv = mCondition = reason;
+    } else {
+      rv = NS_OK;
+    }
+  }
+  if (NS_FAILED(rv)) mTransport->OnOutputClosed(rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketOutputStream::AsyncWait(nsIOutputStreamCallback* callback,
+                                uint32_t flags, uint32_t amount,
+                                nsIEventTarget* target) {
+  SOCKET_LOG(("nsSocketOutputStream::AsyncWait [this=%p]\n", this));
+
+  {
+    MutexAutoLock lock(mTransport->mLock);
+
+    if (callback && target) {
+      //
+      // build event proxy
+      //
+      mCallback = NS_NewOutputStreamReadyEvent(callback, target);
+    } else {
+      mCallback = callback;
+    }
+
+    mCallbackFlags = flags;
+  }
+  mTransport->OnOutputPending();
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// socket transport impl
+//-----------------------------------------------------------------------------
+
+nsSocketTransport::nsSocketTransport()
+    : mFD(this),
+      mSocketTransportService(gSocketTransportService),
+      mInput(this),
+      mOutput(this) {
+  SOCKET_LOG(("creating nsSocketTransport @%p\n", this));
+
+  mTimeouts[TIMEOUT_CONNECT] = UINT16_MAX;     // no timeout
+  mTimeouts[TIMEOUT_READ_WRITE] = UINT16_MAX;  // no timeout
+}
+
+nsSocketTransport::~nsSocketTransport() {
+  MOZ_RELEASE_ASSERT(!mAttached);
+  SOCKET_LOG(("destroying nsSocketTransport @%p\n", this));
+}
+
+nsresult nsSocketTransport::Init(const nsTArray<nsCString>& types,
+                                 const nsACString& host, uint16_t port,
+                                 const nsACString& hostRoute,
+                                 uint16_t portRoute,
+                                 nsIProxyInfo* givenProxyInfo,
+                                 nsIDNSRecord* dnsRecord) {
+  nsCOMPtr<nsProxyInfo> proxyInfo;
+  if (givenProxyInfo) {
+    proxyInfo = do_QueryInterface(givenProxyInfo);
+    NS_ENSURE_ARG(proxyInfo);
+  }
+
+  if (dnsRecord) {
+    mExternalDNSResolution = true;
+    mDNSRecord = do_QueryInterface(dnsRecord);
+    mDNSRecord->IsTRR(&mResolvedByTRR);
+    mDNSRecord->GetEffectiveTRRMode(&mEffectiveTRRMode);
+    mDNSRecord->GetTrrSkipReason(&mTRRSkipReason);
+  }
+
+  // init socket type info
+
+  mOriginHost = host;
+  mOriginPort = port;
+  if (!hostRoute.IsEmpty()) {
+    mHost = hostRoute;
+    mPort = portRoute;
+  } else {
+    mHost = host;
+    mPort = port;
+  }
+
+  // A subtle check we don't enter this method more than once for the socket
+  // transport lifetime.  Disable on TSan builds to prevent race checking, we
+  // don't want an atomic here for perf reasons!
+#ifndef MOZ_TSAN
+  MOZ_ASSERT(!mPortRemappingApplied);
+#endif  // !MOZ_TSAN
+
+  if (proxyInfo) {
+    mHttpsProxy = proxyInfo->IsHTTPS();
+  }
+
+  const char* proxyType = nullptr;
+  mProxyInfo = proxyInfo;
+  if (proxyInfo) {
+    mProxyPort = proxyInfo->Port();
+    mProxyHost = proxyInfo->Host();
+    // grab proxy type (looking for "socks" for example)
+    proxyType = proxyInfo->Type();
+    if (proxyType && (proxyInfo->IsHTTP() || proxyInfo->IsHTTPS() ||
+                      proxyInfo->IsDirect() || !strcmp(proxyType, "unknown"))) {
+      proxyType = nullptr;
+    }
+  }
+
+  SOCKET_LOG1(
+      ("nsSocketTransport::Init [this=%p host=%s:%hu origin=%s:%d "
+       "proxy=%s:%hu]\n",
+       this, mHost.get(), mPort, mOriginHost.get(), mOriginPort,
+       mProxyHost.get(), mProxyPort));
+
+  // include proxy type as a socket type if proxy type is not "http"
+  uint32_t typeCount = types.Length() + (proxyType != nullptr);
+  if (!typeCount) return NS_OK;
+
+  // if we have socket types, then the socket provider service had
+  // better exist!
+  nsresult rv;
+  nsCOMPtr<nsISocketProviderService> spserv =
+      nsSocketProviderService::GetOrCreate();
+
+  if (!mTypes.SetCapacity(typeCount, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // now verify that each socket type has a registered socket provider.
+  for (uint32_t i = 0, type = 0; i < typeCount; ++i) {
+    // store socket types
+    if (i == 0 && proxyType) {
+      mTypes.AppendElement(proxyType);
+    } else {
+      mTypes.AppendElement(types[type++]);
+    }
+
+    nsCOMPtr<nsISocketProvider> provider;
+    rv = spserv->GetSocketProvider(mTypes[i].get(), getter_AddRefs(provider));
+    if (NS_FAILED(rv)) {
+      NS_WARNING("no registered socket provider");
+      return rv;
+    }
+
+    // note if socket type corresponds to a transparent proxy
+    // XXX don't hardcode SOCKS here (use proxy info's flags instead).
+    if (mTypes[i].EqualsLiteral("socks") || mTypes[i].EqualsLiteral("socks4")) {
+      mProxyTransparent = true;
+
+      if (proxyInfo->Flags() & nsIProxyInfo::TRANSPARENT_PROXY_RESOLVES_HOST) {
+        // we want the SOCKS layer to send the hostname
+        // and port to the proxy and let it do the DNS.
+        mProxyTransparentResolvesHost = true;
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+#if defined(XP_UNIX)
+nsresult nsSocketTransport::InitWithFilename(const char* filename) {
+  return InitWithName(filename, strlen(filename));
+}
+
+nsresult nsSocketTransport::InitWithName(const char* name, size_t length) {
+  if (length > sizeof(mNetAddr.local.path) - 1) {
+    return NS_ERROR_FILE_NAME_TOO_LONG;
+  }
+
+  if (!name[0] && length > 1) {
+    // name is abstract address name that is supported on Linux only
+#  if defined(XP_LINUX)
+    mHost.Assign(name + 1, length - 1);
+#  else
+    return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+#  endif
+  } else {
+    // The name isn't abstract socket address.  So this is Unix domain
+    // socket that has file path.
+    mHost.Assign(name, length);
+  }
+  mPort = 0;
+
+  mNetAddr.local.family = AF_LOCAL;
+  memcpy(mNetAddr.local.path, name, length);
+  mNetAddr.local.path[length] = '\0';
+  mNetAddrIsSet = true;
+
+  return NS_OK;
+}
+#endif
+
+nsresult nsSocketTransport::InitWithConnectedSocket(PRFileDesc* fd,
+                                                    const NetAddr* addr) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  char buf[kNetAddrMaxCStrBufSize];
+  addr->ToStringBuffer(buf, sizeof(buf));
+  mHost.Assign(buf);
+
+  uint16_t port;
+  if (addr->raw.family == AF_INET) {
+    port = addr->inet.port;
+  } else if (addr->raw.family == AF_INET6) {
+    port = addr->inet6.port;
+  } else {
+    port = 0;
+  }
+  mPort = ntohs(port);
+
+  memcpy(&mNetAddr, addr, sizeof(NetAddr));
+
+  mPollFlags = (PR_POLL_READ | PR_POLL_WRITE | PR_POLL_EXCEPT);
+  mState = STATE_TRANSFERRING;
+  SetSocketName(fd);
+  mNetAddrIsSet = true;
+
+  {
+    MutexAutoLock lock(mLock);
+    NS_ASSERTION(!mFD.IsInitialized(), "already initialized");
+    mFD = fd;
+    mFDref = 1;
+    mFDconnected = true;
+    mPollTimeout = mTimeouts[TIMEOUT_READ_WRITE];
+  }
+
+  // make sure new socket is non-blocking
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_Nonblocking;
+  opt.value.non_blocking = true;
+  PR_SetSocketOption(fd, &opt);
+
+  SOCKET_LOG(
+      ("nsSocketTransport::InitWithConnectedSocket [this=%p addr=%s:%hu]\n",
+       this, mHost.get(), mPort));
+
+  // jump to InitiateSocket to get ourselves attached to the STS poll list.
+  return PostEvent(MSG_RETRY_INIT_SOCKET);
+}
+
+nsresult nsSocketTransport::InitWithConnectedSocket(
+    PRFileDesc* aFD, const NetAddr* aAddr, nsIInterfaceRequestor* aCallbacks) {
+  {
+    MutexAutoLock lock(mLock);
+    mCallbacks = aCallbacks;
+  }
+  return InitWithConnectedSocket(aFD, aAddr);
+}
+
+nsresult nsSocketTransport::PostEvent(uint32_t type, nsresult status,
+                                      nsISupports* param,
+                                      std::function<void()>&& task) {
+  SOCKET_LOG(("nsSocketTransport::PostEvent [this=%p type=%u status=%" PRIx32
+              " param=%p]\n",
+              this, type, static_cast<uint32_t>(status), param));
+
+  nsCOMPtr<nsIRunnable> event =
+      new nsSocketEvent(this, type, status, param, std::move(task));
+  if (!event) return NS_ERROR_OUT_OF_MEMORY;
+
+  return mSocketTransportService->Dispatch(event, NS_DISPATCH_NORMAL);
+}
+
+void nsSocketTransport::SendStatus(nsresult status) {
+  SOCKET_LOG1(("nsSocketTransport::SendStatus [this=%p status=%" PRIx32 "]\n",
+               this, static_cast<uint32_t>(status)));
+
+  nsCOMPtr<nsITransportEventSink> sink;
+  uint64_t progress;
+  {
+    MutexAutoLock lock(mLock);
+    sink = mEventSink;
+    switch (status) {
+      case NS_NET_STATUS_SENDING_TO:
+        progress = mOutput.ByteCount();
+        break;
+      case NS_NET_STATUS_RECEIVING_FROM:
+        progress = mInput.ByteCount();
+        break;
+      default:
+        progress = 0;
+        break;
+    }
+  }
+  if (sink) {
+    sink->OnTransportStatus(this, status, progress, -1);
+  }
+}
+
+nsresult nsSocketTransport::ResolveHost() {
+  SOCKET_LOG((
+      "nsSocketTransport::ResolveHost [this=%p %s:%d%s] "
+      "mProxyTransparentResolvesHost=%d\n",
+      this, SocketHost().get(), SocketPort(),
+      mConnectionFlags & nsSocketTransport::BYPASS_CACHE ? " bypass cache" : "",
+      mProxyTransparentResolvesHost));
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  nsresult rv;
+
+  if (!mProxyHost.IsEmpty()) {
+    if (!mProxyTransparent || mProxyTransparentResolvesHost) {
+#if defined(XP_UNIX)
+      MOZ_ASSERT(!mNetAddrIsSet || mNetAddr.raw.family != AF_LOCAL,
+                 "Unix domain sockets can't be used with proxies");
+#endif
+      // When not resolving mHost locally, we still want to ensure that
+      // it only contains valid characters.  See bug 304904 for details.
+      // Sometimes the end host is not yet known and mHost is *
+      if (!net_IsValidHostName(mHost) && !mHost.EqualsLiteral("*")) {
+        SOCKET_LOG(("  invalid hostname %s\n", mHost.get()));
+        return NS_ERROR_UNKNOWN_HOST;
+      }
+    }
+    if (mProxyTransparentResolvesHost) {
+      // Name resolution is done on the server side.  Just pretend
+      // client resolution is complete, this will get picked up later.
+      // since we don't need to do DNS now, we bypass the resolving
+      // step by initializing mNetAddr to an empty address, but we
+      // must keep the port. The SOCKS IO layer will use the hostname
+      // we send it when it's created, rather than the empty address
+      // we send with the connect call.
+      mState = STATE_RESOLVING;
+      mNetAddr.raw.family = AF_INET;
+      mNetAddr.inet.port = htons(SocketPort());
+      mNetAddr.inet.ip = htonl(INADDR_ANY);
+      return PostEvent(MSG_DNS_LOOKUP_COMPLETE, NS_OK, nullptr);
+    }
+  }
+
+  if (mExternalDNSResolution) {
+    MOZ_ASSERT(mDNSRecord);
+    mState = STATE_RESOLVING;
+    return PostEvent(MSG_DNS_LOOKUP_COMPLETE, NS_OK, nullptr);
+  }
+
+  nsCOMPtr<nsIDNSService> dns = nullptr;
+  auto initTask = [&dns]() { dns = do_GetService(kDNSServiceCID); };
+  if (!NS_IsMainThread()) {
+    // Forward to the main thread synchronously.
+    RefPtr<nsIThread> mainThread = do_GetMainThread();
+    if (!mainThread) {
+      return NS_ERROR_FAILURE;
+    }
+
+    SyncRunnable::DispatchToThread(
+        mainThread,
+        NS_NewRunnableFunction("nsSocketTransport::ResolveHost->GetDNSService",
+                               initTask));
+  } else {
+    initTask();
+  }
+  if (!dns) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mResolving = true;
+
+  nsIDNSService::DNSFlags dnsFlags = nsIDNSService::RESOLVE_DEFAULT_FLAGS;
+  if (mConnectionFlags & nsSocketTransport::BYPASS_CACHE) {
+    dnsFlags = nsIDNSService::RESOLVE_BYPASS_CACHE;
+  }
+  if (mConnectionFlags & nsSocketTransport::REFRESH_CACHE) {
+    dnsFlags = nsIDNSService::RESOLVE_REFRESH_CACHE;
+  }
+  if (mConnectionFlags & nsSocketTransport::DISABLE_IPV6) {
+    dnsFlags |= nsIDNSService::RESOLVE_DISABLE_IPV6;
+  }
+  if (mConnectionFlags & nsSocketTransport::DISABLE_IPV4) {
+    dnsFlags |= nsIDNSService::RESOLVE_DISABLE_IPV4;
+  }
+  if (mConnectionFlags & nsSocketTransport::DISABLE_TRR) {
+    dnsFlags |= nsIDNSService::RESOLVE_DISABLE_TRR;
+  }
+
+  if (mConnectionFlags & nsSocketTransport::USE_IP_HINT_ADDRESS) {
+    dnsFlags |= nsIDNSService::RESOLVE_IP_HINT;
+  }
+
+  dnsFlags |= nsIDNSService::GetFlagsFromTRRMode(
+      nsISocketTransport::GetTRRModeFromFlags(mConnectionFlags));
+
+  // When we get here, we are not resolving using any configured proxy likely
+  // because of individual proxy setting on the request or because the host is
+  // excluded from proxying.  Hence, force resolution despite global proxy-DNS
+  // configuration.
+  dnsFlags |= nsIDNSService::RESOLVE_IGNORE_SOCKS_DNS;
+
+  NS_ASSERTION(!(dnsFlags & nsIDNSService::RESOLVE_DISABLE_IPV6) ||
+                   !(dnsFlags & nsIDNSService::RESOLVE_DISABLE_IPV4),
+               "Setting both RESOLVE_DISABLE_IPV6 and RESOLVE_DISABLE_IPV4");
+
+  SendStatus(NS_NET_STATUS_RESOLVING_HOST);
+
+  if (!SocketHost().Equals(mOriginHost)) {
+    SOCKET_LOG(("nsSocketTransport %p origin %s doing dns for %s\n", this,
+                mOriginHost.get(), SocketHost().get()));
+  }
+  rv =
+      dns->AsyncResolveNative(SocketHost(), nsIDNSService::RESOLVE_TYPE_DEFAULT,
+                              dnsFlags, nullptr, this, mSocketTransportService,
+                              mOriginAttributes, getter_AddRefs(mDNSRequest));
+
+  if (NS_SUCCEEDED(rv)) {
+    SOCKET_LOG(("  advancing to STATE_RESOLVING\n"));
+    mState = STATE_RESOLVING;
+  }
+  return rv;
+}
+
+nsresult nsSocketTransport::BuildSocket(PRFileDesc*& fd, bool& proxyTransparent,
+                                        bool& usingSSL) {
+  SOCKET_LOG(("nsSocketTransport::BuildSocket [this=%p]\n", this));
+
+  nsresult rv = NS_OK;
+
+  proxyTransparent = false;
+  usingSSL = false;
+
+  if (mTypes.IsEmpty()) {
+    fd = PR_OpenTCPSocket(mNetAddr.raw.family);
+    if (!fd) {
+      SOCKET_LOG(("  error creating TCP nspr socket [rv=%" PRIx32 "]\n",
+                  static_cast<uint32_t>(rv)));
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    return NS_OK;
+  }
+
+#if defined(XP_UNIX)
+  MOZ_ASSERT(!mNetAddrIsSet || mNetAddr.raw.family != AF_LOCAL,
+             "Unix domain sockets can't be used with socket types");
+#endif
+
+  fd = nullptr;
+
+  uint32_t controlFlags = 0;
+  if (mProxyTransparentResolvesHost) {
+    controlFlags |= nsISocketProvider::PROXY_RESOLVES_HOST;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::ANONYMOUS_CONNECT) {
+    controlFlags |= nsISocketProvider::ANONYMOUS_CONNECT;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::NO_PERMANENT_STORAGE) {
+    controlFlags |= nsISocketProvider::NO_PERMANENT_STORAGE;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::BE_CONSERVATIVE) {
+    controlFlags |= nsISocketProvider::BE_CONSERVATIVE;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::DONT_TRY_ECH) {
+    controlFlags |= nsISocketProvider::DONT_TRY_ECH;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::IS_RETRY) {
+    controlFlags |= nsISocketProvider::IS_RETRY;
+  }
+
+  if (mConnectionFlags &
+      nsISocketTransport::ANONYMOUS_CONNECT_ALLOW_CLIENT_CERT) {
+    controlFlags |= nsISocketProvider::ANONYMOUS_CONNECT_ALLOW_CLIENT_CERT;
+  }
+
+  if (mConnectionFlags & nsISocketTransport::IS_SPECULATIVE_CONNECTION) {
+    controlFlags |= nsISocketProvider::IS_SPECULATIVE_CONNECTION;
+  }
+
+  if (mResolvedByTRR) {
+    controlFlags |= nsISocketProvider::USED_PRIVATE_DNS;
+  }
+
+  // by setting host to mOriginHost, instead of mHost we send the
+  // SocketProvider (e.g. PSM) the origin hostname but can still do DNS
+  // on an explicit alternate service host name
+  const char* host = mOriginHost.get();
+  int32_t port = (int32_t)mOriginPort;
+
+  nsCOMPtr<nsISocketProviderService> spserv =
+      nsSocketProviderService::GetOrCreate();
+  nsCOMPtr<nsIProxyInfo> proxyInfo = mProxyInfo;
+
+  uint32_t i;
+  for (i = 0; i < mTypes.Length(); ++i) {
+    nsCOMPtr<nsISocketProvider> provider;
+
+    SOCKET_LOG(("  pushing io layer [%u:%s]\n", i, mTypes[i].get()));
+
+    rv = spserv->GetSocketProvider(mTypes[i].get(), getter_AddRefs(provider));
+    if (NS_FAILED(rv)) break;
+
+    nsCOMPtr<nsITLSSocketControl> tlsSocketControl;
+    if (i == 0) {
+      // if this is the first type, we'll want the
+      // service to allocate a new socket
+
+      // Most layers _ESPECIALLY_ PSM want the origin name here as they
+      // will use it for secure checks, etc.. and any connection management
+      // differences between the origin name and the routed name can be
+      // taken care of via DNS. However, SOCKS is a special case as there is
+      // no DNS. in the case of SOCKS and PSM the PSM is a separate layer
+      // and receives the origin name.
+      const char* socketProviderHost = host;
+      int32_t socketProviderPort = port;
+      if (mProxyTransparentResolvesHost &&
+          (mTypes[0].EqualsLiteral("socks") ||
+           mTypes[0].EqualsLiteral("socks4"))) {
+        SOCKET_LOG(("SOCKS %d Host/Route override: %s:%d -> %s:%d\n",
+                    mHttpsProxy, socketProviderHost, socketProviderPort,
+                    mHost.get(), mPort));
+        socketProviderHost = mHost.get();
+        socketProviderPort = mPort;
+      }
+
+      // when https proxying we want to just connect to the proxy as if
+      // it were the end host (i.e. expect the proxy's cert)
+
+      rv = provider->NewSocket(
+          mNetAddr.raw.family,
+          mHttpsProxy ? mProxyHost.get() : socketProviderHost,
+          mHttpsProxy ? mProxyPort : socketProviderPort, proxyInfo,
+          mOriginAttributes, controlFlags, mTlsFlags, &fd,
+          getter_AddRefs(tlsSocketControl));
+
+      if (NS_SUCCEEDED(rv) && !fd) {
+        MOZ_ASSERT_UNREACHABLE(
+            "NewSocket succeeded but failed to "
+            "create a PRFileDesc");
+        rv = NS_ERROR_UNEXPECTED;
+      }
+    } else {
+      // the socket has already been allocated,
+      // so we just want the service to add itself
+      // to the stack (such as pushing an io layer)
+      rv = provider->AddToSocket(mNetAddr.raw.family, host, port, proxyInfo,
+                                 mOriginAttributes, controlFlags, mTlsFlags, fd,
+                                 getter_AddRefs(tlsSocketControl));
+    }
+
+    // controlFlags = 0; not used below this point...
+    if (NS_FAILED(rv)) break;
+
+    // if the service was ssl or starttls, we want to hold onto the socket
+    // info
+    bool isSSL = mTypes[i].EqualsLiteral("ssl");
+    if (isSSL || mTypes[i].EqualsLiteral("starttls")) {
+      // remember security info
+      {
+        MutexAutoLock lock(mLock);
+        mTLSSocketControl = tlsSocketControl;
+        SOCKET_LOG(("  [tlsSocketControl=%p callbacks=%p]\n",
+                    mTLSSocketControl.get(), mCallbacks.get()));
+      }
+      // remember if socket type is SSL so we can ProxyStartSSL if need be.
+      usingSSL = isSSL;
+    } else if (mTypes[i].EqualsLiteral("socks") ||
+               mTypes[i].EqualsLiteral("socks4")) {
+      // since socks is transparent, any layers above
+      // it do not have to worry about proxy stuff
+      proxyInfo = nullptr;
+      proxyTransparent = true;
+    }
+  }
+
+  if (NS_FAILED(rv)) {
+    SOCKET_LOG(("  error pushing io layer [%u:%s rv=%" PRIx32 "]\n", i,
+                mTypes[i].get(), static_cast<uint32_t>(rv)));
+    if (fd) {
+      CloseSocket(
+          fd, mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase());
+    }
+  }
+  return rv;
+}
+
+nsresult nsSocketTransport::InitiateSocket() {
+  SOCKET_LOG(("nsSocketTransport::InitiateSocket [this=%p]\n", this));
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  nsresult rv;
+  bool isLocal;
+  IsLocal(&isLocal);
+
+  if (gIOService->IsNetTearingDown()) {
+    return NS_ERROR_ABORT;
+  }
+  if (gIOService->IsOffline()) {
+    if (StaticPrefs::network_disable_localhost_when_offline() || !isLocal) {
+      return NS_ERROR_OFFLINE;
+    }
+  } else if (!isLocal) {
+#ifdef DEBUG
+    // all IP networking has to be done from the parent
+    if (NS_SUCCEEDED(mCondition) && ((mNetAddr.raw.family == AF_INET) ||
+                                     (mNetAddr.raw.family == AF_INET6))) {
+      MOZ_ASSERT(!IsNeckoChild());
+    }
+#endif
+
+    if (NS_SUCCEEDED(mCondition) && xpc::AreNonLocalConnectionsDisabled() &&
+        !(mNetAddr.IsIPAddrAny() || mNetAddr.IsIPAddrLocal() ||
+          mNetAddr.IsIPAddrShared())) {
+      nsAutoCString ipaddr;
+      RefPtr<nsNetAddr> netaddr = new nsNetAddr(&mNetAddr);
+      netaddr->GetAddress(ipaddr);
+      fprintf_stderr(
+          stderr,
+          "FATAL ERROR: Non-local network connections are disabled and a "
+          "connection "
+          "attempt to %s (%s) was made.\nYou should only access hostnames "
+          "available via the test networking proxy (if running mochitests) "
+          "or from a test-specific httpd.js server (if running xpcshell "
+          "tests). "
+          "Browser services should be disabled or redirected to a local "
+          "server.\n",
+          mHost.get(), ipaddr.get());
+      return NS_ERROR_NON_LOCAL_CONNECTION_REFUSED;
+    }
+  }
+
+  // Hosts/Proxy Hosts that are Local IP Literals should not be speculatively
+  // connected - Bug 853423.
+  if (mConnectionFlags & nsISocketTransport::DISABLE_RFC1918 &&
+      mNetAddr.IsIPAddrLocal()) {
+    if (SOCKET_LOG_ENABLED()) {
+      nsAutoCString netAddrCString;
+      netAddrCString.SetLength(kIPv6CStrBufSize);
+      if (!mNetAddr.ToStringBuffer(netAddrCString.BeginWriting(),
+                                   kIPv6CStrBufSize)) {
+        netAddrCString = "<IP-to-string failed>"_ns;
+      }
+      SOCKET_LOG(
+          ("nsSocketTransport::InitiateSocket skipping "
+           "speculative connection for host [%s:%d] proxy "
+           "[%s:%d] with Local IP address [%s]",
+           mHost.get(), mPort, mProxyHost.get(), mProxyPort,
+           netAddrCString.get()));
+    }
+    mCondition = NS_ERROR_CONNECTION_REFUSED;
+    OnSocketDetached(nullptr);
+    return mCondition;
+  }
+
+  //
+  // find out if it is going to be ok to attach another socket to the STS.
+  // if not then we have to wait for the STS to tell us that it is ok.
+  // the notification is asynchronous, which means that when we could be
+  // in a race to call AttachSocket once notified.  for this reason, when
+  // we get notified, we just re-enter this function.  as a result, we are
+  // sure to ask again before calling AttachSocket.  in this way we deal
+  // with the race condition.  though it isn't the most elegant solution,
+  // it is far simpler than trying to build a system that would guarantee
+  // FIFO ordering (which wouldn't even be that valuable IMO).  see bug
+  // 194402 for more info.
+  //
+  if (!mSocketTransportService->CanAttachSocket()) {
+    nsCOMPtr<nsIRunnable> event =
+        new nsSocketEvent(this, MSG_RETRY_INIT_SOCKET);
+    if (!event) return NS_ERROR_OUT_OF_MEMORY;
+    return mSocketTransportService->NotifyWhenCanAttachSocket(event);
+  }
+
+  //
+  // if we already have a connected socket, then just attach and return.
+  //
+  {
+    MutexAutoLock lock(mLock);
+    if (mFD.IsInitialized()) {
+      rv = mSocketTransportService->AttachSocket(mFD, this);
+      if (NS_SUCCEEDED(rv)) mAttached = true;
+      return rv;
+    }
+  }
+
+  //
+  // create new socket fd, push io layers, etc.
+  //
+  PRFileDesc* fd;
+  bool proxyTransparent;
+  bool usingSSL;
+
+  rv = BuildSocket(fd, proxyTransparent, usingSSL);
+  if (NS_FAILED(rv)) {
+    SOCKET_LOG(
+        ("  BuildSocket failed [rv=%" PRIx32 "]\n", static_cast<uint32_t>(rv)));
+    return rv;
+  }
+
+  // create proxy via IOActivityMonitor
+  IOActivityMonitor::MonitorSocket(fd);
+
+#ifdef FUZZING
+  if (StaticPrefs::fuzzing_necko_enabled()) {
+    rv = AttachFuzzyIOLayer(fd);
+    if (NS_FAILED(rv)) {
+      SOCKET_LOG(("Failed to attach fuzzing IOLayer [rv=%" PRIx32 "].\n",
+                  static_cast<uint32_t>(rv)));
+      return rv;
+    }
+    SOCKET_LOG(("Successfully attached fuzzing IOLayer.\n"));
+
+    if (usingSSL) {
+      mTLSSocketControl = new FuzzySocketControl();
+    }
+  }
+#endif
+
+  PRStatus status;
+
+  // Make the socket non-blocking...
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_Nonblocking;
+  opt.value.non_blocking = true;
+  status = PR_SetSocketOption(fd, &opt);
+  NS_ASSERTION(status == PR_SUCCESS, "unable to make socket non-blocking");
+
+  if (mReuseAddrPort) {
+    SOCKET_LOG(("  Setting port/addr reuse socket options\n"));
+
+    // Set ReuseAddr for TCP sockets to enable having several
+    // sockets bound to same local IP and port
+    PRSocketOptionData opt_reuseaddr;
+    opt_reuseaddr.option = PR_SockOpt_Reuseaddr;
+    opt_reuseaddr.value.reuse_addr = PR_TRUE;
+    status = PR_SetSocketOption(fd, &opt_reuseaddr);
+    if (status != PR_SUCCESS) {
+      SOCKET_LOG(("  Couldn't set reuse addr socket option: %d\n", status));
+    }
+
+    // And also set ReusePort for platforms supporting this socket option
+    PRSocketOptionData opt_reuseport;
+    opt_reuseport.option = PR_SockOpt_Reuseport;
+    opt_reuseport.value.reuse_port = PR_TRUE;
+    status = PR_SetSocketOption(fd, &opt_reuseport);
+    if (status != PR_SUCCESS &&
+        PR_GetError() != PR_OPERATION_NOT_SUPPORTED_ERROR) {
+      SOCKET_LOG(("  Couldn't set reuse port socket option: %d\n", status));
+    }
+  }
+
+  // disable the nagle algorithm - if we rely on it to coalesce writes into
+  // full packets the final packet of a multi segment POST/PUT or pipeline
+  // sequence is delayed a full rtt
+  opt.option = PR_SockOpt_NoDelay;
+  opt.value.no_delay = true;
+  PR_SetSocketOption(fd, &opt);
+
+  // if the network.tcp.sendbuffer preference is set, use it to size SO_SNDBUF
+  // The Windows default of 8KB is too small and as of vista sp1, autotuning
+  // only applies to receive window
+  int32_t sndBufferSize;
+  mSocketTransportService->GetSendBufferSize(&sndBufferSize);
+  if (sndBufferSize > 0) {
+    opt.option = PR_SockOpt_SendBufferSize;
+    opt.value.send_buffer_size = sndBufferSize;
+    PR_SetSocketOption(fd, &opt);
+  }
+
+  if (mQoSBits) {
+    opt.option = PR_SockOpt_IpTypeOfService;
+    opt.value.tos = mQoSBits;
+    PR_SetSocketOption(fd, &opt);
+  }
+
+#if defined(XP_WIN)
+  // The linger is turned off by default. This is not a hard close, but
+  // closesocket should return immediately and operating system tries to send
+  // remaining data for certain, implementation specific, amount of time.
+  // https://msdn.microsoft.com/en-us/library/ms739165.aspx
+  //
+  // Turn the linger option on an set the interval to 0. This will cause hard
+  // close of the socket.
+  opt.option = PR_SockOpt_Linger;
+  opt.value.linger.polarity = 1;
+  opt.value.linger.linger = 0;
+  PR_SetSocketOption(fd, &opt);
+#endif
+
+  // up to here, mFD will only be accessed by us
+
+  // assign mFD so that we can properly handle OnSocketDetached before we've
+  // established a connection.
+  {
+    MutexAutoLock lock(mLock);
+    // inform socket transport about this newly created socket...
+    rv = mSocketTransportService->AttachSocket(fd, this);
+    if (NS_FAILED(rv)) {
+      CloseSocket(
+          fd, mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase());
+      return rv;
+    }
+    mAttached = true;
+
+    mFD = fd;
+    mFDref = 1;
+    mFDconnected = false;
+    mPollTimeout = mTimeouts[TIMEOUT_CONNECT];
+  }
+
+  SOCKET_LOG(("  advancing to STATE_CONNECTING\n"));
+  mState = STATE_CONNECTING;
+  SendStatus(NS_NET_STATUS_CONNECTING_TO);
+
+  if (SOCKET_LOG_ENABLED()) {
+    char buf[kNetAddrMaxCStrBufSize];
+    mNetAddr.ToStringBuffer(buf, sizeof(buf));
+    SOCKET_LOG(("  trying address: %s\n", buf));
+  }
+
+  //
+  // Initiate the connect() to the host...
+  //
+  PRNetAddr prAddr;
+  memset(&prAddr, 0, sizeof(prAddr));
+  {
+    if (mBindAddr) {
+      MutexAutoLock lock(mLock);
+      NetAddrToPRNetAddr(mBindAddr.get(), &prAddr);
+      status = PR_Bind(fd, &prAddr);
+      if (status != PR_SUCCESS) {
+        return NS_ERROR_FAILURE;
+      }
+      mBindAddr = nullptr;
+    }
+  }
+
+  NetAddrToPRNetAddr(&mNetAddr, &prAddr);
+
+#ifdef XP_WIN
+  // Find the real tcp socket and set non-blocking once again!
+  // Bug 1158189.
+  PRFileDesc* bottom = PR_GetIdentitiesLayer(fd, PR_NSPR_IO_LAYER);
+  if (bottom) {
+    PROsfd osfd = PR_FileDesc2NativeHandle(bottom);
+    u_long nonblocking = 1;
+    if (ioctlsocket(osfd, FIONBIO, &nonblocking) != 0) {
+      NS_WARNING("Socket could not be set non-blocking!");
+      return NS_ERROR_FAILURE;
+    }
+  }
+#endif
+
+  if (mTLSSocketControl) {
+    if (!mEchConfig.IsEmpty() &&
+        !(mConnectionFlags & (DONT_TRY_ECH | BE_CONSERVATIVE))) {
+      SOCKET_LOG(("nsSocketTransport::InitiateSocket set echconfig."));
+      rv = mTLSSocketControl->SetEchConfig(mEchConfig);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      mEchConfigUsed = true;
+    }
+  }
+
+  // We use PRIntervalTime here because we need
+  // nsIOService::LastOfflineStateChange time and
+  // nsIOService::LastConectivityChange time to be atomic.
+  PRIntervalTime connectStarted = 0;
+  if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+    connectStarted = PR_IntervalNow();
+  }
+
+  if (Telemetry::CanRecordPrereleaseData() ||
+      Telemetry::CanRecordReleaseData()) {
+    if (NS_FAILED(AttachNetworkDataCountLayer(fd))) {
+      SOCKET_LOG(
+          ("nsSocketTransport::InitiateSocket "
+           "AttachNetworkDataCountLayer failed [this=%p]\n",
+           this));
+    }
+  }
+
+  bool connectCalled = true;  // This is only needed for telemetry.
+  status = PR_Connect(fd, &prAddr, NS_SOCKET_CONNECT_TIMEOUT);
+  PRErrorCode code = PR_GetError();
+  if (status == PR_SUCCESS) {
+    PR_SetFDInheritable(fd, false);
+  }
+
+  if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase() &&
+      connectStarted && connectCalled) {
+    SendPRBlockingTelemetry(
+        connectStarted, Telemetry::PRCONNECT_BLOCKING_TIME_NORMAL,
+        Telemetry::PRCONNECT_BLOCKING_TIME_SHUTDOWN,
+        Telemetry::PRCONNECT_BLOCKING_TIME_CONNECTIVITY_CHANGE,
+        Telemetry::PRCONNECT_BLOCKING_TIME_LINK_CHANGE,
+        Telemetry::PRCONNECT_BLOCKING_TIME_OFFLINE);
+  }
+
+  if (status == PR_SUCCESS) {
+    //
+    // we are connected!
+    //
+    OnSocketConnected();
+  } else {
+#if defined(TEST_CONNECT_ERRORS)
+    code = RandomizeConnectError(code);
+#endif
+    //
+    // If the PR_Connect(...) would block, then poll for a connection.
+    //
+    if ((PR_WOULD_BLOCK_ERROR == code) || (PR_IN_PROGRESS_ERROR == code)) {
+      mPollFlags = (PR_POLL_EXCEPT | PR_POLL_WRITE);
+      //
+      // If the socket is already connected, then return success...
+      //
+    } else if (PR_IS_CONNECTED_ERROR == code) {
+      //
+      // we are connected!
+      //
+      OnSocketConnected();
+
+      if (mTLSSocketControl && !mProxyHost.IsEmpty() && proxyTransparent &&
+          usingSSL) {
+        // if the connection phase is finished, and the ssl layer has
+        // been pushed, and we were proxying (transparently; ie. nothing
+        // has to happen in the protocol layer above us), it's time for
+        // the ssl to start doing it's thing.
+        SOCKET_LOG(("  calling ProxyStartSSL()\n"));
+        mTLSSocketControl->ProxyStartSSL();
+        // XXX what if we were forced to poll on the socket for a successful
+        // connection... wouldn't we need to call ProxyStartSSL after a call
+        // to PR_ConnectContinue indicates that we are connected?
+        //
+        // XXX this appears to be what the old socket transport did.  why
+        // isn't this broken?
+      }
+    }
+    //
+    // A SOCKS request was rejected; get the actual error code from
+    // the OS error
+    //
+    else if (PR_UNKNOWN_ERROR == code && mProxyTransparent &&
+             !mProxyHost.IsEmpty()) {
+      code = PR_GetOSError();
+      rv = ErrorAccordingToNSPR(code);
+    }
+    //
+    // The connection was refused...
+    //
+    else {
+      if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase() &&
+          connectStarted && connectCalled) {
+        SendPRBlockingTelemetry(
+            connectStarted, Telemetry::PRCONNECT_FAIL_BLOCKING_TIME_NORMAL,
+            Telemetry::PRCONNECT_FAIL_BLOCKING_TIME_SHUTDOWN,
+            Telemetry::PRCONNECT_FAIL_BLOCKING_TIME_CONNECTIVITY_CHANGE,
+            Telemetry::PRCONNECT_FAIL_BLOCKING_TIME_LINK_CHANGE,
+            Telemetry::PRCONNECT_FAIL_BLOCKING_TIME_OFFLINE);
+      }
+
+      rv = ErrorAccordingToNSPR(code);
+      if ((rv == NS_ERROR_CONNECTION_REFUSED) && !mProxyHost.IsEmpty()) {
+        rv = NS_ERROR_PROXY_CONNECTION_REFUSED;
+      }
+    }
+  }
+  return rv;
+}
+
+bool nsSocketTransport::RecoverFromError() {
+  NS_ASSERTION(NS_FAILED(mCondition), "there should be something wrong");
+
+  SOCKET_LOG(
+      ("nsSocketTransport::RecoverFromError [this=%p state=%x cond=%" PRIx32
+       "]\n",
+       this, mState, static_cast<uint32_t>(mCondition)));
+
+  if (mDoNotRetryToConnect) {
+    SOCKET_LOG(
+        ("nsSocketTransport::RecoverFromError do not retry because "
+         "mDoNotRetryToConnect is set [this=%p]\n",
+         this));
+    return false;
+  }
+
+#if defined(XP_UNIX)
+  // Unix domain connections don't have multiple addresses to try,
+  // so the recovery techniques here don't apply.
+  if (mNetAddrIsSet && mNetAddr.raw.family == AF_LOCAL) return false;
+#endif
+
+  if ((mConnectionFlags & nsSocketTransport::USE_IP_HINT_ADDRESS) &&
+      mCondition == NS_ERROR_UNKNOWN_HOST &&
+      (mState == MSG_DNS_LOOKUP_COMPLETE || mState == MSG_ENSURE_CONNECT)) {
+    SOCKET_LOG(("  try again without USE_IP_HINT_ADDRESS"));
+    mConnectionFlags &= ~nsSocketTransport::USE_IP_HINT_ADDRESS;
+    mState = STATE_CLOSED;
+    return NS_SUCCEEDED(PostEvent(MSG_ENSURE_CONNECT, NS_OK));
+  }
+
+  // can only recover from errors in these states
+  if (mState != STATE_RESOLVING && mState != STATE_CONNECTING) {
+    SOCKET_LOG(("  not in a recoverable state"));
+    return false;
+  }
+
+  nsresult rv;
+
+#ifdef DEBUG
+  {
+    MutexAutoLock lock(mLock);
+    NS_ASSERTION(!mFDconnected, "socket should not be connected");
+  }
+#endif
+
+  // all connection failures need to be reported to DNS so that the next
+  // time we will use a different address if available.
+  // NS_BASE_STREAM_CLOSED is not an actual connection failure, so don't report
+  // to DNS.
+  if (mState == STATE_CONNECTING && mDNSRecord &&
+      mCondition != NS_BASE_STREAM_CLOSED) {
+    mDNSRecord->ReportUnusable(SocketPort());
+  }
+
+  if (mCondition != NS_ERROR_CONNECTION_REFUSED &&
+      mCondition != NS_ERROR_PROXY_CONNECTION_REFUSED &&
+      mCondition != NS_ERROR_NET_TIMEOUT &&
+      mCondition != NS_ERROR_UNKNOWN_HOST &&
+      mCondition != NS_ERROR_UNKNOWN_PROXY_HOST) {
+    SOCKET_LOG(("  not a recoverable error %" PRIx32,
+                static_cast<uint32_t>(mCondition)));
+    return false;
+  }
+
+  bool tryAgain = false;
+
+  if ((mState == STATE_CONNECTING) && mDNSRecord) {
+    if (mNetAddr.raw.family == AF_INET) {
+      if (mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+        Telemetry::Accumulate(Telemetry::IPV4_AND_IPV6_ADDRESS_CONNECTIVITY,
+                              UNSUCCESSFUL_CONNECTING_TO_IPV4_ADDRESS);
+      }
+    } else if (mNetAddr.raw.family == AF_INET6) {
+      if (mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+        Telemetry::Accumulate(Telemetry::IPV4_AND_IPV6_ADDRESS_CONNECTIVITY,
+                              UNSUCCESSFUL_CONNECTING_TO_IPV6_ADDRESS);
+      }
+    }
+  }
+
+  if (mConnectionFlags & RETRY_WITH_DIFFERENT_IP_FAMILY &&
+      mCondition == NS_ERROR_UNKNOWN_HOST && mState == STATE_RESOLVING &&
+      !mProxyTransparentResolvesHost) {
+    SOCKET_LOG(("  trying lookup again with opposite ip family\n"));
+    mConnectionFlags ^= (DISABLE_IPV6 | DISABLE_IPV4);
+    mConnectionFlags &= ~RETRY_WITH_DIFFERENT_IP_FAMILY;
+    // This will tell the consuming half-open to reset preference on the
+    // connection entry
+    mResetFamilyPreference = true;
+    tryAgain = true;
+  }
+
+  // try next ip address only if past the resolver stage...
+  if (mState == STATE_CONNECTING && mDNSRecord) {
+    nsresult rv = mDNSRecord->GetNextAddr(SocketPort(), &mNetAddr);
+    mDNSRecord->IsTRR(&mResolvedByTRR);
+    mDNSRecord->GetEffectiveTRRMode(&mEffectiveTRRMode);
+    mDNSRecord->GetTrrSkipReason(&mTRRSkipReason);
+    if (NS_SUCCEEDED(rv)) {
+      SOCKET_LOG(("  trying again with next ip address\n"));
+      tryAgain = true;
+    } else if (mExternalDNSResolution) {
+      mRetryDnsIfPossible = true;
+      bool trrEnabled;
+      mDNSRecord->IsTRR(&trrEnabled);
+      // Bug 1648147 - If the server responded with `0.0.0.0` or `::` then we
+      // should intentionally not fallback to regular DNS.
+      if (trrEnabled && !StaticPrefs::network_trr_fallback_on_zero_response() &&
+          ((mNetAddr.raw.family == AF_INET && mNetAddr.inet.ip == 0) ||
+           (mNetAddr.raw.family == AF_INET6 && mNetAddr.inet6.ip.u64[0] == 0 &&
+            mNetAddr.inet6.ip.u64[1] == 0))) {
+        SOCKET_LOG(("  TRR returned 0.0.0.0 and there are no other IPs"));
+        mRetryDnsIfPossible = false;
+      }
+    } else if (mConnectionFlags & RETRY_WITH_DIFFERENT_IP_FAMILY) {
+      SOCKET_LOG(("  failed to connect, trying with opposite ip family\n"));
+      // Drop state to closed.  This will trigger new round of DNS
+      // resolving bellow.
+      mState = STATE_CLOSED;
+      mConnectionFlags ^= (DISABLE_IPV6 | DISABLE_IPV4);
+      mConnectionFlags &= ~RETRY_WITH_DIFFERENT_IP_FAMILY;
+      // This will tell the consuming half-open to reset preference on the
+      // connection entry
+      mResetFamilyPreference = true;
+      tryAgain = true;
+    } else if (!(mConnectionFlags & DISABLE_TRR)) {
+      bool trrEnabled;
+      mDNSRecord->IsTRR(&trrEnabled);
+
+      // Bug 1648147 - If the server responded with `0.0.0.0` or `::` then we
+      // should intentionally not fallback to regular DNS.
+      if (!StaticPrefs::network_trr_fallback_on_zero_response() &&
+          ((mNetAddr.raw.family == AF_INET && mNetAddr.inet.ip == 0) ||
+           (mNetAddr.raw.family == AF_INET6 && mNetAddr.inet6.ip.u64[0] == 0 &&
+            mNetAddr.inet6.ip.u64[1] == 0))) {
+        SOCKET_LOG(("  TRR returned 0.0.0.0 and there are no other IPs"));
+      } else if (trrEnabled) {
+        nsIRequest::TRRMode trrMode = nsIRequest::TRR_DEFAULT_MODE;
+        mDNSRecord->GetEffectiveTRRMode(&trrMode);
+        // If current trr mode is trr only, we should not retry.
+        if (trrMode != nsIRequest::TRR_ONLY_MODE) {
+          // Drop state to closed.  This will trigger a new round of
+          // DNS resolving. Bypass the cache this time since the
+          // cached data came from TRR and failed already!
+          SOCKET_LOG(("  failed to connect with TRR enabled, try w/o\n"));
+          mState = STATE_CLOSED;
+          mConnectionFlags |= DISABLE_TRR | BYPASS_CACHE | REFRESH_CACHE;
+          tryAgain = true;
+        }
+      }
+    }
+  }
+
+  // prepare to try again.
+  if (tryAgain) {
+    uint32_t msg;
+
+    if (mState == STATE_CONNECTING) {
+      mState = STATE_RESOLVING;
+      msg = MSG_DNS_LOOKUP_COMPLETE;
+    } else {
+      mState = STATE_CLOSED;
+      msg = MSG_ENSURE_CONNECT;
+    }
+
+    rv = PostEvent(msg, NS_OK);
+    if (NS_FAILED(rv)) tryAgain = false;
+  }
+
+  return tryAgain;
+}
+
+// called on the socket thread only
+void nsSocketTransport::OnMsgInputClosed(nsresult reason) {
+  SOCKET_LOG(("nsSocketTransport::OnMsgInputClosed [this=%p reason=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(reason)));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  mInputClosed = true;
+  // check if event should affect entire transport
+  if (NS_FAILED(reason) && (reason != NS_BASE_STREAM_CLOSED)) {
+    mCondition = reason;  // XXX except if NS_FAILED(mCondition), right??
+  } else if (mOutputClosed) {
+    mCondition =
+        NS_BASE_STREAM_CLOSED;  // XXX except if NS_FAILED(mCondition), right??
+  } else {
+    if (mState == STATE_TRANSFERRING) mPollFlags &= ~PR_POLL_READ;
+    mInput.OnSocketReady(reason);
+  }
+}
+
+// called on the socket thread only
+void nsSocketTransport::OnMsgOutputClosed(nsresult reason) {
+  SOCKET_LOG(("nsSocketTransport::OnMsgOutputClosed [this=%p reason=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(reason)));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  mOutputClosed = true;
+  // check if event should affect entire transport
+  if (NS_FAILED(reason) && (reason != NS_BASE_STREAM_CLOSED)) {
+    mCondition = reason;  // XXX except if NS_FAILED(mCondition), right??
+  } else if (mInputClosed) {
+    mCondition =
+        NS_BASE_STREAM_CLOSED;  // XXX except if NS_FAILED(mCondition), right??
+  } else {
+    if (mState == STATE_TRANSFERRING) mPollFlags &= ~PR_POLL_WRITE;
+    mOutput.OnSocketReady(reason);
+  }
+}
+
+void nsSocketTransport::OnSocketConnected() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(("  advancing to STATE_TRANSFERRING\n"));
+
+  mPollFlags = (PR_POLL_READ | PR_POLL_WRITE | PR_POLL_EXCEPT);
+  mState = STATE_TRANSFERRING;
+
+  // Set the m*AddrIsSet flags only when state has reached TRANSFERRING
+  // because we need to make sure its value does not change due to failover
+  mNetAddrIsSet = true;
+
+  // assign mFD (must do this within the transport lock), but take care not
+  // to trample over mFDref if mFD is already set.
+  {
+    MutexAutoLock lock(mLock);
+    NS_ASSERTION(mFD.IsInitialized(), "no socket");
+    NS_ASSERTION(mFDref == 1, "wrong socket ref count");
+    SetSocketName(mFD);
+    mFDconnected = true;
+    mPollTimeout = mTimeouts[TIMEOUT_READ_WRITE];
+  }
+
+  // Ensure keepalive is configured correctly if previously enabled.
+  if (mKeepaliveEnabled) {
+    nsresult rv = SetKeepaliveEnabledInternal(true);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      SOCKET_LOG(("  SetKeepaliveEnabledInternal failed rv[0x%" PRIx32 "]",
+                  static_cast<uint32_t>(rv)));
+    }
+  }
+
+  SendStatus(NS_NET_STATUS_CONNECTED_TO);
+}
+
+void nsSocketTransport::SetSocketName(PRFileDesc* fd) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (mSelfAddrIsSet) {
+    return;
+  }
+
+  PRNetAddr prAddr;
+  memset(&prAddr, 0, sizeof(prAddr));
+  if (PR_GetSockName(fd, &prAddr) == PR_SUCCESS) {
+    PRNetAddrToNetAddr(&prAddr, &mSelfAddr);
+    mSelfAddrIsSet = true;
+  }
+}
+
+PRFileDesc* nsSocketTransport::GetFD_Locked() {
+  mLock.AssertCurrentThreadOwns();
+
+  // mFD is not available to the streams while disconnected.
+  if (!mFDconnected) return nullptr;
+
+  if (mFD.IsInitialized()) mFDref++;
+
+  return mFD;
+}
+
+class ThunkPRClose : public Runnable {
+ public:
+  explicit ThunkPRClose(PRFileDesc* fd)
+      : Runnable("net::ThunkPRClose"), mFD(fd) {}
+
+  NS_IMETHOD Run() override {
+    nsSocketTransport::CloseSocket(
+        mFD, gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase());
+    return NS_OK;
+  }
+
+ private:
+  PRFileDesc* mFD;
+};
+
+void STS_PRCloseOnSocketTransport(PRFileDesc* fd, bool lingerPolarity,
+                                  int16_t lingerTimeout) {
+  if (gSocketTransportService) {
+    // Can't PR_Close() a socket off STS thread. Thunk it to STS to die
+    gSocketTransportService->Dispatch(new ThunkPRClose(fd), NS_DISPATCH_NORMAL);
+  } else {
+    // something horrible has happened
+    NS_ASSERTION(gSocketTransportService, "No STS service");
+  }
+}
+
+void nsSocketTransport::ReleaseFD_Locked(PRFileDesc* fd) {
+  mLock.AssertCurrentThreadOwns();
+
+  NS_ASSERTION(mFD == fd, "wrong fd");
+
+  if (--mFDref == 0) {
+    if (gIOService->IsNetTearingDown() &&
+        ((PR_IntervalNow() - gIOService->NetTearingDownStarted()) >
+         gSocketTransportService->MaxTimeForPrClosePref())) {
+      // If shutdown last to long, let the socket leak and do not close it.
+      SOCKET_LOG(("Intentional leak"));
+    } else {
+      if (mLingerPolarity || mLingerTimeout) {
+        PRSocketOptionData socket_linger;
+        socket_linger.option = PR_SockOpt_Linger;
+        socket_linger.value.linger.polarity = mLingerPolarity;
+        socket_linger.value.linger.linger = mLingerTimeout;
+        PR_SetSocketOption(mFD, &socket_linger);
+      }
+      if (OnSocketThread()) {
+        SOCKET_LOG(("nsSocketTransport: calling PR_Close [this=%p]\n", this));
+        CloseSocket(
+            mFD, mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase());
+      } else {
+        // Can't PR_Close() a socket off STS thread. Thunk it to STS to die
+        STS_PRCloseOnSocketTransport(mFD, mLingerPolarity, mLingerTimeout);
+      }
+    }
+    mFD = nullptr;
+  }
+}
+
+//-----------------------------------------------------------------------------
+// socket event handler impl
+
+void nsSocketTransport::OnSocketEvent(uint32_t type, nsresult status,
+                                      nsISupports* param,
+                                      std::function<void()>&& task) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG(
+      ("nsSocketTransport::OnSocketEvent [this=%p type=%u status=%" PRIx32
+       " param=%p]\n",
+       this, type, static_cast<uint32_t>(status), param));
+
+  if (NS_FAILED(mCondition)) {
+    // block event since we're apparently already dead.
+    SOCKET_LOG(("  blocking event [condition=%" PRIx32 "]\n",
+                static_cast<uint32_t>(mCondition)));
+    //
+    // notify input/output streams in case either has a pending notify.
+    //
+    mInput.OnSocketReady(mCondition);
+    mOutput.OnSocketReady(mCondition);
+    return;
+  }
+
+  switch (type) {
+    case MSG_ENSURE_CONNECT:
+      SOCKET_LOG(("  MSG_ENSURE_CONNECT\n"));
+      if (task) {
+        task();
+      }
+
+      // Apply port remapping here so that we do it on the socket thread and
+      // before we process the resolved DNS name or create the socket the first
+      // time.
+      if (!mPortRemappingApplied) {
+        mPortRemappingApplied = true;
+
+        mSocketTransportService->ApplyPortRemap(&mPort);
+        mSocketTransportService->ApplyPortRemap(&mOriginPort);
+      }
+
+      //
+      // ensure that we have created a socket, attached it, and have a
+      // connection.
+      //
+      if (mState == STATE_CLOSED) {
+        // Unix domain sockets are ready to connect; mNetAddr is all we
+        // need. Internet address families require a DNS lookup (or possibly
+        // several) before we can connect.
+#if defined(XP_UNIX)
+        if (mNetAddrIsSet && mNetAddr.raw.family == AF_LOCAL) {
+          mCondition = InitiateSocket();
+        } else {
+#else
+        {
+#endif
+          mCondition = ResolveHost();
+        }
+
+      } else {
+        SOCKET_LOG(("  ignoring redundant event\n"));
+      }
+      break;
+
+    case MSG_DNS_LOOKUP_COMPLETE:
+      if (mDNSRequest) {  // only send this if we actually resolved anything
+        SendStatus(NS_NET_STATUS_RESOLVED_HOST);
+      }
+
+      SOCKET_LOG(("  MSG_DNS_LOOKUP_COMPLETE\n"));
+      mDNSRequest = nullptr;
+
+      if (mDNSRecord) {
+        mDNSRecord->GetNextAddr(SocketPort(), &mNetAddr);
+        mDNSRecord->IsTRR(&mResolvedByTRR);
+        mDNSRecord->GetEffectiveTRRMode(&mEffectiveTRRMode);
+        mDNSRecord->GetTrrSkipReason(&mTRRSkipReason);
+      }
+      // status contains DNS lookup status
+      if (NS_FAILED(status)) {
+        // When using a HTTP proxy, NS_ERROR_UNKNOWN_HOST means the HTTP
+        // proxy host is not found, so we fixup the error code.
+        // For SOCKS proxies (mProxyTransparent == true), the socket
+        // transport resolves the real host here, so there's no fixup
+        // (see bug 226943).
+        if ((status == NS_ERROR_UNKNOWN_HOST) && !mProxyTransparent &&
+            !mProxyHost.IsEmpty()) {
+          mCondition = NS_ERROR_UNKNOWN_PROXY_HOST;
+        } else {
+          mCondition = status;
+        }
+      } else if (mState == STATE_RESOLVING) {
+        mCondition = InitiateSocket();
+      }
+      break;
+
+    case MSG_RETRY_INIT_SOCKET:
+      mCondition = InitiateSocket();
+      break;
+
+    case MSG_INPUT_CLOSED:
+      SOCKET_LOG(("  MSG_INPUT_CLOSED\n"));
+      OnMsgInputClosed(status);
+      break;
+
+    case MSG_INPUT_PENDING:
+      SOCKET_LOG(("  MSG_INPUT_PENDING\n"));
+      OnMsgInputPending();
+      break;
+
+    case MSG_OUTPUT_CLOSED:
+      SOCKET_LOG(("  MSG_OUTPUT_CLOSED\n"));
+      OnMsgOutputClosed(status);
+      break;
+
+    case MSG_OUTPUT_PENDING:
+      SOCKET_LOG(("  MSG_OUTPUT_PENDING\n"));
+      OnMsgOutputPending();
+      break;
+    case MSG_TIMEOUT_CHANGED:
+      SOCKET_LOG(("  MSG_TIMEOUT_CHANGED\n"));
+      {
+        MutexAutoLock lock(mLock);
+        mPollTimeout =
+            mTimeouts[(mState == STATE_TRANSFERRING) ? TIMEOUT_READ_WRITE
+                                                     : TIMEOUT_CONNECT];
+      }
+      break;
+    default:
+      SOCKET_LOG(("  unhandled event!\n"));
+  }
+
+  if (NS_FAILED(mCondition)) {
+    SOCKET_LOG(("  after event [this=%p cond=%" PRIx32 "]\n", this,
+                static_cast<uint32_t>(mCondition)));
+    if (!mAttached) {  // need to process this error ourselves...
+      OnSocketDetached(nullptr);
+    }
+  } else if (mPollFlags == PR_POLL_EXCEPT) {
+    mPollFlags = 0;  // make idle
+  }
+}
+
+//-----------------------------------------------------------------------------
+// socket handler impl
+
+void nsSocketTransport::OnSocketReady(PRFileDesc* fd, int16_t outFlags) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  SOCKET_LOG1(("nsSocketTransport::OnSocketReady [this=%p outFlags=%hd]\n",
+               this, outFlags));
+
+  if (outFlags == -1) {
+    SOCKET_LOG(("socket timeout expired\n"));
+    mCondition = NS_ERROR_NET_TIMEOUT;
+    return;
+  }
+
+  if (mState == STATE_TRANSFERRING) {
+    // if waiting to write and socket is writable or hit an exception.
+    if ((mPollFlags & PR_POLL_WRITE) && (outFlags & ~PR_POLL_READ)) {
+      // assume that we won't need to poll any longer (the stream will
+      // request that we poll again if it is still pending).
+      mPollFlags &= ~PR_POLL_WRITE;
+      mOutput.OnSocketReady(NS_OK);
+    }
+    // if waiting to read and socket is readable or hit an exception.
+    if ((mPollFlags & PR_POLL_READ) && (outFlags & ~PR_POLL_WRITE)) {
+      // assume that we won't need to poll any longer (the stream will
+      // request that we poll again if it is still pending).
+      mPollFlags &= ~PR_POLL_READ;
+      mInput.OnSocketReady(NS_OK);
+    }
+    // Update poll timeout in case it was changed
+    {
+      MutexAutoLock lock(mLock);
+      mPollTimeout = mTimeouts[TIMEOUT_READ_WRITE];
+    }
+  } else if ((mState == STATE_CONNECTING) && !gIOService->IsNetTearingDown()) {
+    // We do not need to do PR_ConnectContinue when we are already
+    // shutting down.
+
+    // We use PRIntervalTime here because we need
+    // nsIOService::LastOfflineStateChange time and
+    // nsIOService::LastConectivityChange time to be atomic.
+    PRIntervalTime connectStarted = 0;
+    if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+      connectStarted = PR_IntervalNow();
+    }
+
+    PRStatus status = PR_ConnectContinue(fd, outFlags);
+
+    if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase() &&
+        connectStarted) {
+      SendPRBlockingTelemetry(
+          connectStarted, Telemetry::PRCONNECTCONTINUE_BLOCKING_TIME_NORMAL,
+          Telemetry::PRCONNECTCONTINUE_BLOCKING_TIME_SHUTDOWN,
+          Telemetry::PRCONNECTCONTINUE_BLOCKING_TIME_CONNECTIVITY_CHANGE,
+          Telemetry::PRCONNECTCONTINUE_BLOCKING_TIME_LINK_CHANGE,
+          Telemetry::PRCONNECTCONTINUE_BLOCKING_TIME_OFFLINE);
+    }
+
+    if (status == PR_SUCCESS) {
+      //
+      // we are connected!
+      //
+      OnSocketConnected();
+
+      if (mNetAddr.raw.family == AF_INET) {
+        if (mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+          Telemetry::Accumulate(Telemetry::IPV4_AND_IPV6_ADDRESS_CONNECTIVITY,
+                                SUCCESSFUL_CONNECTING_TO_IPV4_ADDRESS);
+        }
+      } else if (mNetAddr.raw.family == AF_INET6) {
+        if (mSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+          Telemetry::Accumulate(Telemetry::IPV4_AND_IPV6_ADDRESS_CONNECTIVITY,
+                                SUCCESSFUL_CONNECTING_TO_IPV6_ADDRESS);
+        }
+      }
+    } else {
+      PRErrorCode code = PR_GetError();
+#if defined(TEST_CONNECT_ERRORS)
+      code = RandomizeConnectError(code);
+#endif
+      //
+      // If the connect is still not ready, then continue polling...
+      //
+      if ((PR_WOULD_BLOCK_ERROR == code) || (PR_IN_PROGRESS_ERROR == code)) {
+        // Set up the select flags for connect...
+        mPollFlags = (PR_POLL_EXCEPT | PR_POLL_WRITE);
+        // Update poll timeout in case it was changed
+        {
+          MutexAutoLock lock(mLock);
+          mPollTimeout = mTimeouts[TIMEOUT_CONNECT];
+        }
+      }
+      //
+      // The SOCKS proxy rejected our request. Find out why.
+      //
+      else if (PR_UNKNOWN_ERROR == code && mProxyTransparent &&
+               !mProxyHost.IsEmpty()) {
+        code = PR_GetOSError();
+        mCondition = ErrorAccordingToNSPR(code);
+      } else {
+        //
+        // else, the connection failed...
+        //
+        mCondition = ErrorAccordingToNSPR(code);
+        if ((mCondition == NS_ERROR_CONNECTION_REFUSED) &&
+            !mProxyHost.IsEmpty()) {
+          mCondition = NS_ERROR_PROXY_CONNECTION_REFUSED;
+        }
+        SOCKET_LOG(("  connection failed! [reason=%" PRIx32 "]\n",
+                    static_cast<uint32_t>(mCondition)));
+      }
+    }
+  } else if ((mState == STATE_CONNECTING) && gIOService->IsNetTearingDown()) {
+    // We do not need to do PR_ConnectContinue when we are already
+    // shutting down.
+    SOCKET_LOG(
+        ("We are in shutdown so skip PR_ConnectContinue and set "
+         "and error.\n"));
+    mCondition = NS_ERROR_ABORT;
+  } else {
+    NS_ERROR("unexpected socket state");
+    mCondition = NS_ERROR_UNEXPECTED;
+  }
+
+  if (mPollFlags == PR_POLL_EXCEPT) mPollFlags = 0;  // make idle
+}
+
+// called on the socket thread only
+void nsSocketTransport::OnSocketDetached(PRFileDesc* fd) {
+  SOCKET_LOG(("nsSocketTransport::OnSocketDetached [this=%p cond=%" PRIx32
+              "]\n",
+              this, static_cast<uint32_t>(mCondition)));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  mAttached = false;
+
+  // if we didn't initiate this detach, then be sure to pass an error
+  // condition up to our consumers.  (e.g., STS is shutting down.)
+  if (NS_SUCCEEDED(mCondition)) {
+    if (gIOService->IsOffline()) {
+      mCondition = NS_ERROR_OFFLINE;
+    } else {
+      mCondition = NS_ERROR_ABORT;
+    }
+  }
+
+  // If we are not shutting down try again.
+  if (!gIOService->IsNetTearingDown() && RecoverFromError()) {
+    mCondition = NS_OK;
+  } else {
+    mState = STATE_CLOSED;
+
+    // make sure there isn't any pending DNS request
+    if (mDNSRequest) {
+      mDNSRequest->Cancel(NS_ERROR_ABORT);
+      mDNSRequest = nullptr;
+    }
+
+    //
+    // notify input/output streams
+    //
+    mInput.OnSocketReady(mCondition);
+    mOutput.OnSocketReady(mCondition);
+    if (gIOService->IsNetTearingDown()) {
+      if (mInputCopyContext) {
+        NS_CancelAsyncCopy(mInputCopyContext, mCondition);
+      }
+      if (mOutputCopyContext) {
+        NS_CancelAsyncCopy(mOutputCopyContext, mCondition);
+      }
+    }
+  }
+
+  if (mCondition == NS_ERROR_NET_RESET && mDNSRecord &&
+      mOutput.ByteCount() == 0) {
+    // If we are here, it's likely that we are retrying a transaction. Blocking
+    // the already used address could increase the successful rate of the retry.
+    mDNSRecord->ReportUnusable(SocketPort());
+  }
+
+  // finally, release our reference to the socket (must do this within
+  // the transport lock) possibly closing the socket. Also release our
+  // listeners to break potential refcount cycles.
+
+  // We should be careful not to release mEventSink and mCallbacks while
+  // we're locked, because releasing it might require acquiring the lock
+  // again, so we just null out mEventSink and mCallbacks while we're
+  // holding the lock, and let the stack based objects' destuctors take
+  // care of destroying it if needed.
+  nsCOMPtr<nsIInterfaceRequestor> ourCallbacks;
+  nsCOMPtr<nsITransportEventSink> ourEventSink;
+  {
+    MutexAutoLock lock(mLock);
+    if (mFD.IsInitialized()) {
+      ReleaseFD_Locked(mFD);
+      // flag mFD as unusable; this prevents other consumers from
+      // acquiring a reference to mFD.
+      mFDconnected = false;
+    }
+
+    // We must release mCallbacks and mEventSink to avoid memory leak
+    // but only when RecoverFromError() above failed. Otherwise we lose
+    // link with UI and security callbacks on next connection attempt
+    // round. That would lead e.g. to a broken certificate exception page.
+    if (NS_FAILED(mCondition)) {
+      mCallbacks.swap(ourCallbacks);
+      mEventSink.swap(ourEventSink);
+    }
+  }
+}
+
+void nsSocketTransport::IsLocal(bool* aIsLocal) {
+  {
+    MutexAutoLock lock(mLock);
+
+#if defined(XP_UNIX)
+    // Unix-domain sockets are always local.
+    if (mNetAddr.raw.family == PR_AF_LOCAL) {
+      *aIsLocal = true;
+      return;
+    }
+#endif
+
+    *aIsLocal = mNetAddr.IsLoopbackAddr();
+  }
+}
+
+//-----------------------------------------------------------------------------
+// xpcom api
+
+NS_IMPL_ISUPPORTS(nsSocketTransport, nsISocketTransport, nsITransport,
+                  nsIDNSListener, nsIClassInfo, nsIInterfaceRequestor)
+NS_IMPL_CI_INTERFACE_GETTER(nsSocketTransport, nsISocketTransport, nsITransport,
+                            nsIDNSListener, nsIInterfaceRequestor)
+
+NS_IMETHODIMP
+nsSocketTransport::OpenInputStream(uint32_t flags, uint32_t segsize,
+                                   uint32_t segcount,
+                                   nsIInputStream** aResult) {
+  SOCKET_LOG(
+      ("nsSocketTransport::OpenInputStream [this=%p flags=%x]\n", this, flags));
+
+  NS_ENSURE_TRUE(!mInput.IsReferenced(), NS_ERROR_UNEXPECTED);
+
+  nsresult rv;
+  nsCOMPtr<nsIAsyncInputStream> pipeIn;
+  nsCOMPtr<nsIInputStream> result;
+  nsCOMPtr<nsISupports> inputCopyContext;
+
+  if (!(flags & OPEN_UNBUFFERED) || (flags & OPEN_BLOCKING)) {
+    // XXX if the caller wants blocking, then the caller also gets buffered!
+    // bool openBuffered = !(flags & OPEN_UNBUFFERED);
+    bool openBlocking = (flags & OPEN_BLOCKING);
+
+    net_ResolveSegmentParams(segsize, segcount);
+
+    // create a pipe
+    nsCOMPtr<nsIAsyncOutputStream> pipeOut;
+    NS_NewPipe2(getter_AddRefs(pipeIn), getter_AddRefs(pipeOut), !openBlocking,
+                true, segsize, segcount);
+
+    // async copy from socket to pipe
+    rv = NS_AsyncCopy(&mInput, pipeOut, mSocketTransportService,
+                      NS_ASYNCCOPY_VIA_WRITESEGMENTS, segsize, nullptr, nullptr,
+                      true, true, getter_AddRefs(inputCopyContext));
+    if (NS_FAILED(rv)) return rv;
+
+    result = pipeIn;
+  } else {
+    result = &mInput;
+  }
+
+  // flag input stream as open
+  mInputClosed = false;
+  // mInputCopyContext can be only touched on socket thread
+  auto task = [self = RefPtr{this}, inputCopyContext(inputCopyContext)]() {
+    MOZ_ASSERT(OnSocketThread());
+    self->mInputCopyContext = inputCopyContext;
+  };
+  rv = PostEvent(MSG_ENSURE_CONNECT, NS_OK, nullptr, std::move(task));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  result.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::OpenOutputStream(uint32_t flags, uint32_t segsize,
+                                    uint32_t segcount,
+                                    nsIOutputStream** aResult) {
+  SOCKET_LOG(("nsSocketTransport::OpenOutputStream [this=%p flags=%x]\n", this,
+              flags));
+
+  NS_ENSURE_TRUE(!mOutput.IsReferenced(), NS_ERROR_UNEXPECTED);
+
+  nsresult rv;
+  nsCOMPtr<nsIAsyncOutputStream> pipeOut;
+  nsCOMPtr<nsIOutputStream> result;
+  nsCOMPtr<nsISupports> outputCopyContext;
+  if (!(flags & OPEN_UNBUFFERED) || (flags & OPEN_BLOCKING)) {
+    // XXX if the caller wants blocking, then the caller also gets buffered!
+    // bool openBuffered = !(flags & OPEN_UNBUFFERED);
+    bool openBlocking = (flags & OPEN_BLOCKING);
+
+    net_ResolveSegmentParams(segsize, segcount);
+
+    // create a pipe
+    nsCOMPtr<nsIAsyncInputStream> pipeIn;
+    NS_NewPipe2(getter_AddRefs(pipeIn), getter_AddRefs(pipeOut), true,
+                !openBlocking, segsize, segcount);
+
+    // async copy from socket to pipe
+    rv = NS_AsyncCopy(pipeIn, &mOutput, mSocketTransportService,
+                      NS_ASYNCCOPY_VIA_READSEGMENTS, segsize, nullptr, nullptr,
+                      true, true, getter_AddRefs(outputCopyContext));
+    if (NS_FAILED(rv)) return rv;
+
+    result = pipeOut;
+  } else {
+    result = &mOutput;
+  }
+
+  // flag output stream as open
+  mOutputClosed = false;
+
+  // mOutputCopyContext can be only touched on socket thread
+  auto task = [self = RefPtr{this}, outputCopyContext(outputCopyContext)]() {
+    MOZ_ASSERT(OnSocketThread());
+    self->mOutputCopyContext = outputCopyContext;
+  };
+  rv = PostEvent(MSG_ENSURE_CONNECT, NS_OK, nullptr, std::move(task));
+  if (NS_FAILED(rv)) return rv;
+
+  result.forget(aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::Close(nsresult reason) {
+  SOCKET_LOG(("nsSocketTransport::Close %p reason=%" PRIx32, this,
+              static_cast<uint32_t>(reason)));
+
+  if (NS_SUCCEEDED(reason)) reason = NS_BASE_STREAM_CLOSED;
+
+  mDoNotRetryToConnect = true;
+
+  mInput.CloseWithStatus(reason);
+  mOutput.CloseWithStatus(reason);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetTlsSocketControl(nsITLSSocketControl** tlsSocketControl) {
+  MutexAutoLock lock(mLock);
+  *tlsSocketControl = do_AddRef(mTLSSocketControl).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetSecurityCallbacks(nsIInterfaceRequestor** callbacks) {
+  MutexAutoLock lock(mLock);
+  *callbacks = do_AddRef(mCallbacks).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetSecurityCallbacks(nsIInterfaceRequestor* callbacks) {
+  nsCOMPtr<nsIInterfaceRequestor> threadsafeCallbacks;
+  NS_NewNotificationCallbacksAggregation(callbacks, nullptr,
+                                         GetCurrentSerialEventTarget(),
+                                         getter_AddRefs(threadsafeCallbacks));
+  MutexAutoLock lock(mLock);
+  mCallbacks = threadsafeCallbacks;
+  SOCKET_LOG(("Reset callbacks for tlsSocketInfo=%p callbacks=%p\n",
+              mTLSSocketControl.get(), mCallbacks.get()));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetEventSink(nsITransportEventSink* sink,
+                                nsIEventTarget* target) {
+  nsCOMPtr<nsITransportEventSink> temp;
+  if (target) {
+    nsresult rv =
+        net_NewTransportEventSinkProxy(getter_AddRefs(temp), sink, target);
+    if (NS_FAILED(rv)) return rv;
+    sink = temp.get();
+  }
+
+  MutexAutoLock lock(mLock);
+  mEventSink = sink;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::IsAlive(bool* result) {
+  *result = false;
+
+  nsresult conditionWhileLocked = NS_OK;
+  PRFileDescAutoLock fd(this, &conditionWhileLocked);
+  if (NS_FAILED(conditionWhileLocked) || !fd.IsInitialized()) {
+    return NS_OK;
+  }
+
+  // XXX do some idle-time based checks??
+
+  char c;
+  int32_t rval = PR_Recv(fd, &c, 1, PR_MSG_PEEK, 0);
+
+  if ((rval > 0) || (rval < 0 && PR_GetError() == PR_WOULD_BLOCK_ERROR)) {
+    *result = true;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetHost(nsACString& host) {
+  host = SocketHost();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetPort(int32_t* port) {
+  *port = (int32_t)SocketPort();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetScriptableOriginAttributes(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aOriginAttributes) {
+  if (NS_WARN_IF(!ToJSValue(aCx, mOriginAttributes, aOriginAttributes))) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetScriptableOriginAttributes(
+    JSContext* aCx, JS::Handle<JS::Value> aOriginAttributes) {
+  MutexAutoLock lock(mLock);
+  NS_ENSURE_FALSE(mFD.IsInitialized(), NS_ERROR_FAILURE);
+
+  OriginAttributes attrs;
+  if (!aOriginAttributes.isObject() || !attrs.Init(aCx, aOriginAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mOriginAttributes = attrs;
+  return NS_OK;
+}
+
+nsresult nsSocketTransport::GetOriginAttributes(
+    OriginAttributes* aOriginAttributes) {
+  NS_ENSURE_ARG(aOriginAttributes);
+  *aOriginAttributes = mOriginAttributes;
+  return NS_OK;
+}
+
+nsresult nsSocketTransport::SetOriginAttributes(
+    const OriginAttributes& aOriginAttributes) {
+  MutexAutoLock lock(mLock);
+  NS_ENSURE_FALSE(mFD.IsInitialized(), NS_ERROR_FAILURE);
+
+  mOriginAttributes = aOriginAttributes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetPeerAddr(NetAddr* addr) {
+  // once we are in the connected state, mNetAddr will not change.
+  // so if we can verify that we are in the connected state, then
+  // we can freely access mNetAddr from any thread without being
+  // inside a critical section.
+
+  if (!mNetAddrIsSet) {
+    SOCKET_LOG(
+        ("nsSocketTransport::GetPeerAddr [this=%p state=%d] "
+         "NOT_AVAILABLE because not yet connected.",
+         this, mState));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  memcpy(addr, &mNetAddr, sizeof(NetAddr));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetSelfAddr(NetAddr* addr) {
+  // once we are in the connected state, mSelfAddr will not change.
+  // so if we can verify that we are in the connected state, then
+  // we can freely access mSelfAddr from any thread without being
+  // inside a critical section.
+
+  if (!mSelfAddrIsSet) {
+    SOCKET_LOG(
+        ("nsSocketTransport::GetSelfAddr [this=%p state=%d] "
+         "NOT_AVAILABLE because not yet connected.",
+         this, mState));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  memcpy(addr, &mSelfAddr, sizeof(NetAddr));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::Bind(NetAddr* aLocalAddr) {
+  NS_ENSURE_ARG(aLocalAddr);
+
+  MutexAutoLock lock(mLock);
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (mAttached) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mBindAddr = MakeUnique<NetAddr>();
+  memcpy(mBindAddr.get(), aLocalAddr, sizeof(NetAddr));
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetScriptablePeerAddr(nsINetAddr** addr) {
+  NetAddr rawAddr;
+
+  nsresult rv;
+  rv = GetPeerAddr(&rawAddr);
+  if (NS_FAILED(rv)) return rv;
+
+  RefPtr<nsNetAddr> netaddr = new nsNetAddr(&rawAddr);
+  netaddr.forget(addr);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetScriptableSelfAddr(nsINetAddr** addr) {
+  NetAddr rawAddr;
+
+  nsresult rv;
+  rv = GetSelfAddr(&rawAddr);
+  if (NS_FAILED(rv)) return rv;
+
+  RefPtr<nsNetAddr> netaddr = new nsNetAddr(&rawAddr);
+  netaddr.forget(addr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetTimeout(uint32_t type, uint32_t* value) {
+  NS_ENSURE_ARG_MAX(type, nsISocketTransport::TIMEOUT_READ_WRITE);
+  MutexAutoLock lock(mLock);
+  *value = (uint32_t)mTimeouts[type];
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetTimeout(uint32_t type, uint32_t value) {
+  NS_ENSURE_ARG_MAX(type, nsISocketTransport::TIMEOUT_READ_WRITE);
+
+  SOCKET_LOG(("nsSocketTransport::SetTimeout %p type=%u, value=%u", this, type,
+              value));
+
+  // truncate overly large timeout values.
+  {
+    MutexAutoLock lock(mLock);
+    mTimeouts[type] = (uint16_t)std::min<uint32_t>(value, UINT16_MAX);
+  }
+  PostEvent(MSG_TIMEOUT_CHANGED);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetReuseAddrPort(bool reuseAddrPort) {
+  mReuseAddrPort = reuseAddrPort;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetLinger(bool aPolarity, int16_t aTimeout) {
+  MutexAutoLock lock(mLock);
+
+  mLingerPolarity = aPolarity;
+  mLingerTimeout = aTimeout;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetQoSBits(uint8_t aQoSBits) {
+  // Don't do any checking here of bits.  Why?  Because as of RFC-4594
+  // several different Class Selector and Assured Forwarding values
+  // have been defined, but that isn't to say more won't be added later.
+  // In that case, any checking would be an impediment to interoperating
+  // with newer QoS definitions.
+
+  mQoSBits = aQoSBits;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetQoSBits(uint8_t* aQoSBits) {
+  *aQoSBits = mQoSBits;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetRecvBufferSize(uint32_t* aSize) {
+  PRFileDescAutoLock fd(this);
+  if (!fd.IsInitialized()) return NS_ERROR_NOT_CONNECTED;
+
+  nsresult rv = NS_OK;
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_RecvBufferSize;
+  if (PR_GetSocketOption(fd, &opt) == PR_SUCCESS) {
+    *aSize = opt.value.recv_buffer_size;
+  } else {
+    rv = NS_ERROR_FAILURE;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetSendBufferSize(uint32_t* aSize) {
+  PRFileDescAutoLock fd(this);
+  if (!fd.IsInitialized()) return NS_ERROR_NOT_CONNECTED;
+
+  nsresult rv = NS_OK;
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_SendBufferSize;
+  if (PR_GetSocketOption(fd, &opt) == PR_SUCCESS) {
+    *aSize = opt.value.send_buffer_size;
+  } else {
+    rv = NS_ERROR_FAILURE;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetRecvBufferSize(uint32_t aSize) {
+  PRFileDescAutoLock fd(this);
+  if (!fd.IsInitialized()) return NS_ERROR_NOT_CONNECTED;
+
+  nsresult rv = NS_OK;
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_RecvBufferSize;
+  opt.value.recv_buffer_size = aSize;
+  if (PR_SetSocketOption(fd, &opt) != PR_SUCCESS) rv = NS_ERROR_FAILURE;
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetSendBufferSize(uint32_t aSize) {
+  PRFileDescAutoLock fd(this);
+  if (!fd.IsInitialized()) return NS_ERROR_NOT_CONNECTED;
+
+  nsresult rv = NS_OK;
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_SendBufferSize;
+  opt.value.send_buffer_size = aSize;
+  if (PR_SetSocketOption(fd, &opt) != PR_SUCCESS) rv = NS_ERROR_FAILURE;
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::OnLookupComplete(nsICancelable* request, nsIDNSRecord* rec,
+                                    nsresult status) {
+  SOCKET_LOG(("nsSocketTransport::OnLookupComplete: this=%p status %" PRIx32
+              ".",
+              this, static_cast<uint32_t>(status)));
+
+  if (NS_SUCCEEDED(status)) {
+    mDNSRecord = do_QueryInterface(rec);
+    MOZ_ASSERT(mDNSRecord);
+  }
+
+  if (nsCOMPtr<nsIDNSAddrRecord> addrRecord = do_QueryInterface(rec)) {
+    addrRecord->IsTRR(&mResolvedByTRR);
+    addrRecord->GetEffectiveTRRMode(&mEffectiveTRRMode);
+    addrRecord->GetTrrSkipReason(&mTRRSkipReason);
+  }
+
+  // flag host lookup complete for the benefit of the ResolveHost method.
+  mResolving = false;
+  nsresult rv = PostEvent(MSG_DNS_LOOKUP_COMPLETE, status, nullptr);
+
+  // if posting a message fails, then we should assume that the socket
+  // transport has been shutdown.  this should never happen!  if it does
+  // it means that the socket transport service was shutdown before the
+  // DNS service.
+  if (NS_FAILED(rv)) {
+    NS_WARNING("unable to post DNS lookup complete message");
+  }
+
+  return NS_OK;
+}
+
+// nsIInterfaceRequestor
+NS_IMETHODIMP
+nsSocketTransport::GetInterface(const nsIID& iid, void** result) {
+  if (iid.Equals(NS_GET_IID(nsIDNSRecord)) ||
+      iid.Equals(NS_GET_IID(nsIDNSAddrRecord))) {
+    return mDNSRecord ? mDNSRecord->QueryInterface(iid, result)
+                      : NS_ERROR_NO_INTERFACE;
+  }
+  return this->QueryInterface(iid, result);
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetInterfaces(nsTArray<nsIID>& array) {
+  return NS_CI_INTERFACE_GETTER_NAME(nsSocketTransport)(array);
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetScriptableHelper(nsIXPCScriptable** _retval) {
+  *_retval = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetContractID(nsACString& aContractID) {
+  aContractID.SetIsVoid(true);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetClassDescription(nsACString& aClassDescription) {
+  aClassDescription.SetIsVoid(true);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetClassID(nsCID** aClassID) {
+  *aClassID = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetFlags(uint32_t* aFlags) {
+  *aFlags = nsIClassInfo::THREADSAFE;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetClassIDNoAlloc(nsCID* aClassIDNoAlloc) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetConnectionFlags(uint32_t* value) {
+  *value = mConnectionFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetConnectionFlags(uint32_t value) {
+  SOCKET_LOG(
+      ("nsSocketTransport::SetConnectionFlags %p flags=%u", this, value));
+
+  mConnectionFlags = value;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetIsPrivate(bool aIsPrivate) {
+  mIsPrivate = aIsPrivate;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetTlsFlags(uint32_t* value) {
+  *value = mTlsFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetTlsFlags(uint32_t value) {
+  mTlsFlags = value;
+  return NS_OK;
+}
+
+void nsSocketTransport::OnKeepaliveEnabledPrefChange(bool aEnabled) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  // The global pref toggles keepalive as a system feature; it only affects
+  // an individual socket if keepalive has been specifically enabled for it.
+  // So, ensure keepalive is configured correctly if previously enabled.
+  if (mKeepaliveEnabled) {
+    nsresult rv = SetKeepaliveEnabledInternal(aEnabled);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      SOCKET_LOG(("  SetKeepaliveEnabledInternal [%s] failed rv[0x%" PRIx32 "]",
+                  aEnabled ? "enable" : "disable", static_cast<uint32_t>(rv)));
+    }
+  }
+}
+
+nsresult nsSocketTransport::SetKeepaliveEnabledInternal(bool aEnable) {
+  MOZ_ASSERT(mKeepaliveIdleTimeS > 0 && mKeepaliveIdleTimeS <= kMaxTCPKeepIdle);
+  MOZ_ASSERT(mKeepaliveRetryIntervalS > 0 &&
+             mKeepaliveRetryIntervalS <= kMaxTCPKeepIntvl);
+  MOZ_ASSERT(mKeepaliveProbeCount > 0 &&
+             mKeepaliveProbeCount <= kMaxTCPKeepCount);
+
+  PRFileDescAutoLock fd(this);
+  if (NS_WARN_IF(!fd.IsInitialized())) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  // Only enable if keepalives are globally enabled, but ensure other
+  // options are set correctly on the fd.
+  bool enable = aEnable && mSocketTransportService->IsKeepaliveEnabled();
+  nsresult rv =
+      fd.SetKeepaliveVals(enable, mKeepaliveIdleTimeS, mKeepaliveRetryIntervalS,
+                          mKeepaliveProbeCount);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    SOCKET_LOG(("  SetKeepaliveVals failed rv[0x%" PRIx32 "]",
+                static_cast<uint32_t>(rv)));
+    return rv;
+  }
+  rv = fd.SetKeepaliveEnabled(enable);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    SOCKET_LOG(("  SetKeepaliveEnabled failed rv[0x%" PRIx32 "]",
+                static_cast<uint32_t>(rv)));
+    return rv;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetKeepaliveEnabled(bool* aResult) {
+  MOZ_ASSERT(aResult);
+
+  *aResult = mKeepaliveEnabled;
+  return NS_OK;
+}
+
+nsresult nsSocketTransport::EnsureKeepaliveValsAreInitialized() {
+  nsresult rv = NS_OK;
+  int32_t val = -1;
+  if (mKeepaliveIdleTimeS == -1) {
+    rv = mSocketTransportService->GetKeepaliveIdleTime(&val);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    mKeepaliveIdleTimeS = val;
+  }
+  if (mKeepaliveRetryIntervalS == -1) {
+    rv = mSocketTransportService->GetKeepaliveRetryInterval(&val);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    mKeepaliveRetryIntervalS = val;
+  }
+  if (mKeepaliveProbeCount == -1) {
+    rv = mSocketTransportService->GetKeepaliveProbeCount(&val);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    mKeepaliveProbeCount = val;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetKeepaliveEnabled(bool aEnable) {
+#if defined(XP_WIN) || defined(XP_UNIX) || defined(XP_MACOSX)
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  if (aEnable == mKeepaliveEnabled) {
+    SOCKET_LOG(("nsSocketTransport::SetKeepaliveEnabled [%p] already %s.", this,
+                aEnable ? "enabled" : "disabled"));
+    return NS_OK;
+  }
+
+  nsresult rv = NS_OK;
+  if (aEnable) {
+    rv = EnsureKeepaliveValsAreInitialized();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      SOCKET_LOG(
+          ("  SetKeepaliveEnabled [%p] "
+           "error [0x%" PRIx32 "] initializing keepalive vals",
+           this, static_cast<uint32_t>(rv)));
+      return rv;
+    }
+  }
+  SOCKET_LOG(
+      ("nsSocketTransport::SetKeepaliveEnabled [%p] "
+       "%s, idle time[%ds] retry interval[%ds] packet count[%d]: "
+       "globally %s.",
+       this, aEnable ? "enabled" : "disabled", mKeepaliveIdleTimeS,
+       mKeepaliveRetryIntervalS, mKeepaliveProbeCount,
+       mSocketTransportService->IsKeepaliveEnabled() ? "enabled" : "disabled"));
+
+  // Set mKeepaliveEnabled here so that state is maintained; it is possible
+  // that we're in between fds, e.g. the 1st IP address failed, so we're about
+  // to retry on a 2nd from the DNS record.
+  mKeepaliveEnabled = aEnable;
+
+  rv = SetKeepaliveEnabledInternal(aEnable);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    SOCKET_LOG(("  SetKeepaliveEnabledInternal failed rv[0x%" PRIx32 "]",
+                static_cast<uint32_t>(rv)));
+    return rv;
+  }
+
+  return NS_OK;
+#else /* !(defined(XP_WIN) || defined(XP_UNIX) || defined(XP_MACOSX)) */
+  SOCKET_LOG(("nsSocketTransport::SetKeepaliveEnabled unsupported platform"));
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetKeepaliveVals(int32_t aIdleTime, int32_t aRetryInterval) {
+#if defined(XP_WIN) || defined(XP_UNIX) || defined(XP_MACOSX)
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (NS_WARN_IF(aIdleTime <= 0 || kMaxTCPKeepIdle < aIdleTime)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (NS_WARN_IF(aRetryInterval <= 0 || kMaxTCPKeepIntvl < aRetryInterval)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (aIdleTime == mKeepaliveIdleTimeS &&
+      aRetryInterval == mKeepaliveRetryIntervalS) {
+    SOCKET_LOG(
+        ("nsSocketTransport::SetKeepaliveVals [%p] idle time "
+         "already %ds and retry interval already %ds.",
+         this, mKeepaliveIdleTimeS, mKeepaliveRetryIntervalS));
+    return NS_OK;
+  }
+  mKeepaliveIdleTimeS = aIdleTime;
+  mKeepaliveRetryIntervalS = aRetryInterval;
+
+  nsresult rv = NS_OK;
+  if (mKeepaliveProbeCount == -1) {
+    int32_t val = -1;
+    nsresult rv = mSocketTransportService->GetKeepaliveProbeCount(&val);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    mKeepaliveProbeCount = val;
+  }
+
+  SOCKET_LOG(
+      ("nsSocketTransport::SetKeepaliveVals [%p] "
+       "keepalive %s, idle time[%ds] retry interval[%ds] "
+       "packet count[%d]",
+       this, mKeepaliveEnabled ? "enabled" : "disabled", mKeepaliveIdleTimeS,
+       mKeepaliveRetryIntervalS, mKeepaliveProbeCount));
+
+  PRFileDescAutoLock fd(this);
+  if (NS_WARN_IF(!fd.IsInitialized())) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  rv = fd.SetKeepaliveVals(mKeepaliveEnabled, mKeepaliveIdleTimeS,
+                           mKeepaliveRetryIntervalS, mKeepaliveProbeCount);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
+#else
+  SOCKET_LOG(("nsSocketTransport::SetKeepaliveVals unsupported platform"));
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
+#ifdef ENABLE_SOCKET_TRACING
+
+#  include <stdio.h>
+#  include <ctype.h>
+#  include "prenv.h"
+
+static void DumpBytesToFile(const char* path, const char* header,
+                            const char* buf, int32_t n) {
+  FILE* fp = fopen(path, "a");
+
+  fprintf(fp, "\n%s [%d bytes]\n", header, n);
+
+  const unsigned char* p;
+  while (n) {
+    p = (const unsigned char*)buf;
+
+    int32_t i, row_max = std::min(16, n);
+
+    for (i = 0; i < row_max; ++i) fprintf(fp, "%02x  ", *p++);
+    for (i = row_max; i < 16; ++i) fprintf(fp, "    ");
+
+    p = (const unsigned char*)buf;
+    for (i = 0; i < row_max; ++i, ++p) {
+      if (isprint(*p))
+        fprintf(fp, "%c", *p);
+      else
+        fprintf(fp, ".");
+    }
+
+    fprintf(fp, "\n");
+    buf += row_max;
+    n -= row_max;
+  }
+
+  fprintf(fp, "\n");
+  fclose(fp);
+}
+
+void nsSocketTransport::TraceInBuf(const char* buf, int32_t n) {
+  char* val = PR_GetEnv("NECKO_SOCKET_TRACE_LOG");
+  if (!val || !*val) return;
+
+  nsAutoCString header;
+  header.AssignLiteral("Reading from: ");
+  header.Append(mHost);
+  header.Append(':');
+  header.AppendInt(mPort);
+
+  DumpBytesToFile(val, header.get(), buf, n);
+}
+
+void nsSocketTransport::TraceOutBuf(const char* buf, int32_t n) {
+  char* val = PR_GetEnv("NECKO_SOCKET_TRACE_LOG");
+  if (!val || !*val) return;
+
+  nsAutoCString header;
+  header.AssignLiteral("Writing to: ");
+  header.Append(mHost);
+  header.Append(':');
+  header.AppendInt(mPort);
+
+  DumpBytesToFile(val, header.get(), buf, n);
+}
+
+#endif
+
+static void LogNSPRError(const char* aPrefix, const void* aObjPtr) {
+#if defined(DEBUG)
+  PRErrorCode errCode = PR_GetError();
+  int errLen = PR_GetErrorTextLength();
+  nsAutoCString errStr;
+  if (errLen > 0) {
+    errStr.SetLength(errLen);
+    PR_GetErrorText(errStr.BeginWriting());
+  }
+  NS_WARNING(
+      nsPrintfCString("%s [%p] NSPR error[0x%x] %s.",
+                      aPrefix ? aPrefix : "nsSocketTransport", aObjPtr, errCode,
+                      errLen > 0 ? errStr.BeginReading() : "<no error text>")
+          .get());
+#endif
+}
+
+nsresult nsSocketTransport::PRFileDescAutoLock::SetKeepaliveEnabled(
+    bool aEnable) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  MOZ_ASSERT(!(aEnable && !gSocketTransportService->IsKeepaliveEnabled()),
+             "Cannot enable keepalive if global pref is disabled!");
+  if (aEnable && !gSocketTransportService->IsKeepaliveEnabled()) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_Keepalive;
+  opt.value.keep_alive = aEnable;
+  PRStatus status = PR_SetSocketOption(mFd, &opt);
+  if (NS_WARN_IF(status != PR_SUCCESS)) {
+    LogNSPRError("nsSocketTransport::PRFileDescAutoLock::SetKeepaliveEnabled",
+                 mSocketTransport);
+    return ErrorAccordingToNSPR(PR_GetError());
+  }
+  return NS_OK;
+}
+
+static void LogOSError(const char* aPrefix, const void* aObjPtr) {
+#if defined(DEBUG)
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+#  ifdef XP_WIN
+  DWORD errCode = WSAGetLastError();
+  char* errMessage;
+  FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+                     FORMAT_MESSAGE_IGNORE_INSERTS,
+                 NULL, errCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                 (LPSTR)&errMessage, 0, NULL);
+  NS_WARNING(nsPrintfCString("%s [%p] OS error[0x%lx] %s",
+                             aPrefix ? aPrefix : "nsSocketTransport", aObjPtr,
+                             errCode,
+                             errMessage ? errMessage : "<no error text>")
+                 .get());
+  LocalFree(errMessage);
+#  else
+  int errCode = errno;
+  char* errMessage = strerror(errno);
+  NS_WARNING(nsPrintfCString("%s [%p] OS error[0x%x] %s",
+                             aPrefix ? aPrefix : "nsSocketTransport", aObjPtr,
+                             errCode,
+                             errMessage ? errMessage : "<no error text>")
+                 .get());
+#  endif
+#endif
+}
+
+/* XXX PR_SetSockOpt does not support setting keepalive values, so native
+ * handles and platform specific apis (setsockopt, WSAIOCtl) are used in this
+ * file. Requires inclusion of NSPR private/pprio.h, and platform headers.
+ */
+
+nsresult nsSocketTransport::PRFileDescAutoLock::SetKeepaliveVals(
+    bool aEnabled, int aIdleTime, int aRetryInterval, int aProbeCount) {
+#if defined(XP_WIN) || defined(XP_UNIX) || defined(XP_MACOSX)
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  if (NS_WARN_IF(aIdleTime <= 0 || kMaxTCPKeepIdle < aIdleTime)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (NS_WARN_IF(aRetryInterval <= 0 || kMaxTCPKeepIntvl < aRetryInterval)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (NS_WARN_IF(aProbeCount <= 0 || kMaxTCPKeepCount < aProbeCount)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  PROsfd sock = PR_FileDesc2NativeHandle(mFd);
+  if (NS_WARN_IF(sock == -1)) {
+    LogNSPRError("nsSocketTransport::PRFileDescAutoLock::SetKeepaliveVals",
+                 mSocketTransport);
+    return ErrorAccordingToNSPR(PR_GetError());
+  }
+#endif
+
+#if defined(XP_WIN)
+  // Windows allows idle time and retry interval to be set; NOT ping count.
+  struct tcp_keepalive keepalive_vals = {(u_long)aEnabled,
+                                         // Windows uses msec.
+                                         (u_long)(aIdleTime * 1000UL),
+                                         (u_long)(aRetryInterval * 1000UL)};
+  DWORD bytes_returned;
+  int err =
+      WSAIoctl(sock, SIO_KEEPALIVE_VALS, &keepalive_vals,
+               sizeof(keepalive_vals), NULL, 0, &bytes_returned, NULL, NULL);
+  if (NS_WARN_IF(err)) {
+    LogOSError("nsSocketTransport WSAIoctl failed", mSocketTransport);
+    return NS_ERROR_UNEXPECTED;
+  }
+  return NS_OK;
+
+#elif defined(XP_DARWIN)
+  // Darwin uses sec; only supports idle time being set.
+  int err = setsockopt(sock, IPPROTO_TCP, TCP_KEEPALIVE, &aIdleTime,
+                       sizeof(aIdleTime));
+  if (NS_WARN_IF(err)) {
+    LogOSError("nsSocketTransport Failed setting TCP_KEEPALIVE",
+               mSocketTransport);
+    return NS_ERROR_UNEXPECTED;
+  }
+  return NS_OK;
+
+#elif defined(XP_UNIX)
+  // Not all *nix OSes support the following setsockopt() options
+  // ... but we assume they are supported in the Android kernel;
+  // build errors will tell us if they are not.
+#  if defined(ANDROID) || defined(TCP_KEEPIDLE)
+  // Idle time until first keepalive probe; interval between ack'd probes;
+  // seconds.
+  int err = setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE, &aIdleTime,
+                       sizeof(aIdleTime));
+  if (NS_WARN_IF(err)) {
+    LogOSError("nsSocketTransport Failed setting TCP_KEEPIDLE",
+               mSocketTransport);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+#  endif
+#  if defined(ANDROID) || defined(TCP_KEEPINTVL)
+  // Interval between unack'd keepalive probes; seconds.
+  err = setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL, &aRetryInterval,
+                   sizeof(aRetryInterval));
+  if (NS_WARN_IF(err)) {
+    LogOSError("nsSocketTransport Failed setting TCP_KEEPINTVL",
+               mSocketTransport);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+#  endif
+#  if defined(ANDROID) || defined(TCP_KEEPCNT)
+  // Number of unack'd keepalive probes before connection times out.
+  err = setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT, &aProbeCount,
+                   sizeof(aProbeCount));
+  if (NS_WARN_IF(err)) {
+    LogOSError("nsSocketTransport Failed setting TCP_KEEPCNT",
+               mSocketTransport);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+#  endif
+  return NS_OK;
+#else
+  MOZ_ASSERT(false,
+             "nsSocketTransport::PRFileDescAutoLock::SetKeepaliveVals "
+             "called on unsupported platform!");
+  return NS_ERROR_UNEXPECTED;
+#endif
+}
+
+void nsSocketTransport::CloseSocket(PRFileDesc* aFd, bool aTelemetryEnabled) {
+#if defined(XP_WIN)
+  AttachShutdownLayer(aFd);
+#endif
+
+  // We use PRIntervalTime here because we need
+  // nsIOService::LastOfflineStateChange time and
+  // nsIOService::LastConectivityChange time to be atomic.
+  PRIntervalTime closeStarted;
+  if (aTelemetryEnabled) {
+    closeStarted = PR_IntervalNow();
+  }
+
+  PR_Close(aFd);
+
+  if (aTelemetryEnabled) {
+    SendPRBlockingTelemetry(
+        closeStarted, Telemetry::PRCLOSE_TCP_BLOCKING_TIME_NORMAL,
+        Telemetry::PRCLOSE_TCP_BLOCKING_TIME_SHUTDOWN,
+        Telemetry::PRCLOSE_TCP_BLOCKING_TIME_CONNECTIVITY_CHANGE,
+        Telemetry::PRCLOSE_TCP_BLOCKING_TIME_LINK_CHANGE,
+        Telemetry::PRCLOSE_TCP_BLOCKING_TIME_OFFLINE);
+  }
+}
+
+void nsSocketTransport::SendPRBlockingTelemetry(
+    PRIntervalTime aStart, Telemetry::HistogramID aIDNormal,
+    Telemetry::HistogramID aIDShutdown,
+    Telemetry::HistogramID aIDConnectivityChange,
+    Telemetry::HistogramID aIDLinkChange, Telemetry::HistogramID aIDOffline) {
+  PRIntervalTime now = PR_IntervalNow();
+  if (gIOService->IsNetTearingDown()) {
+    Telemetry::Accumulate(aIDShutdown, PR_IntervalToMilliseconds(now - aStart));
+
+  } else if (PR_IntervalToSeconds(now - gIOService->LastConnectivityChange()) <
+             60) {
+    Telemetry::Accumulate(aIDConnectivityChange,
+                          PR_IntervalToMilliseconds(now - aStart));
+  } else if (PR_IntervalToSeconds(now - gIOService->LastNetworkLinkChange()) <
+             60) {
+    Telemetry::Accumulate(aIDLinkChange,
+                          PR_IntervalToMilliseconds(now - aStart));
+
+  } else if (PR_IntervalToSeconds(now - gIOService->LastOfflineStateChange()) <
+             60) {
+    Telemetry::Accumulate(aIDOffline, PR_IntervalToMilliseconds(now - aStart));
+  } else {
+    Telemetry::Accumulate(aIDNormal, PR_IntervalToMilliseconds(now - aStart));
+  }
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetResetIPFamilyPreference(bool* aReset) {
+  *aReset = mResetFamilyPreference;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetEchConfigUsed(bool* aEchConfigUsed) {
+  *aEchConfigUsed = mEchConfigUsed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::SetEchConfig(const nsACString& aEchConfig) {
+  mEchConfig = aEchConfig;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::ResolvedByTRR(bool* aResolvedByTRR) {
+  *aResolvedByTRR = mResolvedByTRR;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsSocketTransport::GetEffectiveTRRMode(
+    nsIRequest::TRRMode* aEffectiveTRRMode) {
+  *aEffectiveTRRMode = mEffectiveTRRMode;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsSocketTransport::GetTrrSkipReason(
+    nsITRRSkipReason::value* aSkipReason) {
+  *aSkipReason = mTRRSkipReason;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetRetryDnsIfPossible(bool* aRetryDns) {
+  *aRetryDns = mRetryDnsIfPossible;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransport::GetStatus(nsresult* aStatus) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  *aStatus = mCondition;
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsSocketTransport2.h b/netwerk/base/nsSocketTransport2.h
new file mode 100644
index 0000000000..cafa679404
--- /dev/null
+++ b/netwerk/base/nsSocketTransport2.h
@@ -0,0 +1,485 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsSocketTransport2_h__
+#define nsSocketTransport2_h__
+
+#ifdef DEBUG_darinf
+#  define ENABLE_SOCKET_TRACING
+#endif
+
+#include <functional>
+
+#include "mozilla/Mutex.h"
+#include "nsSocketTransportService2.h"
+#include "nsString.h"
+#include "nsCOMPtr.h"
+
+#include "nsIInterfaceRequestor.h"
+#include "nsISocketTransport.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIDNSListener.h"
+#include "nsIDNSRecord.h"
+#include "nsIClassInfo.h"
+#include "mozilla/net/DNS.h"
+#include "nsASocketHandler.h"
+#include "mozilla/Telemetry.h"
+
+#include "prerror.h"
+#include "ssl.h"
+
+class nsICancelable;
+class nsIDNSRecord;
+class nsIInterfaceRequestor;
+
+//-----------------------------------------------------------------------------
+
+// after this short interval, we will return to PR_Poll
+#define NS_SOCKET_CONNECT_TIMEOUT PR_MillisecondsToInterval(20)
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+nsresult ErrorAccordingToNSPR(PRErrorCode errorCode);
+
+class nsSocketTransport;
+
+class nsSocketInputStream : public nsIAsyncInputStream {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+
+  explicit nsSocketInputStream(nsSocketTransport*);
+  virtual ~nsSocketInputStream() = default;
+
+  bool IsReferenced() { return mReaderRefCnt > 0; }
+  nsresult Condition() { return mCondition; }
+  uint64_t ByteCount() { return mByteCount; }
+
+  // called by the socket transport on the socket thread...
+  void OnSocketReady(nsresult condition);
+
+ private:
+  nsSocketTransport* mTransport;
+  ThreadSafeAutoRefCnt mReaderRefCnt{0};
+
+  // access to these is protected by mTransport->mLock
+  nsresult mCondition{NS_OK};
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  uint32_t mCallbackFlags{0};
+  uint64_t mByteCount{0};
+};
+
+//-----------------------------------------------------------------------------
+
+class nsSocketOutputStream : public nsIAsyncOutputStream {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIOUTPUTSTREAM
+  NS_DECL_NSIASYNCOUTPUTSTREAM
+
+  explicit nsSocketOutputStream(nsSocketTransport*);
+  virtual ~nsSocketOutputStream() = default;
+
+  bool IsReferenced() { return mWriterRefCnt > 0; }
+  nsresult Condition() { return mCondition; }
+  uint64_t ByteCount() { return mByteCount; }
+
+  // called by the socket transport on the socket thread...
+  void OnSocketReady(nsresult condition);
+
+ private:
+  static nsresult WriteFromSegments(nsIInputStream*, void*, const char*,
+                                    uint32_t offset, uint32_t count,
+                                    uint32_t* countRead);
+
+  nsSocketTransport* mTransport;
+  ThreadSafeAutoRefCnt mWriterRefCnt{0};
+
+  // access to these is protected by mTransport->mLock
+  nsresult mCondition{NS_OK};
+  nsCOMPtr<nsIOutputStreamCallback> mCallback;
+  uint32_t mCallbackFlags{0};
+  uint64_t mByteCount{0};
+};
+
+//-----------------------------------------------------------------------------
+
+class nsSocketTransport final : public nsASocketHandler,
+                                public nsISocketTransport,
+                                public nsIDNSListener,
+                                public nsIClassInfo,
+                                public nsIInterfaceRequestor {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITRANSPORT
+  NS_DECL_NSISOCKETTRANSPORT
+  NS_DECL_NSIDNSLISTENER
+  NS_DECL_NSICLASSINFO
+  NS_DECL_NSIINTERFACEREQUESTOR
+
+  nsSocketTransport();
+
+  // this method instructs the socket transport to open a socket of the
+  // given type(s) to the given host or proxy.
+  nsresult Init(const nsTArray<nsCString>& socketTypes, const nsACString& host,
+                uint16_t port, const nsACString& hostRoute, uint16_t portRoute,
+                nsIProxyInfo* proxyInfo, nsIDNSRecord* dnsRecord);
+
+  // this method instructs the socket transport to use an already connected
+  // socket with the given address.
+  nsresult InitWithConnectedSocket(PRFileDesc* socketFD, const NetAddr* addr);
+
+  // this method instructs the socket transport to use an already connected
+  // socket with the given address, and additionally supplies the security
+  // callbacks interface requestor.
+  nsresult InitWithConnectedSocket(PRFileDesc* aFD, const NetAddr* aAddr,
+                                   nsIInterfaceRequestor* aCallbacks);
+
+#ifdef XP_UNIX
+  // This method instructs the socket transport to open a socket
+  // connected to the given Unix domain address. We can only create
+  // unlayered, simple, stream sockets.
+  nsresult InitWithFilename(const char* filename);
+
+  // This method instructs the socket transport to open a socket
+  // connected to the given Unix domain address that includes abstract
+  // socket address. If using abstract socket address, first character of
+  // name parameter has to be \0.
+  // We can only create unlayered, simple, stream sockets.
+  nsresult InitWithName(const char* name, size_t len);
+#endif
+
+  // nsASocketHandler methods:
+  void OnSocketReady(PRFileDesc*, int16_t outFlags) override;
+  void OnSocketDetached(PRFileDesc*) override;
+  void IsLocal(bool* aIsLocal) override;
+  void OnKeepaliveEnabledPrefChange(bool aEnabled) final;
+
+  // called when a socket event is handled
+  void OnSocketEvent(uint32_t type, nsresult status, nsISupports* param,
+                     std::function<void()>&& task);
+
+  uint64_t ByteCountReceived() override { return mInput.ByteCount(); }
+  uint64_t ByteCountSent() override { return mOutput.ByteCount(); }
+  static void CloseSocket(PRFileDesc* aFd, bool aTelemetryEnabled);
+  static void SendPRBlockingTelemetry(
+      PRIntervalTime aStart, Telemetry::HistogramID aIDNormal,
+      Telemetry::HistogramID aIDShutdown,
+      Telemetry::HistogramID aIDConnectivityChange,
+      Telemetry::HistogramID aIDLinkChange, Telemetry::HistogramID aIDOffline);
+
+ protected:
+  virtual ~nsSocketTransport();
+
+ private:
+  // event types
+  enum {
+    MSG_ENSURE_CONNECT,
+    MSG_DNS_LOOKUP_COMPLETE,
+    MSG_RETRY_INIT_SOCKET,
+    MSG_TIMEOUT_CHANGED,
+    MSG_INPUT_CLOSED,
+    MSG_INPUT_PENDING,
+    MSG_OUTPUT_CLOSED,
+    MSG_OUTPUT_PENDING
+  };
+  nsresult PostEvent(uint32_t type, nsresult status = NS_OK,
+                     nsISupports* param = nullptr,
+                     std::function<void()>&& task = nullptr);
+
+  enum {
+    STATE_CLOSED,
+    STATE_IDLE,
+    STATE_RESOLVING,
+    STATE_CONNECTING,
+    STATE_TRANSFERRING
+  };
+
+  // Safer way to get and automatically release PRFileDesc objects.
+  class MOZ_STACK_CLASS PRFileDescAutoLock {
+   public:
+    explicit PRFileDescAutoLock(nsSocketTransport* aSocketTransport,
+                                nsresult* aConditionWhileLocked = nullptr)
+        : mSocketTransport(aSocketTransport), mFd(nullptr) {
+      MOZ_ASSERT(aSocketTransport);
+      MutexAutoLock lock(mSocketTransport->mLock);
+      if (aConditionWhileLocked) {
+        *aConditionWhileLocked = mSocketTransport->mCondition;
+        if (NS_FAILED(mSocketTransport->mCondition)) {
+          return;
+        }
+      }
+      mFd = mSocketTransport->GetFD_Locked();
+    }
+    ~PRFileDescAutoLock() {
+      MutexAutoLock lock(mSocketTransport->mLock);
+      if (mFd) {
+        mSocketTransport->ReleaseFD_Locked(mFd);
+      }
+    }
+    bool IsInitialized() { return mFd; }
+    operator PRFileDesc*() { return mFd; }
+    nsresult SetKeepaliveEnabled(bool aEnable);
+    nsresult SetKeepaliveVals(bool aEnabled, int aIdleTime, int aRetryInterval,
+                              int aProbeCount);
+
+   private:
+    operator PRFileDescAutoLock*() { return nullptr; }
+
+    // Weak ptr to nsSocketTransport since this is a stack class only.
+    nsSocketTransport* mSocketTransport;
+    PRFileDesc* mFd;
+  };
+  friend class PRFileDescAutoLock;
+
+  class LockedPRFileDesc {
+   public:
+    explicit LockedPRFileDesc(nsSocketTransport* aSocketTransport)
+        : mSocketTransport(aSocketTransport), mFd(nullptr) {
+      MOZ_ASSERT(aSocketTransport);
+    }
+    ~LockedPRFileDesc() = default;
+    bool IsInitialized() { return mFd; }
+    LockedPRFileDesc& operator=(PRFileDesc* aFd) {
+      mSocketTransport->mLock.AssertCurrentThreadOwns();
+      mFd = aFd;
+      return *this;
+    }
+    operator PRFileDesc*() {
+      if (mSocketTransport->mAttached) {
+        mSocketTransport->mLock.AssertCurrentThreadOwns();
+      }
+      return mFd;
+    }
+    bool operator==(PRFileDesc* aFd) {
+      mSocketTransport->mLock.AssertCurrentThreadOwns();
+      return mFd == aFd;
+    }
+
+   private:
+    operator LockedPRFileDesc*() { return nullptr; }
+    // Weak ptr to nsSocketTransport since it owns this class.
+    nsSocketTransport* mSocketTransport;
+    PRFileDesc* mFd;
+  };
+  friend class LockedPRFileDesc;
+
+  //-------------------------------------------------------------------------
+  // these members are "set" at initialization time and are never modified
+  // afterwards.  this allows them to be safely accessed from any thread.
+  //-------------------------------------------------------------------------
+
+  // socket type info:
+  nsTArray<nsCString> mTypes;
+  nsCString mHost;
+  nsCString mProxyHost;
+  nsCString mOriginHost;
+  uint16_t mPort{0};
+  nsCOMPtr<nsIProxyInfo> mProxyInfo;
+  uint16_t mProxyPort{0};
+  uint16_t mOriginPort{0};
+  bool mProxyTransparent{false};
+  bool mProxyTransparentResolvesHost{false};
+  bool mHttpsProxy{false};
+  uint32_t mConnectionFlags{0};
+  // When we fail to connect using a prefered IP family, we tell the consumer to
+  // reset the IP family preference on the connection entry.
+  bool mResetFamilyPreference{false};
+  uint32_t mTlsFlags{0};
+  bool mReuseAddrPort{false};
+
+  // The origin attributes are used to create sockets.  The first party domain
+  // will eventually be used to isolate OCSP cache and is only non-empty when
+  // "privacy.firstparty.isolate" is enabled.  Setting this is the only way to
+  // carry origin attributes down to NSPR layers which are final consumers.
+  // It must be set before the socket transport is built.
+  OriginAttributes mOriginAttributes;
+
+  uint16_t SocketPort() {
+    return (!mProxyHost.IsEmpty() && !mProxyTransparent) ? mProxyPort : mPort;
+  }
+  const nsCString& SocketHost() {
+    return (!mProxyHost.IsEmpty() && !mProxyTransparent) ? mProxyHost : mHost;
+  }
+
+  Atomic<bool> mInputClosed{true};
+  Atomic<bool> mOutputClosed{true};
+
+  //-------------------------------------------------------------------------
+  // members accessible only on the socket transport thread:
+  //  (the exception being initialization/shutdown time)
+  //-------------------------------------------------------------------------
+
+  // socket state vars:
+  uint32_t mState{STATE_CLOSED};  // STATE_??? flags
+  bool mAttached{false};
+
+  // this flag is used to determine if the results of a host lookup arrive
+  // recursively or not.  this flag is not protected by any lock.
+  bool mResolving{false};
+
+  nsCOMPtr<nsICancelable> mDNSRequest;
+  nsCOMPtr<nsIDNSAddrRecord> mDNSRecord;
+
+  nsCString mEchConfig;
+  bool mEchConfigUsed = false;
+  bool mResolvedByTRR{false};
+  nsIRequest::TRRMode mEffectiveTRRMode{nsIRequest::TRR_DEFAULT_MODE};
+  nsITRRSkipReason::value mTRRSkipReason{nsITRRSkipReason::TRR_UNSET};
+
+  nsCOMPtr<nsISupports> mInputCopyContext;
+  nsCOMPtr<nsISupports> mOutputCopyContext;
+
+  // mNetAddr/mSelfAddr is valid from GetPeerAddr()/GetSelfAddr() once we have
+  // reached STATE_TRANSFERRING. It must not change after that.
+  void SetSocketName(PRFileDesc* fd);
+  NetAddr mNetAddr;
+  NetAddr mSelfAddr;  // getsockname()
+  Atomic<bool, Relaxed> mNetAddrIsSet{false};
+  Atomic<bool, Relaxed> mSelfAddrIsSet{false};
+
+  UniquePtr<NetAddr> mBindAddr;
+
+  // socket methods (these can only be called on the socket thread):
+
+  void SendStatus(nsresult status);
+  nsresult ResolveHost();
+  nsresult BuildSocket(PRFileDesc*&, bool&, bool&);
+  nsresult InitiateSocket();
+  bool RecoverFromError();
+
+  void OnMsgInputPending() {
+    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+    if (mState == STATE_TRANSFERRING) {
+      mPollFlags |= (PR_POLL_READ | PR_POLL_EXCEPT);
+    }
+  }
+  void OnMsgOutputPending() {
+    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+    if (mState == STATE_TRANSFERRING) {
+      mPollFlags |= (PR_POLL_WRITE | PR_POLL_EXCEPT);
+    }
+  }
+  void OnMsgInputClosed(nsresult reason);
+  void OnMsgOutputClosed(nsresult reason);
+
+  // called when the socket is connected
+  void OnSocketConnected();
+
+  //-------------------------------------------------------------------------
+  // socket input/output objects.  these may be accessed on any thread with
+  // the exception of some specific methods (XXX).
+
+  // protects members in this section.
+  Mutex mLock MOZ_UNANNOTATED{"nsSocketTransport.mLock"};
+  LockedPRFileDesc mFD;
+  nsrefcnt mFDref{0};        // mFD is closed when mFDref goes to zero.
+  bool mFDconnected{false};  // mFD is available to consumer when TRUE.
+
+  // A delete protector reference to gSocketTransportService held for lifetime
+  // of 'this'. Sometimes used interchangably with gSocketTransportService due
+  // to scoping.
+  RefPtr<nsSocketTransportService> mSocketTransportService;
+
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsITransportEventSink> mEventSink;
+  nsCOMPtr<nsITLSSocketControl> mTLSSocketControl;
+
+  nsSocketInputStream mInput;
+  nsSocketOutputStream mOutput;
+
+  friend class nsSocketInputStream;
+  friend class nsSocketOutputStream;
+
+  // socket timeouts are protected by mLock.
+  uint16_t mTimeouts[2]{0};
+
+  // linger options to use when closing
+  bool mLingerPolarity{false};
+  int16_t mLingerTimeout{0};
+
+  // QoS setting for socket
+  uint8_t mQoSBits{0x00};
+
+  //
+  // mFD access methods: called with mLock held.
+  //
+  PRFileDesc* GetFD_Locked();
+  void ReleaseFD_Locked(PRFileDesc* fd);
+
+  //
+  // stream state changes (called outside mLock):
+  //
+  void OnInputClosed(nsresult reason) {
+    // no need to post an event if called on the socket thread
+    if (OnSocketThread()) {
+      OnMsgInputClosed(reason);
+    } else {
+      PostEvent(MSG_INPUT_CLOSED, reason);
+    }
+  }
+  void OnInputPending() {
+    // no need to post an event if called on the socket thread
+    if (OnSocketThread()) {
+      OnMsgInputPending();
+    } else {
+      PostEvent(MSG_INPUT_PENDING);
+    }
+  }
+  void OnOutputClosed(nsresult reason) {
+    // no need to post an event if called on the socket thread
+    if (OnSocketThread()) {
+      OnMsgOutputClosed(reason);  // XXX need to not be inside lock!
+    } else {
+      PostEvent(MSG_OUTPUT_CLOSED, reason);
+    }
+  }
+  void OnOutputPending() {
+    // no need to post an event if called on the socket thread
+    if (OnSocketThread()) {
+      OnMsgOutputPending();
+    } else {
+      PostEvent(MSG_OUTPUT_PENDING);
+    }
+  }
+
+#ifdef ENABLE_SOCKET_TRACING
+  void TraceInBuf(const char* buf, int32_t n);
+  void TraceOutBuf(const char* buf, int32_t n);
+#endif
+
+  // Reads prefs to get default keepalive config.
+  nsresult EnsureKeepaliveValsAreInitialized();
+
+  // Groups calls to fd.SetKeepaliveEnabled and fd.SetKeepaliveVals.
+  nsresult SetKeepaliveEnabledInternal(bool aEnable);
+
+  // True if keepalive has been enabled by the socket owner. Note: Keepalive
+  // must also be enabled globally for it to be enabled in TCP.
+  bool mKeepaliveEnabled{false};
+
+  // Keepalive config (support varies by platform).
+  int32_t mKeepaliveIdleTimeS{-1};
+  int32_t mKeepaliveRetryIntervalS{-1};
+  int32_t mKeepaliveProbeCount{-1};
+
+  Atomic<bool> mDoNotRetryToConnect{false};
+
+  // Whether the port remapping has already been applied.  We definitely want to
+  // prevent duplicate calls in case of chaining remapping.
+  bool mPortRemappingApplied = false;
+
+  bool mExternalDNSResolution = false;
+  bool mRetryDnsIfPossible = false;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // !nsSocketTransport_h__
diff --git a/netwerk/base/nsSocketTransportService2.cpp b/netwerk/base/nsSocketTransportService2.cpp
new file mode 100644
index 0000000000..aa0596e10d
--- /dev/null
+++ b/netwerk/base/nsSocketTransportService2.cpp
@@ -0,0 +1,1932 @@
+// vim:set sw=2 sts=2 et cin:
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsSocketTransportService2.h"
+
+#include "IOActivityMonitor.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/ChaosMode.h"
+#include "mozilla/IntegerPrintfMacros.h"
+#include "mozilla/Likely.h"
+#include "mozilla/PodOperations.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/ProfilerMarkers.h"
+#include "mozilla/ProfilerThreadSleep.h"
+#include "mozilla/PublicSSL.h"
+#include "mozilla/ReverseIterator.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Tokenizer.h"
+#include "mozilla/Telemetry.h"
+#include "nsASocketHandler.h"
+#include "nsError.h"
+#include "nsIFile.h"
+#include "nsINetworkLinkService.h"
+#include "nsIOService.h"
+#include "nsIObserverService.h"
+#include "nsIWidget.h"
+#include "nsServiceManagerUtils.h"
+#include "nsSocketTransport2.h"
+#include "nsThreadUtils.h"
+#include "prerror.h"
+#include "prnetdb.h"
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gSocketTransportLog("nsSocketTransport");
+LazyLogModule gUDPSocketLog("UDPSocket");
+LazyLogModule gTCPSocketLog("TCPSocket");
+
+nsSocketTransportService* gSocketTransportService = nullptr;
+static Atomic<PRThread*, Relaxed> gSocketThread(nullptr);
+
+#define SEND_BUFFER_PREF "network.tcp.sendbuffer"
+#define KEEPALIVE_ENABLED_PREF "network.tcp.keepalive.enabled"
+#define KEEPALIVE_IDLE_TIME_PREF "network.tcp.keepalive.idle_time"
+#define KEEPALIVE_RETRY_INTERVAL_PREF "network.tcp.keepalive.retry_interval"
+#define KEEPALIVE_PROBE_COUNT_PREF "network.tcp.keepalive.probe_count"
+#define SOCKET_LIMIT_TARGET 1000U
+#define MAX_TIME_BETWEEN_TWO_POLLS \
+  "network.sts.max_time_for_events_between_two_polls"
+#define POLL_BUSY_WAIT_PERIOD "network.sts.poll_busy_wait_period"
+#define POLL_BUSY_WAIT_PERIOD_TIMEOUT \
+  "network.sts.poll_busy_wait_period_timeout"
+#define MAX_TIME_FOR_PR_CLOSE_DURING_SHUTDOWN \
+  "network.sts.max_time_for_pr_close_during_shutdown"
+#define POLLABLE_EVENT_TIMEOUT "network.sts.pollable_event_timeout"
+
+#define REPAIR_POLLABLE_EVENT_TIME 10
+
+uint32_t nsSocketTransportService::gMaxCount;
+PRCallOnceType nsSocketTransportService::gMaxCountInitOnce;
+
+// Utility functions
+bool OnSocketThread() { return PR_GetCurrentThread() == gSocketThread; }
+
+//-----------------------------------------------------------------------------
+
+bool nsSocketTransportService::SocketContext::IsTimedOut(
+    PRIntervalTime now) const {
+  return TimeoutIn(now) == 0;
+}
+
+void nsSocketTransportService::SocketContext::EnsureTimeout(
+    PRIntervalTime now) {
+  SOCKET_LOG(("SocketContext::EnsureTimeout socket=%p", mHandler.get()));
+  if (!mPollStartEpoch) {
+    SOCKET_LOG(("  engaging"));
+    mPollStartEpoch = now;
+  }
+}
+
+void nsSocketTransportService::SocketContext::DisengageTimeout() {
+  SOCKET_LOG(("SocketContext::DisengageTimeout socket=%p", mHandler.get()));
+  mPollStartEpoch = 0;
+}
+
+PRIntervalTime nsSocketTransportService::SocketContext::TimeoutIn(
+    PRIntervalTime now) const {
+  SOCKET_LOG(("SocketContext::TimeoutIn socket=%p, timeout=%us", mHandler.get(),
+              mHandler->mPollTimeout));
+
+  if (mHandler->mPollTimeout == UINT16_MAX || !mPollStartEpoch) {
+    SOCKET_LOG(("  not engaged"));
+    return NS_SOCKET_POLL_TIMEOUT;
+  }
+
+  PRIntervalTime elapsed = (now - mPollStartEpoch);
+  PRIntervalTime timeout = PR_SecondsToInterval(mHandler->mPollTimeout);
+
+  if (elapsed >= timeout) {
+    SOCKET_LOG(("  timed out!"));
+    return 0;
+  }
+  SOCKET_LOG(("  remains %us", PR_IntervalToSeconds(timeout - elapsed)));
+  return timeout - elapsed;
+}
+
+void nsSocketTransportService::SocketContext::MaybeResetEpoch() {
+  if (mPollStartEpoch && mHandler->mPollTimeout == UINT16_MAX) {
+    mPollStartEpoch = 0;
+  }
+}
+
+//-----------------------------------------------------------------------------
+// ctor/dtor (called on the main/UI thread by the service manager)
+
+nsSocketTransportService::nsSocketTransportService()
+    : mPollableEventTimeout(TimeDuration::FromSeconds(6)),
+      mMaxTimeForPrClosePref(PR_SecondsToInterval(5)),
+      mNetworkLinkChangeBusyWaitPeriod(PR_SecondsToInterval(50)),
+      mNetworkLinkChangeBusyWaitTimeout(PR_SecondsToInterval(7)) {
+  NS_ASSERTION(NS_IsMainThread(), "wrong thread");
+
+  PR_CallOnce(&gMaxCountInitOnce, DiscoverMaxCount);
+
+  NS_ASSERTION(!gSocketTransportService, "must not instantiate twice");
+  gSocketTransportService = this;
+
+  // The Poll list always has an entry at [0].   The rest of the
+  // list is a duplicate of the Active list's PRFileDesc file descriptors.
+  PRPollDesc entry = {nullptr, PR_POLL_READ | PR_POLL_EXCEPT, 0};
+  mPollList.InsertElementAt(0, entry);
+}
+
+void nsSocketTransportService::ApplyPortRemap(uint16_t* aPort) {
+  MOZ_ASSERT(IsOnCurrentThreadInfallible());
+
+  if (!mPortRemapping) {
+    return;
+  }
+
+  // Reverse the array to make later rules override earlier rules.
+  for (auto const& portMapping : Reversed(*mPortRemapping)) {
+    if (*aPort < std::get<0>(portMapping)) {
+      continue;
+    }
+    if (*aPort > std::get<1>(portMapping)) {
+      continue;
+    }
+
+    *aPort = std::get<2>(portMapping);
+    return;
+  }
+}
+
+bool nsSocketTransportService::UpdatePortRemapPreference(
+    nsACString const& aPortMappingPref) {
+  TPortRemapping portRemapping;
+
+  auto consumePreference = [&]() -> bool {
+    Tokenizer tokenizer(aPortMappingPref);
+
+    tokenizer.SkipWhites();
+    if (tokenizer.CheckEOF()) {
+      return true;
+    }
+
+    nsTArray<std::tuple<uint16_t, uint16_t>> ranges(2);
+    while (true) {
+      uint16_t loPort;
+      tokenizer.SkipWhites();
+      if (!tokenizer.ReadInteger(&loPort)) {
+        break;
+      }
+
+      uint16_t hiPort;
+      tokenizer.SkipWhites();
+      if (tokenizer.CheckChar('-')) {
+        tokenizer.SkipWhites();
+        if (!tokenizer.ReadInteger(&hiPort)) {
+          break;
+        }
+      } else {
+        hiPort = loPort;
+      }
+
+      ranges.AppendElement(std::make_tuple(loPort, hiPort));
+
+      tokenizer.SkipWhites();
+      if (tokenizer.CheckChar(',')) {
+        continue;  // another port or port range is expected
+      }
+
+      if (tokenizer.CheckChar('=')) {
+        uint16_t targetPort;
+        tokenizer.SkipWhites();
+        if (!tokenizer.ReadInteger(&targetPort)) {
+          break;
+        }
+
+        // Storing reversed, because the most common cases (like 443) will very
+        // likely be listed as first, less common cases will be added to the end
+        // of the list mapping to the same port. As we iterate the whole
+        // remapping array from the end, this may have a small perf win by
+        // hitting the most common cases earlier.
+        for (auto const& range : Reversed(ranges)) {
+          portRemapping.AppendElement(std::make_tuple(
+              std::get<0>(range), std::get<1>(range), targetPort));
+        }
+        ranges.Clear();
+
+        tokenizer.SkipWhites();
+        if (tokenizer.CheckChar(';')) {
+          continue;  // more mappings (or EOF) expected
+        }
+        if (tokenizer.CheckEOF()) {
+          return true;
+        }
+      }
+
+      // Anything else is unexpected.
+      break;
+    }
+
+    // 'break' from the parsing loop means ill-formed preference
+    portRemapping.Clear();
+    return false;
+  };
+
+  bool rv = consumePreference();
+
+  if (!IsOnCurrentThread()) {
+    nsCOMPtr<nsIThread> thread = GetThreadSafely();
+    if (!thread) {
+      // Init hasn't been called yet. Could probably just assert.
+      // If shutdown, the dispatch below will just silently fail.
+      NS_ASSERTION(false, "ApplyPortRemapPreference before STS::Init");
+      return false;
+    }
+    thread->Dispatch(NewRunnableMethod<TPortRemapping>(
+        "net::ApplyPortRemapping", this,
+        &nsSocketTransportService::ApplyPortRemapPreference, portRemapping));
+  } else {
+    ApplyPortRemapPreference(portRemapping);
+  }
+
+  return rv;
+}
+
+nsSocketTransportService::~nsSocketTransportService() {
+  NS_ASSERTION(NS_IsMainThread(), "wrong thread");
+  NS_ASSERTION(!mInitialized, "not shutdown properly");
+
+  gSocketTransportService = nullptr;
+}
+
+//-----------------------------------------------------------------------------
+// event queue (any thread)
+
+already_AddRefed<nsIThread> nsSocketTransportService::GetThreadSafely() {
+  MutexAutoLock lock(mLock);
+  nsCOMPtr<nsIThread> result = mThread;
+  return result.forget();
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::DispatchFromScript(nsIRunnable* event,
+                                             uint32_t flags) {
+  nsCOMPtr<nsIRunnable> event_ref(event);
+  return Dispatch(event_ref.forget(), flags);
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::Dispatch(already_AddRefed<nsIRunnable> event,
+                                   uint32_t flags) {
+  nsCOMPtr<nsIRunnable> event_ref(event);
+  SOCKET_LOG(("STS dispatch [%p]\n", event_ref.get()));
+
+  nsCOMPtr<nsIThread> thread = GetThreadSafely();
+  nsresult rv;
+  rv = thread ? thread->Dispatch(event_ref.forget(), flags)
+              : NS_ERROR_NOT_INITIALIZED;
+  if (rv == NS_ERROR_UNEXPECTED) {
+    // Thread is no longer accepting events. We must have just shut it
+    // down on the main thread. Pretend we never saw it.
+    rv = NS_ERROR_NOT_INITIALIZED;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::DelayedDispatch(already_AddRefed<nsIRunnable>,
+                                          uint32_t) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::RegisterShutdownTask(nsITargetShutdownTask* task) {
+  nsCOMPtr<nsIThread> thread = GetThreadSafely();
+  return thread ? thread->RegisterShutdownTask(task) : NS_ERROR_UNEXPECTED;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::UnregisterShutdownTask(nsITargetShutdownTask* task) {
+  nsCOMPtr<nsIThread> thread = GetThreadSafely();
+  return thread ? thread->UnregisterShutdownTask(task) : NS_ERROR_UNEXPECTED;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::IsOnCurrentThread(bool* result) {
+  *result = OnSocketThread();
+  return NS_OK;
+}
+
+NS_IMETHODIMP_(bool)
+nsSocketTransportService::IsOnCurrentThreadInfallible() {
+  return OnSocketThread();
+}
+
+//-----------------------------------------------------------------------------
+// nsIDirectTaskDispatcher
+
+already_AddRefed<nsIDirectTaskDispatcher>
+nsSocketTransportService::GetDirectTaskDispatcherSafely() {
+  MutexAutoLock lock(mLock);
+  nsCOMPtr<nsIDirectTaskDispatcher> result = mDirectTaskDispatcher;
+  return result.forget();
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::DispatchDirectTask(
+    already_AddRefed<nsIRunnable> aEvent) {
+  nsCOMPtr<nsIDirectTaskDispatcher> dispatcher =
+      GetDirectTaskDispatcherSafely();
+  NS_ENSURE_TRUE(dispatcher, NS_ERROR_NOT_INITIALIZED);
+  return dispatcher->DispatchDirectTask(std::move(aEvent));
+}
+
+NS_IMETHODIMP nsSocketTransportService::DrainDirectTasks() {
+  nsCOMPtr<nsIDirectTaskDispatcher> dispatcher =
+      GetDirectTaskDispatcherSafely();
+  if (!dispatcher) {
+    // nothing to drain.
+    return NS_OK;
+  }
+  return dispatcher->DrainDirectTasks();
+}
+
+NS_IMETHODIMP nsSocketTransportService::HaveDirectTasks(bool* aValue) {
+  nsCOMPtr<nsIDirectTaskDispatcher> dispatcher =
+      GetDirectTaskDispatcherSafely();
+  if (!dispatcher) {
+    *aValue = false;
+    return NS_OK;
+  }
+  return dispatcher->HaveDirectTasks(aValue);
+}
+
+//-----------------------------------------------------------------------------
+// socket api (socket thread only)
+
+NS_IMETHODIMP
+nsSocketTransportService::NotifyWhenCanAttachSocket(nsIRunnable* event) {
+  SOCKET_LOG(("nsSocketTransportService::NotifyWhenCanAttachSocket\n"));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  if (CanAttachSocket()) {
+    return Dispatch(event, NS_DISPATCH_NORMAL);
+  }
+
+  auto* runnable = new LinkedRunnableEvent(event);
+  mPendingSocketQueue.insertBack(runnable);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::AttachSocket(PRFileDesc* fd,
+                                       nsASocketHandler* handler) {
+  SOCKET_LOG(
+      ("nsSocketTransportService::AttachSocket [handler=%p]\n", handler));
+
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  if (!CanAttachSocket()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  SocketContext sock{fd, handler, 0};
+
+  AddToIdleList(&sock);
+  return NS_OK;
+}
+
+// the number of sockets that can be attached at any given time is
+// limited.  this is done because some operating systems (e.g., Win9x)
+// limit the number of sockets that can be created by an application.
+// AttachSocket will fail if the limit is exceeded.  consumers should
+// call CanAttachSocket and check the result before creating a socket.
+
+bool nsSocketTransportService::CanAttachSocket() {
+  static bool reported900FDLimit = false;
+
+  MOZ_ASSERT(!mShuttingDown);
+  uint32_t total = mActiveList.Length() + mIdleList.Length();
+  bool rv = total < gMaxCount;
+
+  if (Telemetry::CanRecordPrereleaseData() &&
+      (((total >= 900) || !rv) && !reported900FDLimit)) {
+    reported900FDLimit = true;
+    Telemetry::Accumulate(Telemetry::NETWORK_SESSION_AT_900FD, true);
+  }
+  MOZ_ASSERT(mInitialized);
+  return rv;
+}
+
+nsresult nsSocketTransportService::DetachSocket(SocketContextList& listHead,
+                                                SocketContext* sock) {
+  SOCKET_LOG(("nsSocketTransportService::DetachSocket [handler=%p]\n",
+              sock->mHandler.get()));
+  MOZ_ASSERT((&listHead == &mActiveList) || (&listHead == &mIdleList),
+             "DetachSocket invalid head");
+
+  {
+    // inform the handler that this socket is going away
+    sock->mHandler->OnSocketDetached(sock->mFD);
+  }
+  mSentBytesCount += sock->mHandler->ByteCountSent();
+  mReceivedBytesCount += sock->mHandler->ByteCountReceived();
+
+  // cleanup
+  sock->mFD = nullptr;
+
+  if (&listHead == &mActiveList) {
+    RemoveFromPollList(sock);
+  } else {
+    RemoveFromIdleList(sock);
+  }
+
+  // NOTE: sock is now an invalid pointer
+
+  //
+  // notify the first element on the pending socket queue...
+  //
+  nsCOMPtr<nsIRunnable> event;
+  LinkedRunnableEvent* runnable = mPendingSocketQueue.getFirst();
+  if (runnable) {
+    event = runnable->TakeEvent();
+    runnable->remove();
+    delete runnable;
+  }
+  if (event) {
+    // move event from pending queue to dispatch queue
+    return Dispatch(event, NS_DISPATCH_NORMAL);
+  }
+  return NS_OK;
+}
+
+// Returns the index of a SocketContext within a list, or -1 if it's
+// not a pointer to a list element
+// NOTE: this could be supplied by nsTArray<>
+int64_t nsSocketTransportService::SockIndex(SocketContextList& aList,
+                                            SocketContext* aSock) {
+  ptrdiff_t index = -1;
+  if (!aList.IsEmpty()) {
+    index = aSock - &aList[0];
+    if (index < 0 || (size_t)index + 1 > aList.Length()) {
+      index = -1;
+    }
+  }
+  return (int64_t)index;
+}
+
+void nsSocketTransportService::AddToPollList(SocketContext* sock) {
+  MOZ_ASSERT(SockIndex(mActiveList, sock) == -1,
+             "AddToPollList Socket Already Active");
+
+  SOCKET_LOG(("nsSocketTransportService::AddToPollList %p [handler=%p]\n", sock,
+              sock->mHandler.get()));
+
+  sock->EnsureTimeout(PR_IntervalNow());
+  PRPollDesc poll;
+  poll.fd = sock->mFD;
+  poll.in_flags = sock->mHandler->mPollFlags;
+  poll.out_flags = 0;
+  if (ChaosMode::isActive(ChaosFeature::NetworkScheduling)) {
+    auto newSocketIndex = mActiveList.Length();
+    newSocketIndex = ChaosMode::randomUint32LessThan(newSocketIndex + 1);
+    mActiveList.InsertElementAt(newSocketIndex, *sock);
+    // mPollList is offset by 1
+    mPollList.InsertElementAt(newSocketIndex + 1, poll);
+  } else {
+    // Avoid refcount bump/decrease
+    mActiveList.EmplaceBack(sock->mFD, sock->mHandler.forget(),
+                            sock->mPollStartEpoch);
+    mPollList.AppendElement(poll);
+  }
+
+  SOCKET_LOG(
+      ("  active=%zu idle=%zu\n", mActiveList.Length(), mIdleList.Length()));
+}
+
+void nsSocketTransportService::RemoveFromPollList(SocketContext* sock) {
+  SOCKET_LOG(("nsSocketTransportService::RemoveFromPollList %p [handler=%p]\n",
+              sock, sock->mHandler.get()));
+
+  auto index = SockIndex(mActiveList, sock);
+  MOZ_RELEASE_ASSERT(index != -1, "invalid index");
+
+  SOCKET_LOG(("  index=%" PRId64 " mActiveList.Length()=%zu\n", index,
+              mActiveList.Length()));
+  mActiveList.UnorderedRemoveElementAt(index);
+  // mPollList is offset by 1
+  mPollList.UnorderedRemoveElementAt(index + 1);
+
+  SOCKET_LOG(
+      ("  active=%zu idle=%zu\n", mActiveList.Length(), mIdleList.Length()));
+}
+
+void nsSocketTransportService::AddToIdleList(SocketContext* sock) {
+  MOZ_ASSERT(SockIndex(mIdleList, sock) == -1,
+             "AddToIdleList Socket Already Idle");
+
+  SOCKET_LOG(("nsSocketTransportService::AddToIdleList %p [handler=%p]\n", sock,
+              sock->mHandler.get()));
+
+  // Avoid refcount bump/decrease
+  mIdleList.EmplaceBack(sock->mFD, sock->mHandler.forget(),
+                        sock->mPollStartEpoch);
+
+  SOCKET_LOG(
+      ("  active=%zu idle=%zu\n", mActiveList.Length(), mIdleList.Length()));
+}
+
+void nsSocketTransportService::RemoveFromIdleList(SocketContext* sock) {
+  SOCKET_LOG(("nsSocketTransportService::RemoveFromIdleList [handler=%p]\n",
+              sock->mHandler.get()));
+  auto index = SockIndex(mIdleList, sock);
+  MOZ_RELEASE_ASSERT(index != -1);
+  mIdleList.UnorderedRemoveElementAt(index);
+
+  SOCKET_LOG(
+      ("  active=%zu idle=%zu\n", mActiveList.Length(), mIdleList.Length()));
+}
+
+void nsSocketTransportService::MoveToIdleList(SocketContext* sock) {
+  SOCKET_LOG(("nsSocketTransportService::MoveToIdleList %p [handler=%p]\n",
+              sock, sock->mHandler.get()));
+  MOZ_ASSERT(SockIndex(mIdleList, sock) == -1);
+  MOZ_ASSERT(SockIndex(mActiveList, sock) != -1);
+  AddToIdleList(sock);
+  RemoveFromPollList(sock);
+}
+
+void nsSocketTransportService::MoveToPollList(SocketContext* sock) {
+  SOCKET_LOG(("nsSocketTransportService::MoveToPollList %p [handler=%p]\n",
+              sock, sock->mHandler.get()));
+  MOZ_ASSERT(SockIndex(mIdleList, sock) != -1);
+  MOZ_ASSERT(SockIndex(mActiveList, sock) == -1);
+  AddToPollList(sock);
+  RemoveFromIdleList(sock);
+}
+
+void nsSocketTransportService::ApplyPortRemapPreference(
+    TPortRemapping const& portRemapping) {
+  MOZ_ASSERT(IsOnCurrentThreadInfallible());
+
+  mPortRemapping.reset();
+  if (!portRemapping.IsEmpty()) {
+    mPortRemapping.emplace(portRemapping);
+  }
+}
+
+PRIntervalTime nsSocketTransportService::PollTimeout(PRIntervalTime now) {
+  if (mActiveList.IsEmpty()) {
+    return NS_SOCKET_POLL_TIMEOUT;
+  }
+
+  // compute minimum time before any socket timeout expires.
+  PRIntervalTime minR = NS_SOCKET_POLL_TIMEOUT;
+  for (uint32_t i = 0; i < mActiveList.Length(); ++i) {
+    const SocketContext& s = mActiveList[i];
+    PRIntervalTime r = s.TimeoutIn(now);
+    if (r < minR) {
+      minR = r;
+    }
+  }
+  if (minR == NS_SOCKET_POLL_TIMEOUT) {
+    SOCKET_LOG(("poll timeout: none\n"));
+    return NS_SOCKET_POLL_TIMEOUT;
+  }
+  SOCKET_LOG(("poll timeout: %" PRIu32 "\n", PR_IntervalToSeconds(minR)));
+  return minR;
+}
+
+int32_t nsSocketTransportService::Poll(TimeDuration* pollDuration,
+                                       PRIntervalTime ts) {
+  MOZ_ASSERT(IsOnCurrentThread());
+  PRPollDesc* firstPollEntry;
+  uint32_t pollCount;
+  PRIntervalTime pollTimeout;
+  *pollDuration = nullptr;
+
+  // If there are pending events for this thread then
+  // DoPollIteration() should service the network without blocking.
+  bool pendingEvents = false;
+  mRawThread->HasPendingEvents(&pendingEvents);
+
+  if (mPollList[0].fd) {
+    mPollList[0].out_flags = 0;
+    firstPollEntry = &mPollList[0];
+    pollCount = mPollList.Length();
+    pollTimeout = pendingEvents ? PR_INTERVAL_NO_WAIT : PollTimeout(ts);
+  } else {
+    // no pollable event, so busy wait...
+    pollCount = mActiveList.Length();
+    if (pollCount) {
+      firstPollEntry = &mPollList[1];
+    } else {
+      firstPollEntry = nullptr;
+    }
+    pollTimeout =
+        pendingEvents ? PR_INTERVAL_NO_WAIT : PR_MillisecondsToInterval(25);
+  }
+
+  if ((ts - mLastNetworkLinkChangeTime) < mNetworkLinkChangeBusyWaitPeriod) {
+    // Being here means we are few seconds after a network change has
+    // been detected.
+    PRIntervalTime to = mNetworkLinkChangeBusyWaitTimeout;
+    if (to) {
+      pollTimeout = std::min(to, pollTimeout);
+      SOCKET_LOG(("  timeout shorthened after network change event"));
+    }
+  }
+
+  TimeStamp pollStart;
+  if (Telemetry::CanRecordPrereleaseData()) {
+    pollStart = TimeStamp::NowLoRes();
+  }
+
+  SOCKET_LOG(("    timeout = %i milliseconds\n",
+              PR_IntervalToMilliseconds(pollTimeout)));
+
+  int32_t rv;
+  {
+#ifdef MOZ_GECKO_PROFILER
+    TimeStamp startTime = TimeStamp::Now();
+    if (pollTimeout != PR_INTERVAL_NO_WAIT) {
+      // There will be an actual non-zero wait, let the profiler know about it
+      // by marking thread as sleeping around the polling call.
+      profiler_thread_sleep();
+    }
+#endif
+
+    rv = PR_Poll(firstPollEntry, pollCount, pollTimeout);
+
+#ifdef MOZ_GECKO_PROFILER
+    if (pollTimeout != PR_INTERVAL_NO_WAIT) {
+      profiler_thread_wake();
+    }
+    if (profiler_thread_is_being_profiled_for_markers()) {
+      PROFILER_MARKER_TEXT(
+          "SocketTransportService::Poll", NETWORK,
+          MarkerTiming::IntervalUntilNowFrom(startTime),
+          pollTimeout == PR_INTERVAL_NO_TIMEOUT
+              ? nsPrintfCString("Poll count: %u, Poll timeout: NO_TIMEOUT",
+                                pollCount)
+          : pollTimeout == PR_INTERVAL_NO_WAIT
+              ? nsPrintfCString("Poll count: %u, Poll timeout: NO_WAIT",
+                                pollCount)
+              : nsPrintfCString("Poll count: %u, Poll timeout: %ums", pollCount,
+                                PR_IntervalToMilliseconds(pollTimeout)));
+    }
+#endif
+  }
+
+  if (Telemetry::CanRecordPrereleaseData() && !pollStart.IsNull()) {
+    *pollDuration = TimeStamp::NowLoRes() - pollStart;
+  }
+
+  SOCKET_LOG(("    ...returned after %i milliseconds\n",
+              PR_IntervalToMilliseconds(PR_IntervalNow() - ts)));
+
+  return rv;
+}
+
+//-----------------------------------------------------------------------------
+// xpcom api
+
+NS_IMPL_ISUPPORTS(nsSocketTransportService, nsISocketTransportService,
+                  nsIRoutedSocketTransportService, nsIEventTarget,
+                  nsISerialEventTarget, nsIThreadObserver, nsIRunnable,
+                  nsPISocketTransportService, nsIObserver, nsINamed,
+                  nsIDirectTaskDispatcher)
+
+static const char* gCallbackPrefs[] = {
+    SEND_BUFFER_PREF,
+    KEEPALIVE_ENABLED_PREF,
+    KEEPALIVE_IDLE_TIME_PREF,
+    KEEPALIVE_RETRY_INTERVAL_PREF,
+    KEEPALIVE_PROBE_COUNT_PREF,
+    MAX_TIME_BETWEEN_TWO_POLLS,
+    MAX_TIME_FOR_PR_CLOSE_DURING_SHUTDOWN,
+    POLLABLE_EVENT_TIMEOUT,
+    "network.socket.forcePort",
+    nullptr,
+};
+
+/* static */
+void nsSocketTransportService::UpdatePrefs(const char* aPref, void* aSelf) {
+  static_cast<nsSocketTransportService*>(aSelf)->UpdatePrefs();
+}
+
+static uint32_t GetThreadStackSize() {
+#ifdef XP_WIN
+  if (!StaticPrefs::network_allow_large_stack_size_for_socket_thread()) {
+    return nsIThreadManager::DEFAULT_STACK_SIZE;
+  }
+
+  const uint32_t kWindowsThreadStackSize = 512 * 1024;
+  // We can remove this custom stack size when DEFAULT_STACK_SIZE is increased.
+  static_assert(kWindowsThreadStackSize > nsIThreadManager::DEFAULT_STACK_SIZE);
+  return kWindowsThreadStackSize;
+#else
+  return nsIThreadManager::DEFAULT_STACK_SIZE;
+#endif
+}
+
+// called from main thread only
+NS_IMETHODIMP
+nsSocketTransportService::Init() {
+  if (!NS_IsMainThread()) {
+    NS_ERROR("wrong thread");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mInitialized) {
+    return NS_OK;
+  }
+
+  if (mShuttingDown) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIThread> thread;
+
+  if (!XRE_IsContentProcess() ||
+      StaticPrefs::network_allow_raw_sockets_in_content_processes_AtStartup()) {
+    nsresult rv = NS_NewNamedThread("Socket Thread", getter_AddRefs(thread),
+                                    this, {.stackSize = GetThreadStackSize()});
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    // In the child process, we just want a regular nsThread with no socket
+    // polling. So we don't want to run the nsSocketTransportService runnable on
+    // it.
+    nsresult rv =
+        NS_NewNamedThread("Socket Thread", getter_AddRefs(thread), nullptr);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Set up some of the state that nsSocketTransportService::Run would set.
+    PRThread* prthread = nullptr;
+    thread->GetPRThread(&prthread);
+    gSocketThread = prthread;
+    mRawThread = thread;
+  }
+
+  {
+    MutexAutoLock lock(mLock);
+    // Install our mThread, protecting against concurrent readers
+    thread.swap(mThread);
+    mDirectTaskDispatcher = do_QueryInterface(mThread);
+    MOZ_DIAGNOSTIC_ASSERT(
+        mDirectTaskDispatcher,
+        "Underlying thread must support direct task dispatching");
+  }
+
+  Preferences::RegisterCallbacks(UpdatePrefs, gCallbackPrefs, this);
+  UpdatePrefs();
+
+  nsCOMPtr<nsIObserverService> obsSvc = services::GetObserverService();
+  // Note that the observr notifications are forwarded from parent process to
+  // socket process. We have to make sure the topics registered below are also
+  // registered in nsIObserver::Init().
+  if (obsSvc) {
+    obsSvc->AddObserver(this, "profile-initial-state", false);
+    obsSvc->AddObserver(this, "last-pb-context-exited", false);
+    obsSvc->AddObserver(this, NS_WIDGET_SLEEP_OBSERVER_TOPIC, true);
+    obsSvc->AddObserver(this, NS_WIDGET_WAKE_OBSERVER_TOPIC, true);
+    obsSvc->AddObserver(this, "xpcom-shutdown-threads", false);
+    obsSvc->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
+  }
+
+  // We can now dispatch tasks to the socket thread.
+  mInitialized = true;
+  return NS_OK;
+}
+
+// called from main thread only
+NS_IMETHODIMP
+nsSocketTransportService::Shutdown(bool aXpcomShutdown) {
+  SOCKET_LOG(("nsSocketTransportService::Shutdown\n"));
+
+  NS_ENSURE_STATE(NS_IsMainThread());
+
+  if (!mInitialized || mShuttingDown) {
+    // We never inited, or shutdown has already started
+    return NS_OK;
+  }
+
+  {
+    auto observersCopy = mShutdownObservers;
+    for (auto& observer : observersCopy) {
+      observer->Observe();
+    }
+  }
+
+  mShuttingDown = true;
+
+  {
+    MutexAutoLock lock(mLock);
+
+    if (mPollableEvent) {
+      mPollableEvent->Signal();
+    }
+  }
+
+  // If we're shutting down due to going offline (rather than due to XPCOM
+  // shutdown), also tear down the thread. The thread will be shutdown during
+  // xpcom-shutdown-threads if during xpcom-shutdown proper.
+  if (!aXpcomShutdown) {
+    ShutdownThread();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsSocketTransportService::ShutdownThread() {
+  SOCKET_LOG(("nsSocketTransportService::ShutdownThread\n"));
+
+  NS_ENSURE_STATE(NS_IsMainThread());
+
+  if (!mInitialized) {
+    return NS_OK;
+  }
+
+  // join with thread
+  nsCOMPtr<nsIThread> thread = GetThreadSafely();
+  thread->Shutdown();
+  {
+    MutexAutoLock lock(mLock);
+    // Drop our reference to mThread and make sure that any concurrent readers
+    // are excluded
+    mThread = nullptr;
+    mDirectTaskDispatcher = nullptr;
+  }
+
+  Preferences::UnregisterCallbacks(UpdatePrefs, gCallbackPrefs, this);
+
+  nsCOMPtr<nsIObserverService> obsSvc = services::GetObserverService();
+  if (obsSvc) {
+    obsSvc->RemoveObserver(this, "profile-initial-state");
+    obsSvc->RemoveObserver(this, "last-pb-context-exited");
+    obsSvc->RemoveObserver(this, NS_WIDGET_SLEEP_OBSERVER_TOPIC);
+    obsSvc->RemoveObserver(this, NS_WIDGET_WAKE_OBSERVER_TOPIC);
+    obsSvc->RemoveObserver(this, "xpcom-shutdown-threads");
+    obsSvc->RemoveObserver(this, NS_NETWORK_LINK_TOPIC);
+  }
+
+  if (mAfterWakeUpTimer) {
+    mAfterWakeUpTimer->Cancel();
+    mAfterWakeUpTimer = nullptr;
+  }
+
+  IOActivityMonitor::Shutdown();
+
+  mInitialized = false;
+  mShuttingDown = false;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetOffline(bool* offline) {
+  MutexAutoLock lock(mLock);
+  *offline = mOffline;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::SetOffline(bool offline) {
+  MutexAutoLock lock(mLock);
+  if (!mOffline && offline) {
+    // signal the socket thread to go offline, so it will detach sockets
+    mGoingOffline = true;
+    mOffline = true;
+  } else if (mOffline && !offline) {
+    mOffline = false;
+  }
+  if (mPollableEvent) {
+    mPollableEvent->Signal();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetKeepaliveIdleTime(int32_t* aKeepaliveIdleTimeS) {
+  MOZ_ASSERT(aKeepaliveIdleTimeS);
+  if (NS_WARN_IF(!aKeepaliveIdleTimeS)) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aKeepaliveIdleTimeS = mKeepaliveIdleTimeS;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetKeepaliveRetryInterval(
+    int32_t* aKeepaliveRetryIntervalS) {
+  MOZ_ASSERT(aKeepaliveRetryIntervalS);
+  if (NS_WARN_IF(!aKeepaliveRetryIntervalS)) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aKeepaliveRetryIntervalS = mKeepaliveRetryIntervalS;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetKeepaliveProbeCount(
+    int32_t* aKeepaliveProbeCount) {
+  MOZ_ASSERT(aKeepaliveProbeCount);
+  if (NS_WARN_IF(!aKeepaliveProbeCount)) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aKeepaliveProbeCount = mKeepaliveProbeCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::CreateTransport(const nsTArray<nsCString>& types,
+                                          const nsACString& host, int32_t port,
+                                          nsIProxyInfo* proxyInfo,
+                                          nsIDNSRecord* dnsRecord,
+                                          nsISocketTransport** result) {
+  return CreateRoutedTransport(types, host, port, ""_ns, 0, proxyInfo,
+                               dnsRecord, result);
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::CreateRoutedTransport(
+    const nsTArray<nsCString>& types, const nsACString& host, int32_t port,
+    const nsACString& hostRoute, int32_t portRoute, nsIProxyInfo* proxyInfo,
+    nsIDNSRecord* dnsRecord, nsISocketTransport** result) {
+  NS_ENSURE_TRUE(mInitialized, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(port >= 0 && port <= 0xFFFF, NS_ERROR_ILLEGAL_VALUE);
+
+  RefPtr<nsSocketTransport> trans = new nsSocketTransport();
+  nsresult rv = trans->Init(types, host, port, hostRoute, portRoute, proxyInfo,
+                            dnsRecord);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  trans.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::CreateUnixDomainTransport(
+    nsIFile* aPath, nsISocketTransport** result) {
+#ifdef XP_UNIX
+  nsresult rv;
+
+  NS_ENSURE_TRUE(mInitialized, NS_ERROR_NOT_INITIALIZED);
+
+  nsAutoCString path;
+  rv = aPath->GetNativePath(path);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<nsSocketTransport> trans = new nsSocketTransport();
+
+  rv = trans->InitWithFilename(path.get());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  trans.forget(result);
+  return NS_OK;
+#else
+  return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::CreateUnixDomainAbstractAddressTransport(
+    const nsACString& aName, nsISocketTransport** result) {
+  // Abstract socket address is supported on Linux only
+#ifdef XP_LINUX
+  RefPtr<nsSocketTransport> trans = new nsSocketTransport();
+  // First character of Abstract socket address is null
+  UniquePtr<char[]> name(new char[aName.Length() + 1]);
+  *(name.get()) = 0;
+  memcpy(name.get() + 1, aName.BeginReading(), aName.Length());
+  nsresult rv = trans->InitWithName(name.get(), aName.Length() + 1);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  trans.forget(result);
+  return NS_OK;
+#else
+  return NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::OnDispatchedEvent() {
+#ifndef XP_WIN
+  // On windows poll can hang and this became worse when we introduced the
+  // patch for bug 698882 (see also bug 1292181), therefore we reverted the
+  // behavior on windows to be as before bug 698882, e.g. write to the socket
+  // also if an event dispatch is on the socket thread and writing to the
+  // socket for each event.
+  if (OnSocketThread()) {
+    // this check is redundant to one done inside ::Signal(), but
+    // we can do it here and skip obtaining the lock - given that
+    // this is a relatively common occurance its worth the
+    // redundant code
+    SOCKET_LOG(("OnDispatchedEvent Same Thread Skip Signal\n"));
+    return NS_OK;
+  }
+#else
+  if (gIOService->IsNetTearingDown()) {
+    // Poll can hang sometimes. If we are in shutdown, we are going to
+    // start a watchdog. If we do not exit poll within
+    // REPAIR_POLLABLE_EVENT_TIME signal a pollable event again.
+    StartPollWatchdog();
+  }
+#endif
+
+  MutexAutoLock lock(mLock);
+  if (mPollableEvent) {
+    mPollableEvent->Signal();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::OnProcessNextEvent(nsIThreadInternal* thread,
+                                             bool mayWait) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::AfterProcessNextEvent(nsIThreadInternal* thread,
+                                                bool eventWasProcessed) {
+  return NS_OK;
+}
+
+void nsSocketTransportService::MarkTheLastElementOfPendingQueue() {
+  mServingPendingQueue = false;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::Run() {
+  SOCKET_LOG(("STS thread init %d sockets\n", gMaxCount));
+
+#if defined(XP_WIN)
+  // see bug 1361495, gethostname() triggers winsock initialization.
+  // so do it here (on parent and child) to protect against it being done first
+  // accidentally on the main thread.. especially via PR_GetSystemInfo(). This
+  // will also improve latency of first real winsock operation
+  // ..
+  // If STS-thread is no longer needed this should still be run before exiting
+
+  char ignoredStackBuffer[255];
+  Unused << gethostname(ignoredStackBuffer, 255);
+#endif
+
+  psm::InitializeSSLServerCertVerificationThreads();
+
+  gSocketThread = PR_GetCurrentThread();
+
+  {
+    // See bug 1843384:
+    // Avoid blocking the main thread by allocating the PollableEvent outside
+    // the mutex. Still has the potential to hang the socket thread, but the
+    // main thread remains responsive.
+    PollableEvent* pollable = new PollableEvent();
+    MutexAutoLock lock(mLock);
+    mPollableEvent.reset(pollable);
+
+    //
+    // NOTE: per bug 190000, this failure could be caused by Zone-Alarm
+    // or similar software.
+    //
+    // NOTE: per bug 191739, this failure could also be caused by lack
+    // of a loopback device on Windows and OS/2 platforms (it creates
+    // a loopback socket pair on these platforms to implement a pollable
+    // event object).  if we can't create a pollable event, then we'll
+    // have to "busy wait" to implement the socket event queue :-(
+    //
+    if (!mPollableEvent->Valid()) {
+      mPollableEvent = nullptr;
+      NS_WARNING("running socket transport thread without a pollable event");
+      SOCKET_LOG(("running socket transport thread without a pollable event"));
+    }
+
+    PRPollDesc entry = {mPollableEvent ? mPollableEvent->PollableFD() : nullptr,
+                        PR_POLL_READ | PR_POLL_EXCEPT, 0};
+    SOCKET_LOG(("Setting entry 0"));
+    mPollList[0] = entry;
+  }
+
+  mRawThread = NS_GetCurrentThread();
+
+  // Ensure a call to GetCurrentSerialEventTarget() returns this event target.
+  SerialEventTargetGuard guard(this);
+
+  // hook ourselves up to observe event processing for this thread
+  nsCOMPtr<nsIThreadInternal> threadInt = do_QueryInterface(mRawThread);
+  threadInt->SetObserver(this);
+
+  // make sure the pseudo random number generator is seeded on this thread
+  srand(static_cast<unsigned>(PR_Now()));
+
+  // For the calculation of the duration of the last cycle (i.e. the last
+  // for-loop iteration before shutdown).
+  TimeStamp startOfCycleForLastCycleCalc;
+
+  // For measuring of the poll iteration duration without time spent blocked
+  // in poll().
+  TimeStamp pollCycleStart;
+  // Time blocked in poll().
+  TimeDuration singlePollDuration;
+
+  // For calculating the time needed for a new element to run.
+  TimeStamp startOfIteration;
+  TimeStamp startOfNextIteration;
+
+  // If there is too many pending events queued, we will run some poll()
+  // between them and the following variable is cumulative time spent
+  // blocking in poll().
+  TimeDuration pollDuration;
+
+  for (;;) {
+    bool pendingEvents = false;
+    if (Telemetry::CanRecordPrereleaseData()) {
+      startOfCycleForLastCycleCalc = TimeStamp::NowLoRes();
+      startOfNextIteration = TimeStamp::NowLoRes();
+    }
+    pollDuration = nullptr;
+    // We pop out to this loop when there are no pending events.
+    // If we don't reset these, we may not re-enter ProcessNextEvent()
+    // until we have events to process, and it may seem like we have
+    // an event running for a very long time.
+    mRawThread->SetRunningEventDelay(TimeDuration(), TimeStamp());
+
+    do {
+      if (Telemetry::CanRecordPrereleaseData()) {
+        pollCycleStart = TimeStamp::NowLoRes();
+      }
+
+      DoPollIteration(&singlePollDuration);
+
+      if (Telemetry::CanRecordPrereleaseData() && !pollCycleStart.IsNull()) {
+        Telemetry::Accumulate(Telemetry::STS_POLL_BLOCK_TIME,
+                              singlePollDuration.ToMilliseconds());
+        Telemetry::AccumulateTimeDelta(Telemetry::STS_POLL_CYCLE,
+                                       pollCycleStart + singlePollDuration,
+                                       TimeStamp::NowLoRes());
+        pollDuration += singlePollDuration;
+      }
+
+      mRawThread->HasPendingEvents(&pendingEvents);
+      if (pendingEvents) {
+        if (!mServingPendingQueue) {
+          nsresult rv = Dispatch(
+              NewRunnableMethod(
+                  "net::nsSocketTransportService::"
+                  "MarkTheLastElementOfPendingQueue",
+                  this,
+                  &nsSocketTransportService::MarkTheLastElementOfPendingQueue),
+              nsIEventTarget::DISPATCH_NORMAL);
+          if (NS_FAILED(rv)) {
+            NS_WARNING(
+                "Could not dispatch a new event on the "
+                "socket thread.");
+          } else {
+            mServingPendingQueue = true;
+          }
+
+          if (Telemetry::CanRecordPrereleaseData()) {
+            startOfIteration = startOfNextIteration;
+            // Everything that comes after this point will
+            // be served in the next iteration. If no even
+            // arrives, startOfNextIteration will be reset at the
+            // beginning of each for-loop.
+            startOfNextIteration = TimeStamp::NowLoRes();
+          }
+        }
+        TimeStamp eventQueueStart = TimeStamp::NowLoRes();
+        do {
+          NS_ProcessNextEvent(mRawThread);
+          pendingEvents = false;
+          mRawThread->HasPendingEvents(&pendingEvents);
+        } while (pendingEvents && mServingPendingQueue &&
+                 ((TimeStamp::NowLoRes() - eventQueueStart).ToMilliseconds() <
+                  mMaxTimePerPollIter));
+
+        if (Telemetry::CanRecordPrereleaseData() && !mServingPendingQueue &&
+            !startOfIteration.IsNull()) {
+          Telemetry::AccumulateTimeDelta(Telemetry::STS_POLL_AND_EVENTS_CYCLE,
+                                         startOfIteration + pollDuration,
+                                         TimeStamp::NowLoRes());
+          pollDuration = nullptr;
+        }
+      }
+    } while (pendingEvents);
+
+    bool goingOffline = false;
+    // now that our event queue is empty, check to see if we should exit
+    if (mShuttingDown) {
+      if (Telemetry::CanRecordPrereleaseData() &&
+          !startOfCycleForLastCycleCalc.IsNull()) {
+        Telemetry::AccumulateTimeDelta(
+            Telemetry::STS_POLL_AND_EVENT_THE_LAST_CYCLE,
+            startOfCycleForLastCycleCalc, TimeStamp::NowLoRes());
+      }
+      break;
+    }
+    {
+      MutexAutoLock lock(mLock);
+      if (mGoingOffline) {
+        mGoingOffline = false;
+        goingOffline = true;
+      }
+    }
+    // Avoid potential deadlock
+    if (goingOffline) {
+      Reset(true);
+    }
+  }
+
+  SOCKET_LOG(("STS shutting down thread\n"));
+
+  // detach all sockets, including locals
+  Reset(false);
+
+  // We don't clear gSocketThread so that OnSocketThread() won't be a false
+  // alarm for events generated by stopping the SSL threads during shutdown.
+  psm::StopSSLServerCertVerificationThreads();
+
+  // Final pass over the event queue. This makes sure that events posted by
+  // socket detach handlers get processed.
+  NS_ProcessPendingEvents(mRawThread);
+
+  SOCKET_LOG(("STS thread exit\n"));
+  MOZ_ASSERT(mPollList.Length() == 1);
+  MOZ_ASSERT(mActiveList.IsEmpty());
+  MOZ_ASSERT(mIdleList.IsEmpty());
+
+  return NS_OK;
+}
+
+void nsSocketTransportService::DetachSocketWithGuard(
+    bool aGuardLocals, SocketContextList& socketList, int32_t index) {
+  bool isGuarded = false;
+  if (aGuardLocals) {
+    socketList[index].mHandler->IsLocal(&isGuarded);
+    if (!isGuarded) {
+      socketList[index].mHandler->KeepWhenOffline(&isGuarded);
+    }
+  }
+  if (!isGuarded) {
+    DetachSocket(socketList, &socketList[index]);
+  }
+}
+
+void nsSocketTransportService::Reset(bool aGuardLocals) {
+  // detach any sockets
+  int32_t i;
+  for (i = mActiveList.Length() - 1; i >= 0; --i) {
+    DetachSocketWithGuard(aGuardLocals, mActiveList, i);
+  }
+  for (i = mIdleList.Length() - 1; i >= 0; --i) {
+    DetachSocketWithGuard(aGuardLocals, mIdleList, i);
+  }
+}
+
+nsresult nsSocketTransportService::DoPollIteration(TimeDuration* pollDuration) {
+  SOCKET_LOG(("STS poll iter\n"));
+
+  PRIntervalTime now = PR_IntervalNow();
+
+  // We can't have more than int32_max sockets in use
+  int32_t i, count;
+  //
+  // poll loop
+  //
+  // walk active list backwards to see if any sockets should actually be
+  // idle, then walk the idle list backwards to see if any idle sockets
+  // should become active.  take care to check only idle sockets that
+  // were idle to begin with ;-)
+  //
+  count = mIdleList.Length();
+  for (i = mActiveList.Length() - 1; i >= 0; --i) {
+    //---
+    SOCKET_LOG(("  active [%u] { handler=%p condition=%" PRIx32
+                " pollflags=%hu }\n",
+                i, mActiveList[i].mHandler.get(),
+                static_cast<uint32_t>(mActiveList[i].mHandler->mCondition),
+                mActiveList[i].mHandler->mPollFlags));
+    //---
+    if (NS_FAILED(mActiveList[i].mHandler->mCondition)) {
+      DetachSocket(mActiveList, &mActiveList[i]);
+    } else {
+      uint16_t in_flags = mActiveList[i].mHandler->mPollFlags;
+      if (in_flags == 0) {
+        MoveToIdleList(&mActiveList[i]);
+      } else {
+        // update poll flags
+        mPollList[i + 1].in_flags = in_flags;
+        mPollList[i + 1].out_flags = 0;
+        mActiveList[i].EnsureTimeout(now);
+      }
+    }
+  }
+  for (i = count - 1; i >= 0; --i) {
+    //---
+    SOCKET_LOG(("  idle [%u] { handler=%p condition=%" PRIx32
+                " pollflags=%hu }\n",
+                i, mIdleList[i].mHandler.get(),
+                static_cast<uint32_t>(mIdleList[i].mHandler->mCondition),
+                mIdleList[i].mHandler->mPollFlags));
+    //---
+    if (NS_FAILED(mIdleList[i].mHandler->mCondition)) {
+      DetachSocket(mIdleList, &mIdleList[i]);
+    } else if (mIdleList[i].mHandler->mPollFlags != 0) {
+      MoveToPollList(&mIdleList[i]);
+    }
+  }
+
+  {
+    MutexAutoLock lock(mLock);
+    if (mPollableEvent) {
+      // we want to make sure the timeout is measured from the time
+      // we enter poll().  This method resets the timestamp to 'now',
+      // if we were first signalled between leaving poll() and here.
+      // If we didn't do this and processing events took longer than
+      // the allowed signal timeout, we would detect it as a
+      // false-positive.  AdjustFirstSignalTimestamp is then a no-op
+      // until mPollableEvent->Clear() is called.
+      mPollableEvent->AdjustFirstSignalTimestamp();
+    }
+  }
+
+  SOCKET_LOG(("  calling PR_Poll [active=%zu idle=%zu]\n", mActiveList.Length(),
+              mIdleList.Length()));
+
+#if defined(XP_WIN)
+  // 30 active connections is the historic limit before firefox 7's 256. A few
+  //  windows systems have troubles with the higher limit, so actively probe a
+  // limit the first time we exceed 30.
+  if ((mActiveList.Length() > 30) && !mProbedMaxCount) ProbeMaxCount();
+#endif
+
+  // Measures seconds spent while blocked on PR_Poll
+  int32_t n = 0;
+  *pollDuration = nullptr;
+
+  if (!gIOService->IsNetTearingDown()) {
+    // Let's not do polling during shutdown.
+#if defined(XP_WIN)
+    StartPolling();
+#endif
+    n = Poll(pollDuration, now);
+#if defined(XP_WIN)
+    EndPolling();
+#endif
+  }
+
+  now = PR_IntervalNow();
+
+  if (n < 0) {
+    SOCKET_LOG(("  PR_Poll error [%d] os error [%d]\n", PR_GetError(),
+                PR_GetOSError()));
+  } else {
+    //
+    // service "active" sockets...
+    //
+    for (i = 0; i < int32_t(mActiveList.Length()); ++i) {
+      PRPollDesc& desc = mPollList[i + 1];
+      SocketContext& s = mActiveList[i];
+      if (n > 0 && desc.out_flags != 0) {
+        s.DisengageTimeout();
+        s.mHandler->OnSocketReady(desc.fd, desc.out_flags);
+      } else if (s.IsTimedOut(now)) {
+        SOCKET_LOG(("socket %p timed out", s.mHandler.get()));
+        s.DisengageTimeout();
+        s.mHandler->OnSocketReady(desc.fd, -1);
+      } else {
+        s.MaybeResetEpoch();
+      }
+    }
+    //
+    // check for "dead" sockets and remove them (need to do this in
+    // reverse order obviously).
+    //
+    for (i = mActiveList.Length() - 1; i >= 0; --i) {
+      if (NS_FAILED(mActiveList[i].mHandler->mCondition)) {
+        DetachSocket(mActiveList, &mActiveList[i]);
+      }
+    }
+
+    {
+      MutexAutoLock lock(mLock);
+      // acknowledge pollable event (should not block)
+      if (n != 0 &&
+          (mPollList[0].out_flags & (PR_POLL_READ | PR_POLL_EXCEPT)) &&
+          mPollableEvent &&
+          ((mPollList[0].out_flags & PR_POLL_EXCEPT) ||
+           !mPollableEvent->Clear())) {
+        // On Windows, the TCP loopback connection in the
+        // pollable event may become broken when a laptop
+        // switches between wired and wireless networks or
+        // wakes up from hibernation.  We try to create a
+        // new pollable event.  If that fails, we fall back
+        // on "busy wait".
+        TryRepairPollableEvent();
+      }
+
+      if (mPollableEvent &&
+          !mPollableEvent->IsSignallingAlive(mPollableEventTimeout)) {
+        SOCKET_LOG(("Pollable event signalling failed/timed out"));
+        TryRepairPollableEvent();
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+void nsSocketTransportService::UpdateSendBufferPref() {
+  int32_t bufferSize;
+
+  // If the pref is set, honor it. 0 means use OS defaults.
+  nsresult rv = Preferences::GetInt(SEND_BUFFER_PREF, &bufferSize);
+  if (NS_SUCCEEDED(rv)) {
+    mSendBufferSize = bufferSize;
+    return;
+  }
+
+#if defined(XP_WIN)
+  mSendBufferSize = 131072 * 4;
+#endif
+}
+
+nsresult nsSocketTransportService::UpdatePrefs() {
+  mSendBufferSize = 0;
+
+  UpdateSendBufferPref();
+
+  // Default TCP Keepalive Values.
+  int32_t keepaliveIdleTimeS;
+  nsresult rv =
+      Preferences::GetInt(KEEPALIVE_IDLE_TIME_PREF, &keepaliveIdleTimeS);
+  if (NS_SUCCEEDED(rv)) {
+    mKeepaliveIdleTimeS = clamped(keepaliveIdleTimeS, 1, kMaxTCPKeepIdle);
+  }
+
+  int32_t keepaliveRetryIntervalS;
+  rv = Preferences::GetInt(KEEPALIVE_RETRY_INTERVAL_PREF,
+                           &keepaliveRetryIntervalS);
+  if (NS_SUCCEEDED(rv)) {
+    mKeepaliveRetryIntervalS =
+        clamped(keepaliveRetryIntervalS, 1, kMaxTCPKeepIntvl);
+  }
+
+  int32_t keepaliveProbeCount;
+  rv = Preferences::GetInt(KEEPALIVE_PROBE_COUNT_PREF, &keepaliveProbeCount);
+  if (NS_SUCCEEDED(rv)) {
+    mKeepaliveProbeCount = clamped(keepaliveProbeCount, 1, kMaxTCPKeepCount);
+  }
+  bool keepaliveEnabled = false;
+  rv = Preferences::GetBool(KEEPALIVE_ENABLED_PREF, &keepaliveEnabled);
+  if (NS_SUCCEEDED(rv) && keepaliveEnabled != mKeepaliveEnabledPref) {
+    mKeepaliveEnabledPref = keepaliveEnabled;
+    OnKeepaliveEnabledPrefChange();
+  }
+
+  int32_t maxTimePref;
+  rv = Preferences::GetInt(MAX_TIME_BETWEEN_TWO_POLLS, &maxTimePref);
+  if (NS_SUCCEEDED(rv) && maxTimePref >= 0) {
+    mMaxTimePerPollIter = maxTimePref;
+  }
+
+  int32_t pollBusyWaitPeriod;
+  rv = Preferences::GetInt(POLL_BUSY_WAIT_PERIOD, &pollBusyWaitPeriod);
+  if (NS_SUCCEEDED(rv) && pollBusyWaitPeriod > 0) {
+    mNetworkLinkChangeBusyWaitPeriod = PR_SecondsToInterval(pollBusyWaitPeriod);
+  }
+
+  int32_t pollBusyWaitPeriodTimeout;
+  rv = Preferences::GetInt(POLL_BUSY_WAIT_PERIOD_TIMEOUT,
+                           &pollBusyWaitPeriodTimeout);
+  if (NS_SUCCEEDED(rv) && pollBusyWaitPeriodTimeout > 0) {
+    mNetworkLinkChangeBusyWaitTimeout =
+        PR_SecondsToInterval(pollBusyWaitPeriodTimeout);
+  }
+
+  int32_t maxTimeForPrClosePref;
+  rv = Preferences::GetInt(MAX_TIME_FOR_PR_CLOSE_DURING_SHUTDOWN,
+                           &maxTimeForPrClosePref);
+  if (NS_SUCCEEDED(rv) && maxTimeForPrClosePref >= 0) {
+    mMaxTimeForPrClosePref = PR_MillisecondsToInterval(maxTimeForPrClosePref);
+  }
+
+  int32_t pollableEventTimeout;
+  rv = Preferences::GetInt(POLLABLE_EVENT_TIMEOUT, &pollableEventTimeout);
+  if (NS_SUCCEEDED(rv) && pollableEventTimeout >= 0) {
+    MutexAutoLock lock(mLock);
+    mPollableEventTimeout = TimeDuration::FromSeconds(pollableEventTimeout);
+  }
+
+  nsAutoCString portMappingPref;
+  rv = Preferences::GetCString("network.socket.forcePort", portMappingPref);
+  if (NS_SUCCEEDED(rv)) {
+    bool rv = UpdatePortRemapPreference(portMappingPref);
+    if (!rv) {
+      NS_ERROR(
+          "network.socket.forcePort preference is ill-formed, this will likely "
+          "make everything unexpectedly fail!");
+    }
+  }
+
+  return NS_OK;
+}
+
+void nsSocketTransportService::OnKeepaliveEnabledPrefChange() {
+  // Dispatch to socket thread if we're not executing there.
+  if (!OnSocketThread()) {
+    gSocketTransportService->Dispatch(
+        NewRunnableMethod(
+            "net::nsSocketTransportService::OnKeepaliveEnabledPrefChange", this,
+            &nsSocketTransportService::OnKeepaliveEnabledPrefChange),
+        NS_DISPATCH_NORMAL);
+    return;
+  }
+
+  SOCKET_LOG(("nsSocketTransportService::OnKeepaliveEnabledPrefChange %s",
+              mKeepaliveEnabledPref ? "enabled" : "disabled"));
+
+  // Notify each socket that keepalive has been en/disabled globally.
+  for (int32_t i = mActiveList.Length() - 1; i >= 0; --i) {
+    NotifyKeepaliveEnabledPrefChange(&mActiveList[i]);
+  }
+  for (int32_t i = mIdleList.Length() - 1; i >= 0; --i) {
+    NotifyKeepaliveEnabledPrefChange(&mIdleList[i]);
+  }
+}
+
+void nsSocketTransportService::NotifyKeepaliveEnabledPrefChange(
+    SocketContext* sock) {
+  MOZ_ASSERT(sock, "SocketContext cannot be null!");
+  MOZ_ASSERT(sock->mHandler, "SocketContext does not have a handler!");
+
+  if (!sock || !sock->mHandler) {
+    return;
+  }
+
+  sock->mHandler->OnKeepaliveEnabledPrefChange(mKeepaliveEnabledPref);
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetName(nsACString& aName) {
+  aName.AssignLiteral("nsSocketTransportService");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::Observe(nsISupports* subject, const char* topic,
+                                  const char16_t* data) {
+  SOCKET_LOG(("nsSocketTransportService::Observe topic=%s", topic));
+
+  if (!strcmp(topic, "profile-initial-state")) {
+    if (!Preferences::GetBool(IO_ACTIVITY_ENABLED_PREF, false)) {
+      return NS_OK;
+    }
+    return net::IOActivityMonitor::Init();
+  }
+
+  if (!strcmp(topic, "last-pb-context-exited")) {
+    nsCOMPtr<nsIRunnable> ev = NewRunnableMethod(
+        "net::nsSocketTransportService::ClosePrivateConnections", this,
+        &nsSocketTransportService::ClosePrivateConnections);
+    nsresult rv = Dispatch(ev, nsIEventTarget::DISPATCH_NORMAL);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!strcmp(topic, NS_TIMER_CALLBACK_TOPIC)) {
+    nsCOMPtr<nsITimer> timer = do_QueryInterface(subject);
+    if (timer == mAfterWakeUpTimer) {
+      mAfterWakeUpTimer = nullptr;
+      mSleepPhase = false;
+    }
+
+#if defined(XP_WIN)
+    if (timer == mPollRepairTimer) {
+      DoPollRepair();
+    }
+#endif
+
+  } else if (!strcmp(topic, NS_WIDGET_SLEEP_OBSERVER_TOPIC)) {
+    mSleepPhase = true;
+    if (mAfterWakeUpTimer) {
+      mAfterWakeUpTimer->Cancel();
+      mAfterWakeUpTimer = nullptr;
+    }
+  } else if (!strcmp(topic, NS_WIDGET_WAKE_OBSERVER_TOPIC)) {
+    if (mSleepPhase && !mAfterWakeUpTimer) {
+      NS_NewTimerWithObserver(getter_AddRefs(mAfterWakeUpTimer), this, 2000,
+                              nsITimer::TYPE_ONE_SHOT);
+    }
+  } else if (!strcmp(topic, "xpcom-shutdown-threads")) {
+    ShutdownThread();
+  } else if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
+    mLastNetworkLinkChangeTime = PR_IntervalNow();
+  }
+
+  return NS_OK;
+}
+
+void nsSocketTransportService::ClosePrivateConnections() {
+  MOZ_ASSERT(IsOnCurrentThread(), "Must be called on the socket thread");
+
+  for (int32_t i = mActiveList.Length() - 1; i >= 0; --i) {
+    if (mActiveList[i].mHandler->mIsPrivate) {
+      DetachSocket(mActiveList, &mActiveList[i]);
+    }
+  }
+  for (int32_t i = mIdleList.Length() - 1; i >= 0; --i) {
+    if (mIdleList[i].mHandler->mIsPrivate) {
+      DetachSocket(mIdleList, &mIdleList[i]);
+    }
+  }
+
+  ClearPrivateSSLState();
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::GetSendBufferSize(int32_t* value) {
+  *value = mSendBufferSize;
+  return NS_OK;
+}
+
+/// ugly OS specific includes are placed at the bottom of the src for clarity
+
+#if defined(XP_WIN)
+#  include <windows.h>
+#elif defined(XP_UNIX) && !defined(AIX) && !defined(NEXTSTEP) && !defined(QNX)
+#  include <sys/resource.h>
+#endif
+
+// Right now the only need to do this is on windows.
+#if defined(XP_WIN)
+void nsSocketTransportService::ProbeMaxCount() {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+
+  if (mProbedMaxCount) {
+    return;
+  }
+  mProbedMaxCount = true;
+
+  // Allocate and test a PR_Poll up to the gMaxCount number of unconnected
+  // sockets. See bug 692260 - windows should be able to handle 1000 sockets
+  // in select() without a problem, but LSPs have been known to balk at lower
+  // numbers. (64 in the bug).
+
+  // Allocate
+  struct PRPollDesc pfd[SOCKET_LIMIT_TARGET];
+  uint32_t numAllocated = 0;
+
+  for (uint32_t index = 0; index < gMaxCount; ++index) {
+    pfd[index].in_flags = PR_POLL_READ | PR_POLL_WRITE | PR_POLL_EXCEPT;
+    pfd[index].out_flags = 0;
+    pfd[index].fd = PR_OpenTCPSocket(PR_AF_INET);
+    if (!pfd[index].fd) {
+      SOCKET_LOG(("Socket Limit Test index %d failed\n", index));
+      if (index < SOCKET_LIMIT_MIN)
+        gMaxCount = SOCKET_LIMIT_MIN;
+      else
+        gMaxCount = index;
+      break;
+    }
+    ++numAllocated;
+  }
+
+  // Test
+  static_assert(SOCKET_LIMIT_MIN >= 32U, "Minimum Socket Limit is >= 32");
+  while (gMaxCount <= numAllocated) {
+    int32_t rv = PR_Poll(pfd, gMaxCount, PR_MillisecondsToInterval(0));
+
+    SOCKET_LOG(("Socket Limit Test poll() size=%d rv=%d\n", gMaxCount, rv));
+
+    if (rv >= 0) break;
+
+    SOCKET_LOG(("Socket Limit Test poll confirmationSize=%d rv=%d error=%d\n",
+                gMaxCount, rv, PR_GetError()));
+
+    gMaxCount -= 32;
+    if (gMaxCount <= SOCKET_LIMIT_MIN) {
+      gMaxCount = SOCKET_LIMIT_MIN;
+      break;
+    }
+  }
+
+  // Free
+  for (uint32_t index = 0; index < numAllocated; ++index)
+    if (pfd[index].fd) PR_Close(pfd[index].fd);
+
+  Telemetry::Accumulate(Telemetry::NETWORK_PROBE_MAXCOUNT, gMaxCount);
+  SOCKET_LOG(("Socket Limit Test max was confirmed at %d\n", gMaxCount));
+}
+#endif  // windows
+
+PRStatus nsSocketTransportService::DiscoverMaxCount() {
+  gMaxCount = SOCKET_LIMIT_MIN;
+
+#if defined(XP_UNIX) && !defined(AIX) && !defined(NEXTSTEP) && !defined(QNX)
+  // On unix and os x network sockets and file
+  // descriptors are the same. OS X comes defaulted at 256,
+  // most linux at 1000. We can reliably use [sg]rlimit to
+  // query that and raise it if needed.
+
+  struct rlimit rlimitData {};
+  if (getrlimit(RLIMIT_NOFILE, &rlimitData) == -1) {  // rlimit broken - use min
+    return PR_SUCCESS;
+  }
+
+  if (rlimitData.rlim_cur >= SOCKET_LIMIT_TARGET) {  // larger than target!
+    gMaxCount = SOCKET_LIMIT_TARGET;
+    return PR_SUCCESS;
+  }
+
+  int32_t maxallowed = rlimitData.rlim_max;
+  if ((uint32_t)maxallowed <= SOCKET_LIMIT_MIN) {
+    return PR_SUCCESS;  // so small treat as if rlimit is broken
+  }
+
+  if ((maxallowed == -1) ||  // no hard cap - ok to set target
+      ((uint32_t)maxallowed >= SOCKET_LIMIT_TARGET)) {
+    maxallowed = SOCKET_LIMIT_TARGET;
+  }
+
+  rlimitData.rlim_cur = maxallowed;
+  setrlimit(RLIMIT_NOFILE, &rlimitData);
+  if ((getrlimit(RLIMIT_NOFILE, &rlimitData) != -1) &&
+      (rlimitData.rlim_cur > SOCKET_LIMIT_MIN)) {
+    gMaxCount = rlimitData.rlim_cur;
+  }
+
+#elif defined(XP_WIN) && !defined(WIN_CE)
+  // >= XP is confirmed to have at least 1000
+  static_assert(SOCKET_LIMIT_TARGET <= 1000,
+                "SOCKET_LIMIT_TARGET max value is 1000");
+  gMaxCount = SOCKET_LIMIT_TARGET;
+#else
+  // other platforms are harder to test - so leave at safe legacy value
+#endif
+
+  return PR_SUCCESS;
+}
+
+// Used to return connection info to Dashboard.cpp
+void nsSocketTransportService::AnalyzeConnection(nsTArray<SocketInfo>* data,
+                                                 SocketContext* context,
+                                                 bool aActive) {
+  if (context->mHandler->mIsPrivate) {
+    return;
+  }
+  PRFileDesc* aFD = context->mFD;
+
+  PRFileDesc* idLayer = PR_GetIdentitiesLayer(aFD, PR_NSPR_IO_LAYER);
+
+  NS_ENSURE_TRUE_VOID(idLayer);
+
+  PRDescType type = PR_GetDescType(idLayer);
+  char host[64] = {0};
+  uint16_t port;
+  const char* type_desc;
+
+  if (type == PR_DESC_SOCKET_TCP) {
+    type_desc = "TCP";
+    PRNetAddr peer_addr;
+    PodZero(&peer_addr);
+
+    PRStatus rv = PR_GetPeerName(aFD, &peer_addr);
+    if (rv != PR_SUCCESS) {
+      return;
+    }
+
+    rv = PR_NetAddrToString(&peer_addr, host, sizeof(host));
+    if (rv != PR_SUCCESS) {
+      return;
+    }
+
+    if (peer_addr.raw.family == PR_AF_INET) {
+      port = peer_addr.inet.port;
+    } else {
+      port = peer_addr.ipv6.port;
+    }
+    port = PR_ntohs(port);
+  } else {
+    if (type == PR_DESC_SOCKET_UDP) {
+      type_desc = "UDP";
+    } else {
+      type_desc = "other";
+    }
+    NetAddr addr;
+    if (context->mHandler->GetRemoteAddr(&addr) != NS_OK) {
+      return;
+    }
+    if (!addr.ToStringBuffer(host, sizeof(host))) {
+      return;
+    }
+    if (addr.GetPort(&port) != NS_OK) {
+      return;
+    }
+  }
+
+  uint64_t sent = context->mHandler->ByteCountSent();
+  uint64_t received = context->mHandler->ByteCountReceived();
+  SocketInfo info = {nsCString(host),     sent, received, port, aActive,
+                     nsCString(type_desc)};
+
+  data->AppendElement(info);
+}
+
+void nsSocketTransportService::GetSocketConnections(
+    nsTArray<SocketInfo>* data) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  for (uint32_t i = 0; i < mActiveList.Length(); i++) {
+    AnalyzeConnection(data, &mActiveList[i], true);
+  }
+  for (uint32_t i = 0; i < mIdleList.Length(); i++) {
+    AnalyzeConnection(data, &mIdleList[i], false);
+  }
+}
+
+bool nsSocketTransportService::IsTelemetryEnabledAndNotSleepPhase() {
+  return Telemetry::CanRecordPrereleaseData() && !mSleepPhase;
+}
+
+#if defined(XP_WIN)
+void nsSocketTransportService::StartPollWatchdog() {
+  // Start off the timer from a runnable off of the main thread in order to
+  // avoid a deadlock, see bug 1370448.
+  RefPtr<nsSocketTransportService> self(this);
+  NS_DispatchToMainThread(NS_NewRunnableFunction(
+      "nsSocketTransportService::StartPollWatchdog", [self] {
+        MutexAutoLock lock(self->mLock);
+
+        // Poll can hang sometimes. If we are in shutdown, we are going to start
+        // a watchdog. If we do not exit poll within REPAIR_POLLABLE_EVENT_TIME
+        // signal a pollable event again.
+        MOZ_ASSERT(gIOService->IsNetTearingDown());
+        if (self->mPolling && !self->mPollRepairTimer) {
+          NS_NewTimerWithObserver(getter_AddRefs(self->mPollRepairTimer), self,
+                                  REPAIR_POLLABLE_EVENT_TIME,
+                                  nsITimer::TYPE_REPEATING_SLACK);
+        }
+      }));
+}
+
+void nsSocketTransportService::DoPollRepair() {
+  MutexAutoLock lock(mLock);
+  if (mPolling && mPollableEvent) {
+    mPollableEvent->Signal();
+  } else if (mPollRepairTimer) {
+    mPollRepairTimer->Cancel();
+  }
+}
+
+void nsSocketTransportService::StartPolling() {
+  MutexAutoLock lock(mLock);
+  mPolling = true;
+}
+
+void nsSocketTransportService::EndPolling() {
+  MutexAutoLock lock(mLock);
+  mPolling = false;
+  if (mPollRepairTimer) {
+    mPollRepairTimer->Cancel();
+  }
+}
+
+#endif
+
+void nsSocketTransportService::TryRepairPollableEvent() {
+  mLock.AssertCurrentThreadOwns();
+
+  NS_WARNING("Trying to repair mPollableEvent");
+  mPollableEvent.reset(new PollableEvent());
+  if (!mPollableEvent->Valid()) {
+    mPollableEvent = nullptr;
+  }
+  SOCKET_LOG(
+      ("running socket transport thread without "
+       "a pollable event now valid=%d",
+       !!mPollableEvent));
+  mPollList[0].fd = mPollableEvent ? mPollableEvent->PollableFD() : nullptr;
+  mPollList[0].in_flags = PR_POLL_READ | PR_POLL_EXCEPT;
+  mPollList[0].out_flags = 0;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::AddShutdownObserver(
+    nsISTSShutdownObserver* aObserver) {
+  mShutdownObservers.AppendElement(aObserver);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSocketTransportService::RemoveShutdownObserver(
+    nsISTSShutdownObserver* aObserver) {
+  mShutdownObservers.RemoveElement(aObserver);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsSocketTransportService2.h b/netwerk/base/nsSocketTransportService2.h
new file mode 100644
index 0000000000..ceede5f2ee
--- /dev/null
+++ b/netwerk/base/nsSocketTransportService2.h
@@ -0,0 +1,361 @@
+/* vim:set ts=4 sw=2 sts=2 ci et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsSocketTransportService2_h__
+#define nsSocketTransportService2_h__
+
+#include "PollableEvent.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/LinkedList.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+
+#include "mozilla/UniquePtr.h"
+#include "mozilla/net/DashboardTypes.h"
+#include "nsCOMPtr.h"
+#include "nsASocketHandler.h"
+#include "nsIDirectTaskDispatcher.h"
+#include "nsIObserver.h"
+#include "nsIRunnable.h"
+#include "nsIThreadInternal.h"
+#include "nsITimer.h"
+#include "nsPISocketTransportService.h"
+#include "prinit.h"
+#include "prinrval.h"
+
+struct PRPollDesc;
+class nsIPrefBranch;
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+//
+// set MOZ_LOG=nsSocketTransport:5
+//
+extern LazyLogModule gSocketTransportLog;
+#define SOCKET_LOG(args) MOZ_LOG(gSocketTransportLog, LogLevel::Debug, args)
+#define SOCKET_LOG1(args) MOZ_LOG(gSocketTransportLog, LogLevel::Error, args)
+#define SOCKET_LOG_ENABLED() MOZ_LOG_TEST(gSocketTransportLog, LogLevel::Debug)
+
+//
+// set MOZ_LOG=UDPSocket:5
+//
+extern LazyLogModule gUDPSocketLog;
+#define UDPSOCKET_LOG(args) MOZ_LOG(gUDPSocketLog, LogLevel::Debug, args)
+#define UDPSOCKET_LOG_ENABLED() MOZ_LOG_TEST(gUDPSocketLog, LogLevel::Debug)
+
+//-----------------------------------------------------------------------------
+
+#define NS_SOCKET_POLL_TIMEOUT PR_INTERVAL_NO_TIMEOUT
+
+//-----------------------------------------------------------------------------
+
+// These maximums are borrowed from the linux kernel.
+static const int32_t kMaxTCPKeepIdle = 32767;  // ~9 hours.
+static const int32_t kMaxTCPKeepIntvl = 32767;
+static const int32_t kMaxTCPKeepCount = 127;
+static const int32_t kDefaultTCPKeepCount =
+#if defined(XP_WIN)
+    10;  // Hardcoded in Windows.
+#elif defined(XP_MACOSX)
+    8;  // Hardcoded in OSX.
+#else
+    4;  // Specifiable in Linux.
+#endif
+
+class LinkedRunnableEvent final
+    : public LinkedListElement<LinkedRunnableEvent> {
+ public:
+  explicit LinkedRunnableEvent(nsIRunnable* event) : mEvent(event) {}
+  ~LinkedRunnableEvent() = default;
+
+  already_AddRefed<nsIRunnable> TakeEvent() { return mEvent.forget(); }
+
+ private:
+  nsCOMPtr<nsIRunnable> mEvent;
+};
+
+//-----------------------------------------------------------------------------
+
+class nsSocketTransportService final : public nsPISocketTransportService,
+                                       public nsISerialEventTarget,
+                                       public nsIThreadObserver,
+                                       public nsIRunnable,
+                                       public nsIObserver,
+                                       public nsINamed,
+                                       public nsIDirectTaskDispatcher {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSPISOCKETTRANSPORTSERVICE
+  NS_DECL_NSISOCKETTRANSPORTSERVICE
+  NS_DECL_NSIROUTEDSOCKETTRANSPORTSERVICE
+  NS_DECL_NSIEVENTTARGET_FULL
+  NS_DECL_NSITHREADOBSERVER
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSINAMED
+  NS_DECL_NSIDIRECTTASKDISPATCHER
+
+  static const uint32_t SOCKET_LIMIT_MIN = 50U;
+
+  nsSocketTransportService();
+
+  // Max Socket count may need to get initialized/used by nsHttpHandler
+  // before this class is initialized.
+  static uint32_t gMaxCount;
+  static PRCallOnceType gMaxCountInitOnce;
+  static PRStatus DiscoverMaxCount();
+
+  bool CanAttachSocket();
+
+  // Called by the networking dashboard on the socket thread only
+  // Fills the passed array with socket information
+  void GetSocketConnections(nsTArray<SocketInfo>*);
+  uint64_t GetSentBytes() { return mSentBytesCount; }
+  uint64_t GetReceivedBytes() { return mReceivedBytesCount; }
+
+  // Returns true if keepalives are enabled in prefs.
+  bool IsKeepaliveEnabled() { return mKeepaliveEnabledPref; }
+
+  bool IsTelemetryEnabledAndNotSleepPhase();
+  PRIntervalTime MaxTimeForPrClosePref() { return mMaxTimeForPrClosePref; }
+
+  // According the preference value of `network.socket.forcePort` this method
+  // possibly remaps the port number passed as the arg.
+  void ApplyPortRemap(uint16_t* aPort);
+
+  // Reads the preference string and updates (rewrites) the mPortRemapping
+  // array on the socket thread.  Returns true if the whole pref string was
+  // correctly formed.
+  bool UpdatePortRemapPreference(nsACString const& aPortMappingPref);
+
+ protected:
+  virtual ~nsSocketTransportService();
+
+ private:
+  //-------------------------------------------------------------------------
+  // misc (any thread)
+  //-------------------------------------------------------------------------
+
+  // The value is guaranteed to be valid and not dangling while on the socket
+  // thread as mThread is only ever reset after it's been shutdown.
+  // This member should only ever be read on the socket thread.
+  nsIThread* mRawThread{nullptr};
+
+  // Returns mThread in a thread-safe manner.
+  already_AddRefed<nsIThread> GetThreadSafely();
+  // Same as above, but return mThread as a nsIDirectTaskDispatcher
+  already_AddRefed<nsIDirectTaskDispatcher> GetDirectTaskDispatcherSafely();
+
+  //-------------------------------------------------------------------------
+  // initialization and shutdown (any thread)
+  //-------------------------------------------------------------------------
+
+  Atomic<bool> mInitialized{false};
+  // indicates whether we are currently in the process of shutting down
+  Atomic<bool> mShuttingDown{false};
+
+  Mutex mLock{"nsSocketTransportService::mLock"};
+  // Variables in the next section protected by mLock
+
+  // mThread and mDirectTaskDispatcher are only ever modified on the main
+  // thread. Will be set on Init and set to null after shutdown. You must access
+  // mThread and mDirectTaskDispatcher outside the main thread via respectively
+  // GetThreadSafely and GetDirectTaskDispatchedSafely().
+  nsCOMPtr<nsIThread> mThread MOZ_GUARDED_BY(mLock);
+  // We store a pointer to mThread as a direct task dispatcher to avoid having
+  // to do do_QueryInterface whenever we need to access the interface.
+  nsCOMPtr<nsIDirectTaskDispatcher> mDirectTaskDispatcher MOZ_GUARDED_BY(mLock);
+  UniquePtr<PollableEvent> mPollableEvent MOZ_GUARDED_BY(mLock);
+  bool mOffline MOZ_GUARDED_BY(mLock) = false;
+  bool mGoingOffline MOZ_GUARDED_BY(mLock) = false;
+
+  // Detaches all sockets.
+  void Reset(bool aGuardLocals);
+
+  nsresult ShutdownThread();
+
+  //-------------------------------------------------------------------------
+  // socket lists (socket thread only)
+  //
+  // only "active" sockets are on the poll list.  the active list is kept
+  // in sync with the poll list such that:
+  //
+  //   mActiveList[k].mFD == mPollList[k+1].fd
+  //
+  // where k=0,1,2,...
+  //-------------------------------------------------------------------------
+
+  class SocketContext {
+   public:
+    SocketContext(PRFileDesc* aFD,
+                  already_AddRefed<nsASocketHandler>&& aHandler,
+                  PRIntervalTime aPollStartEpoch)
+        : mFD(aFD), mHandler(aHandler), mPollStartEpoch(aPollStartEpoch) {}
+    SocketContext(PRFileDesc* aFD, nsASocketHandler* aHandler,
+                  PRIntervalTime aPollStartEpoch)
+        : mFD(aFD), mHandler(aHandler), mPollStartEpoch(aPollStartEpoch) {}
+    ~SocketContext() = default;
+
+    // Returns true iff the socket has not been signalled longer than
+    // the desired timeout (mHandler->mPollTimeout).
+    bool IsTimedOut(PRIntervalTime now) const;
+    // Engages the timeout by marking the epoch we start polling this socket.
+    // If epoch is already marked this does nothing, hence, this method can be
+    // called everytime we put this socket to poll() list with in-flags set.
+    void EnsureTimeout(PRIntervalTime now);
+    // Called after an event on a socket has been signalled to turn of the
+    // timeout calculation.
+    void DisengageTimeout();
+    // Returns the number of intervals this socket is about to timeout in,
+    // or 0 (zero) when it has already timed out.  Returns
+    // NS_SOCKET_POLL_TIMEOUT when there is no timeout set on the socket.
+    PRIntervalTime TimeoutIn(PRIntervalTime now) const;
+    // When a socket timeout is reset and later set again, it may happen
+    // that mPollStartEpoch is not reset in between.  We have to manually
+    // call this on every iteration over sockets to ensure the epoch reset.
+    void MaybeResetEpoch();
+
+    PRFileDesc* mFD;
+    RefPtr<nsASocketHandler> mHandler;
+    PRIntervalTime mPollStartEpoch;  // time we started to poll this socket
+  };
+
+  using SocketContextList = AutoTArray<SocketContext, SOCKET_LIMIT_MIN>;
+  int64_t SockIndex(SocketContextList& aList, SocketContext* aSock);
+
+  SocketContextList mActiveList;
+  SocketContextList mIdleList;
+
+  nsresult DetachSocket(SocketContextList& listHead, SocketContext*);
+  void AddToIdleList(SocketContext* sock);
+  void AddToPollList(SocketContext* sock);
+  void RemoveFromIdleList(SocketContext* sock);
+  void RemoveFromPollList(SocketContext* sock);
+  void MoveToIdleList(SocketContext* sock);
+  void MoveToPollList(SocketContext* sock);
+
+  void InitMaxCount();
+
+  // Total bytes number transfered through all the sockets except active ones
+  uint64_t mSentBytesCount{0};
+  uint64_t mReceivedBytesCount{0};
+  //-------------------------------------------------------------------------
+  // poll list (socket thread only)
+  //
+  // first element of the poll list is mPollableEvent (or null if the pollable
+  // event cannot be created).
+  //-------------------------------------------------------------------------
+
+  nsTArray<PRPollDesc> mPollList;
+
+  PRIntervalTime PollTimeout(
+      PRIntervalTime now);  // computes ideal poll timeout
+  nsresult DoPollIteration(TimeDuration* pollDuration);
+  // perfoms a single poll iteration
+  int32_t Poll(TimeDuration* pollDuration, PRIntervalTime ts);
+  // calls PR_Poll.  the out param
+  // interval indicates the poll
+  // duration in seconds.
+  // pollDuration is used only for
+  // telemetry
+
+  //-------------------------------------------------------------------------
+  // pending socket queue - see NotifyWhenCanAttachSocket
+  //-------------------------------------------------------------------------
+  AutoCleanLinkedList<LinkedRunnableEvent> mPendingSocketQueue;
+
+  // Preference Monitor for SendBufferSize and Keepalive prefs.
+  nsresult UpdatePrefs();
+  static void UpdatePrefs(const char* aPref, void* aSelf);
+  void UpdateSendBufferPref();
+  int32_t mSendBufferSize{0};
+  // Number of seconds of connection is idle before first keepalive ping.
+  int32_t mKeepaliveIdleTimeS{600};
+  // Number of seconds between retries should keepalive pings fail.
+  int32_t mKeepaliveRetryIntervalS{1};
+  // Number of keepalive probes to send.
+  int32_t mKeepaliveProbeCount{kDefaultTCPKeepCount};
+  // True if TCP keepalive is enabled globally.
+  bool mKeepaliveEnabledPref{false};
+  // Timeout of pollable event signalling.
+  TimeDuration mPollableEventTimeout MOZ_GUARDED_BY(mLock);
+
+  Atomic<bool> mServingPendingQueue{false};
+  Atomic<int32_t, Relaxed> mMaxTimePerPollIter{100};
+  Atomic<PRIntervalTime, Relaxed> mMaxTimeForPrClosePref;
+  // Timestamp of the last network link change event, tracked
+  // also on child processes.
+  Atomic<PRIntervalTime, Relaxed> mLastNetworkLinkChangeTime{0};
+  // Preference for how long we do busy wait after network link
+  // change has been detected.
+  Atomic<PRIntervalTime, Relaxed> mNetworkLinkChangeBusyWaitPeriod;
+  // Preference for the value of timeout for poll() we use during
+  // the network link change event period.
+  Atomic<PRIntervalTime, Relaxed> mNetworkLinkChangeBusyWaitTimeout;
+
+  // Between a computer going to sleep and waking up the PR_*** telemetry
+  // will be corrupted - so do not record it.
+  Atomic<bool, Relaxed> mSleepPhase{false};
+  nsCOMPtr<nsITimer> mAfterWakeUpTimer;
+
+  // Lazily created array of forced port remappings.  The tuple members meaning
+  // is exactly:
+  // <0> the greater-or-equal port number of the range to remap
+  // <1> the less-or-equal port number of the range to remap
+  // <2> the port number to remap to, when the given port number falls to the
+  // range
+  using TPortRemapping =
+      CopyableTArray<std::tuple<uint16_t, uint16_t, uint16_t>>;
+  Maybe<TPortRemapping> mPortRemapping;
+
+  // Called on the socket thread to apply the mapping build on the main thread
+  // from the preference.
+  void ApplyPortRemapPreference(TPortRemapping const& portRemapping);
+
+  void OnKeepaliveEnabledPrefChange();
+  void NotifyKeepaliveEnabledPrefChange(SocketContext* sock);
+
+  // Socket thread only for dynamically adjusting max socket size
+#if defined(XP_WIN)
+  void ProbeMaxCount();
+#endif
+  bool mProbedMaxCount{false};
+
+  // Report socket status to about:networking
+  void AnalyzeConnection(nsTArray<SocketInfo>* data, SocketContext* context,
+                         bool aActive);
+
+  void ClosePrivateConnections();
+  void DetachSocketWithGuard(bool aGuardLocals, SocketContextList& socketList,
+                             int32_t index);
+
+  void MarkTheLastElementOfPendingQueue();
+
+#if defined(XP_WIN)
+  Atomic<bool> mPolling{false};
+  nsCOMPtr<nsITimer> mPollRepairTimer;
+  void StartPollWatchdog();
+  void DoPollRepair();
+  void StartPolling();
+  void EndPolling();
+#endif
+
+  void TryRepairPollableEvent();
+
+  CopyableTArray<nsCOMPtr<nsISTSShutdownObserver>> mShutdownObservers;
+};
+
+extern nsSocketTransportService* gSocketTransportService;
+bool OnSocketThread();
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // !nsSocketTransportService_h__
diff --git a/netwerk/base/nsStandardURL.cpp b/netwerk/base/nsStandardURL.cpp
new file mode 100644
index 0000000000..10f336f8e0
--- /dev/null
+++ b/netwerk/base/nsStandardURL.cpp
@@ -0,0 +1,3910 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ipc/IPCMessageUtils.h"
+
+#include "nsASCIIMask.h"
+#include "nsStandardURL.h"
+#include "nsCRT.h"
+#include "nsEscape.h"
+#include "nsIFile.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "nsIIDNService.h"
+#include "mozilla/Logging.h"
+#include "nsIURLParser.h"
+#include "nsPrintfCString.h"
+#include "nsNetCID.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/TextUtils.h"
+#include <algorithm>
+#include "nsContentUtils.h"
+#include "prprf.h"
+#include "nsReadableUtils.h"
+#include "mozilla/net/MozURL_ffi.h"
+#include "mozilla/TextUtils.h"
+#include "mozilla/Utf8.h"
+#include "nsIClassInfoImpl.h"
+#include <string.h>
+
+//
+// setenv MOZ_LOG nsStandardURL:5
+//
+static mozilla::LazyLogModule gStandardURLLog("nsStandardURL");
+
+// The Chromium code defines its own LOG macro which we don't want
+#undef LOG
+#define LOG(args) MOZ_LOG(gStandardURLLog, LogLevel::Debug, args)
+#undef LOG_ENABLED
+#define LOG_ENABLED() MOZ_LOG_TEST(gStandardURLLog, LogLevel::Debug)
+
+using namespace mozilla::ipc;
+
+namespace mozilla {
+namespace net {
+
+static NS_DEFINE_CID(kThisImplCID, NS_THIS_STANDARDURL_IMPL_CID);
+
+// This will always be initialized and destroyed on the main thread, but
+// can be safely used on other threads.
+StaticRefPtr<nsIIDNService> nsStandardURL::gIDN;
+
+// This value will only be updated on the main thread once.
+static Atomic<bool, Relaxed> gInitialized{false};
+
+const char nsStandardURL::gHostLimitDigits[] = {'/', '\\', '?', '#', 0};
+
+// Invalid host characters
+// Note that the array below will be initialized at compile time,
+// so we do not need to "optimize" TestForInvalidHostCharacters.
+//
+constexpr bool TestForInvalidHostCharacters(char c) {
+  // Testing for these:
+  // CONTROL_CHARACTERS " #/:?@[\\]*<>|\"";
+  return (c > 0 && c < 32) ||  // The control characters are [1, 31]
+         c == 0x7F ||          // // DEL (delete)
+         c == ' ' || c == '#' || c == '/' || c == ':' || c == '?' || c == '@' ||
+         c == '[' || c == '\\' || c == ']' || c == '*' || c == '<' ||
+         c == '^' ||
+#if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
+         // Mailnews %-escapes file paths into URLs.
+         c == '>' || c == '|' || c == '"';
+#else
+         c == '>' || c == '|' || c == '"' || c == '%';
+#endif
+}
+constexpr ASCIIMaskArray sInvalidHostChars =
+    CreateASCIIMask(TestForInvalidHostCharacters);
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsSegmentEncoder
+//----------------------------------------------------------------------------
+
+nsStandardURL::nsSegmentEncoder::nsSegmentEncoder(const Encoding* encoding)
+    : mEncoding(encoding) {
+  if (mEncoding == UTF_8_ENCODING) {
+    mEncoding = nullptr;
+  }
+}
+
+int32_t nsStandardURL::nsSegmentEncoder::EncodeSegmentCount(
+    const char* aStr, const URLSegment& aSeg, int16_t aMask, nsCString& aOut,
+    bool& aAppended, uint32_t aExtraLen) {
+  // aExtraLen is characters outside the segment that will be
+  // added when the segment is not empty (like the @ following
+  // a username).
+  if (!aStr || aSeg.mLen <= 0) {
+    // Empty segment, so aExtraLen not added per above.
+    aAppended = false;
+    return 0;
+  }
+
+  uint32_t origLen = aOut.Length();
+
+  Span<const char> span = Span(aStr + aSeg.mPos, aSeg.mLen);
+
+  // first honor the origin charset if appropriate. as an optimization,
+  // only do this if the segment is non-ASCII.  Further, if mEncoding is
+  // null, then the origin charset is UTF-8 and there is nothing to do.
+  if (mEncoding) {
+    size_t upTo;
+    if (MOZ_UNLIKELY(mEncoding == ISO_2022_JP_ENCODING)) {
+      upTo = Encoding::ISO2022JPASCIIValidUpTo(AsBytes(span));
+    } else {
+      upTo = Encoding::ASCIIValidUpTo(AsBytes(span));
+    }
+    if (upTo != span.Length()) {
+      // we have to encode this segment
+      char bufferArr[512];
+      Span<char> buffer = Span(bufferArr);
+
+      auto encoder = mEncoding->NewEncoder();
+
+      nsAutoCString valid;  // has to be declared in this scope
+      if (MOZ_UNLIKELY(!IsUtf8(span.From(upTo)))) {
+        MOZ_ASSERT_UNREACHABLE("Invalid UTF-8 passed to nsStandardURL.");
+        // It's UB to pass invalid UTF-8 to
+        // EncodeFromUTF8WithoutReplacement(), so let's make our input valid
+        // UTF-8 by replacing invalid sequences with the REPLACEMENT
+        // CHARACTER.
+        UTF_8_ENCODING->Decode(
+            nsDependentCSubstring(span.Elements(), span.Length()), valid);
+        // This assigment is OK. `span` can't be used after `valid` has
+        // been destroyed because the only way out of the scope that `valid`
+        // was declared in is via return inside the loop below. Specifically,
+        // the return is the only way out of the loop.
+        span = valid;
+      }
+
+      size_t totalRead = 0;
+      for (;;) {
+        auto [encoderResult, read, written] =
+            encoder->EncodeFromUTF8WithoutReplacement(
+                AsBytes(span.From(totalRead)), AsWritableBytes(buffer), true);
+        totalRead += read;
+        auto bufferWritten = buffer.To(written);
+        if (!NS_EscapeURLSpan(bufferWritten, aMask, aOut)) {
+          aOut.Append(bufferWritten);
+        }
+        if (encoderResult == kInputEmpty) {
+          aAppended = true;
+          // Difference between original and current output
+          // string lengths plus extra length
+          return aOut.Length() - origLen + aExtraLen;
+        }
+        if (encoderResult == kOutputFull) {
+          continue;
+        }
+        aOut.AppendLiteral("%26%23");
+        aOut.AppendInt(encoderResult);
+        aOut.AppendLiteral("%3B");
+      }
+      MOZ_RELEASE_ASSERT(
+          false,
+          "There's supposed to be no way out of the above loop except return.");
+    }
+  }
+
+  if (NS_EscapeURLSpan(span, aMask, aOut)) {
+    aAppended = true;
+    // Difference between original and current output
+    // string lengths plus extra length
+    return aOut.Length() - origLen + aExtraLen;
+  }
+  aAppended = false;
+  // Original segment length plus extra length
+  return span.Length() + aExtraLen;
+}
+
+const nsACString& nsStandardURL::nsSegmentEncoder::EncodeSegment(
+    const nsACString& str, int16_t mask, nsCString& result) {
+  const char* text;
+  bool encoded;
+  EncodeSegmentCount(str.BeginReading(text), URLSegment(0, str.Length()), mask,
+                     result, encoded);
+  if (encoded) {
+    return result;
+  }
+  return str;
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL <public>
+//----------------------------------------------------------------------------
+
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+static StaticMutex gAllURLsMutex MOZ_UNANNOTATED;
+static LinkedList<nsStandardURL> gAllURLs;
+#endif
+
+nsStandardURL::nsStandardURL(bool aSupportsFileURL, bool aTrackURL)
+    : mURLType(URLTYPE_STANDARD),
+      mSupportsFileURL(aSupportsFileURL),
+      mCheckedIfHostA(false) {
+  LOG(("Creating nsStandardURL @%p\n", this));
+
+  // gInitialized changes value only once (false->true) on the main thread.
+  // It's OK to race here because in the worst case we'll just
+  // dispatch a noop runnable to the main thread.
+  MOZ_ASSERT(gInitialized);
+
+  // default parser in case nsIStandardURL::Init is never called
+  mParser = net_GetStdURLParser();
+
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+  if (aTrackURL) {
+    StaticMutexAutoLock lock(gAllURLsMutex);
+    gAllURLs.insertBack(this);
+  }
+#endif
+}
+
+bool nsStandardURL::IsValid() {
+  auto checkSegment = [&](const nsStandardURL::URLSegment& aSeg) {
+#ifdef EARLY_BETA_OR_EARLIER
+    // If the parity is not the same, we assume that this is caused by a memory
+    // error. In this case, we think this URLSegment is valid.
+    if ((aSeg.mPos.Parity() != aSeg.mPos.CalculateParity()) ||
+        (aSeg.mLen.Parity() != aSeg.mLen.CalculateParity())) {
+      MOZ_ASSERT(false);
+      return true;
+    }
+#endif
+    // Bad value
+    if (NS_WARN_IF(aSeg.mLen < -1)) {
+      return false;
+    }
+    if (aSeg.mLen == -1) {
+      return true;
+    }
+
+    // Points out of string
+    if (NS_WARN_IF(aSeg.mPos + aSeg.mLen > mSpec.Length())) {
+      return false;
+    }
+
+    // Overflow
+    if (NS_WARN_IF(aSeg.mPos + aSeg.mLen < aSeg.mPos)) {
+      return false;
+    }
+
+    return true;
+  };
+
+  bool allSegmentsValid = checkSegment(mScheme) && checkSegment(mAuthority) &&
+                          checkSegment(mUsername) && checkSegment(mPassword) &&
+                          checkSegment(mHost) && checkSegment(mPath) &&
+                          checkSegment(mFilepath) && checkSegment(mDirectory) &&
+                          checkSegment(mBasename) && checkSegment(mExtension) &&
+                          checkSegment(mQuery) && checkSegment(mRef);
+  if (!allSegmentsValid) {
+    return false;
+  }
+
+  if (mScheme.mPos != 0) {
+    return false;
+  }
+
+  return true;
+}
+
+void nsStandardURL::SanityCheck() {
+  if (!IsValid()) {
+    nsPrintfCString msg(
+        "mLen:%zX, mScheme (%X,%X), mAuthority (%X,%X), mUsername (%X,%X), "
+        "mPassword (%X,%X), mHost (%X,%X), mPath (%X,%X), mFilepath (%X,%X), "
+        "mDirectory (%X,%X), mBasename (%X,%X), mExtension (%X,%X), mQuery "
+        "(%X,%X), mRef (%X,%X)",
+        mSpec.Length(), (uint32_t)mScheme.mPos, (int32_t)mScheme.mLen,
+        (uint32_t)mAuthority.mPos, (int32_t)mAuthority.mLen,
+        (uint32_t)mUsername.mPos, (int32_t)mUsername.mLen,
+        (uint32_t)mPassword.mPos, (int32_t)mPassword.mLen, (uint32_t)mHost.mPos,
+        (int32_t)mHost.mLen, (uint32_t)mPath.mPos, (int32_t)mPath.mLen,
+        (uint32_t)mFilepath.mPos, (int32_t)mFilepath.mLen,
+        (uint32_t)mDirectory.mPos, (int32_t)mDirectory.mLen,
+        (uint32_t)mBasename.mPos, (int32_t)mBasename.mLen,
+        (uint32_t)mExtension.mPos, (int32_t)mExtension.mLen,
+        (uint32_t)mQuery.mPos, (int32_t)mQuery.mLen, (uint32_t)mRef.mPos,
+        (int32_t)mRef.mLen);
+    CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::URLSegments,
+                                       msg);
+
+    MOZ_CRASH("nsStandardURL::SanityCheck failed");
+  }
+}
+
+nsStandardURL::~nsStandardURL() {
+  LOG(("Destroying nsStandardURL @%p\n", this));
+
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+  {
+    StaticMutexAutoLock lock(gAllURLsMutex);
+    if (isInList()) {
+      remove();
+    }
+  }
+#endif
+}
+
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+struct DumpLeakedURLs {
+  DumpLeakedURLs() = default;
+  ~DumpLeakedURLs();
+};
+
+DumpLeakedURLs::~DumpLeakedURLs() {
+  MOZ_ASSERT(NS_IsMainThread());
+  StaticMutexAutoLock lock(gAllURLsMutex);
+  if (!gAllURLs.isEmpty()) {
+    printf("Leaked URLs:\n");
+    for (auto* url : gAllURLs) {
+      url->PrintSpec();
+    }
+    gAllURLs.clear();
+  }
+}
+#endif
+
+void nsStandardURL::InitGlobalObjects() {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+
+  if (gInitialized) {
+    return;
+  }
+
+  gInitialized = true;
+
+  nsCOMPtr<nsIIDNService> serv(do_GetService(NS_IDNSERVICE_CONTRACTID));
+  if (serv) {
+    gIDN = serv;
+  }
+  MOZ_DIAGNOSTIC_ASSERT(gIDN);
+
+  // Make sure nsURLHelper::InitGlobals() gets called on the main thread
+  nsCOMPtr<nsIURLParser> parser = net_GetStdURLParser();
+  MOZ_DIAGNOSTIC_ASSERT(parser);
+  Unused << parser;
+}
+
+void nsStandardURL::ShutdownGlobalObjects() {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+  gIDN = nullptr;
+
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+  if (gInitialized) {
+    // This instanciates a dummy class, and will trigger the class
+    // destructor when libxul is unloaded. This is equivalent to atexit(),
+    // but gracefully handles dlclose().
+    StaticMutexAutoLock lock(gAllURLsMutex);
+    static DumpLeakedURLs d;
+  }
+#endif
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL <private>
+//----------------------------------------------------------------------------
+
+void nsStandardURL::Clear() {
+  mSpec.Truncate();
+
+  mPort = -1;
+
+  mScheme.Reset();
+  mAuthority.Reset();
+  mUsername.Reset();
+  mPassword.Reset();
+  mHost.Reset();
+
+  mPath.Reset();
+  mFilepath.Reset();
+  mDirectory.Reset();
+  mBasename.Reset();
+
+  mExtension.Reset();
+  mQuery.Reset();
+  mRef.Reset();
+
+  InvalidateCache();
+}
+
+void nsStandardURL::InvalidateCache(bool invalidateCachedFile) {
+  if (invalidateCachedFile) {
+    mFile = nullptr;
+  }
+}
+
+// Return the number of "dots" in the string, or -1 if invalid.  Note that the
+// number of relevant entries in the bases/starts/ends arrays is number of
+// dots + 1.
+// Since the trailing dot is allowed, we pass and adjust "length".
+//
+// length is assumed to be <= host.Length(); the callers is responsible for that
+//
+// Note that the value returned is guaranteed to be in [-1, 3] range.
+inline int32_t ValidateIPv4Number(const nsACString& host, int32_t bases[4],
+                                  int32_t dotIndex[3], bool& onlyBase10,
+                                  int32_t& length) {
+  MOZ_ASSERT(length <= (int32_t)host.Length());
+  if (length <= 0) {
+    return -1;
+  }
+
+  bool lastWasNumber = false;  // We count on this being false for i == 0
+  int32_t dotCount = 0;
+  onlyBase10 = true;
+
+  for (int32_t i = 0; i < length; i++) {
+    char current = host[i];
+    if (current == '.') {
+      if (!lastWasNumber) {  // A dot should not follow an X or a dot, or be
+                             // first
+        return -1;
+      }
+
+      if (dotCount > 0 &&
+          i == (length - 1)) {  // Trailing dot is OK; shorten and return
+        length--;
+        return dotCount;
+      }
+
+      if (dotCount > 2) {
+        return -1;
+      }
+      lastWasNumber = false;
+      dotIndex[dotCount] = i;
+      dotCount++;
+    } else if (current == 'X' || current == 'x') {
+      if (!lastWasNumber ||  // An X should not follow an X or a dot or be first
+          i == (length - 1) ||  // No trailing Xs allowed
+          (dotCount == 0 &&
+           i != 1) ||            // If we had no dots, an X should be second
+          host[i - 1] != '0' ||  // X should always follow a 0.  Guaranteed i >
+                                 // 0 as lastWasNumber is true
+          (dotCount > 0 &&
+           host[i - 2] != '.')) {  // And that zero follows a dot if it exists
+        return -1;
+      }
+      lastWasNumber = false;
+      bases[dotCount] = 16;
+      onlyBase10 = false;
+
+    } else if (current == '0') {
+      if (i < length - 1 &&      // Trailing zero doesn't signal octal
+          host[i + 1] != '.' &&  // Lone zero is not octal
+          (i == 0 || host[i - 1] == '.')) {  // Zero at start or following a dot
+                                             // is a candidate for octal
+        bases[dotCount] = 8;  // This will turn to 16 above if X shows up
+        onlyBase10 = false;
+      }
+      lastWasNumber = true;
+
+    } else if (current >= '1' && current <= '7') {
+      lastWasNumber = true;
+
+    } else if (current >= '8' && current <= '9') {
+      if (bases[dotCount] == 8) {
+        return -1;
+      }
+      lastWasNumber = true;
+
+    } else if ((current >= 'a' && current <= 'f') ||
+               (current >= 'A' && current <= 'F')) {
+      if (bases[dotCount] != 16) {
+        return -1;
+      }
+      lastWasNumber = true;
+
+    } else {
+      return -1;
+    }
+  }
+
+  return dotCount;
+}
+
+inline nsresult ParseIPv4Number10(const nsACString& input, uint32_t& number,
+                                  uint32_t maxNumber) {
+  uint64_t value = 0;
+  const char* current = input.BeginReading();
+  const char* end = input.EndReading();
+  for (; current < end; ++current) {
+    char c = *current;
+    MOZ_ASSERT(c >= '0' && c <= '9');
+    value *= 10;
+    value += c - '0';
+  }
+  if (value <= maxNumber) {
+    number = value;
+    return NS_OK;
+  }
+
+  // The error case
+  number = 0;
+  return NS_ERROR_FAILURE;
+}
+
+inline nsresult ParseIPv4Number(const nsACString& input, int32_t base,
+                                uint32_t& number, uint32_t maxNumber) {
+  // Accumulate in the 64-bit value
+  uint64_t value = 0;
+  const char* current = input.BeginReading();
+  const char* end = input.EndReading();
+  switch (base) {
+    case 16:
+      ++current;
+      [[fallthrough]];
+    case 8:
+      ++current;
+      break;
+    case 10:
+    default:
+      break;
+  }
+  for (; current < end; ++current) {
+    value *= base;
+    char c = *current;
+    MOZ_ASSERT((base == 10 && IsAsciiDigit(c)) ||
+               (base == 8 && c >= '0' && c <= '7') ||
+               (base == 16 && IsAsciiHexDigit(c)));
+    if (IsAsciiDigit(c)) {
+      value += c - '0';
+    } else if (c >= 'a' && c <= 'f') {
+      value += c - 'a' + 10;
+    } else if (c >= 'A' && c <= 'F') {
+      value += c - 'A' + 10;
+    }
+  }
+
+  if (value <= maxNumber) {
+    number = value;
+    return NS_OK;
+  }
+
+  // The error case
+  number = 0;
+  return NS_ERROR_FAILURE;
+}
+
+// IPv4 parser spec: https://url.spec.whatwg.org/#concept-ipv4-parser
+/* static */
+nsresult nsStandardURL::NormalizeIPv4(const nsACString& host,
+                                      nsCString& result) {
+  int32_t bases[4] = {10, 10, 10, 10};
+  bool onlyBase10 = true;  // Track this as a special case
+  int32_t dotIndex[3];     // The positions of the dots in the string
+
+  // The length may be adjusted by ValidateIPv4Number (ignoring the trailing
+  // period) so use "length", rather than host.Length() after that call.
+  int32_t length = static_cast<int32_t>(host.Length());
+  int32_t dotCount =
+      ValidateIPv4Number(host, bases, dotIndex, onlyBase10, length);
+  if (dotCount < 0 || length <= 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Max values specified by the spec
+  static const uint32_t upperBounds[] = {0xffffffffu, 0xffffffu, 0xffffu,
+                                         0xffu};
+  uint32_t ipv4;
+  int32_t start = (dotCount > 0 ? dotIndex[dotCount - 1] + 1 : 0);
+
+  nsresult res;
+  // Doing a special case for all items being base 10 gives ~35% speedup
+  res = (onlyBase10
+             ? ParseIPv4Number10(Substring(host, start, length - start), ipv4,
+                                 upperBounds[dotCount])
+             : ParseIPv4Number(Substring(host, start, length - start),
+                               bases[dotCount], ipv4, upperBounds[dotCount]));
+  if (NS_FAILED(res)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t lastUsed = -1;
+  for (int32_t i = 0; i < dotCount; i++) {
+    uint32_t number;
+    start = lastUsed + 1;
+    lastUsed = dotIndex[i];
+    res =
+        (onlyBase10 ? ParseIPv4Number10(
+                          Substring(host, start, lastUsed - start), number, 255)
+                    : ParseIPv4Number(Substring(host, start, lastUsed - start),
+                                      bases[i], number, 255));
+    if (NS_FAILED(res)) {
+      return NS_ERROR_FAILURE;
+    }
+    ipv4 += number << (8 * (3 - i));
+  }
+
+  // A special case for ipv4 URL like "127." should have the same result as
+  // "127".
+  if (dotCount == 1 && dotIndex[0] == length - 1) {
+    ipv4 = (ipv4 & 0xff000000) >> 24;
+  }
+
+  uint8_t ipSegments[4];
+  NetworkEndian::writeUint32(ipSegments, ipv4);
+  result = nsPrintfCString("%d.%d.%d.%d", ipSegments[0], ipSegments[1],
+                           ipSegments[2], ipSegments[3]);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::NormalizeIDN(const nsCString& host, nsCString& result) {
+  result.Truncate();
+  mDisplayHost.Truncate();
+  nsresult rv;
+
+  if (!gIDN) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Even if it's already ACE, we must still call ConvertUTF8toACE in order
+  // for the input normalization to take place.
+  rv = gIDN->ConvertUTF8toACE(host, result);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // If the ASCII representation doesn't contain the xn-- token then we don't
+  // need to call ConvertToDisplayIDN as that would not change anything.
+  if (!StringBeginsWith(result, "xn--"_ns) &&
+      result.Find(".xn--"_ns) == kNotFound) {
+    mCheckedIfHostA = true;
+    return NS_OK;
+  }
+
+  bool isAscii = true;
+  nsAutoCString displayHost;
+  rv = gIDN->ConvertToDisplayIDN(result, &isAscii, displayHost);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mCheckedIfHostA = true;
+  if (!isAscii) {
+    mDisplayHost = displayHost;
+  }
+  return NS_OK;
+}
+
+bool nsStandardURL::ValidIPv6orHostname(const char* host, uint32_t length) {
+  if (!host || !*host) {
+    // Should not be NULL or empty string
+    return false;
+  }
+
+  if (length != strlen(host)) {
+    // Embedded null
+    return false;
+  }
+
+  bool openBracket = host[0] == '[';
+  bool closeBracket = host[length - 1] == ']';
+
+  if (openBracket && closeBracket) {
+    return net_IsValidIPv6Addr(Substring(host + 1, length - 2));
+  }
+
+  if (openBracket || closeBracket) {
+    // Fail if only one of the brackets is present
+    return false;
+  }
+
+  const char* end = host + length;
+  const char* iter = host;
+  for (; iter != end && *iter; ++iter) {
+    if (ASCIIMask::IsMasked(sInvalidHostChars, *iter)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void nsStandardURL::CoalescePath(netCoalesceFlags coalesceFlag, char* path) {
+  net_CoalesceDirs(coalesceFlag, path);
+  int32_t newLen = strlen(path);
+  if (newLen < mPath.mLen) {
+    int32_t diff = newLen - mPath.mLen;
+    mPath.mLen = newLen;
+    mDirectory.mLen += diff;
+    mFilepath.mLen += diff;
+    ShiftFromBasename(diff);
+  }
+}
+
+uint32_t nsStandardURL::AppendSegmentToBuf(char* buf, uint32_t i,
+                                           const char* str,
+                                           const URLSegment& segInput,
+                                           URLSegment& segOutput,
+                                           const nsCString* escapedStr,
+                                           bool useEscaped, int32_t* diff) {
+  MOZ_ASSERT(segInput.mLen == segOutput.mLen);
+
+  if (diff) {
+    *diff = 0;
+  }
+
+  if (segInput.mLen > 0) {
+    if (useEscaped) {
+      MOZ_ASSERT(diff);
+      segOutput.mLen = escapedStr->Length();
+      *diff = segOutput.mLen - segInput.mLen;
+      memcpy(buf + i, escapedStr->get(), segOutput.mLen);
+    } else {
+      memcpy(buf + i, str + segInput.mPos, segInput.mLen);
+    }
+    segOutput.mPos = i;
+    i += segOutput.mLen;
+  } else {
+    segOutput.mPos = i;
+  }
+  return i;
+}
+
+uint32_t nsStandardURL::AppendToBuf(char* buf, uint32_t i, const char* str,
+                                    uint32_t len) {
+  memcpy(buf + i, str, len);
+  return i + len;
+}
+
+// basic algorithm:
+//  1- escape url segments (for improved GetSpec efficiency)
+//  2- allocate spec buffer
+//  3- write url segments
+//  4- update url segment positions and lengths
+nsresult nsStandardURL::BuildNormalizedSpec(const char* spec,
+                                            const Encoding* encoding) {
+  // Assumptions: all member URLSegments must be relative the |spec| argument
+  // passed to this function.
+
+  // buffers for holding escaped url segments (these will remain empty unless
+  // escaping is required).
+  nsAutoCString encUsername, encPassword, encHost, encDirectory, encBasename,
+      encExtension, encQuery, encRef;
+  bool useEncUsername, useEncPassword, useEncHost = false, useEncDirectory,
+                                       useEncBasename, useEncExtension,
+                                       useEncQuery, useEncRef;
+  nsAutoCString portbuf;
+
+  //
+  // escape each URL segment, if necessary, and calculate approximate normalized
+  // spec length.
+  //
+  // [scheme://][username[:password]@]host[:port]/path[?query_string][#ref]
+
+  uint32_t approxLen = 0;
+
+  // the scheme is already ASCII
+  if (mScheme.mLen > 0) {
+    approxLen +=
+        mScheme.mLen + 3;  // includes room for "://", which we insert always
+  }
+
+  // encode URL segments; convert UTF-8 to origin charset and possibly escape.
+  // results written to encXXX variables only if |spec| is not already in the
+  // appropriate encoding.
+  {
+    nsSegmentEncoder encoder;
+    nsSegmentEncoder queryEncoder(encoding);
+    // Username@
+    approxLen += encoder.EncodeSegmentCount(spec, mUsername, esc_Username,
+                                            encUsername, useEncUsername, 0);
+    approxLen += 1;  // reserve length for @
+    // :password - we insert the ':' even if there's no actual password if
+    // "user:@" was in the spec
+    if (mPassword.mLen > 0) {
+      approxLen += 1 + encoder.EncodeSegmentCount(spec, mPassword, esc_Password,
+                                                  encPassword, useEncPassword);
+    }
+    // mHost is handled differently below due to encoding differences
+    MOZ_ASSERT(mPort >= -1, "Invalid negative mPort");
+    if (mPort != -1 && mPort != mDefaultPort) {
+      // :port
+      portbuf.AppendInt(mPort);
+      approxLen += portbuf.Length() + 1;
+    }
+
+    approxLen +=
+        1;  // reserve space for possible leading '/' - may not be needed
+    // Should just use mPath?  These are pessimistic, and thus waste space
+    approxLen += encoder.EncodeSegmentCount(spec, mDirectory, esc_Directory,
+                                            encDirectory, useEncDirectory, 1);
+    approxLen += encoder.EncodeSegmentCount(spec, mBasename, esc_FileBaseName,
+                                            encBasename, useEncBasename);
+    approxLen += encoder.EncodeSegmentCount(spec, mExtension, esc_FileExtension,
+                                            encExtension, useEncExtension, 1);
+
+    // These next ones *always* add their leading character even if length is 0
+    // Handles items like "http://#"
+    // ?query
+    if (mQuery.mLen >= 0) {
+      approxLen += 1 + queryEncoder.EncodeSegmentCount(spec, mQuery, esc_Query,
+                                                       encQuery, useEncQuery);
+    }
+    // #ref
+
+    if (mRef.mLen >= 0) {
+      approxLen += 1 + encoder.EncodeSegmentCount(spec, mRef, esc_Ref, encRef,
+                                                  useEncRef);
+    }
+  }
+
+  // do not escape the hostname, if IPv6 address literal, mHost will
+  // already point to a [ ] delimited IPv6 address literal.
+  // However, perform Unicode normalization on it, as IDN does.
+  // Note that we don't disallow URLs without a host - file:, etc
+  if (mHost.mLen > 0) {
+    nsAutoCString tempHost;
+    NS_UnescapeURL(spec + mHost.mPos, mHost.mLen, esc_AlwaysCopy | esc_Host,
+                   tempHost);
+    if (tempHost.Contains('\0')) {
+      return NS_ERROR_MALFORMED_URI;  // null embedded in hostname
+    }
+    if (tempHost.Contains(' ')) {
+      return NS_ERROR_MALFORMED_URI;  // don't allow spaces in the hostname
+    }
+    nsresult rv = NormalizeIDN(tempHost, encHost);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    if (!SegmentIs(spec, mScheme, "resource") &&
+        !SegmentIs(spec, mScheme, "chrome")) {
+      nsAutoCString ipString;
+      if (encHost.Length() > 0 && encHost.First() == '[' &&
+          encHost.Last() == ']' &&
+          ValidIPv6orHostname(encHost.get(), encHost.Length())) {
+        rv = (nsresult)rusturl_parse_ipv6addr(&encHost, &ipString);
+        if (NS_FAILED(rv)) {
+          return rv;
+        }
+        encHost = ipString;
+      } else if (NS_SUCCEEDED(NormalizeIPv4(encHost, ipString))) {
+        encHost = ipString;
+      }
+    }
+
+    // NormalizeIDN always copies, if the call was successful.
+    useEncHost = true;
+    approxLen += encHost.Length();
+
+    if (!ValidIPv6orHostname(encHost.BeginReading(), encHost.Length())) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+  } else {
+    // empty host means empty mDisplayHost
+    mDisplayHost.Truncate();
+    mCheckedIfHostA = true;
+  }
+
+  // We must take a copy of every single segment because they are pointing to
+  // the |spec| while we are changing their value, in case we must use
+  // encoded strings.
+  URLSegment username(mUsername);
+  URLSegment password(mPassword);
+  URLSegment host(mHost);
+  URLSegment path(mPath);
+  URLSegment directory(mDirectory);
+  URLSegment basename(mBasename);
+  URLSegment extension(mExtension);
+  URLSegment query(mQuery);
+  URLSegment ref(mRef);
+
+  // The encoded string could be longer than the original input, so we need
+  // to check the final URI isn't longer than the max length.
+  if (approxLen + 1 > StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  //
+  // generate the normalized URL string
+  //
+  // approxLen should be correct or 1 high
+  if (!mSpec.SetLength(approxLen + 1,
+                       fallible)) {  // buf needs a trailing '\0' below
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  char* buf = mSpec.BeginWriting();
+  uint32_t i = 0;
+  int32_t diff = 0;
+
+  if (mScheme.mLen > 0) {
+    i = AppendSegmentToBuf(buf, i, spec, mScheme, mScheme);
+    net_ToLowerCase(buf + mScheme.mPos, mScheme.mLen);
+    i = AppendToBuf(buf, i, "://", 3);
+  }
+
+  // record authority starting position
+  mAuthority.mPos = i;
+
+  // append authority
+  if (mUsername.mLen > 0 || mPassword.mLen > 0) {
+    if (mUsername.mLen > 0) {
+      i = AppendSegmentToBuf(buf, i, spec, username, mUsername, &encUsername,
+                             useEncUsername, &diff);
+      ShiftFromPassword(diff);
+    } else {
+      mUsername.mLen = -1;
+    }
+    if (password.mLen > 0) {
+      buf[i++] = ':';
+      i = AppendSegmentToBuf(buf, i, spec, password, mPassword, &encPassword,
+                             useEncPassword, &diff);
+      ShiftFromHost(diff);
+    } else {
+      mPassword.mLen = -1;
+    }
+    buf[i++] = '@';
+  } else {
+    mUsername.mLen = -1;
+    mPassword.mLen = -1;
+  }
+  if (host.mLen > 0) {
+    i = AppendSegmentToBuf(buf, i, spec, host, mHost, &encHost, useEncHost,
+                           &diff);
+    ShiftFromPath(diff);
+
+    net_ToLowerCase(buf + mHost.mPos, mHost.mLen);
+    MOZ_ASSERT(mPort >= -1, "Invalid negative mPort");
+    if (mPort != -1 && mPort != mDefaultPort) {
+      buf[i++] = ':';
+      // Already formatted while building approxLen
+      i = AppendToBuf(buf, i, portbuf.get(), portbuf.Length());
+    }
+  }
+
+  // record authority length
+  mAuthority.mLen = i - mAuthority.mPos;
+
+  // path must always start with a "/"
+  if (mPath.mLen <= 0) {
+    LOG(("setting path=/"));
+    mDirectory.mPos = mFilepath.mPos = mPath.mPos = i;
+    mDirectory.mLen = mFilepath.mLen = mPath.mLen = 1;
+    // basename must exist, even if empty (bug 113508)
+    mBasename.mPos = i + 1;
+    mBasename.mLen = 0;
+    buf[i++] = '/';
+  } else {
+    uint32_t leadingSlash = 0;
+    if (spec[path.mPos] != '/') {
+      LOG(("adding leading slash to path\n"));
+      leadingSlash = 1;
+      buf[i++] = '/';
+      // basename must exist, even if empty (bugs 113508, 429347)
+      if (mBasename.mLen == -1) {
+        mBasename.mPos = basename.mPos = i;
+        mBasename.mLen = basename.mLen = 0;
+      }
+    }
+
+    // record corrected (file)path starting position
+    mPath.mPos = mFilepath.mPos = i - leadingSlash;
+
+    i = AppendSegmentToBuf(buf, i, spec, directory, mDirectory, &encDirectory,
+                           useEncDirectory, &diff);
+    ShiftFromBasename(diff);
+
+    // the directory must end with a '/'
+    if (buf[i - 1] != '/') {
+      buf[i++] = '/';
+      mDirectory.mLen++;
+    }
+
+    i = AppendSegmentToBuf(buf, i, spec, basename, mBasename, &encBasename,
+                           useEncBasename, &diff);
+    ShiftFromExtension(diff);
+
+    // make corrections to directory segment if leadingSlash
+    if (leadingSlash) {
+      mDirectory.mPos = mPath.mPos;
+      if (mDirectory.mLen >= 0) {
+        mDirectory.mLen += leadingSlash;
+      } else {
+        mDirectory.mLen = 1;
+      }
+    }
+
+    if (mExtension.mLen >= 0) {
+      buf[i++] = '.';
+      i = AppendSegmentToBuf(buf, i, spec, extension, mExtension, &encExtension,
+                             useEncExtension, &diff);
+      ShiftFromQuery(diff);
+    }
+    // calculate corrected filepath length
+    mFilepath.mLen = i - mFilepath.mPos;
+
+    if (mQuery.mLen >= 0) {
+      buf[i++] = '?';
+      i = AppendSegmentToBuf(buf, i, spec, query, mQuery, &encQuery,
+                             useEncQuery, &diff);
+      ShiftFromRef(diff);
+    }
+    if (mRef.mLen >= 0) {
+      buf[i++] = '#';
+      i = AppendSegmentToBuf(buf, i, spec, ref, mRef, &encRef, useEncRef,
+                             &diff);
+    }
+    // calculate corrected path length
+    mPath.mLen = i - mPath.mPos;
+  }
+
+  buf[i] = '\0';
+
+  // https://url.spec.whatwg.org/#path-state (1.4.1.2)
+  // https://url.spec.whatwg.org/#windows-drive-letter
+  if (SegmentIs(buf, mScheme, "file")) {
+    char* path = &buf[mPath.mPos];
+    if (mPath.mLen >= 3 && path[0] == '/' && IsAsciiAlpha(path[1]) &&
+        path[2] == '|') {
+      buf[mPath.mPos + 2] = ':';
+    }
+  }
+
+  if (mDirectory.mLen > 1) {
+    netCoalesceFlags coalesceFlag = NET_COALESCE_NORMAL;
+    if (SegmentIs(buf, mScheme, "ftp")) {
+      coalesceFlag =
+          (netCoalesceFlags)(coalesceFlag | NET_COALESCE_ALLOW_RELATIVE_ROOT |
+                             NET_COALESCE_DOUBLE_SLASH_IS_ROOT);
+    }
+    CoalescePath(coalesceFlag, buf + mDirectory.mPos);
+  }
+  mSpec.Truncate(strlen(buf));
+  NS_ASSERTION(mSpec.Length() <= approxLen,
+               "We've overflowed the mSpec buffer!");
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
+             "The spec should never be this long, we missed a check.");
+
+  MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
+  return NS_OK;
+}
+
+bool nsStandardURL::SegmentIs(const URLSegment& seg, const char* val,
+                              bool ignoreCase) {
+  // one or both may be null
+  if (!val || mSpec.IsEmpty()) {
+    return (!val && (mSpec.IsEmpty() || seg.mLen < 0));
+  }
+  if (seg.mLen < 0) {
+    return false;
+  }
+  // if the first |seg.mLen| chars of |val| match, then |val| must
+  // also be null terminated at |seg.mLen|.
+  if (ignoreCase) {
+    return !nsCRT::strncasecmp(mSpec.get() + seg.mPos, val, seg.mLen) &&
+           (val[seg.mLen] == '\0');
+  }
+
+  return !strncmp(mSpec.get() + seg.mPos, val, seg.mLen) &&
+         (val[seg.mLen] == '\0');
+}
+
+bool nsStandardURL::SegmentIs(const char* spec, const URLSegment& seg,
+                              const char* val, bool ignoreCase) {
+  // one or both may be null
+  if (!val || !spec) {
+    return (!val && (!spec || seg.mLen < 0));
+  }
+  if (seg.mLen < 0) {
+    return false;
+  }
+  // if the first |seg.mLen| chars of |val| match, then |val| must
+  // also be null terminated at |seg.mLen|.
+  if (ignoreCase) {
+    return !nsCRT::strncasecmp(spec + seg.mPos, val, seg.mLen) &&
+           (val[seg.mLen] == '\0');
+  }
+
+  return !strncmp(spec + seg.mPos, val, seg.mLen) && (val[seg.mLen] == '\0');
+}
+
+bool nsStandardURL::SegmentIs(const URLSegment& seg1, const char* val,
+                              const URLSegment& seg2, bool ignoreCase) {
+  if (seg1.mLen != seg2.mLen) {
+    return false;
+  }
+  if (seg1.mLen == -1 || (!val && mSpec.IsEmpty())) {
+    return true;  // both are empty
+  }
+  if (!val) {
+    return false;
+  }
+  if (ignoreCase) {
+    return !nsCRT::strncasecmp(mSpec.get() + seg1.mPos, val + seg2.mPos,
+                               seg1.mLen);
+  }
+
+  return !strncmp(mSpec.get() + seg1.mPos, val + seg2.mPos, seg1.mLen);
+}
+
+int32_t nsStandardURL::ReplaceSegment(uint32_t pos, uint32_t len,
+                                      const char* val, uint32_t valLen) {
+  if (val && valLen) {
+    if (len == 0) {
+      mSpec.Insert(val, pos, valLen);
+    } else {
+      mSpec.Replace(pos, len, nsDependentCString(val, valLen));
+    }
+    return valLen - len;
+  }
+
+  // else remove the specified segment
+  mSpec.Cut(pos, len);
+  return -int32_t(len);
+}
+
+int32_t nsStandardURL::ReplaceSegment(uint32_t pos, uint32_t len,
+                                      const nsACString& val) {
+  if (len == 0) {
+    mSpec.Insert(val, pos);
+  } else {
+    mSpec.Replace(pos, len, val);
+  }
+  return val.Length() - len;
+}
+
+nsresult nsStandardURL::ParseURL(const char* spec, int32_t specLen) {
+  nsresult rv;
+
+  if (specLen > (int32_t)StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  //
+  // parse given URL string
+  //
+  uint32_t schemePos = mScheme.mPos;
+  int32_t schemeLen = mScheme.mLen;
+  uint32_t authorityPos = mAuthority.mPos;
+  int32_t authorityLen = mAuthority.mLen;
+  uint32_t pathPos = mPath.mPos;
+  int32_t pathLen = mPath.mLen;
+  rv = mParser->ParseURL(spec, specLen, &schemePos, &schemeLen, &authorityPos,
+                         &authorityLen, &pathPos, &pathLen);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mScheme.mPos = schemePos;
+  mScheme.mLen = schemeLen;
+  mAuthority.mPos = authorityPos;
+  mAuthority.mLen = authorityLen;
+  mPath.mPos = pathPos;
+  mPath.mLen = pathLen;
+
+#ifdef DEBUG
+  if (mScheme.mLen <= 0) {
+    printf("spec=%s\n", spec);
+    NS_WARNING("malformed url: no scheme");
+  }
+#endif
+
+  if (mAuthority.mLen > 0) {
+    uint32_t usernamePos = mUsername.mPos;
+    int32_t usernameLen = mUsername.mLen;
+    uint32_t passwordPos = mPassword.mPos;
+    int32_t passwordLen = mPassword.mLen;
+    uint32_t hostPos = mHost.mPos;
+    int32_t hostLen = mHost.mLen;
+    rv = mParser->ParseAuthority(spec + mAuthority.mPos, mAuthority.mLen,
+                                 &usernamePos, &usernameLen, &passwordPos,
+                                 &passwordLen, &hostPos, &hostLen, &mPort);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    mUsername.mPos = usernamePos;
+    mUsername.mLen = usernameLen;
+    mPassword.mPos = passwordPos;
+    mPassword.mLen = passwordLen;
+    mHost.mPos = hostPos;
+    mHost.mLen = hostLen;
+
+    // Don't allow mPort to be set to this URI's default port
+    if (mPort == mDefaultPort) {
+      mPort = -1;
+    }
+
+    mUsername.mPos += mAuthority.mPos;
+    mPassword.mPos += mAuthority.mPos;
+    mHost.mPos += mAuthority.mPos;
+  }
+
+  if (mPath.mLen > 0) {
+    rv = ParsePath(spec, mPath.mPos, mPath.mLen);
+  }
+
+  return rv;
+}
+
+nsresult nsStandardURL::ParsePath(const char* spec, uint32_t pathPos,
+                                  int32_t pathLen) {
+  LOG(("ParsePath: %s pathpos %d len %d\n", spec, pathPos, pathLen));
+
+  if (pathLen > (int32_t)StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  uint32_t filePathPos = mFilepath.mPos;
+  int32_t filePathLen = mFilepath.mLen;
+  uint32_t queryPos = mQuery.mPos;
+  int32_t queryLen = mQuery.mLen;
+  uint32_t refPos = mRef.mPos;
+  int32_t refLen = mRef.mLen;
+  nsresult rv =
+      mParser->ParsePath(spec + pathPos, pathLen, &filePathPos, &filePathLen,
+                         &queryPos, &queryLen, &refPos, &refLen);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mFilepath.mPos = filePathPos;
+  mFilepath.mLen = filePathLen;
+  mQuery.mPos = queryPos;
+  mQuery.mLen = queryLen;
+  mRef.mPos = refPos;
+  mRef.mLen = refLen;
+
+  mFilepath.mPos += pathPos;
+  mQuery.mPos += pathPos;
+  mRef.mPos += pathPos;
+
+  if (mFilepath.mLen > 0) {
+    uint32_t directoryPos = mDirectory.mPos;
+    int32_t directoryLen = mDirectory.mLen;
+    uint32_t basenamePos = mBasename.mPos;
+    int32_t basenameLen = mBasename.mLen;
+    uint32_t extensionPos = mExtension.mPos;
+    int32_t extensionLen = mExtension.mLen;
+    rv = mParser->ParseFilePath(spec + mFilepath.mPos, mFilepath.mLen,
+                                &directoryPos, &directoryLen, &basenamePos,
+                                &basenameLen, &extensionPos, &extensionLen);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    mDirectory.mPos = directoryPos;
+    mDirectory.mLen = directoryLen;
+    mBasename.mPos = basenamePos;
+    mBasename.mLen = basenameLen;
+    mExtension.mPos = extensionPos;
+    mExtension.mLen = extensionLen;
+
+    mDirectory.mPos += mFilepath.mPos;
+    mBasename.mPos += mFilepath.mPos;
+    mExtension.mPos += mFilepath.mPos;
+  }
+  return NS_OK;
+}
+
+char* nsStandardURL::AppendToSubstring(uint32_t pos, int32_t len,
+                                       const char* tail) {
+  // Verify pos and length are within boundaries
+  if (pos > mSpec.Length()) {
+    return nullptr;
+  }
+  if (len < 0) {
+    return nullptr;
+  }
+  if ((uint32_t)len > (mSpec.Length() - pos)) {
+    return nullptr;
+  }
+  if (!tail) {
+    return nullptr;
+  }
+
+  uint32_t tailLen = strlen(tail);
+
+  // Check for int overflow for proposed length of combined string
+  if (UINT32_MAX - ((uint32_t)len + 1) < tailLen) {
+    return nullptr;
+  }
+
+  char* result = (char*)moz_xmalloc(len + tailLen + 1);
+  memcpy(result, mSpec.get() + pos, len);
+  memcpy(result + len, tail, tailLen);
+  result[len + tailLen] = '\0';
+  return result;
+}
+
+nsresult nsStandardURL::ReadSegment(nsIBinaryInputStream* stream,
+                                    URLSegment& seg) {
+  nsresult rv;
+
+  uint32_t pos = seg.mPos;
+  rv = stream->Read32(&pos);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  seg.mPos = pos;
+
+  uint32_t len = seg.mLen;
+  rv = stream->Read32(&len);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  CheckedInt<int32_t> checkedLen(len);
+  if (!checkedLen.isValid()) {
+    seg.mLen = -1;
+  } else {
+    seg.mLen = len;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsStandardURL::WriteSegment(nsIBinaryOutputStream* stream,
+                                     const URLSegment& seg) {
+  nsresult rv;
+
+  rv = stream->Write32(seg.mPos);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->Write32(uint32_t(seg.mLen));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+#define SHIFT_FROM(name, what)                         \
+  void nsStandardURL::name(int32_t diff) {             \
+    if (!diff) return;                                 \
+    if ((what).mLen >= 0) {                            \
+      CheckedInt<int32_t> pos = (uint32_t)(what).mPos; \
+      pos += diff;                                     \
+      MOZ_ASSERT(pos.isValid());                       \
+      (what).mPos = pos.value();                       \
+    } else {                                           \
+      MOZ_RELEASE_ASSERT((what).mLen == -1);           \
+    }
+
+#define SHIFT_FROM_NEXT(name, what, next) \
+  SHIFT_FROM(name, what)                  \
+  next(diff);                             \
+  }
+
+#define SHIFT_FROM_LAST(name, what) \
+  SHIFT_FROM(name, what)            \
+  }
+
+SHIFT_FROM_NEXT(ShiftFromAuthority, mAuthority, ShiftFromUsername)
+SHIFT_FROM_NEXT(ShiftFromUsername, mUsername, ShiftFromPassword)
+SHIFT_FROM_NEXT(ShiftFromPassword, mPassword, ShiftFromHost)
+SHIFT_FROM_NEXT(ShiftFromHost, mHost, ShiftFromPath)
+SHIFT_FROM_NEXT(ShiftFromPath, mPath, ShiftFromFilepath)
+SHIFT_FROM_NEXT(ShiftFromFilepath, mFilepath, ShiftFromDirectory)
+SHIFT_FROM_NEXT(ShiftFromDirectory, mDirectory, ShiftFromBasename)
+SHIFT_FROM_NEXT(ShiftFromBasename, mBasename, ShiftFromExtension)
+SHIFT_FROM_NEXT(ShiftFromExtension, mExtension, ShiftFromQuery)
+SHIFT_FROM_NEXT(ShiftFromQuery, mQuery, ShiftFromRef)
+SHIFT_FROM_LAST(ShiftFromRef, mRef)
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsIClassInfo
+//----------------------------------------------------------------------------
+
+NS_IMPL_CLASSINFO(nsStandardURL, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_STANDARDURL_CID)
+// Empty CI getter. We only need nsIClassInfo for Serialization
+NS_IMPL_CI_INTERFACE_GETTER0(nsStandardURL)
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsISupports
+//----------------------------------------------------------------------------
+
+NS_IMPL_ADDREF(nsStandardURL)
+NS_IMPL_RELEASE(nsStandardURL)
+
+NS_INTERFACE_MAP_BEGIN(nsStandardURL)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIStandardURL)
+  NS_INTERFACE_MAP_ENTRY(nsIURI)
+  NS_INTERFACE_MAP_ENTRY(nsIURL)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIFileURL, mSupportsFileURL)
+  NS_INTERFACE_MAP_ENTRY(nsIStandardURL)
+  NS_INTERFACE_MAP_ENTRY(nsISerializable)
+  NS_IMPL_QUERY_CLASSINFO(nsStandardURL)
+  NS_INTERFACE_MAP_ENTRY(nsISensitiveInfoHiddenURI)
+  // see nsStandardURL::Equals
+  if (aIID.Equals(kThisImplCID)) {
+    foundInterface = static_cast<nsIURI*>(this);
+  } else
+    NS_INTERFACE_MAP_ENTRY(nsISizeOf)
+NS_INTERFACE_MAP_END
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsIURI
+//----------------------------------------------------------------------------
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetSpec(nsACString& result) {
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
+             "The spec should never be this long, we missed a check.");
+  result = mSpec;
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetSensitiveInfoHiddenSpec(nsACString& result) {
+  nsresult rv = GetSpec(result);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (mPassword.mLen > 0) {
+    result.ReplaceLiteral(mPassword.mPos, mPassword.mLen, "****");
+  }
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetSpecIgnoringRef(nsACString& result) {
+  // URI without ref is 0 to one char before ref
+  if (mRef.mLen < 0) {
+    return GetSpec(result);
+  }
+
+  URLSegment noRef(0, mRef.mPos - 1);
+  result = Segment(noRef);
+  MOZ_ASSERT(mCheckedIfHostA);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::CheckIfHostIsAscii() {
+  nsresult rv;
+  if (mCheckedIfHostA) {
+    return NS_OK;
+  }
+
+  mCheckedIfHostA = true;
+
+  if (!gIDN) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsAutoCString displayHost;
+  bool isAscii;
+  rv = gIDN->ConvertToDisplayIDN(Host(), &isAscii, displayHost);
+  if (NS_FAILED(rv)) {
+    mDisplayHost.Truncate();
+    mCheckedIfHostA = false;
+    return rv;
+  }
+
+  if (!isAscii) {
+    mDisplayHost = displayHost;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetDisplaySpec(nsACString& aUnicodeSpec) {
+  aUnicodeSpec.Assign(mSpec);
+  MOZ_ASSERT(mCheckedIfHostA);
+  if (!mDisplayHost.IsEmpty()) {
+    aUnicodeSpec.Replace(mHost.mPos, mHost.mLen, mDisplayHost);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetDisplayHostPort(nsACString& aUnicodeHostPort) {
+  nsAutoCString unicodeHostPort;
+
+  nsresult rv = GetDisplayHost(unicodeHostPort);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (StringBeginsWith(Hostport(), "["_ns)) {
+    aUnicodeHostPort.AssignLiteral("[");
+    aUnicodeHostPort.Append(unicodeHostPort);
+    aUnicodeHostPort.AppendLiteral("]");
+  } else {
+    aUnicodeHostPort.Assign(unicodeHostPort);
+  }
+
+  uint32_t pos = mHost.mPos + mHost.mLen;
+  if (pos < mPath.mPos) {
+    aUnicodeHostPort += Substring(mSpec, pos, mPath.mPos - pos);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetDisplayHost(nsACString& aUnicodeHost) {
+  MOZ_ASSERT(mCheckedIfHostA);
+  if (mDisplayHost.IsEmpty()) {
+    return GetAsciiHost(aUnicodeHost);
+  }
+
+  aUnicodeHost = mDisplayHost;
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetPrePath(nsACString& result) {
+  result = Prepath();
+  MOZ_ASSERT(mCheckedIfHostA);
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetDisplayPrePath(nsACString& result) {
+  result = Prepath();
+  MOZ_ASSERT(mCheckedIfHostA);
+  if (!mDisplayHost.IsEmpty()) {
+    result.Replace(mHost.mPos, mHost.mLen, mDisplayHost);
+  }
+  return NS_OK;
+}
+
+// result is strictly US-ASCII
+NS_IMETHODIMP
+nsStandardURL::GetScheme(nsACString& result) {
+  result = Scheme();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetUserPass(nsACString& result) {
+  result = Userpass();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetUsername(nsACString& result) {
+  result = Username();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetPassword(nsACString& result) {
+  result = Password();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetHostPort(nsACString& result) {
+  return GetAsciiHostPort(result);
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetHost(nsACString& result) { return GetAsciiHost(result); }
+
+NS_IMETHODIMP
+nsStandardURL::GetPort(int32_t* result) {
+  // should never be more than 16 bit
+  MOZ_ASSERT(mPort <= std::numeric_limits<uint16_t>::max());
+  *result = mPort;
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetPathQueryRef(nsACString& result) {
+  result = Path();
+  return NS_OK;
+}
+
+// result is ASCII
+NS_IMETHODIMP
+nsStandardURL::GetAsciiSpec(nsACString& result) {
+  result = mSpec;
+  return NS_OK;
+}
+
+// result is ASCII
+NS_IMETHODIMP
+nsStandardURL::GetAsciiHostPort(nsACString& result) {
+  result = Hostport();
+  return NS_OK;
+}
+
+// result is ASCII
+NS_IMETHODIMP
+nsStandardURL::GetAsciiHost(nsACString& result) {
+  result = Host();
+  return NS_OK;
+}
+
+static bool IsSpecialProtocol(const nsACString& input) {
+  nsACString::const_iterator start, end;
+  input.BeginReading(start);
+  nsACString::const_iterator iterator(start);
+  input.EndReading(end);
+
+  while (iterator != end && *iterator != ':') {
+    iterator++;
+  }
+
+  nsAutoCString protocol(nsDependentCSubstring(start.get(), iterator.get()));
+
+  return protocol.LowerCaseEqualsLiteral("http") ||
+         protocol.LowerCaseEqualsLiteral("https") ||
+         protocol.LowerCaseEqualsLiteral("ftp") ||
+         protocol.LowerCaseEqualsLiteral("ws") ||
+         protocol.LowerCaseEqualsLiteral("wss") ||
+         protocol.LowerCaseEqualsLiteral("file") ||
+         protocol.LowerCaseEqualsLiteral("gopher");
+}
+
+nsresult nsStandardURL::SetSpecInternal(const nsACString& input) {
+  return SetSpecWithEncoding(input, nullptr);
+}
+
+nsresult nsStandardURL::SetSpecWithEncoding(const nsACString& input,
+                                            const Encoding* encoding) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(input);
+  LOG(("nsStandardURL::SetSpec [spec=%s]\n", flat.get()));
+
+  if (input.Length() > StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  // filter out unexpected chars "\r\n\t" if necessary
+  nsAutoCString filteredURI;
+  net_FilterURIString(flat, filteredURI);
+
+  if (filteredURI.Length() == 0) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  // Make a backup of the current URL
+  nsStandardURL prevURL(false, false);
+  prevURL.CopyMembers(this, eHonorRef, ""_ns);
+  Clear();
+
+  if (IsSpecialProtocol(filteredURI)) {
+    // Bug 652186: Replace all backslashes with slashes when parsing paths
+    // Stop when we reach the query or the hash.
+    auto* start = filteredURI.BeginWriting();
+    auto* end = filteredURI.EndWriting();
+    while (start != end) {
+      if (*start == '?' || *start == '#') {
+        break;
+      }
+      if (*start == '\\') {
+        *start = '/';
+      }
+      start++;
+    }
+  }
+
+  const char* spec = filteredURI.get();
+  int32_t specLength = filteredURI.Length();
+
+  // parse the given URL...
+  nsresult rv = ParseURL(spec, specLength);
+  if (mScheme.mLen <= 0) {
+    rv = NS_ERROR_MALFORMED_URI;
+  }
+  if (NS_SUCCEEDED(rv)) {
+    // finally, use the URLSegment member variables to build a normalized
+    // copy of |spec|
+    rv = BuildNormalizedSpec(spec, encoding);
+  }
+
+  // Make sure that a URLTYPE_AUTHORITY has a non-empty hostname.
+  if (mURLType == URLTYPE_AUTHORITY && mHost.mLen == -1) {
+    rv = NS_ERROR_MALFORMED_URI;
+  }
+
+  if (NS_FAILED(rv)) {
+    Clear();
+    // If parsing the spec has failed, restore the old URL
+    // so we don't end up with an empty URL.
+    CopyMembers(&prevURL, eHonorRef, ""_ns);
+    return rv;
+  }
+
+  if (LOG_ENABLED()) {
+    LOG((" spec      = %s\n", mSpec.get()));
+    LOG((" port      = %d\n", mPort));
+    LOG((" scheme    = (%u,%d)\n", (uint32_t)mScheme.mPos,
+         (int32_t)mScheme.mLen));
+    LOG((" authority = (%u,%d)\n", (uint32_t)mAuthority.mPos,
+         (int32_t)mAuthority.mLen));
+    LOG((" username  = (%u,%d)\n", (uint32_t)mUsername.mPos,
+         (int32_t)mUsername.mLen));
+    LOG((" password  = (%u,%d)\n", (uint32_t)mPassword.mPos,
+         (int32_t)mPassword.mLen));
+    LOG((" hostname  = (%u,%d)\n", (uint32_t)mHost.mPos, (int32_t)mHost.mLen));
+    LOG((" path      = (%u,%d)\n", (uint32_t)mPath.mPos, (int32_t)mPath.mLen));
+    LOG((" filepath  = (%u,%d)\n", (uint32_t)mFilepath.mPos,
+         (int32_t)mFilepath.mLen));
+    LOG((" directory = (%u,%d)\n", (uint32_t)mDirectory.mPos,
+         (int32_t)mDirectory.mLen));
+    LOG((" basename  = (%u,%d)\n", (uint32_t)mBasename.mPos,
+         (int32_t)mBasename.mLen));
+    LOG((" extension = (%u,%d)\n", (uint32_t)mExtension.mPos,
+         (int32_t)mExtension.mLen));
+    LOG((" query     = (%u,%d)\n", (uint32_t)mQuery.mPos,
+         (int32_t)mQuery.mLen));
+    LOG((" ref       = (%u,%d)\n", (uint32_t)mRef.mPos, (int32_t)mRef.mLen));
+  }
+
+  SanityCheck();
+  return rv;
+}
+
+nsresult nsStandardURL::SetScheme(const nsACString& input) {
+  // Strip tabs, newlines, carriage returns from input
+  nsAutoCString scheme(input);
+  scheme.StripTaggedASCII(ASCIIMask::MaskCRLFTab());
+
+  LOG(("nsStandardURL::SetScheme [scheme=%s]\n", scheme.get()));
+
+  if (scheme.IsEmpty()) {
+    NS_WARNING("cannot remove the scheme from an url");
+    return NS_ERROR_UNEXPECTED;
+  }
+  if (mScheme.mLen < 0) {
+    NS_WARNING("uninitialized");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!net_IsValidScheme(scheme)) {
+    NS_WARNING("the given url scheme contains invalid characters");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mSpec.Length() + input.Length() - Scheme().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  InvalidateCache();
+
+  int32_t shift = ReplaceSegment(mScheme.mPos, mScheme.mLen, scheme);
+
+  if (shift) {
+    mScheme.mLen = scheme.Length();
+    ShiftFromAuthority(shift);
+  }
+
+  // ensure new scheme is lowercase
+  //
+  // XXX the string code unfortunately doesn't provide a ToLowerCase
+  //     that operates on a substring.
+  net_ToLowerCase((char*)mSpec.get(), mScheme.mLen);
+
+  // If the scheme changes the default port also changes.
+  if (Scheme() == "http"_ns || Scheme() == "ws"_ns) {
+    mDefaultPort = 80;
+  } else if (Scheme() == "https"_ns || Scheme() == "wss"_ns) {
+    mDefaultPort = 443;
+  }
+  if (mPort == mDefaultPort) {
+    MOZ_ALWAYS_SUCCEEDS(SetPort(-1));
+  }
+
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetUserPass(const nsACString& input) {
+  const nsPromiseFlatCString& userpass = PromiseFlatCString(input);
+
+  LOG(("nsStandardURL::SetUserPass [userpass=%s]\n", userpass.get()));
+
+  if (mURLType == URLTYPE_NO_AUTHORITY) {
+    if (userpass.IsEmpty()) {
+      return NS_OK;
+    }
+    NS_WARNING("cannot set user:pass on no-auth url");
+    return NS_ERROR_UNEXPECTED;
+  }
+  if (mAuthority.mLen < 0) {
+    NS_WARNING("uninitialized");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (mSpec.Length() + input.Length() - Userpass(true).Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+  InvalidateCache();
+
+  NS_ASSERTION(mHost.mLen >= 0, "uninitialized");
+
+  nsresult rv;
+  uint32_t usernamePos, passwordPos;
+  int32_t usernameLen, passwordLen;
+
+  rv = mParser->ParseUserInfo(userpass.get(), userpass.Length(), &usernamePos,
+                              &usernameLen, &passwordPos, &passwordLen);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // build new user:pass in |buf|
+  nsAutoCString buf;
+  if (usernameLen > 0 || passwordLen > 0) {
+    nsSegmentEncoder encoder;
+    bool ignoredOut;
+    usernameLen = encoder.EncodeSegmentCount(
+        userpass.get(), URLSegment(usernamePos, usernameLen),
+        esc_Username | esc_AlwaysCopy, buf, ignoredOut);
+    if (passwordLen > 0) {
+      buf.Append(':');
+      passwordLen = encoder.EncodeSegmentCount(
+          userpass.get(), URLSegment(passwordPos, passwordLen),
+          esc_Password | esc_AlwaysCopy, buf, ignoredOut);
+    } else {
+      passwordLen = -1;
+    }
+    if (mUsername.mLen < 0 && mPassword.mLen < 0) {
+      buf.Append('@');
+    }
+  }
+
+  int32_t shift = 0;
+
+  if (mUsername.mLen < 0 && mPassword.mLen < 0) {
+    // no existing user:pass
+    if (!buf.IsEmpty()) {
+      mSpec.Insert(buf, mHost.mPos);
+      mUsername.mPos = mHost.mPos;
+      shift = buf.Length();
+    }
+  } else {
+    // replace existing user:pass
+    uint32_t userpassLen = 0;
+    if (mUsername.mLen > 0) {
+      userpassLen += mUsername.mLen;
+    }
+    if (mPassword.mLen > 0) {
+      userpassLen += (mPassword.mLen + 1);
+    }
+    if (buf.IsEmpty()) {
+      // remove `@` character too
+      userpassLen++;
+    }
+    mSpec.Replace(mAuthority.mPos, userpassLen, buf);
+    shift = buf.Length() - userpassLen;
+  }
+  if (shift) {
+    ShiftFromHost(shift);
+    MOZ_DIAGNOSTIC_ASSERT(mAuthority.mLen >= -shift);
+    mAuthority.mLen += shift;
+  }
+  // update positions and lengths
+  mUsername.mLen = usernameLen > 0 ? usernameLen : -1;
+  mUsername.mPos = mAuthority.mPos;
+  mPassword.mLen = passwordLen > 0 ? passwordLen : -1;
+  if (passwordLen > 0) {
+    if (mUsername.mLen > 0) {
+      mPassword.mPos = mUsername.mPos + mUsername.mLen + 1;
+    } else {
+      mPassword.mPos = mAuthority.mPos + 1;
+    }
+  }
+
+  MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetUsername(const nsACString& input) {
+  const nsPromiseFlatCString& username = PromiseFlatCString(input);
+
+  LOG(("nsStandardURL::SetUsername [username=%s]\n", username.get()));
+
+  if (mURLType == URLTYPE_NO_AUTHORITY) {
+    if (username.IsEmpty()) {
+      return NS_OK;
+    }
+    NS_WARNING("cannot set username on no-auth url");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mSpec.Length() + input.Length() - Username().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  InvalidateCache();
+
+  // escape username if necessary
+  nsAutoCString buf;
+  nsSegmentEncoder encoder;
+  const nsACString& escUsername =
+      encoder.EncodeSegment(username, esc_Username, buf);
+
+  int32_t shift = 0;
+
+  if (mUsername.mLen < 0 && escUsername.IsEmpty()) {
+    return NS_OK;
+  }
+
+  if (mUsername.mLen < 0 && mPassword.mLen < 0) {
+    MOZ_ASSERT(!escUsername.IsEmpty(), "Should not be empty at this point");
+    mUsername.mPos = mAuthority.mPos;
+    mSpec.Insert(escUsername + "@"_ns, mUsername.mPos);
+    shift = escUsername.Length() + 1;
+    mUsername.mLen = escUsername.Length() > 0 ? escUsername.Length() : -1;
+  } else {
+    uint32_t pos = mUsername.mLen < 0 ? mAuthority.mPos : mUsername.mPos;
+    int32_t len = mUsername.mLen < 0 ? 0 : mUsername.mLen;
+
+    if (mPassword.mLen < 0 && escUsername.IsEmpty()) {
+      len++;  // remove the @ character too
+    }
+    shift = ReplaceSegment(pos, len, escUsername);
+    mUsername.mLen = escUsername.Length() > 0 ? escUsername.Length() : -1;
+    mUsername.mPos = pos;
+  }
+
+  if (shift) {
+    mAuthority.mLen += shift;
+    ShiftFromPassword(shift);
+  }
+
+  MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetPassword(const nsACString& input) {
+  const nsPromiseFlatCString& password = PromiseFlatCString(input);
+
+  auto clearedPassword = MakeScopeExit([&password, this]() {
+    // Check that if this method is called with the empty string then the
+    // password is definitely cleared when exiting this method.
+    if (password.IsEmpty()) {
+      MOZ_DIAGNOSTIC_ASSERT(this->Password().IsEmpty());
+    }
+    Unused << this;  // silence compiler -Wunused-lambda-capture
+  });
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  LOG(("nsStandardURL::SetPassword [password=%s]\n", password.get()));
+
+  if (mURLType == URLTYPE_NO_AUTHORITY) {
+    if (password.IsEmpty()) {
+      return NS_OK;
+    }
+    NS_WARNING("cannot set password on no-auth url");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (mSpec.Length() + input.Length() - Password().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  InvalidateCache();
+
+  if (password.IsEmpty()) {
+    if (mPassword.mLen > 0) {
+      // cut(":password")
+      int32_t len = mPassword.mLen;
+      if (mUsername.mLen < 0) {
+        len++;  // also cut the @ character
+      }
+      len++;  // for the : character
+      mSpec.Cut(mPassword.mPos - 1, len);
+      ShiftFromHost(-len);
+      mAuthority.mLen -= len;
+      mPassword.mLen = -1;
+    }
+    MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
+    return NS_OK;
+  }
+
+  // escape password if necessary
+  nsAutoCString buf;
+  nsSegmentEncoder encoder;
+  const nsACString& escPassword =
+      encoder.EncodeSegment(password, esc_Password, buf);
+
+  int32_t shift;
+
+  if (mPassword.mLen < 0) {
+    if (mUsername.mLen > 0) {
+      mPassword.mPos = mUsername.mPos + mUsername.mLen + 1;
+      mSpec.Insert(":"_ns + escPassword, mPassword.mPos - 1);
+      shift = escPassword.Length() + 1;
+    } else {
+      mPassword.mPos = mAuthority.mPos + 1;
+      mSpec.Insert(":"_ns + escPassword + "@"_ns, mPassword.mPos - 1);
+      shift = escPassword.Length() + 2;
+    }
+  } else {
+    shift = ReplaceSegment(mPassword.mPos, mPassword.mLen, escPassword);
+  }
+
+  if (shift) {
+    mPassword.mLen = escPassword.Length();
+    mAuthority.mLen += shift;
+    ShiftFromHost(shift);
+  }
+
+  MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
+  return NS_OK;
+}
+
+void nsStandardURL::FindHostLimit(nsACString::const_iterator& aStart,
+                                  nsACString::const_iterator& aEnd) {
+  for (int32_t i = 0; gHostLimitDigits[i]; ++i) {
+    nsACString::const_iterator c(aStart);
+    if (FindCharInReadable(gHostLimitDigits[i], c, aEnd)) {
+      aEnd = c;
+    }
+  }
+}
+
+// If aValue only has a host part and no port number, the port
+// will not be reset!!!
+nsresult nsStandardURL::SetHostPort(const nsACString& aValue) {
+  // We cannot simply call nsIURI::SetHost because that would treat the name as
+  // an IPv6 address (like http:://[server:443]/).  We also cannot call
+  // nsIURI::SetHostPort because that isn't implemented.  Sadfaces.
+
+  nsACString::const_iterator start, end;
+  aValue.BeginReading(start);
+  aValue.EndReading(end);
+  nsACString::const_iterator iter(start);
+  bool isIPv6 = false;
+
+  FindHostLimit(start, end);
+
+  if (*start == '[') {  // IPv6 address
+    if (!FindCharInReadable(']', iter, end)) {
+      // the ] character is missing
+      return NS_ERROR_MALFORMED_URI;
+    }
+    // iter now at the ']' character
+    isIPv6 = true;
+  } else {
+    nsACString::const_iterator iter2(start);
+    if (FindCharInReadable(']', iter2, end)) {
+      // if the first char isn't [ then there should be no ] character
+      return NS_ERROR_MALFORMED_URI;
+    }
+  }
+
+  FindCharInReadable(':', iter, end);
+
+  if (!isIPv6 && iter != end) {
+    nsACString::const_iterator iter2(iter);
+    iter2++;  // Skip over the first ':' character
+    if (FindCharInReadable(':', iter2, end)) {
+      // If there is more than one ':' character it suggests an IPv6
+      // The format should be [2001::1]:80 where the port is optional
+      return NS_ERROR_MALFORMED_URI;
+    }
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  nsresult rv = SetHost(Substring(start, iter));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (iter == end) {
+    // does not end in colon
+    return NS_OK;
+  }
+
+  iter++;  // advance over the colon
+  if (iter == end) {
+    // port number is missing
+    return NS_OK;
+  }
+
+  nsCString portStr(Substring(iter, end));
+  int32_t port = portStr.ToInteger(&rv);
+  if (NS_FAILED(rv)) {
+    // Failure parsing the port number
+    return NS_OK;
+  }
+
+  Unused << SetPort(port);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetHost(const nsACString& input) {
+  const nsPromiseFlatCString& hostname = PromiseFlatCString(input);
+
+  nsACString::const_iterator start, end;
+  hostname.BeginReading(start);
+  hostname.EndReading(end);
+
+  FindHostLimit(start, end);
+
+  const nsCString unescapedHost(Substring(start, end));
+  // Do percent decoding on the the input.
+  nsAutoCString flat;
+  NS_UnescapeURL(unescapedHost.BeginReading(), unescapedHost.Length(),
+                 esc_AlwaysCopy | esc_Host, flat);
+  const char* host = flat.get();
+
+  LOG(("nsStandardURL::SetHost [host=%s]\n", host));
+
+  if (mURLType == URLTYPE_NO_AUTHORITY) {
+    if (flat.IsEmpty()) {
+      return NS_OK;
+    }
+    NS_WARNING("cannot set host on no-auth url");
+    return NS_ERROR_UNEXPECTED;
+  }
+  if (flat.IsEmpty()) {
+    // Setting an empty hostname is not allowed for
+    // URLTYPE_STANDARD and URLTYPE_AUTHORITY.
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (strlen(host) < flat.Length()) {
+    return NS_ERROR_MALFORMED_URI;  // found embedded null
+  }
+
+  // For consistency with SetSpec/nsURLParsers, don't allow spaces
+  // in the hostname.
+  if (strchr(host, ' ')) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  if (mSpec.Length() + strlen(host) - Host().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+  InvalidateCache();
+
+  uint32_t len;
+  nsAutoCString hostBuf;
+  nsresult rv = NormalizeIDN(flat, hostBuf);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (!SegmentIs(mScheme, "resource") && !SegmentIs(mScheme, "chrome")) {
+    nsAutoCString ipString;
+    if (hostBuf.Length() > 0 && hostBuf.First() == '[' &&
+        hostBuf.Last() == ']' &&
+        ValidIPv6orHostname(hostBuf.get(), hostBuf.Length())) {
+      rv = (nsresult)rusturl_parse_ipv6addr(&hostBuf, &ipString);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      hostBuf = ipString;
+    } else if (NS_SUCCEEDED(NormalizeIPv4(hostBuf, ipString))) {
+      hostBuf = ipString;
+    }
+  }
+
+  // NormalizeIDN always copies if the call was successful
+  host = hostBuf.get();
+  len = hostBuf.Length();
+
+  if (!ValidIPv6orHostname(host, len)) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  if (mHost.mLen < 0) {
+    int port_length = 0;
+    if (mPort != -1) {
+      nsAutoCString buf;
+      buf.Assign(':');
+      buf.AppendInt(mPort);
+      port_length = buf.Length();
+    }
+    if (mAuthority.mLen > 0) {
+      mHost.mPos = mAuthority.mPos + mAuthority.mLen - port_length;
+      mHost.mLen = 0;
+    } else if (mScheme.mLen > 0) {
+      mHost.mPos = mScheme.mPos + mScheme.mLen + 3;
+      mHost.mLen = 0;
+    }
+  }
+
+  int32_t shift = ReplaceSegment(mHost.mPos, mHost.mLen, host, len);
+
+  if (shift) {
+    mHost.mLen = len;
+    mAuthority.mLen += shift;
+    ShiftFromPath(shift);
+  }
+
+  // Now canonicalize the host to lowercase
+  net_ToLowerCase(mSpec.BeginWriting() + mHost.mPos, mHost.mLen);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetPort(int32_t port) {
+  LOG(("nsStandardURL::SetPort [port=%d]\n", port));
+
+  if ((port == mPort) || (mPort == -1 && port == mDefaultPort)) {
+    return NS_OK;
+  }
+
+  // ports must be >= 0 and 16 bit
+  // -1 == use default
+  if (port < -1 || port > std::numeric_limits<uint16_t>::max()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  if (mURLType == URLTYPE_NO_AUTHORITY) {
+    NS_WARNING("cannot set port on no-auth url");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  InvalidateCache();
+  if (port == mDefaultPort) {
+    port = -1;
+  }
+
+  ReplacePortInSpec(port);
+
+  mPort = port;
+  return NS_OK;
+}
+
+/**
+ * Replaces the existing port in mSpec with aNewPort.
+ *
+ * The caller is responsible for:
+ *  - Calling InvalidateCache (since our mSpec is changing).
+ *  - Checking whether aNewPort is mDefaultPort (in which case the
+ *    caller should pass aNewPort=-1).
+ */
+void nsStandardURL::ReplacePortInSpec(int32_t aNewPort) {
+  NS_ASSERTION(aNewPort != mDefaultPort || mDefaultPort == -1,
+               "Caller should check its passed-in value and pass -1 instead of "
+               "mDefaultPort, to avoid encoding default port into mSpec");
+
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  // Create the (possibly empty) string that we're planning to replace:
+  nsAutoCString buf;
+  if (mPort != -1) {
+    buf.Assign(':');
+    buf.AppendInt(mPort);
+  }
+  // Find the position & length of that string:
+  const uint32_t replacedLen = buf.Length();
+  const uint32_t replacedStart =
+      mAuthority.mPos + mAuthority.mLen - replacedLen;
+
+  // Create the (possibly empty) replacement string:
+  if (aNewPort == -1) {
+    buf.Truncate();
+  } else {
+    buf.Assign(':');
+    buf.AppendInt(aNewPort);
+  }
+  // Perform the replacement:
+  mSpec.Replace(replacedStart, replacedLen, buf);
+
+  // Bookkeeping to reflect the new length:
+  int32_t shift = buf.Length() - replacedLen;
+  mAuthority.mLen += shift;
+  ShiftFromPath(shift);
+}
+
+nsresult nsStandardURL::SetPathQueryRef(const nsACString& input) {
+  const nsPromiseFlatCString& path = PromiseFlatCString(input);
+  LOG(("nsStandardURL::SetPathQueryRef [path=%s]\n", path.get()));
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  InvalidateCache();
+
+  if (!path.IsEmpty()) {
+    nsAutoCString spec;
+
+    spec.Assign(mSpec.get(), mPath.mPos);
+    if (path.First() != '/') {
+      spec.Append('/');
+    }
+    spec.Append(path);
+
+    return SetSpecInternal(spec);
+  }
+  if (mPath.mLen >= 1) {
+    mSpec.Cut(mPath.mPos + 1, mPath.mLen - 1);
+    // these contain only a '/'
+    mPath.mLen = 1;
+    mDirectory.mLen = 1;
+    mFilepath.mLen = 1;
+    // these are no longer defined
+    mBasename.mLen = -1;
+    mExtension.mLen = -1;
+    mQuery.mLen = -1;
+    mRef.mLen = -1;
+  }
+  return NS_OK;
+}
+
+// When updating this also update SubstitutingURL::Mutator
+// Queries this list of interfaces. If none match, it queries mURI.
+NS_IMPL_NSIURIMUTATOR_ISUPPORTS(nsStandardURL::Mutator, nsIURISetters,
+                                nsIURIMutator, nsIStandardURLMutator,
+                                nsIURLMutator, nsIFileURLMutator,
+                                nsISerializable)
+
+NS_IMETHODIMP
+nsStandardURL::Mutate(nsIURIMutator** aMutator) {
+  RefPtr<nsStandardURL::Mutator> mutator = new nsStandardURL::Mutator();
+  nsresult rv = mutator->InitFromURI(this);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mutator.forget(aMutator);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::Equals(nsIURI* unknownOther, bool* result) {
+  return EqualsInternal(unknownOther, eHonorRef, result);
+}
+
+NS_IMETHODIMP
+nsStandardURL::EqualsExceptRef(nsIURI* unknownOther, bool* result) {
+  return EqualsInternal(unknownOther, eIgnoreRef, result);
+}
+
+nsresult nsStandardURL::EqualsInternal(
+    nsIURI* unknownOther, nsStandardURL::RefHandlingEnum refHandlingMode,
+    bool* result) {
+  NS_ENSURE_ARG_POINTER(unknownOther);
+  MOZ_ASSERT(result, "null pointer");
+
+  RefPtr<nsStandardURL> other;
+  nsresult rv =
+      unknownOther->QueryInterface(kThisImplCID, getter_AddRefs(other));
+  if (NS_FAILED(rv)) {
+    *result = false;
+    return NS_OK;
+  }
+
+  // First, check whether one URIs is an nsIFileURL while the other
+  // is not.  If that's the case, they're different.
+  if (mSupportsFileURL != other->mSupportsFileURL) {
+    *result = false;
+    return NS_OK;
+  }
+
+  // Next check parts of a URI that, if different, automatically make the
+  // URIs different
+  if (!SegmentIs(mScheme, other->mSpec.get(), other->mScheme) ||
+      // Check for host manually, since conversion to file will
+      // ignore the host!
+      !SegmentIs(mHost, other->mSpec.get(), other->mHost) ||
+      !SegmentIs(mQuery, other->mSpec.get(), other->mQuery) ||
+      !SegmentIs(mUsername, other->mSpec.get(), other->mUsername) ||
+      !SegmentIs(mPassword, other->mSpec.get(), other->mPassword) ||
+      Port() != other->Port()) {
+    // No need to compare files or other URI parts -- these are different
+    // beasties
+    *result = false;
+    return NS_OK;
+  }
+
+  if (refHandlingMode == eHonorRef &&
+      !SegmentIs(mRef, other->mSpec.get(), other->mRef)) {
+    *result = false;
+    return NS_OK;
+  }
+
+  // Then check for exact identity of URIs.  If we have it, they're equal
+  if (SegmentIs(mDirectory, other->mSpec.get(), other->mDirectory) &&
+      SegmentIs(mBasename, other->mSpec.get(), other->mBasename) &&
+      SegmentIs(mExtension, other->mSpec.get(), other->mExtension)) {
+    *result = true;
+    return NS_OK;
+  }
+
+  // At this point, the URIs are not identical, but they only differ in the
+  // directory/filename/extension.  If these are file URLs, then get the
+  // corresponding file objects and compare those, since two filenames that
+  // differ, eg, only in case could still be equal.
+  if (mSupportsFileURL) {
+    // Assume not equal for failure cases... but failures in GetFile are
+    // really failures, more or less, so propagate them to caller.
+    *result = false;
+
+    rv = EnsureFile();
+    nsresult rv2 = other->EnsureFile();
+    // special case for resource:// urls that don't resolve to files
+    if (rv == NS_ERROR_NO_INTERFACE && rv == rv2) {
+      return NS_OK;
+    }
+
+    if (NS_FAILED(rv)) {
+      LOG(("nsStandardURL::Equals [this=%p spec=%s] failed to ensure file",
+           this, mSpec.get()));
+      return rv;
+    }
+    NS_ASSERTION(mFile, "EnsureFile() lied!");
+    rv = rv2;
+    if (NS_FAILED(rv)) {
+      LOG(
+          ("nsStandardURL::Equals [other=%p spec=%s] other failed to ensure "
+           "file",
+           other.get(), other->mSpec.get()));
+      return rv;
+    }
+    NS_ASSERTION(other->mFile, "EnsureFile() lied!");
+    return mFile->Equals(other->mFile, result);
+  }
+
+  // The URLs are not identical, and they do not correspond to the
+  // same file, so they are different.
+  *result = false;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::SchemeIs(const char* scheme, bool* result) {
+  MOZ_ASSERT(result, "null pointer");
+  if (!scheme) {
+    *result = false;
+    return NS_OK;
+  }
+
+  *result = SegmentIs(mScheme, scheme);
+  return NS_OK;
+}
+
+/* virtual */ nsStandardURL* nsStandardURL::StartClone() {
+  nsStandardURL* clone = new nsStandardURL();
+  return clone;
+}
+
+nsresult nsStandardURL::Clone(nsIURI** aURI) {
+  return CloneInternal(eHonorRef, ""_ns, aURI);
+}
+
+nsresult nsStandardURL::CloneInternal(
+    nsStandardURL::RefHandlingEnum aRefHandlingMode, const nsACString& aNewRef,
+    nsIURI** aClone)
+
+{
+  RefPtr<nsStandardURL> clone = StartClone();
+  if (!clone) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Copy local members into clone.
+  // Also copies the cached members mFile, mDisplayHost
+  clone->CopyMembers(this, aRefHandlingMode, aNewRef, true);
+
+  clone.forget(aClone);
+  return NS_OK;
+}
+
+nsresult nsStandardURL::CopyMembers(
+    nsStandardURL* source, nsStandardURL::RefHandlingEnum refHandlingMode,
+    const nsACString& newRef, bool copyCached) {
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  mSpec = source->mSpec;
+  mDefaultPort = source->mDefaultPort;
+  mPort = source->mPort;
+  mScheme = source->mScheme;
+  mAuthority = source->mAuthority;
+  mUsername = source->mUsername;
+  mPassword = source->mPassword;
+  mHost = source->mHost;
+  mPath = source->mPath;
+  mFilepath = source->mFilepath;
+  mDirectory = source->mDirectory;
+  mBasename = source->mBasename;
+  mExtension = source->mExtension;
+  mQuery = source->mQuery;
+  mRef = source->mRef;
+  mURLType = source->mURLType;
+  mParser = source->mParser;
+  mSupportsFileURL = source->mSupportsFileURL;
+  mCheckedIfHostA = source->mCheckedIfHostA;
+  mDisplayHost = source->mDisplayHost;
+
+  if (copyCached) {
+    mFile = source->mFile;
+  } else {
+    InvalidateCache(true);
+  }
+
+  if (refHandlingMode == eIgnoreRef) {
+    SetRef(""_ns);
+  } else if (refHandlingMode == eReplaceRef) {
+    SetRef(newRef);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::Resolve(const nsACString& in, nsACString& out) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(in);
+  // filter out unexpected chars "\r\n\t" if necessary
+  nsAutoCString buf;
+  net_FilterURIString(flat, buf);
+
+  const char* relpath = buf.get();
+  int32_t relpathLen = buf.Length();
+
+  char* result = nullptr;
+
+  LOG(("nsStandardURL::Resolve [this=%p spec=%s relpath=%s]\n", this,
+       mSpec.get(), relpath));
+
+  NS_ASSERTION(mParser, "no parser: unitialized");
+
+  // NOTE: there is no need for this function to produce normalized
+  // output.  normalization will occur when the result is used to
+  // initialize a nsStandardURL object.
+
+  if (mScheme.mLen < 0) {
+    NS_WARNING("unable to Resolve URL: this URL not initialized");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+  URLSegment scheme;
+  char* resultPath = nullptr;
+  bool relative = false;
+  uint32_t offset = 0;
+  netCoalesceFlags coalesceFlag = NET_COALESCE_NORMAL;
+
+  nsAutoCString baseProtocol(Scheme());
+  nsAutoCString protocol;
+  rv = net_ExtractURLScheme(buf, protocol);
+
+  // Normally, if we parse a scheme, then it's an absolute URI. But because
+  // we still support a deprecated form of relative URIs such as: http:file or
+  // http:/path/file we can't do that for all protocols.
+  // So we just make sure that if there a protocol, it's the same as the
+  // current one, otherwise we treat it as an absolute URI.
+  if (NS_SUCCEEDED(rv) && protocol != baseProtocol) {
+    out = buf;
+    return NS_OK;
+  }
+
+  // relative urls should never contain a host, so we always want to use
+  // the noauth url parser.
+  // use it to extract a possible scheme
+  uint32_t schemePos = scheme.mPos;
+  int32_t schemeLen = scheme.mLen;
+  rv = mParser->ParseURL(relpath, relpathLen, &schemePos, &schemeLen, nullptr,
+                         nullptr, nullptr, nullptr);
+
+  // if the parser fails (for example because there is no valid scheme)
+  // reset the scheme and assume a relative url
+  if (NS_FAILED(rv)) {
+    scheme.Reset();
+  }
+
+  scheme.mPos = schemePos;
+  scheme.mLen = schemeLen;
+
+  protocol.Assign(Segment(scheme));
+
+  // We need to do backslash replacement for the following cases:
+  // 1. The input is an absolute path with a http/https/ftp scheme
+  // 2. The input is a relative path, and the base URL has a http/https/ftp
+  // scheme
+  if ((protocol.IsEmpty() && IsSpecialProtocol(baseProtocol)) ||
+      IsSpecialProtocol(protocol)) {
+    auto* start = buf.BeginWriting();
+    auto* end = buf.EndWriting();
+    while (start != end) {
+      if (*start == '?' || *start == '#') {
+        break;
+      }
+      if (*start == '\\') {
+        *start = '/';
+      }
+      start++;
+    }
+  }
+
+  if (scheme.mLen >= 0) {
+    // add some flags to coalesceFlag if it is an ftp-url
+    // need this later on when coalescing the resulting URL
+    if (SegmentIs(relpath, scheme, "ftp", true)) {
+      coalesceFlag =
+          (netCoalesceFlags)(coalesceFlag | NET_COALESCE_ALLOW_RELATIVE_ROOT |
+                             NET_COALESCE_DOUBLE_SLASH_IS_ROOT);
+    }
+    // this URL appears to be absolute
+    // but try to find out more
+    if (SegmentIs(mScheme, relpath, scheme, true)) {
+      // mScheme and Scheme are the same
+      // but this can still be relative
+      if (strncmp(relpath + scheme.mPos + scheme.mLen, "://", 3) == 0) {
+        // now this is really absolute
+        // because a :// follows the scheme
+        result = NS_xstrdup(relpath);
+      } else {
+        // This is a deprecated form of relative urls like
+        // http:file or http:/path/file
+        // we will support it for now ...
+        relative = true;
+        offset = scheme.mLen + 1;
+      }
+    } else {
+      // the schemes are not the same, we are also done
+      // because we have to assume this is absolute
+      result = NS_xstrdup(relpath);
+    }
+  } else {
+    // add some flags to coalesceFlag if it is an ftp-url
+    // need this later on when coalescing the resulting URL
+    if (SegmentIs(mScheme, "ftp")) {
+      coalesceFlag =
+          (netCoalesceFlags)(coalesceFlag | NET_COALESCE_ALLOW_RELATIVE_ROOT |
+                             NET_COALESCE_DOUBLE_SLASH_IS_ROOT);
+    }
+    if (relpath[0] == '/' && relpath[1] == '/') {
+      // this URL //host/path is almost absolute
+      result = AppendToSubstring(mScheme.mPos, mScheme.mLen + 1, relpath);
+    } else {
+      // then it must be relative
+      relative = true;
+    }
+  }
+  if (relative) {
+    uint32_t len = 0;
+    const char* realrelpath = relpath + offset;
+    switch (*realrelpath) {
+      case '/':
+        // overwrite everything after the authority
+        len = mAuthority.mPos + mAuthority.mLen;
+        break;
+      case '?':
+        // overwrite the existing ?query and #ref
+        if (mQuery.mLen >= 0) {
+          len = mQuery.mPos - 1;
+        } else if (mRef.mLen >= 0) {
+          len = mRef.mPos - 1;
+        } else {
+          len = mPath.mPos + mPath.mLen;
+        }
+        break;
+      case '#':
+      case '\0':
+        // overwrite the existing #ref
+        if (mRef.mLen < 0) {
+          len = mPath.mPos + mPath.mLen;
+        } else {
+          len = mRef.mPos - 1;
+        }
+        break;
+      default:
+        if (coalesceFlag & NET_COALESCE_DOUBLE_SLASH_IS_ROOT) {
+          if (Filename().Equals("%2F"_ns, nsCaseInsensitiveCStringComparator)) {
+            // if ftp URL ends with %2F then simply
+            // append relative part because %2F also
+            // marks the root directory with ftp-urls
+            len = mFilepath.mPos + mFilepath.mLen;
+          } else {
+            // overwrite everything after the directory
+            len = mDirectory.mPos + mDirectory.mLen;
+          }
+        } else {
+          // overwrite everything after the directory
+          len = mDirectory.mPos + mDirectory.mLen;
+        }
+    }
+    result = AppendToSubstring(0, len, realrelpath);
+    // locate result path
+    resultPath = result + mPath.mPos;
+  }
+  if (!result) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  if (resultPath) {
+    net_CoalesceDirs(coalesceFlag, resultPath);
+  } else {
+    // locate result path
+    resultPath = strstr(result, "://");
+    if (resultPath) {
+      // If there are multiple slashes after :// we must ignore them
+      // otherwise net_CoalesceDirs may think the host is a part of the path.
+      resultPath += 3;
+      if (protocol.IsEmpty() && Scheme() != "file") {
+        while (*resultPath == '/') {
+          resultPath++;
+        }
+      }
+      resultPath = strchr(resultPath, '/');
+      if (resultPath) {
+        net_CoalesceDirs(coalesceFlag, resultPath);
+      }
+    }
+  }
+  out.Adopt(result);
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetCommonBaseSpec(nsIURI* uri2, nsACString& aResult) {
+  NS_ENSURE_ARG_POINTER(uri2);
+
+  // if uri's are equal, then return uri as is
+  bool isEquals = false;
+  if (NS_SUCCEEDED(Equals(uri2, &isEquals)) && isEquals) {
+    return GetSpec(aResult);
+  }
+
+  aResult.Truncate();
+
+  // check pre-path; if they don't match, then return empty string
+  RefPtr<nsStandardURL> stdurl2;
+  nsresult rv = uri2->QueryInterface(kThisImplCID, getter_AddRefs(stdurl2));
+  isEquals = NS_SUCCEEDED(rv) &&
+             SegmentIs(mScheme, stdurl2->mSpec.get(), stdurl2->mScheme) &&
+             SegmentIs(mHost, stdurl2->mSpec.get(), stdurl2->mHost) &&
+             SegmentIs(mUsername, stdurl2->mSpec.get(), stdurl2->mUsername) &&
+             SegmentIs(mPassword, stdurl2->mSpec.get(), stdurl2->mPassword) &&
+             (Port() == stdurl2->Port());
+  if (!isEquals) {
+    return NS_OK;
+  }
+
+  // scan for first mismatched character
+  const char *thisIndex, *thatIndex, *startCharPos;
+  startCharPos = mSpec.get() + mDirectory.mPos;
+  thisIndex = startCharPos;
+  thatIndex = stdurl2->mSpec.get() + mDirectory.mPos;
+  while ((*thisIndex == *thatIndex) && *thisIndex) {
+    thisIndex++;
+    thatIndex++;
+  }
+
+  // backup to just after previous slash so we grab an appropriate path
+  // segment such as a directory (not partial segments)
+  // todo:  also check for file matches which include '?' and '#'
+  while ((thisIndex != startCharPos) && (*(thisIndex - 1) != '/')) {
+    thisIndex--;
+  }
+
+  // grab spec from beginning to thisIndex
+  aResult = Substring(mSpec, mScheme.mPos, thisIndex - mSpec.get());
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetRelativeSpec(nsIURI* uri2, nsACString& aResult) {
+  NS_ENSURE_ARG_POINTER(uri2);
+
+  aResult.Truncate();
+
+  // if uri's are equal, then return empty string
+  bool isEquals = false;
+  if (NS_SUCCEEDED(Equals(uri2, &isEquals)) && isEquals) {
+    return NS_OK;
+  }
+
+  RefPtr<nsStandardURL> stdurl2;
+  nsresult rv = uri2->QueryInterface(kThisImplCID, getter_AddRefs(stdurl2));
+  isEquals = NS_SUCCEEDED(rv) &&
+             SegmentIs(mScheme, stdurl2->mSpec.get(), stdurl2->mScheme) &&
+             SegmentIs(mHost, stdurl2->mSpec.get(), stdurl2->mHost) &&
+             SegmentIs(mUsername, stdurl2->mSpec.get(), stdurl2->mUsername) &&
+             SegmentIs(mPassword, stdurl2->mSpec.get(), stdurl2->mPassword) &&
+             (Port() == stdurl2->Port());
+  if (!isEquals) {
+    return uri2->GetSpec(aResult);
+  }
+
+  // scan for first mismatched character
+  const char *thisIndex, *thatIndex, *startCharPos;
+  startCharPos = mSpec.get() + mDirectory.mPos;
+  thisIndex = startCharPos;
+  thatIndex = stdurl2->mSpec.get() + mDirectory.mPos;
+
+#ifdef XP_WIN
+  bool isFileScheme = SegmentIs(mScheme, "file");
+  if (isFileScheme) {
+    // on windows, we need to match the first segment of the path
+    // if these don't match then we need to return an absolute path
+    // skip over any leading '/' in path
+    while ((*thisIndex == *thatIndex) && (*thisIndex == '/')) {
+      thisIndex++;
+      thatIndex++;
+    }
+    // look for end of first segment
+    while ((*thisIndex == *thatIndex) && *thisIndex && (*thisIndex != '/')) {
+      thisIndex++;
+      thatIndex++;
+    }
+
+    // if we didn't match through the first segment, return absolute path
+    if ((*thisIndex != '/') || (*thatIndex != '/')) {
+      return uri2->GetSpec(aResult);
+    }
+  }
+#endif
+
+  while ((*thisIndex == *thatIndex) && *thisIndex) {
+    thisIndex++;
+    thatIndex++;
+  }
+
+  // backup to just after previous slash so we grab an appropriate path
+  // segment such as a directory (not partial segments)
+  // todo:  also check for file matches with '#' and '?'
+  while ((*(thatIndex - 1) != '/') && (thatIndex != startCharPos)) {
+    thatIndex--;
+  }
+
+  const char* limit = mSpec.get() + mFilepath.mPos + mFilepath.mLen;
+
+  // need to account for slashes and add corresponding "../"
+  for (; thisIndex <= limit && *thisIndex; ++thisIndex) {
+    if (*thisIndex == '/') {
+      aResult.AppendLiteral("../");
+    }
+  }
+
+  // grab spec from thisIndex to end
+  uint32_t startPos = stdurl2->mScheme.mPos + thatIndex - stdurl2->mSpec.get();
+  aResult.Append(
+      Substring(stdurl2->mSpec, startPos, stdurl2->mSpec.Length() - startPos));
+
+  return rv;
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsIURL
+//----------------------------------------------------------------------------
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetFilePath(nsACString& result) {
+  result = Filepath();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetQuery(nsACString& result) {
+  result = Query();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetRef(nsACString& result) {
+  result = Ref();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetHasRef(bool* result) {
+  *result = (mRef.mLen >= 0);
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetDirectory(nsACString& result) {
+  result = Directory();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetFileName(nsACString& result) {
+  result = Filename();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetFileBaseName(nsACString& result) {
+  result = Basename();
+  return NS_OK;
+}
+
+// result may contain unescaped UTF-8 characters
+NS_IMETHODIMP
+nsStandardURL::GetFileExtension(nsACString& result) {
+  result = Extension();
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetFilePath(const nsACString& input) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(input);
+  const char* filepath = flat.get();
+
+  LOG(("nsStandardURL::SetFilePath [filepath=%s]\n", filepath));
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  // if there isn't a filepath, then there can't be anything
+  // after the path either.  this url is likely uninitialized.
+  if (mFilepath.mLen < 0) {
+    return SetPathQueryRef(flat);
+  }
+
+  if (filepath && *filepath) {
+    nsAutoCString spec;
+    uint32_t dirPos, basePos, extPos;
+    int32_t dirLen, baseLen, extLen;
+    nsresult rv;
+
+    rv = mParser->ParseFilePath(filepath, flat.Length(), &dirPos, &dirLen,
+                                &basePos, &baseLen, &extPos, &extLen);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // build up new candidate spec
+    spec.Assign(mSpec.get(), mPath.mPos);
+
+    // ensure leading '/'
+    if (filepath[dirPos] != '/') {
+      spec.Append('/');
+    }
+
+    nsSegmentEncoder encoder;
+
+    // append encoded filepath components
+    if (dirLen > 0) {
+      encoder.EncodeSegment(
+          Substring(filepath + dirPos, filepath + dirPos + dirLen),
+          esc_Directory | esc_AlwaysCopy, spec);
+    }
+    if (baseLen > 0) {
+      encoder.EncodeSegment(
+          Substring(filepath + basePos, filepath + basePos + baseLen),
+          esc_FileBaseName | esc_AlwaysCopy, spec);
+    }
+    if (extLen >= 0) {
+      spec.Append('.');
+      if (extLen > 0) {
+        encoder.EncodeSegment(
+            Substring(filepath + extPos, filepath + extPos + extLen),
+            esc_FileExtension | esc_AlwaysCopy, spec);
+      }
+    }
+
+    // compute the ending position of the current filepath
+    if (mFilepath.mLen >= 0) {
+      uint32_t end = mFilepath.mPos + mFilepath.mLen;
+      if (mSpec.Length() > end) {
+        spec.Append(mSpec.get() + end, mSpec.Length() - end);
+      }
+    }
+
+    return SetSpecInternal(spec);
+  }
+  if (mPath.mLen > 1) {
+    mSpec.Cut(mPath.mPos + 1, mFilepath.mLen - 1);
+    // left shift query, and ref
+    ShiftFromQuery(1 - mFilepath.mLen);
+    // One character for '/', and if we have a query or ref we add their
+    // length and one extra for each '?' or '#' characters
+    mPath.mLen = 1 + (mQuery.mLen >= 0 ? (mQuery.mLen + 1) : 0) +
+                 (mRef.mLen >= 0 ? (mRef.mLen + 1) : 0);
+    // these contain only a '/'
+    mDirectory.mLen = 1;
+    mFilepath.mLen = 1;
+    // these are no longer defined
+    mBasename.mLen = -1;
+    mExtension.mLen = -1;
+  }
+  return NS_OK;
+}
+
+inline bool IsUTFEncoding(const Encoding* aEncoding) {
+  return aEncoding == UTF_8_ENCODING || aEncoding == UTF_16BE_ENCODING ||
+         aEncoding == UTF_16LE_ENCODING;
+}
+
+nsresult nsStandardURL::SetQuery(const nsACString& input) {
+  return SetQueryWithEncoding(input, nullptr);
+}
+
+nsresult nsStandardURL::SetQueryWithEncoding(const nsACString& input,
+                                             const Encoding* encoding) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(input);
+  const char* query = flat.get();
+
+  LOG(("nsStandardURL::SetQuery [query=%s]\n", query));
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  if (IsUTFEncoding(encoding)) {
+    encoding = nullptr;
+  }
+
+  if (mPath.mLen < 0) {
+    return SetPathQueryRef(flat);
+  }
+
+  if (mSpec.Length() + input.Length() - Query().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  InvalidateCache();
+
+  if (!query || !*query) {
+    // remove existing query
+    if (mQuery.mLen >= 0) {
+      // remove query and leading '?'
+      mSpec.Cut(mQuery.mPos - 1, mQuery.mLen + 1);
+      ShiftFromRef(-(mQuery.mLen + 1));
+      mPath.mLen -= (mQuery.mLen + 1);
+      mQuery.mPos = 0;
+      mQuery.mLen = -1;
+    }
+    return NS_OK;
+  }
+
+  // filter out unexpected chars "\r\n\t" if necessary
+  nsAutoCString filteredURI(flat);
+  const ASCIIMaskArray& mask = ASCIIMask::MaskCRLFTab();
+  filteredURI.StripTaggedASCII(mask);
+
+  query = filteredURI.get();
+  int32_t queryLen = filteredURI.Length();
+  if (query[0] == '?') {
+    query++;
+    queryLen--;
+  }
+
+  if (mQuery.mLen < 0) {
+    if (mRef.mLen < 0) {
+      mQuery.mPos = mSpec.Length();
+    } else {
+      mQuery.mPos = mRef.mPos - 1;
+    }
+    mSpec.Insert('?', mQuery.mPos);
+    mQuery.mPos++;
+    mQuery.mLen = 0;
+    // the insertion pushes these out by 1
+    mPath.mLen++;
+    mRef.mPos++;
+  }
+
+  // encode query if necessary
+  nsAutoCString buf;
+  bool encoded;
+  nsSegmentEncoder encoder(encoding);
+  encoder.EncodeSegmentCount(query, URLSegment(0, queryLen), esc_Query, buf,
+                             encoded);
+  if (encoded) {
+    query = buf.get();
+    queryLen = buf.Length();
+  }
+
+  int32_t shift = ReplaceSegment(mQuery.mPos, mQuery.mLen, query, queryLen);
+
+  if (shift) {
+    mQuery.mLen = queryLen;
+    mPath.mLen += shift;
+    ShiftFromRef(shift);
+  }
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetRef(const nsACString& input) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(input);
+  const char* ref = flat.get();
+
+  LOG(("nsStandardURL::SetRef [ref=%s]\n", ref));
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  if (mPath.mLen < 0) {
+    return SetPathQueryRef(flat);
+  }
+
+  if (mSpec.Length() + input.Length() - Ref().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  InvalidateCache();
+
+  if (input.IsEmpty()) {
+    // remove existing ref
+    if (mRef.mLen >= 0) {
+      // remove ref and leading '#'
+      mSpec.Cut(mRef.mPos - 1, mRef.mLen + 1);
+      mPath.mLen -= (mRef.mLen + 1);
+      mRef.mPos = 0;
+      mRef.mLen = -1;
+    }
+    return NS_OK;
+  }
+
+  // filter out unexpected chars "\r\n\t" if necessary
+  nsAutoCString filteredURI(flat);
+  const ASCIIMaskArray& mask = ASCIIMask::MaskCRLFTab();
+  filteredURI.StripTaggedASCII(mask);
+
+  ref = filteredURI.get();
+  int32_t refLen = filteredURI.Length();
+  if (ref[0] == '#') {
+    ref++;
+    refLen--;
+  }
+
+  if (mRef.mLen < 0) {
+    mSpec.Append('#');
+    ++mPath.mLen;  // Include the # in the path.
+    mRef.mPos = mSpec.Length();
+    mRef.mLen = 0;
+  }
+
+  // If precent encoding is necessary, `ref` will point to `buf`'s content.
+  // `buf` needs to outlive any use of the `ref` pointer.
+  nsAutoCString buf;
+  // encode ref if necessary
+  bool encoded;
+  nsSegmentEncoder encoder;
+  encoder.EncodeSegmentCount(ref, URLSegment(0, refLen), esc_Ref, buf, encoded);
+  if (encoded) {
+    ref = buf.get();
+    refLen = buf.Length();
+  }
+
+  int32_t shift = ReplaceSegment(mRef.mPos, mRef.mLen, ref, refLen);
+  mPath.mLen += shift;
+  mRef.mLen = refLen;
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetFileNameInternal(const nsACString& input) {
+  const nsPromiseFlatCString& flat = PromiseFlatCString(input);
+  const char* filename = flat.get();
+
+  LOG(("nsStandardURL::SetFileNameInternal [filename=%s]\n", filename));
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+
+  if (mPath.mLen < 0) {
+    return SetPathQueryRef(flat);
+  }
+
+  if (mSpec.Length() + input.Length() - Filename().Length() >
+      StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  int32_t shift = 0;
+
+  if (!(filename && *filename)) {
+    // remove the filename
+    if (mBasename.mLen > 0) {
+      if (mExtension.mLen >= 0) {
+        mBasename.mLen += (mExtension.mLen + 1);
+      }
+      mSpec.Cut(mBasename.mPos, mBasename.mLen);
+      shift = -mBasename.mLen;
+      mBasename.mLen = 0;
+      mExtension.mLen = -1;
+    }
+  } else {
+    nsresult rv;
+    uint32_t basenamePos = 0;
+    int32_t basenameLen = -1;
+    uint32_t extensionPos = 0;
+    int32_t extensionLen = -1;
+    // let the parser locate the basename and extension
+    rv = mParser->ParseFileName(filename, flat.Length(), &basenamePos,
+                                &basenameLen, &extensionPos, &extensionLen);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    URLSegment basename(basenamePos, basenameLen);
+    URLSegment extension(extensionPos, extensionLen);
+
+    if (basename.mLen < 0) {
+      // remove existing filename
+      if (mBasename.mLen >= 0) {
+        uint32_t len = mBasename.mLen;
+        if (mExtension.mLen >= 0) {
+          len += (mExtension.mLen + 1);
+        }
+        mSpec.Cut(mBasename.mPos, len);
+        shift = -int32_t(len);
+        mBasename.mLen = 0;
+        mExtension.mLen = -1;
+      }
+    } else {
+      nsAutoCString newFilename;
+      bool ignoredOut;
+      nsSegmentEncoder encoder;
+      basename.mLen = encoder.EncodeSegmentCount(
+          filename, basename, esc_FileBaseName | esc_AlwaysCopy, newFilename,
+          ignoredOut);
+      if (extension.mLen >= 0) {
+        newFilename.Append('.');
+        extension.mLen = encoder.EncodeSegmentCount(
+            filename, extension, esc_FileExtension | esc_AlwaysCopy,
+            newFilename, ignoredOut);
+      }
+
+      if (mBasename.mLen < 0) {
+        // insert new filename
+        mBasename.mPos = mDirectory.mPos + mDirectory.mLen;
+        mSpec.Insert(newFilename, mBasename.mPos);
+        shift = newFilename.Length();
+      } else {
+        // replace existing filename
+        uint32_t oldLen = uint32_t(mBasename.mLen);
+        if (mExtension.mLen >= 0) {
+          oldLen += (mExtension.mLen + 1);
+        }
+        mSpec.Replace(mBasename.mPos, oldLen, newFilename);
+        shift = newFilename.Length() - oldLen;
+      }
+
+      mBasename.mLen = basename.mLen;
+      mExtension.mLen = extension.mLen;
+      if (mExtension.mLen >= 0) {
+        mExtension.mPos = mBasename.mPos + mBasename.mLen + 1;
+      }
+    }
+  }
+  if (shift) {
+    ShiftFromQuery(shift);
+    mFilepath.mLen += shift;
+    mPath.mLen += shift;
+  }
+  return NS_OK;
+}
+
+nsresult nsStandardURL::SetFileBaseNameInternal(const nsACString& input) {
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+  nsAutoCString extension;
+  nsresult rv = GetFileExtension(extension);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString newFileName(input);
+
+  if (!extension.IsEmpty()) {
+    newFileName.Append('.');
+    newFileName.Append(extension);
+  }
+
+  return SetFileNameInternal(newFileName);
+}
+
+nsresult nsStandardURL::SetFileExtensionInternal(const nsACString& input) {
+  auto onExitGuard = MakeScopeExit([&] { SanityCheck(); });
+  nsAutoCString newFileName;
+  nsresult rv = GetFileBaseName(newFileName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!input.IsEmpty()) {
+    newFileName.Append('.');
+    newFileName.Append(input);
+  }
+
+  return SetFileNameInternal(newFileName);
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsIFileURL
+//----------------------------------------------------------------------------
+
+nsresult nsStandardURL::EnsureFile() {
+  MOZ_ASSERT(mSupportsFileURL,
+             "EnsureFile() called on a URL that doesn't support files!");
+
+  if (mFile) {
+    // Nothing to do
+    return NS_OK;
+  }
+
+  // Parse the spec if we don't have a cached result
+  if (mSpec.IsEmpty()) {
+    NS_WARNING("url not initialized");
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!SegmentIs(mScheme, "file")) {
+    NS_WARNING("not a file URL");
+    return NS_ERROR_FAILURE;
+  }
+
+  return net_GetFileFromURLSpec(mSpec, getter_AddRefs(mFile));
+}
+
+NS_IMETHODIMP
+nsStandardURL::GetFile(nsIFile** result) {
+  MOZ_ASSERT(mSupportsFileURL,
+             "GetFile() called on a URL that doesn't support files!");
+
+  nsresult rv = EnsureFile();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (LOG_ENABLED()) {
+    LOG(("nsStandardURL::GetFile [this=%p spec=%s resulting_path=%s]\n", this,
+         mSpec.get(), mFile->HumanReadablePath().get()));
+  }
+
+  // clone the file, so the caller can modify it.
+  // XXX nsIFileURL.idl specifies that the consumer must _not_ modify the
+  // nsIFile returned from this method; but it seems that some folks do
+  // (see bug 161921). until we can be sure that all the consumers are
+  // behaving themselves, we'll stay on the safe side and clone the file.
+  // see bug 212724 about fixing the consumers.
+  return mFile->Clone(result);
+}
+
+nsresult nsStandardURL::SetFile(nsIFile* file) {
+  NS_ENSURE_ARG_POINTER(file);
+
+  nsresult rv;
+  nsAutoCString url;
+
+  rv = net_GetURLSpecFromFile(file, url);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  uint32_t oldURLType = mURLType;
+  uint32_t oldDefaultPort = mDefaultPort;
+  rv = Init(nsIStandardURL::URLTYPE_NO_AUTHORITY, -1, url, nullptr, nullptr);
+
+  if (NS_FAILED(rv)) {
+    // Restore the old url type and default port if the call to Init fails.
+    mURLType = oldURLType;
+    mDefaultPort = oldDefaultPort;
+    return rv;
+  }
+
+  // must clone |file| since its value is not guaranteed to remain constant
+  InvalidateCache();
+  if (NS_FAILED(file->Clone(getter_AddRefs(mFile)))) {
+    NS_WARNING("nsIFile::Clone failed");
+    // failure to clone is not fatal (GetFile will generate mFile)
+    mFile = nullptr;
+  }
+
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsIStandardURL
+//----------------------------------------------------------------------------
+
+nsresult nsStandardURL::Init(uint32_t urlType, int32_t defaultPort,
+                             const nsACString& spec, const char* charset,
+                             nsIURI* baseURI) {
+  if (spec.Length() > StaticPrefs::network_standard_url_max_length() ||
+      defaultPort > std::numeric_limits<uint16_t>::max()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  InvalidateCache();
+
+  switch (urlType) {
+    case URLTYPE_STANDARD:
+      mParser = net_GetStdURLParser();
+      break;
+    case URLTYPE_AUTHORITY:
+      mParser = net_GetAuthURLParser();
+      break;
+    case URLTYPE_NO_AUTHORITY:
+      mParser = net_GetNoAuthURLParser();
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("bad urlType");
+      return NS_ERROR_INVALID_ARG;
+  }
+  mDefaultPort = defaultPort;
+  mURLType = urlType;
+
+  const auto* encoding =
+      charset ? Encoding::ForLabelNoReplacement(MakeStringSpan(charset))
+              : nullptr;
+  // URI can't be encoded in UTF-16BE or UTF-16LE. Truncate encoding
+  // if it is one of utf encodings (since a null encoding implies
+  // UTF-8, this is safe even if encoding is UTF-8).
+  if (IsUTFEncoding(encoding)) {
+    encoding = nullptr;
+  }
+
+  if (baseURI && net_IsAbsoluteURL(spec)) {
+    baseURI = nullptr;
+  }
+
+  if (!baseURI) {
+    return SetSpecWithEncoding(spec, encoding);
+  }
+
+  nsAutoCString buf;
+  nsresult rv = baseURI->Resolve(spec, buf);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return SetSpecWithEncoding(buf, encoding);
+}
+
+nsresult nsStandardURL::SetDefaultPort(int32_t aNewDefaultPort) {
+  InvalidateCache();
+
+  // should never be more than 16 bit
+  if (aNewDefaultPort >= std::numeric_limits<uint16_t>::max()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  // If we're already using the new default-port as a custom port, then clear
+  // it off of our mSpec & set mPort to -1, to indicate that we'll be using
+  // the default from now on (which happens to match what we already had).
+  if (mPort == aNewDefaultPort) {
+    ReplacePortInSpec(-1);
+    mPort = -1;
+  }
+  mDefaultPort = aNewDefaultPort;
+
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsISerializable
+//----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsStandardURL::Read(nsIObjectInputStream* stream) {
+  MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsStandardURL::ReadPrivate(nsIObjectInputStream* stream) {
+  MOZ_ASSERT(mDisplayHost.IsEmpty(), "Shouldn't have cached unicode host");
+
+  // If we exit early, make sure to clear the URL so we don't fail the sanity
+  // check in the destructor
+  auto clearOnExit = MakeScopeExit([&] { Clear(); });
+
+  nsresult rv;
+
+  uint32_t urlType;
+  rv = stream->Read32(&urlType);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mURLType = urlType;
+  switch (mURLType) {
+    case URLTYPE_STANDARD:
+      mParser = net_GetStdURLParser();
+      break;
+    case URLTYPE_AUTHORITY:
+      mParser = net_GetAuthURLParser();
+      break;
+    case URLTYPE_NO_AUTHORITY:
+      mParser = net_GetNoAuthURLParser();
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("bad urlType");
+      return NS_ERROR_FAILURE;
+  }
+
+  rv = stream->Read32((uint32_t*)&mPort);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->Read32((uint32_t*)&mDefaultPort);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = NS_ReadOptionalCString(stream, mSpec);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mScheme);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mAuthority);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mUsername);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mPassword);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mHost);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mPath);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mFilepath);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mDirectory);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mBasename);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mExtension);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // handle forward compatibility from older serializations that included mParam
+  URLSegment old_param;
+  rv = ReadSegment(stream, old_param);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mQuery);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = ReadSegment(stream, mRef);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsAutoCString oldOriginCharset;
+  rv = NS_ReadOptionalCString(stream, oldOriginCharset);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  bool isMutable;
+  rv = stream->ReadBoolean(&isMutable);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  Unused << isMutable;
+
+  bool supportsFileURL;
+  rv = stream->ReadBoolean(&supportsFileURL);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mSupportsFileURL = supportsFileURL;
+
+  // wait until object is set up, then modify path to include the param
+  if (old_param.mLen >= 0) {  // note that mLen=0 is ";"
+    // If this wasn't empty, it marks characters between the end of the
+    // file and start of the query - mPath should include the param,
+    // query and ref already.  Bump the mFilePath and
+    // directory/basename/extension components to include this.
+    mFilepath.Merge(mSpec, ';', old_param);
+    mDirectory.Merge(mSpec, ';', old_param);
+    mBasename.Merge(mSpec, ';', old_param);
+    mExtension.Merge(mSpec, ';', old_param);
+  }
+
+  rv = CheckIfHostIsAscii();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (!IsValid()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  clearOnExit.release();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStandardURL::Write(nsIObjectOutputStream* stream) {
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
+             "The spec should never be this long, we missed a check.");
+  nsresult rv;
+
+  rv = stream->Write32(mURLType);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->Write32(uint32_t(mPort));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->Write32(uint32_t(mDefaultPort));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = NS_WriteOptionalStringZ(stream, mSpec.get());
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mScheme);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mAuthority);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mUsername);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mPassword);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mHost);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mPath);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mFilepath);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mDirectory);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mBasename);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mExtension);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // for backwards compatibility since we removed mParam.  Note that this will
+  // mean that an older browser will read "" for mParam, and the param(s) will
+  // be part of mPath (as they after the removal of special handling).  It only
+  // matters if you downgrade a browser to before the patch.
+  URLSegment empty;
+  rv = WriteSegment(stream, empty);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mQuery);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = WriteSegment(stream, mRef);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // former origin charset
+  rv = NS_WriteOptionalStringZ(stream, "");
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // former mMutable
+  rv = stream->WriteBoolean(false);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = stream->WriteBoolean(mSupportsFileURL);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // mDisplayHost is just a cache that can be recovered as needed.
+
+  return NS_OK;
+}
+
+inline ipc::StandardURLSegment ToIPCSegment(
+    const nsStandardURL::URLSegment& aSegment) {
+  return ipc::StandardURLSegment(aSegment.mPos, aSegment.mLen);
+}
+
+[[nodiscard]] inline bool FromIPCSegment(
+    const nsACString& aSpec, const ipc::StandardURLSegment& aSegment,
+    nsStandardURL::URLSegment& aTarget) {
+  // This seems to be just an empty segment.
+  if (aSegment.length() == -1) {
+    aTarget = nsStandardURL::URLSegment();
+    return true;
+  }
+
+  // A value of -1 means an empty segment, but < -1 is undefined.
+  if (NS_WARN_IF(aSegment.length() < -1)) {
+    return false;
+  }
+
+  CheckedInt<uint32_t> segmentLen = aSegment.position();
+  segmentLen += aSegment.length();
+  // Make sure the segment does not extend beyond the spec.
+  if (NS_WARN_IF(!segmentLen.isValid() ||
+                 segmentLen.value() > aSpec.Length())) {
+    return false;
+  }
+
+  aTarget.mPos = aSegment.position();
+  aTarget.mLen = aSegment.length();
+
+  return true;
+}
+
+void nsStandardURL::Serialize(URIParams& aParams) {
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
+             "The spec should never be this long, we missed a check.");
+  StandardURLParams params;
+
+  params.urlType() = mURLType;
+  params.port() = mPort;
+  params.defaultPort() = mDefaultPort;
+  params.spec() = mSpec;
+  params.scheme() = ToIPCSegment(mScheme);
+  params.authority() = ToIPCSegment(mAuthority);
+  params.username() = ToIPCSegment(mUsername);
+  params.password() = ToIPCSegment(mPassword);
+  params.host() = ToIPCSegment(mHost);
+  params.path() = ToIPCSegment(mPath);
+  params.filePath() = ToIPCSegment(mFilepath);
+  params.directory() = ToIPCSegment(mDirectory);
+  params.baseName() = ToIPCSegment(mBasename);
+  params.extension() = ToIPCSegment(mExtension);
+  params.query() = ToIPCSegment(mQuery);
+  params.ref() = ToIPCSegment(mRef);
+  params.supportsFileURL() = !!mSupportsFileURL;
+  params.isSubstituting() = false;
+  // mDisplayHost is just a cache that can be recovered as needed.
+
+  aParams = params;
+}
+
+bool nsStandardURL::Deserialize(const URIParams& aParams) {
+  MOZ_ASSERT(mDisplayHost.IsEmpty(), "Shouldn't have cached unicode host");
+  MOZ_ASSERT(!mFile, "Shouldn't have cached file");
+
+  if (aParams.type() != URIParams::TStandardURLParams) {
+    NS_ERROR("Received unknown parameters from the other process!");
+    return false;
+  }
+
+  // If we exit early, make sure to clear the URL so we don't fail the sanity
+  // check in the destructor
+  auto clearOnExit = MakeScopeExit([&] { Clear(); });
+
+  const StandardURLParams& params = aParams.get_StandardURLParams();
+
+  mURLType = params.urlType();
+  switch (mURLType) {
+    case URLTYPE_STANDARD:
+      mParser = net_GetStdURLParser();
+      break;
+    case URLTYPE_AUTHORITY:
+      mParser = net_GetAuthURLParser();
+      break;
+    case URLTYPE_NO_AUTHORITY:
+      mParser = net_GetNoAuthURLParser();
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("bad urlType");
+      return false;
+  }
+
+  mPort = params.port();
+  mDefaultPort = params.defaultPort();
+  mSpec = params.spec();
+  NS_ENSURE_TRUE(
+      mSpec.Length() <= StaticPrefs::network_standard_url_max_length(), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.scheme(), mScheme), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.authority(), mAuthority), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.username(), mUsername), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.password(), mPassword), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.host(), mHost), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.path(), mPath), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.filePath(), mFilepath), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.directory(), mDirectory), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.baseName(), mBasename), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.extension(), mExtension), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.query(), mQuery), false);
+  NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.ref(), mRef), false);
+
+  mSupportsFileURL = params.supportsFileURL();
+
+  nsresult rv = CheckIfHostIsAscii();
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  // Some sanity checks
+  NS_ENSURE_TRUE(mScheme.mPos == 0, false);
+  NS_ENSURE_TRUE(mScheme.mLen > 0, false);
+  // Make sure scheme is followed by :// (3 characters)
+  NS_ENSURE_TRUE(mScheme.mLen < INT32_MAX - 3, false);  // avoid overflow
+  NS_ENSURE_TRUE(mSpec.Length() >= (uint32_t)mScheme.mLen + 3, false);
+  NS_ENSURE_TRUE(
+      nsDependentCSubstring(mSpec, mScheme.mLen, 3).EqualsLiteral("://"),
+      false);
+  NS_ENSURE_TRUE(mPath.mLen != -1 && mSpec.CharAt(mPath.mPos) == '/', false);
+  NS_ENSURE_TRUE(mPath.mPos == mFilepath.mPos, false);
+  NS_ENSURE_TRUE(mQuery.mLen == -1 ||
+                     (mQuery.mPos > 0 && mSpec.CharAt(mQuery.mPos - 1) == '?'),
+                 false);
+  NS_ENSURE_TRUE(
+      mRef.mLen == -1 || (mRef.mPos > 0 && mSpec.CharAt(mRef.mPos - 1) == '#'),
+      false);
+
+  if (!IsValid()) {
+    return false;
+  }
+
+  clearOnExit.release();
+
+  return true;
+}
+
+//----------------------------------------------------------------------------
+// nsStandardURL::nsISizeOf
+//----------------------------------------------------------------------------
+
+size_t nsStandardURL::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  return mSpec.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
+         mDisplayHost.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+
+  // Measurement of the following members may be added later if DMD finds it is
+  // worthwhile:
+  // - mParser
+  // - mFile
+}
+
+size_t nsStandardURL::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+}  // namespace net
+}  // namespace mozilla
+
+// For unit tests.  Including nsStandardURL.h seems to cause problems
+nsresult Test_NormalizeIPv4(const nsACString& host, nsCString& result) {
+  return mozilla::net::nsStandardURL::NormalizeIPv4(host, result);
+}
diff --git a/netwerk/base/nsStandardURL.h b/netwerk/base/nsStandardURL.h
new file mode 100644
index 0000000000..a4f644e722
--- /dev/null
+++ b/netwerk/base/nsStandardURL.h
@@ -0,0 +1,626 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsStandardURL_h__
+#define nsStandardURL_h__
+
+#include <bitset>
+
+#include "nsString.h"
+#include "nsISerializable.h"
+#include "nsIFileURL.h"
+#include "nsIStandardURL.h"
+#include "mozilla/Encoding.h"
+#include "nsCOMPtr.h"
+#include "nsURLHelper.h"
+#include "nsISizeOf.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/LinkedList.h"
+#include "mozilla/MemoryReporting.h"
+#include "nsISensitiveInfoHiddenURI.h"
+#include "nsIURIMutator.h"
+
+#ifdef NS_BUILD_REFCNT_LOGGING
+#  define DEBUG_DUMP_URLS_AT_SHUTDOWN
+#endif
+
+class nsIBinaryInputStream;
+class nsIBinaryOutputStream;
+class nsIIDNService;
+class nsIPrefBranch;
+class nsIFile;
+class nsIURLParser;
+
+namespace mozilla {
+class Encoding;
+namespace net {
+
+template <typename T>
+class URLSegmentNumber {
+  T mData{0};
+  bool mParity{false};
+
+ public:
+  URLSegmentNumber() = default;
+  explicit URLSegmentNumber(T data) : mData(data) {
+    mParity = CalculateParity();
+  }
+  bool operator==(URLSegmentNumber value) const { return mData == value.mData; }
+  bool operator!=(URLSegmentNumber value) const { return mData != value.mData; }
+  bool operator>(URLSegmentNumber value) const { return mData > value.mData; }
+  URLSegmentNumber operator+(int32_t value) const {
+    return URLSegmentNumber(mData + value);
+  }
+  URLSegmentNumber operator+(uint32_t value) const {
+    return URLSegmentNumber(mData + value);
+  }
+  URLSegmentNumber operator-(int32_t value) const {
+    return URLSegmentNumber(mData - value);
+  }
+  URLSegmentNumber operator-(uint32_t value) const {
+    return URLSegmentNumber(mData - value);
+  }
+  URLSegmentNumber operator+=(URLSegmentNumber value) {
+    mData += value.mData;
+    mParity = CalculateParity();
+    return *this;
+  }
+  URLSegmentNumber operator+=(T value) {
+    mData += value;
+    mParity = CalculateParity();
+    return *this;
+  }
+  URLSegmentNumber operator-=(URLSegmentNumber value) {
+    mData -= value.mData;
+    mParity = CalculateParity();
+    return *this;
+  }
+  URLSegmentNumber operator-=(T value) {
+    mData -= value;
+    mParity = CalculateParity();
+    return *this;
+  }
+  operator T() const { return mData; }
+  URLSegmentNumber& operator=(T value) {
+    mData = value;
+    mParity = CalculateParity();
+    return *this;
+  }
+  URLSegmentNumber& operator++() {
+    ++mData;
+    mParity = CalculateParity();
+    return *this;
+  }
+  URLSegmentNumber operator++(int) {
+    URLSegmentNumber value = *this;
+    *this += 1;
+    return value;
+  }
+  bool CalculateParity() const {
+    std::bitset<32> bits((uint32_t)mData);
+    return bits.count() % 2 == 0 ? false : true;
+  }
+  bool Parity() const { return mParity; }
+};
+
+//-----------------------------------------------------------------------------
+// standard URL implementation
+//-----------------------------------------------------------------------------
+
+class nsStandardURL : public nsIFileURL,
+                      public nsIStandardURL,
+                      public nsISerializable,
+                      public nsISizeOf,
+                      public nsISensitiveInfoHiddenURI
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+    ,
+                      public LinkedListElement<nsStandardURL>
+#endif
+{
+ protected:
+  virtual ~nsStandardURL();
+  explicit nsStandardURL(bool aSupportsFileURL = false, bool aTrackURL = true);
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIURI
+  NS_DECL_NSIURL
+  NS_DECL_NSIFILEURL
+  NS_DECL_NSISTANDARDURL
+  NS_DECL_NSISERIALIZABLE
+  NS_DECL_NSISENSITIVEINFOHIDDENURI
+
+  // nsISizeOf
+  virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override;
+  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override;
+
+  static void InitGlobalObjects();
+  static void ShutdownGlobalObjects();
+
+ public: /* internal -- HPUX compiler can't handle this being private */
+  //
+  // location and length of an url segment relative to mSpec
+  //
+  struct URLSegment {
+#ifdef EARLY_BETA_OR_EARLIER
+    URLSegmentNumber<uint32_t> mPos{0};
+    URLSegmentNumber<int32_t> mLen{-1};
+#else
+    uint32_t mPos{0};
+    int32_t mLen{-1};
+#endif
+
+    URLSegment() = default;
+    URLSegment(uint32_t pos, int32_t len) : mPos(pos), mLen(len) {}
+    URLSegment(const URLSegment& aCopy) = default;
+    void Reset() {
+      mPos = 0;
+      mLen = -1;
+    }
+    // Merge another segment following this one to it if they're contiguous
+    // Assumes we have something like "foo;bar" where this object is 'foo' and
+    // right is 'bar'.
+    void Merge(const nsCString& spec, const char separator,
+               const URLSegment& right) {
+      if (mLen >= 0 && *(spec.get() + mPos + mLen) == separator &&
+          mPos + mLen + 1 == right.mPos) {
+        mLen += 1 + right.mLen;
+      }
+    }
+  };
+
+  //
+  // URL segment encoder : performs charset conversion and URL escaping.
+  //
+  class nsSegmentEncoder {
+   public:
+    explicit nsSegmentEncoder(const Encoding* encoding = nullptr);
+
+    // Encode the given segment if necessary, and return the length of
+    // the encoded segment.  The encoded segment is appended to |aOut|
+    // if and only if encoding is required.
+    int32_t EncodeSegmentCount(const char* str, const URLSegment& aSeg,
+                               int16_t mask, nsCString& aOut, bool& appended,
+                               uint32_t extraLen = 0);
+
+    // Encode the given string if necessary, and return a reference to
+    // the encoded string.  Returns a reference to |result| if encoding
+    // is required.  Otherwise, a reference to |str| is returned.
+    const nsACString& EncodeSegment(const nsACString& str, int16_t mask,
+                                    nsCString& result);
+
+   private:
+    const Encoding* mEncoding;
+  };
+  friend class nsSegmentEncoder;
+
+  static nsresult NormalizeIPv4(const nsACString& host, nsCString& result);
+
+ protected:
+  // enum used in a few places to specify how .ref attribute should be handled
+  enum RefHandlingEnum { eIgnoreRef, eHonorRef, eReplaceRef };
+
+  // Helper to share code between Equals and EqualsExceptRef
+  // NOTE: *not* virtual, because no one needs to override this so far...
+  nsresult EqualsInternal(nsIURI* unknownOther, RefHandlingEnum refHandlingMode,
+                          bool* result);
+
+  virtual nsStandardURL* StartClone();
+
+  // Helper to share code between Clone methods.
+  nsresult CloneInternal(RefHandlingEnum aRefHandlingMode,
+                         const nsACString& aNewRef, nsIURI** aClone);
+  // Helper method that copies member variables from the source StandardURL
+  // if copyCached = true, it will also copy mFile and mDisplayHost
+  nsresult CopyMembers(nsStandardURL* source, RefHandlingEnum mode,
+                       const nsACString& newRef, bool copyCached = false);
+
+  // Helper for subclass implementation of GetFile().  Subclasses that map
+  // URIs to files in a special way should implement this method.  It should
+  // ensure that our mFile is initialized, if it's possible.
+  // returns NS_ERROR_NO_INTERFACE if the url does not map to a file
+  virtual nsresult EnsureFile();
+
+  virtual nsresult Clone(nsIURI** aURI);
+  virtual nsresult SetSpecInternal(const nsACString& input);
+  virtual nsresult SetScheme(const nsACString& input);
+  virtual nsresult SetUserPass(const nsACString& input);
+  virtual nsresult SetUsername(const nsACString& input);
+  virtual nsresult SetPassword(const nsACString& input);
+  virtual nsresult SetHostPort(const nsACString& aValue);
+  virtual nsresult SetHost(const nsACString& input);
+  virtual nsresult SetPort(int32_t port);
+  virtual nsresult SetPathQueryRef(const nsACString& input);
+  virtual nsresult SetRef(const nsACString& input);
+  virtual nsresult SetFilePath(const nsACString& input);
+  virtual nsresult SetQuery(const nsACString& input);
+  virtual nsresult SetQueryWithEncoding(const nsACString& input,
+                                        const Encoding* encoding);
+  bool Deserialize(const mozilla::ipc::URIParams&);
+  nsresult ReadPrivate(nsIObjectInputStream* stream);
+
+ private:
+  nsresult Init(uint32_t urlType, int32_t defaultPort, const nsACString& spec,
+                const char* charset, nsIURI* baseURI);
+  nsresult SetDefaultPort(int32_t aNewDefaultPort);
+  nsresult SetFile(nsIFile* file);
+
+  nsresult SetFileNameInternal(const nsACString& input);
+  nsresult SetFileBaseNameInternal(const nsACString& input);
+  nsresult SetFileExtensionInternal(const nsACString& input);
+
+  int32_t Port() { return mPort == -1 ? mDefaultPort : mPort; }
+
+  void ReplacePortInSpec(int32_t aNewPort);
+  void Clear();
+  void InvalidateCache(bool invalidateCachedFile = true);
+
+  bool ValidIPv6orHostname(const char* host, uint32_t length);
+  static bool IsValidOfBase(unsigned char c, const uint32_t base);
+  nsresult NormalizeIDN(const nsCString& host, nsCString& result);
+  nsresult CheckIfHostIsAscii();
+  void CoalescePath(netCoalesceFlags coalesceFlag, char* path);
+
+  uint32_t AppendSegmentToBuf(char*, uint32_t, const char*,
+                              const URLSegment& input, URLSegment& output,
+                              const nsCString* esc = nullptr,
+                              bool useEsc = false, int32_t* diff = nullptr);
+  uint32_t AppendToBuf(char*, uint32_t, const char*, uint32_t);
+
+  nsresult BuildNormalizedSpec(const char* spec, const Encoding* encoding);
+  nsresult SetSpecWithEncoding(const nsACString& input,
+                               const Encoding* encoding);
+
+  bool SegmentIs(const URLSegment& seg, const char* val,
+                 bool ignoreCase = false);
+  bool SegmentIs(const char* spec, const URLSegment& seg, const char* val,
+                 bool ignoreCase = false);
+  bool SegmentIs(const URLSegment& seg1, const char* val,
+                 const URLSegment& seg2, bool ignoreCase = false);
+
+  int32_t ReplaceSegment(uint32_t pos, uint32_t len, const char* val,
+                         uint32_t valLen);
+  int32_t ReplaceSegment(uint32_t pos, uint32_t len, const nsACString& val);
+
+  nsresult ParseURL(const char* spec, int32_t specLen);
+  nsresult ParsePath(const char* spec, uint32_t pathPos, int32_t pathLen = -1);
+
+  char* AppendToSubstring(uint32_t pos, int32_t len, const char* tail);
+
+  // dependent substring helpers
+  nsDependentCSubstring Segment(uint32_t pos, int32_t len);  // see below
+  nsDependentCSubstring Segment(const URLSegment& s) {
+    return Segment(s.mPos, s.mLen);
+  }
+
+  // dependent substring getters
+  nsDependentCSubstring Prepath();  // see below
+  nsDependentCSubstring Scheme() { return Segment(mScheme); }
+  nsDependentCSubstring Userpass(bool includeDelim = false);  // see below
+  nsDependentCSubstring Username() { return Segment(mUsername); }
+  nsDependentCSubstring Password() { return Segment(mPassword); }
+  nsDependentCSubstring Hostport();  // see below
+  nsDependentCSubstring Host();      // see below
+  nsDependentCSubstring Path() { return Segment(mPath); }
+  nsDependentCSubstring Filepath() { return Segment(mFilepath); }
+  nsDependentCSubstring Directory() { return Segment(mDirectory); }
+  nsDependentCSubstring Filename();  // see below
+  nsDependentCSubstring Basename() { return Segment(mBasename); }
+  nsDependentCSubstring Extension() { return Segment(mExtension); }
+  nsDependentCSubstring Query() { return Segment(mQuery); }
+  nsDependentCSubstring Ref() { return Segment(mRef); }
+
+  // shift the URLSegments to the right by diff
+  void ShiftFromAuthority(int32_t diff);
+  void ShiftFromUsername(int32_t diff);
+  void ShiftFromPassword(int32_t diff);
+  void ShiftFromHost(int32_t diff);
+  void ShiftFromPath(int32_t diff);
+  void ShiftFromFilepath(int32_t diff);
+  void ShiftFromDirectory(int32_t diff);
+  void ShiftFromBasename(int32_t diff);
+  void ShiftFromExtension(int32_t diff);
+  void ShiftFromQuery(int32_t diff);
+  void ShiftFromRef(int32_t diff);
+
+  // fastload helper functions
+  nsresult ReadSegment(nsIBinaryInputStream*, URLSegment&);
+  nsresult WriteSegment(nsIBinaryOutputStream*, const URLSegment&);
+
+  void FindHostLimit(nsACString::const_iterator& aStart,
+                     nsACString::const_iterator& aEnd);
+
+  // Asserts that the URL has sane values
+  void SanityCheck();
+
+  // Checks if the URL has a valid representation.
+  bool IsValid();
+
+  // mSpec contains the normalized version of the URL spec (UTF-8 encoded).
+  nsCString mSpec;
+  int32_t mDefaultPort{-1};
+  int32_t mPort{-1};
+
+  // url parts (relative to mSpec)
+  URLSegment mScheme;
+  URLSegment mAuthority;
+  URLSegment mUsername;
+  URLSegment mPassword;
+  URLSegment mHost;
+  URLSegment mPath;
+  URLSegment mFilepath;
+  URLSegment mDirectory;
+  URLSegment mBasename;
+  URLSegment mExtension;
+  URLSegment mQuery;
+  URLSegment mRef;
+
+  nsCOMPtr<nsIURLParser> mParser;
+
+  // mFile is protected so subclasses can access it directly
+ protected:
+  nsCOMPtr<nsIFile> mFile;  // cached result for nsIFileURL::GetFile
+
+ private:
+  // cached result for nsIURI::GetDisplayHost
+  nsCString mDisplayHost;
+
+  enum { eEncoding_Unknown, eEncoding_ASCII, eEncoding_UTF8 };
+
+  uint32_t mURLType : 2;          // nsIStandardURL::URLTYPE_xxx
+  uint32_t mSupportsFileURL : 1;  // QI to nsIFileURL?
+  uint32_t mCheckedIfHostA : 1;   // If set to true, it means either that
+                                  // mDisplayHost has a been initialized, or
+                                  // that the hostname is not punycode
+
+  // global objects.
+  static StaticRefPtr<nsIIDNService> gIDN;
+  static const char gHostLimitDigits[];
+
+ public:
+#ifdef DEBUG_DUMP_URLS_AT_SHUTDOWN
+  void PrintSpec() const { printf("  %s\n", mSpec.get()); }
+#endif
+
+ public:
+  // We make this implementation a template so that we can avoid writing
+  // the same code for SubstitutingURL (which extends nsStandardURL)
+  template <class T>
+  class TemplatedMutator : public nsIURIMutator,
+                           public BaseURIMutator<T>,
+                           public nsIStandardURLMutator,
+                           public nsIURLMutator,
+                           public nsIFileURLMutator,
+                           public nsISerializable {
+    NS_FORWARD_SAFE_NSIURISETTERS_RET(BaseURIMutator<T>::mURI)
+
+    [[nodiscard]] NS_IMETHOD Deserialize(
+        const mozilla::ipc::URIParams& aParams) override {
+      return BaseURIMutator<T>::InitFromIPCParams(aParams);
+    }
+
+    NS_IMETHOD
+    Write(nsIObjectOutputStream* aOutputStream) override {
+      MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+      return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    [[nodiscard]] NS_IMETHOD Read(nsIObjectInputStream* aStream) override {
+      return BaseURIMutator<T>::InitFromInputStream(aStream);
+    }
+
+    [[nodiscard]] NS_IMETHOD Finalize(nsIURI** aURI) override {
+      BaseURIMutator<T>::mURI.forget(aURI);
+      return NS_OK;
+    }
+
+    [[nodiscard]] NS_IMETHOD SetSpec(const nsACString& aSpec,
+                                     nsIURIMutator** aMutator) override {
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return BaseURIMutator<T>::InitFromSpec(aSpec);
+    }
+
+    [[nodiscard]] NS_IMETHOD Init(uint32_t aURLType, int32_t aDefaultPort,
+                                  const nsACString& aSpec, const char* aCharset,
+                                  nsIURI* aBaseURI,
+                                  nsIURIMutator** aMutator) override {
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      RefPtr<T> uri;
+      if (BaseURIMutator<T>::mURI) {
+        // We don't need a new URI object if we already have one
+        BaseURIMutator<T>::mURI.swap(uri);
+      } else {
+        uri = Create();
+      }
+      nsresult rv =
+          uri->Init(aURLType, aDefaultPort, aSpec, aCharset, aBaseURI);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      BaseURIMutator<T>::mURI = std::move(uri);
+      return NS_OK;
+    }
+
+    [[nodiscard]] NS_IMETHODIMP SetDefaultPort(
+        int32_t aNewDefaultPort, nsIURIMutator** aMutator) override {
+      if (!BaseURIMutator<T>::mURI) {
+        return NS_ERROR_NULL_POINTER;
+      }
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return BaseURIMutator<T>::mURI->SetDefaultPort(aNewDefaultPort);
+    }
+
+    [[nodiscard]] NS_IMETHOD SetFileName(const nsACString& aFileName,
+                                         nsIURIMutator** aMutator) override {
+      if (!BaseURIMutator<T>::mURI) {
+        return NS_ERROR_NULL_POINTER;
+      }
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return BaseURIMutator<T>::mURI->SetFileNameInternal(aFileName);
+    }
+
+    [[nodiscard]] NS_IMETHOD SetFileBaseName(
+        const nsACString& aFileBaseName, nsIURIMutator** aMutator) override {
+      if (!BaseURIMutator<T>::mURI) {
+        return NS_ERROR_NULL_POINTER;
+      }
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return BaseURIMutator<T>::mURI->SetFileBaseNameInternal(aFileBaseName);
+    }
+
+    [[nodiscard]] NS_IMETHOD SetFileExtension(
+        const nsACString& aFileExtension, nsIURIMutator** aMutator) override {
+      if (!BaseURIMutator<T>::mURI) {
+        return NS_ERROR_NULL_POINTER;
+      }
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return BaseURIMutator<T>::mURI->SetFileExtensionInternal(aFileExtension);
+    }
+
+    T* Create() override { return new T(mMarkedFileURL); }
+
+    [[nodiscard]] NS_IMETHOD MarkFileURL() override {
+      mMarkedFileURL = true;
+      return NS_OK;
+    }
+
+    [[nodiscard]] NS_IMETHOD SetFile(nsIFile* aFile) override {
+      RefPtr<T> uri;
+      if (BaseURIMutator<T>::mURI) {
+        // We don't need a new URI object if we already have one
+        BaseURIMutator<T>::mURI.swap(uri);
+      } else {
+        uri = new T(/* aSupportsFileURL = */ true);
+      }
+
+      nsresult rv = uri->SetFile(aFile);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      BaseURIMutator<T>::mURI.swap(uri);
+      return NS_OK;
+    }
+
+    explicit TemplatedMutator() = default;
+
+   private:
+    virtual ~TemplatedMutator() = default;
+
+    bool mMarkedFileURL = false;
+
+    friend T;
+  };
+
+  class Mutator final : public TemplatedMutator<nsStandardURL> {
+    NS_DECL_ISUPPORTS
+   public:
+    explicit Mutator() = default;
+
+   private:
+    virtual ~Mutator() = default;
+  };
+
+  friend BaseURIMutator<nsStandardURL>;
+};
+
+#define NS_THIS_STANDARDURL_IMPL_CID                 \
+  { /* b8e3e97b-1ccd-4b45-af5a-79596770f5d7 */       \
+    0xb8e3e97b, 0x1ccd, 0x4b45, {                    \
+      0xaf, 0x5a, 0x79, 0x59, 0x67, 0x70, 0xf5, 0xd7 \
+    }                                                \
+  }
+
+//-----------------------------------------------------------------------------
+// Dependent substring getters
+//-----------------------------------------------------------------------------
+
+inline nsDependentCSubstring nsStandardURL::Segment(uint32_t pos, int32_t len) {
+  if (len < 0) {
+    pos = 0;
+    len = 0;
+  }
+  return Substring(mSpec, pos, uint32_t(len));
+}
+
+inline nsDependentCSubstring nsStandardURL::Prepath() {
+  uint32_t len = 0;
+  if (mAuthority.mLen >= 0) len = mAuthority.mPos + mAuthority.mLen;
+  return Substring(mSpec, 0, len);
+}
+
+inline nsDependentCSubstring nsStandardURL::Userpass(bool includeDelim) {
+  uint32_t pos = 0, len = 0;
+  if (mUsername.mLen > 0 || mPassword.mLen > 0) {
+    if (mUsername.mLen > 0) {
+      pos = mUsername.mPos;
+      len = mUsername.mLen;
+      if (mPassword.mLen >= 0) {
+        len += (mPassword.mLen + 1);
+      }
+    } else {
+      pos = mPassword.mPos - 1;
+      len = mPassword.mLen + 1;
+    }
+
+    if (includeDelim) len++;
+  }
+  return Substring(mSpec, pos, len);
+}
+
+inline nsDependentCSubstring nsStandardURL::Hostport() {
+  uint32_t pos = 0, len = 0;
+  if (mAuthority.mLen > 0) {
+    pos = mHost.mPos;
+    len = mAuthority.mPos + mAuthority.mLen - pos;
+  }
+  return Substring(mSpec, pos, len);
+}
+
+inline nsDependentCSubstring nsStandardURL::Host() {
+  uint32_t pos = 0, len = 0;
+  if (mHost.mLen > 0) {
+    pos = mHost.mPos;
+    len = mHost.mLen;
+    if (mSpec.CharAt(pos) == '[' && mSpec.CharAt(pos + len - 1) == ']') {
+      pos++;
+      len -= 2;
+    }
+  }
+  return Substring(mSpec, pos, len);
+}
+
+inline nsDependentCSubstring nsStandardURL::Filename() {
+  uint32_t pos = 0, len = 0;
+  // if there is no basename, then there can be no extension
+  if (mBasename.mLen > 0) {
+    pos = mBasename.mPos;
+    len = mBasename.mLen;
+    if (mExtension.mLen >= 0) len += (mExtension.mLen + 1);
+  }
+  return Substring(mSpec, pos, len);
+}
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsStandardURL_h__
diff --git a/netwerk/base/nsStreamListenerTee.cpp b/netwerk/base/nsStreamListenerTee.cpp
new file mode 100644
index 0000000000..445d0fe81a
--- /dev/null
+++ b/netwerk/base/nsStreamListenerTee.cpp
@@ -0,0 +1,159 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsStreamListenerTee.h"
+#include "nsProxyRelease.h"
+#include "nsIRequest.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsStreamListenerTee, nsIStreamListener, nsIRequestObserver,
+                  nsIStreamListenerTee, nsIThreadRetargetableStreamListener,
+                  nsIMultiPartChannelListener)
+
+NS_IMETHODIMP
+nsStreamListenerTee::OnStartRequest(nsIRequest* request) {
+  NS_ENSURE_TRUE(mListener, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIMultiPartChannel> multiPartChannel = do_QueryInterface(request);
+  if (multiPartChannel) {
+    mIsMultiPart = true;
+  }
+
+  nsresult rv1 = mListener->OnStartRequest(request);
+  nsresult rv2 = NS_OK;
+  if (mObserver) rv2 = mObserver->OnStartRequest(request);
+
+  // Preserve NS_SUCCESS_XXX in rv1 in case mObserver didn't throw
+  return (NS_FAILED(rv2) && NS_SUCCEEDED(rv1)) ? rv2 : rv1;
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::OnStopRequest(nsIRequest* request, nsresult status) {
+  NS_ENSURE_TRUE(mListener, NS_ERROR_NOT_INITIALIZED);
+  // it is critical that we close out the input stream tee
+  if (mInputTee) {
+    mInputTee->SetSink(nullptr);
+    mInputTee = nullptr;
+  }
+
+  if (!mIsMultiPart) {
+    // release sink on the same thread where the data was written (bug 716293)
+    if (mEventTarget) {
+      NS_ProxyRelease("nsStreamListenerTee::mSink", mEventTarget,
+                      mSink.forget());
+    } else {
+      mSink = nullptr;
+    }
+  }
+
+  nsresult rv = mListener->OnStopRequest(request, status);
+  if (mObserver) mObserver->OnStopRequest(request, status);
+  if (!mIsMultiPart) {
+    mObserver = nullptr;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::OnDataAvailable(nsIRequest* request, nsIInputStream* input,
+                                     uint64_t offset, uint32_t count) {
+  NS_ENSURE_TRUE(mListener, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mSink, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsIInputStream> tee;
+  nsresult rv;
+
+  if (!mInputTee) {
+    if (mEventTarget) {
+      rv = NS_NewInputStreamTeeAsync(getter_AddRefs(tee), input, mSink,
+                                     mEventTarget);
+    } else {
+      rv = NS_NewInputStreamTee(getter_AddRefs(tee), input, mSink);
+    }
+    if (NS_FAILED(rv)) return rv;
+
+    mInputTee = do_QueryInterface(tee, &rv);
+    if (NS_FAILED(rv)) return rv;
+  } else {
+    // re-initialize the input tee since the input stream may have changed.
+    rv = mInputTee->SetSource(input);
+    if (NS_FAILED(rv)) return rv;
+
+    tee = mInputTee;
+  }
+
+  return mListener->OnDataAvailable(request, tee, offset, count);
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::OnAfterLastPart(nsresult aStatus) {
+  // release sink on the same thread where the data was written (bug 716293)
+  if (mEventTarget) {
+    NS_ProxyRelease("nsStreamListenerTee::mSink", mEventTarget, mSink.forget());
+  } else {
+    mSink = nullptr;
+  }
+
+  if (nsCOMPtr<nsIMultiPartChannelListener> multi =
+          do_QueryInterface(mListener)) {
+    multi->OnAfterLastPart(aStatus);
+  }
+  if (!SameCOMIdentity(mListener, mObserver)) {
+    if (nsCOMPtr<nsIMultiPartChannelListener> multi =
+            do_QueryInterface(mObserver)) {
+      multi->OnAfterLastPart(aStatus);
+    }
+  }
+
+  mObserver = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::CheckListenerChain() {
+  NS_ASSERTION(NS_IsMainThread(), "Should be on main thread!");
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+      do_QueryInterface(mListener, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (!mObserver) {
+    return rv;
+  }
+  retargetableListener = do_QueryInterface(mObserver, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::Init(nsIStreamListener* listener, nsIOutputStream* sink,
+                          nsIRequestObserver* requestObserver) {
+  NS_ENSURE_ARG_POINTER(listener);
+  NS_ENSURE_ARG_POINTER(sink);
+  mListener = listener;
+  mSink = sink;
+  mObserver = requestObserver;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamListenerTee::InitAsync(nsIStreamListener* listener,
+                               nsIEventTarget* eventTarget,
+                               nsIOutputStream* sink,
+                               nsIRequestObserver* requestObserver) {
+  NS_ENSURE_ARG_POINTER(eventTarget);
+  mEventTarget = eventTarget;
+  return Init(listener, sink, requestObserver);
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsStreamListenerTee.h b/netwerk/base/nsStreamListenerTee.h
new file mode 100644
index 0000000000..0b54bbf5dd
--- /dev/null
+++ b/netwerk/base/nsStreamListenerTee.h
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsStreamListenerTee_h__
+#define nsStreamListenerTee_h__
+
+#include "nsIStreamListenerTee.h"
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsIInputStreamTee.h"
+#include "nsIOutputStream.h"
+#include "nsCOMPtr.h"
+#include "nsIEventTarget.h"
+#include "nsIMultiPartChannel.h"
+
+namespace mozilla {
+namespace net {
+
+class nsStreamListenerTee : public nsIStreamListenerTee,
+                            public nsIThreadRetargetableStreamListener,
+                            public nsIMultiPartChannelListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+  NS_DECL_NSISTREAMLISTENERTEE
+  NS_DECL_NSIMULTIPARTCHANNELLISTENER
+
+  nsStreamListenerTee() = default;
+
+ private:
+  virtual ~nsStreamListenerTee() = default;
+
+  nsCOMPtr<nsIInputStreamTee> mInputTee;
+  nsCOMPtr<nsIOutputStream> mSink;
+  nsCOMPtr<nsIStreamListener> mListener;
+  nsCOMPtr<nsIRequestObserver> mObserver;
+  nsCOMPtr<nsIEventTarget> mEventTarget;
+  bool mIsMultiPart = false;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif
diff --git a/netwerk/base/nsStreamListenerWrapper.cpp b/netwerk/base/nsStreamListenerWrapper.cpp
new file mode 100644
index 0000000000..d72a5c66e4
--- /dev/null
+++ b/netwerk/base/nsStreamListenerWrapper.cpp
@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsStreamListenerWrapper.h"
+#ifdef DEBUG
+#  include "MainThreadUtils.h"
+#endif
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsStreamListenerWrapper, nsIStreamListener,
+                  nsIRequestObserver, nsIMultiPartChannelListener,
+                  nsIThreadRetargetableStreamListener)
+
+NS_IMETHODIMP
+nsStreamListenerWrapper::OnAfterLastPart(nsresult aStatus) {
+  if (nsCOMPtr<nsIMultiPartChannelListener> listener =
+          do_QueryInterface(mListener)) {
+    return listener->OnAfterLastPart(aStatus);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamListenerWrapper::CheckListenerChain() {
+  NS_ASSERTION(NS_IsMainThread(), "Should be on main thread!");
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+      do_QueryInterface(mListener, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  return rv;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsStreamListenerWrapper.h b/netwerk/base/nsStreamListenerWrapper.h
new file mode 100644
index 0000000000..9871adf71c
--- /dev/null
+++ b/netwerk/base/nsStreamListenerWrapper.h
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsStreamListenerWrapper_h__
+#define nsStreamListenerWrapper_h__
+
+#include "nsCOMPtr.h"
+#include "nsIStreamListener.h"
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsIMultiPartChannel.h"
+#include "mozilla/Attributes.h"
+
+namespace mozilla {
+namespace net {
+
+// Wrapper class to make replacement of nsHttpChannel's listener
+// from JavaScript possible. It is workaround for bug 433711 and 682305.
+class nsStreamListenerWrapper final
+    : public nsIStreamListener,
+      public nsIMultiPartChannelListener,
+      public nsIThreadRetargetableStreamListener {
+ public:
+  explicit nsStreamListenerWrapper(nsIStreamListener* listener)
+      : mListener(listener) {
+    MOZ_ASSERT(mListener, "no stream listener specified");
+  }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_FORWARD_SAFE_NSIREQUESTOBSERVER(mListener)
+  NS_FORWARD_SAFE_NSISTREAMLISTENER(mListener)
+  NS_DECL_NSIMULTIPARTCHANNELLISTENER
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+
+ private:
+  ~nsStreamListenerWrapper() = default;
+  nsCOMPtr<nsIStreamListener> mListener;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsStreamListenerWrapper_h__
diff --git a/netwerk/base/nsStreamLoader.cpp b/netwerk/base/nsStreamLoader.cpp
new file mode 100644
index 0000000000..bd3ff25de9
--- /dev/null
+++ b/netwerk/base/nsStreamLoader.cpp
@@ -0,0 +1,137 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsStreamLoader.h"
+#include "nsIInputStream.h"
+#include "nsIChannel.h"
+#include "nsError.h"
+#include "mozilla/ProfilerLabels.h"
+
+#include <limits>
+
+namespace mozilla {
+namespace net {
+
+nsStreamLoader::nsStreamLoader() : mData() {}
+
+NS_IMETHODIMP
+nsStreamLoader::Init(nsIStreamLoaderObserver* aStreamObserver,
+                     nsIRequestObserver* aRequestObserver) {
+  NS_ENSURE_ARG_POINTER(aStreamObserver);
+  mObserver = aStreamObserver;
+  mRequestObserver = aRequestObserver;
+  return NS_OK;
+}
+
+nsresult nsStreamLoader::Create(REFNSIID aIID, void** aResult) {
+  RefPtr<nsStreamLoader> it = new nsStreamLoader();
+  return it->QueryInterface(aIID, aResult);
+}
+
+NS_IMPL_ISUPPORTS(nsStreamLoader, nsIStreamLoader, nsIRequestObserver,
+                  nsIStreamListener, nsIThreadRetargetableStreamListener)
+
+NS_IMETHODIMP
+nsStreamLoader::GetNumBytesRead(uint32_t* aNumBytes) {
+  *aNumBytes = mBytesRead;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamLoader::GetRequest(nsIRequest** aRequest) {
+  nsCOMPtr<nsIRequest> req = mRequest;
+  req.forget(aRequest);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamLoader::OnStartRequest(nsIRequest* request) {
+  nsCOMPtr<nsIChannel> chan(do_QueryInterface(request));
+  if (chan) {
+    int64_t contentLength = -1;
+    chan->GetContentLength(&contentLength);
+    if (contentLength >= 0) {
+      // On 64bit platforms size of uint64_t coincides with the size of size_t,
+      // so we want to compare with the minimum from size_t and int64_t.
+      if (static_cast<uint64_t>(contentLength) >
+          std::min(std::numeric_limits<size_t>::max(),
+                   static_cast<size_t>(std::numeric_limits<int64_t>::max()))) {
+        // Too big to fit into size_t, so let's bail.
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+      // preallocate buffer
+      if (!mData.initCapacity(contentLength)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+  }
+  if (mRequestObserver) {
+    mRequestObserver->OnStartRequest(request);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamLoader::OnStopRequest(nsIRequest* request, nsresult aStatus) {
+  AUTO_PROFILER_LABEL("nsStreamLoader::OnStopRequest", NETWORK);
+
+  if (mObserver) {
+    // provide nsIStreamLoader::request during call to OnStreamComplete
+    mRequest = request;
+    size_t length = mData.length();
+    uint8_t* elems = mData.extractOrCopyRawBuffer();
+    nsresult rv =
+        mObserver->OnStreamComplete(this, mContext, aStatus, length, elems);
+    if (rv != NS_SUCCESS_ADOPTED_DATA) {
+      // The observer didn't take ownership of the extracted data buffer, so
+      // put it back into mData.
+      mData.replaceRawBuffer(elems, length);
+    }
+    // done.. cleanup
+    ReleaseData();
+    mRequest = nullptr;
+    mObserver = nullptr;
+  }
+
+  if (mRequestObserver) {
+    mRequestObserver->OnStopRequest(request, aStatus);
+    mRequestObserver = nullptr;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsStreamLoader::WriteSegmentFun(nsIInputStream* inStr, void* closure,
+                                         const char* fromSegment,
+                                         uint32_t toOffset, uint32_t count,
+                                         uint32_t* writeCount) {
+  nsStreamLoader* self = (nsStreamLoader*)closure;
+
+  if (!self->mData.append(fromSegment, count)) {
+    self->mData.clearAndFree();
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  *writeCount = count;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamLoader::OnDataAvailable(nsIRequest* request, nsIInputStream* inStr,
+                                uint64_t sourceOffset, uint32_t count) {
+  uint32_t countRead;
+  nsresult rv = inStr->ReadSegments(WriteSegmentFun, this, count, &countRead);
+  NS_ENSURE_SUCCESS(rv, rv);
+  mBytesRead += countRead;
+  return NS_OK;
+}
+
+void nsStreamLoader::ReleaseData() { mData.clearAndFree(); }
+
+NS_IMETHODIMP
+nsStreamLoader::CheckListenerChain() { return NS_OK; }
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsStreamLoader.h b/netwerk/base/nsStreamLoader.h
new file mode 100644
index 0000000000..100510583c
--- /dev/null
+++ b/netwerk/base/nsStreamLoader.h
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsStreamLoader_h__
+#define nsStreamLoader_h__
+
+#include "nsIThreadRetargetableStreamListener.h"
+#include "nsIStreamLoader.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Vector.h"
+
+class nsIRequest;
+
+namespace mozilla {
+namespace net {
+
+class nsStreamLoader final : public nsIStreamLoader,
+                             public nsIThreadRetargetableStreamListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISTREAMLOADER
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+
+  nsStreamLoader();
+
+  static nsresult Create(REFNSIID aIID, void** aResult);
+
+ protected:
+  ~nsStreamLoader() = default;
+
+  static nsresult WriteSegmentFun(nsIInputStream*, void*, const char*, uint32_t,
+                                  uint32_t, uint32_t*);
+
+  // Utility method to free mData, if present, and update other state to
+  // reflect that no data has been allocated.
+  void ReleaseData();
+
+  nsCOMPtr<nsIStreamLoaderObserver> mObserver;
+  nsCOMPtr<nsISupports> mContext;  // the observer's context
+  nsCOMPtr<nsIRequest> mRequest;
+  nsCOMPtr<nsIRequestObserver> mRequestObserver;
+
+  mozilla::Atomic<uint32_t, mozilla::MemoryOrdering::Relaxed> mBytesRead;
+
+  // Buffer to accumulate incoming data. We preallocate if contentSize is
+  // available.
+  mozilla::Vector<uint8_t, 0> mData;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsStreamLoader_h__
diff --git a/netwerk/base/nsStreamTransportService.cpp b/netwerk/base/nsStreamTransportService.cpp
new file mode 100644
index 0000000000..e1369bbcb5
--- /dev/null
+++ b/netwerk/base/nsStreamTransportService.cpp
@@ -0,0 +1,429 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsStreamTransportService.h"
+#include "ErrorList.h"
+#include "nsXPCOMCIDInternal.h"
+#include "nsNetSegmentUtils.h"
+#include "nsTransportUtils.h"
+#include "nsStreamUtils.h"
+#include "nsError.h"
+#include "nsNetCID.h"
+
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIPipe.h"
+#include "nsITransport.h"
+#include "nsIObserverService.h"
+#include "nsThreadPool.h"
+#include "mozilla/Services.h"
+
+namespace mozilla {
+namespace net {
+
+//-----------------------------------------------------------------------------
+// nsInputStreamTransport
+//
+// Implements nsIInputStream as a wrapper around the real input stream.  This
+// allows the transport to support seeking, range-limiting, progress reporting,
+// and close-when-done semantics while utilizing NS_AsyncCopy.
+//-----------------------------------------------------------------------------
+
+class nsInputStreamTransport : public nsITransport,
+                               public nsIAsyncInputStream,
+                               public nsIInputStreamCallback {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITRANSPORT
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+
+  nsInputStreamTransport(nsIInputStream* source, bool closeWhenDone)
+      : mSource(source), mCloseWhenDone(closeWhenDone) {
+    mAsyncSource = do_QueryInterface(mSource);
+  }
+
+ private:
+  virtual ~nsInputStreamTransport() = default;
+
+  Mutex mMutex MOZ_UNANNOTATED{"nsInputStreamTransport::mMutex"};
+
+  // This value is protected by mutex.
+  nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback;
+
+  nsCOMPtr<nsIAsyncInputStream> mPipeIn;
+
+  // while the copy is active, these members may only be accessed from the
+  // nsIInputStream implementation.
+  nsCOMPtr<nsITransportEventSink> mEventSink;
+  nsCOMPtr<nsIInputStream> mSource;
+
+  // It can be null.
+  nsCOMPtr<nsIAsyncInputStream> mAsyncSource;
+
+  int64_t mOffset{0};
+  const bool mCloseWhenDone;
+
+  // this variable serves as a lock to prevent the state of the transport
+  // from being modified once the copy is in progress.
+  bool mInProgress{false};
+};
+
+NS_IMPL_ADDREF(nsInputStreamTransport);
+NS_IMPL_RELEASE(nsInputStreamTransport);
+
+NS_INTERFACE_MAP_BEGIN(nsInputStreamTransport)
+  NS_INTERFACE_MAP_ENTRY(nsITransport)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStream)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, !!mAsyncSource)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback, !!mAsyncSource)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsITransport)
+NS_INTERFACE_MAP_END
+
+/** nsITransport **/
+
+NS_IMETHODIMP
+nsInputStreamTransport::OpenInputStream(uint32_t flags, uint32_t segsize,
+                                        uint32_t segcount,
+                                        nsIInputStream** result) {
+  NS_ENSURE_TRUE(!mInProgress, NS_ERROR_IN_PROGRESS);
+
+  nsresult rv;
+  nsCOMPtr<nsIEventTarget> target =
+      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  // XXX if the caller requests an unbuffered stream, then perhaps
+  //     we'd want to simply return mSource; however, then we would
+  //     not be reading mSource on a background thread.  is this ok?
+
+  bool nonblocking = !(flags & OPEN_BLOCKING);
+
+  net_ResolveSegmentParams(segsize, segcount);
+
+  nsCOMPtr<nsIAsyncOutputStream> pipeOut;
+  NS_NewPipe2(getter_AddRefs(mPipeIn), getter_AddRefs(pipeOut), nonblocking,
+              true, segsize, segcount);
+
+  mInProgress = true;
+
+  // startup async copy process...
+  rv = NS_AsyncCopy(this, pipeOut, target, NS_ASYNCCOPY_VIA_WRITESEGMENTS,
+                    segsize);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  *result = do_AddRef(mPipeIn).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::OpenOutputStream(uint32_t flags, uint32_t segsize,
+                                         uint32_t segcount,
+                                         nsIOutputStream** result) {
+  // this transport only supports reading!
+  MOZ_ASSERT_UNREACHABLE("nsInputStreamTransport::OpenOutputStream");
+  return NS_ERROR_UNEXPECTED;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::Close(nsresult reason) {
+  if (NS_SUCCEEDED(reason)) reason = NS_BASE_STREAM_CLOSED;
+
+  return mPipeIn->CloseWithStatus(reason);
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::SetEventSink(nsITransportEventSink* sink,
+                                     nsIEventTarget* target) {
+  NS_ENSURE_TRUE(!mInProgress, NS_ERROR_IN_PROGRESS);
+
+  if (target) {
+    return net_NewTransportEventSinkProxy(getter_AddRefs(mEventSink), sink,
+                                          target);
+  }
+
+  mEventSink = sink;
+  return NS_OK;
+}
+
+/** nsIInputStream **/
+
+NS_IMETHODIMP
+nsInputStreamTransport::Close() {
+  if (mCloseWhenDone) mSource->Close();
+
+  // make additional reads return early...
+  mOffset = 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::Available(uint64_t* result) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::StreamStatus() { return mSource->StreamStatus(); }
+
+NS_IMETHODIMP
+nsInputStreamTransport::Read(char* buf, uint32_t count, uint32_t* result) {
+  nsresult rv = mSource->Read(buf, count, result);
+
+  if (NS_SUCCEEDED(rv)) {
+    mOffset += *result;
+    if (mEventSink) {
+      mEventSink->OnTransportStatus(this, NS_NET_STATUS_READING, mOffset, -1);
+    }
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                     uint32_t count, uint32_t* result) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsInputStreamTransport::IsNonBlocking(bool* result) {
+  *result = false;
+  return NS_OK;
+}
+
+// nsIAsyncInputStream interface
+
+NS_IMETHODIMP
+nsInputStreamTransport::CloseWithStatus(nsresult aStatus) { return Close(); }
+
+NS_IMETHODIMP
+nsInputStreamTransport::AsyncWait(nsIInputStreamCallback* aCallback,
+                                  uint32_t aFlags, uint32_t aRequestedCount,
+                                  nsIEventTarget* aEventTarget) {
+  NS_ENSURE_STATE(!!mAsyncSource);
+
+  nsCOMPtr<nsIInputStreamCallback> callback = aCallback ? this : nullptr;
+
+  {
+    MutexAutoLock lock(mMutex);
+
+    if (NS_WARN_IF(mAsyncWaitCallback && aCallback &&
+                   mAsyncWaitCallback != aCallback)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mAsyncWaitCallback = aCallback;
+  }
+
+  return mAsyncSource->AsyncWait(callback, aFlags, aRequestedCount,
+                                 aEventTarget);
+}
+
+// nsIInputStreamCallback
+
+NS_IMETHODIMP
+nsInputStreamTransport::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  nsCOMPtr<nsIInputStreamCallback> callback;
+  {
+    MutexAutoLock lock(mMutex);
+
+    // We have been canceled in the meanwhile.
+    if (!mAsyncWaitCallback) {
+      return NS_OK;
+    }
+
+    callback.swap(mAsyncWaitCallback);
+  }
+
+  MOZ_ASSERT(callback);
+  return callback->OnInputStreamReady(this);
+}
+
+//-----------------------------------------------------------------------------
+// nsStreamTransportService
+//-----------------------------------------------------------------------------
+
+nsStreamTransportService::nsStreamTransportService() = default;
+
+nsStreamTransportService::~nsStreamTransportService() {
+  NS_ASSERTION(!mPool, "thread pool wasn't shutdown");
+}
+
+nsresult nsStreamTransportService::Init() {
+  // Can't be used multithreaded before this
+  MOZ_PUSH_IGNORE_THREAD_SAFETY
+  MOZ_ASSERT(!mPool);
+  mPool = new nsThreadPool();
+
+  // Configure the pool
+  mPool->SetName("StreamTrans"_ns);
+  mPool->SetThreadLimit(25);
+  mPool->SetIdleThreadLimit(5);
+  mPool->SetIdleThreadTimeoutRegressive(true);
+  mPool->SetIdleThreadTimeout(PR_SecondsToInterval(30));
+  MOZ_POP_THREAD_SAFETY
+
+  nsCOMPtr<nsIObserverService> obsSvc = mozilla::services::GetObserverService();
+  if (obsSvc) obsSvc->AddObserver(this, "xpcom-shutdown-threads", false);
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(nsStreamTransportService, nsIStreamTransportService,
+                  nsIEventTarget, nsIObserver)
+
+NS_IMETHODIMP
+nsStreamTransportService::DispatchFromScript(nsIRunnable* task,
+                                             uint32_t flags) {
+  nsCOMPtr<nsIRunnable> event(task);
+  return Dispatch(event.forget(), flags);
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::Dispatch(already_AddRefed<nsIRunnable> task,
+                                   uint32_t flags) {
+  nsCOMPtr<nsIRunnable> event(task);  // so it gets released on failure paths
+  nsCOMPtr<nsIThreadPool> pool;
+  {
+    mozilla::MutexAutoLock lock(mShutdownLock);
+    if (mIsShutdown) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+    pool = mPool;
+  }
+  NS_ENSURE_TRUE(pool, NS_ERROR_NOT_INITIALIZED);
+  return pool->Dispatch(event.forget(), flags);
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::DelayedDispatch(already_AddRefed<nsIRunnable> aEvent,
+                                          uint32_t aDelayMs) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::RegisterShutdownTask(nsITargetShutdownTask*) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::UnregisterShutdownTask(nsITargetShutdownTask*) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP_(bool)
+nsStreamTransportService::IsOnCurrentThreadInfallible() {
+  nsCOMPtr<nsIThreadPool> pool;
+  {
+    mozilla::MutexAutoLock lock(mShutdownLock);
+    pool = mPool;
+  }
+  if (!pool) {
+    return false;
+  }
+  return pool->IsOnCurrentThread();
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::IsOnCurrentThread(bool* result) {
+  nsCOMPtr<nsIThreadPool> pool;
+  {
+    mozilla::MutexAutoLock lock(mShutdownLock);
+    if (mIsShutdown) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+    pool = mPool;
+  }
+  NS_ENSURE_TRUE(pool, NS_ERROR_NOT_INITIALIZED);
+  return pool->IsOnCurrentThread(result);
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::CreateInputTransport(nsIInputStream* stream,
+                                               bool closeWhenDone,
+                                               nsITransport** result) {
+  RefPtr<nsInputStreamTransport> trans =
+      new nsInputStreamTransport(stream, closeWhenDone);
+  trans.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsStreamTransportService::Observe(nsISupports* subject, const char* topic,
+                                  const char16_t* data) {
+  NS_ASSERTION(strcmp(topic, "xpcom-shutdown-threads") == 0, "oops");
+
+  {
+    nsCOMPtr<nsIThreadPool> pool;
+    {
+      mozilla::MutexAutoLock lock(mShutdownLock);
+      mIsShutdown = true;
+      pool = mPool.forget();
+    }
+
+    if (pool) {
+      pool->Shutdown();
+    }
+  }
+  return NS_OK;
+}
+
+class AvailableEvent final : public Runnable {
+ public:
+  AvailableEvent(nsIInputStream* stream, nsIInputAvailableCallback* callback)
+      : Runnable("net::AvailableEvent"),
+        mStream(stream),
+        mCallback(callback),
+        mDoingCallback(false),
+        mSize(0),
+        mResultForCallback(NS_OK) {
+    mCallbackTarget = GetCurrentSerialEventTarget();
+  }
+
+  NS_IMETHOD Run() override {
+    if (mDoingCallback) {
+      // pong
+      mCallback->OnInputAvailableComplete(mSize, mResultForCallback);
+      mCallback = nullptr;
+    } else {
+      // ping
+      mResultForCallback = mStream->Available(&mSize);
+      mStream = nullptr;
+      mDoingCallback = true;
+
+      nsCOMPtr<nsIRunnable> event(this);  // overly cute
+      mCallbackTarget->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
+      mCallbackTarget = nullptr;
+    }
+    return NS_OK;
+  }
+
+ private:
+  virtual ~AvailableEvent() = default;
+
+  nsCOMPtr<nsIInputStream> mStream;
+  nsCOMPtr<nsIInputAvailableCallback> mCallback;
+  nsCOMPtr<nsIEventTarget> mCallbackTarget;
+  bool mDoingCallback;
+  uint64_t mSize;
+  nsresult mResultForCallback;
+};
+
+NS_IMETHODIMP
+nsStreamTransportService::InputAvailable(nsIInputStream* stream,
+                                         nsIInputAvailableCallback* callback) {
+  nsCOMPtr<nsIThreadPool> pool;
+  {
+    mozilla::MutexAutoLock lock(mShutdownLock);
+    if (mIsShutdown) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+    pool = mPool;
+  }
+  nsCOMPtr<nsIRunnable> event = new AvailableEvent(stream, callback);
+  return pool->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsStreamTransportService.h b/netwerk/base/nsStreamTransportService.h
new file mode 100644
index 0000000000..1229c0ca44
--- /dev/null
+++ b/netwerk/base/nsStreamTransportService.h
@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsStreamTransportService_h__
+#define nsStreamTransportService_h__
+
+#include "nsIStreamTransportService.h"
+#include "nsIEventTarget.h"
+#include "nsIObserver.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/DataMutex.h"
+#include "mozilla/Mutex.h"
+
+class nsIThreadPool;
+
+namespace mozilla {
+namespace net {
+
+class nsStreamTransportService final : public nsIStreamTransportService,
+                                       public nsIEventTarget,
+                                       public nsIObserver {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSISTREAMTRANSPORTSERVICE
+  NS_DECL_NSIEVENTTARGET_FULL
+  NS_DECL_NSIOBSERVER
+
+  nsresult Init();
+
+  nsStreamTransportService();
+
+ private:
+  ~nsStreamTransportService();
+
+  nsCOMPtr<nsIThreadPool> mPool MOZ_GUARDED_BY(mShutdownLock);
+
+  mozilla::Mutex mShutdownLock{"nsStreamTransportService.mShutdownLock"};
+  bool mIsShutdown MOZ_GUARDED_BY(mShutdownLock){false};
+};
+
+}  // namespace net
+}  // namespace mozilla
+#endif
diff --git a/netwerk/base/nsSyncStreamListener.cpp b/netwerk/base/nsSyncStreamListener.cpp
new file mode 100644
index 0000000000..7e5ec94231
--- /dev/null
+++ b/netwerk/base/nsSyncStreamListener.cpp
@@ -0,0 +1,169 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/SpinEventLoopUntil.h"
+#include "nsIOService.h"
+#include "nsIPipe.h"
+#include "nsSyncStreamListener.h"
+#include "nsThreadUtils.h"
+#include <algorithm>
+
+using namespace mozilla::net;
+
+nsSyncStreamListener::nsSyncStreamListener() {
+  MOZ_ASSERT(NS_IsMainThread());
+  NS_NewPipe(getter_AddRefs(mPipeIn), getter_AddRefs(mPipeOut),
+             mozilla::net::nsIOService::gDefaultSegmentSize,
+             UINT32_MAX,  // no size limit
+             false, false);
+}
+
+nsresult nsSyncStreamListener::WaitForData() {
+  mKeepWaiting = true;
+
+  if (!mozilla::SpinEventLoopUntil("nsSyncStreamListener::Create"_ns,
+                                   [&]() { return !mKeepWaiting; })) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsSyncStreamListener, nsIStreamListener, nsIRequestObserver,
+                  nsIInputStream, nsISyncStreamListener)
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsISyncStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::GetInputStream(nsIInputStream** result) {
+  *result = do_AddRef(this).take();
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsIStreamListener
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnStartRequest(nsIRequest* request) { return NS_OK; }
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnDataAvailable(nsIRequest* request,
+                                      nsIInputStream* stream, uint64_t offset,
+                                      uint32_t count) {
+  uint32_t bytesWritten;
+
+  nsresult rv = mPipeOut->WriteFrom(stream, count, &bytesWritten);
+
+  // if we get an error, then return failure.  this will cause the
+  // channel to be canceled, and as a result our OnStopRequest method
+  // will be called immediately.  because of this we do not need to
+  // set mStatus or mKeepWaiting here.
+  if (NS_FAILED(rv)) return rv;
+
+  // we expect that all data will be written to the pipe because
+  // the pipe was created to have "infinite" room.
+  NS_ASSERTION(bytesWritten == count, "did not write all data");
+
+  mKeepWaiting = false;  // unblock Read
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::OnStopRequest(nsIRequest* request, nsresult status) {
+  mStatus = status;
+  mKeepWaiting = false;  // unblock Read
+  mDone = true;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsSyncStreamListener::nsIInputStream
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsSyncStreamListener::Close() {
+  mStatus = NS_BASE_STREAM_CLOSED;
+  mDone = true;
+
+  // It'd be nice if we could explicitly cancel the request at this point,
+  // but we don't have a reference to it, so the best we can do is close the
+  // pipe so that the next OnDataAvailable event will fail.
+  if (mPipeIn) {
+    mPipeIn->Close();
+    mPipeIn = nullptr;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::Available(uint64_t* result) {
+  if (NS_FAILED(mStatus)) return mStatus;
+
+  mStatus = mPipeIn->Available(result);
+  if (NS_SUCCEEDED(mStatus) && (*result == 0) && !mDone) {
+    nsresult rv = WaitForData();
+    if (NS_FAILED(rv)) {
+      // Note that `WaitForData` could fail `mStatus`. Do not overwrite if it's
+      // the case.
+      mStatus = NS_SUCCEEDED(mStatus) ? rv : mStatus;
+    } else if (NS_SUCCEEDED(mStatus)) {
+      mStatus = mPipeIn->Available(result);
+    }
+  }
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::StreamStatus() {
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  mStatus = mPipeIn->StreamStatus();
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::Read(char* buf, uint32_t bufLen, uint32_t* result) {
+  if (mStatus == NS_BASE_STREAM_CLOSED) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  uint64_t avail64;
+  if (NS_FAILED(Available(&avail64))) return mStatus;
+
+  uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)bufLen);
+  mStatus = mPipeIn->Read(buf, avail, result);
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::ReadSegments(nsWriteSegmentFun writer, void* closure,
+                                   uint32_t count, uint32_t* result) {
+  if (mStatus == NS_BASE_STREAM_CLOSED) {
+    *result = 0;
+    return NS_OK;
+  }
+
+  uint64_t avail64;
+  if (NS_FAILED(Available(&avail64))) return mStatus;
+
+  uint32_t avail = (uint32_t)std::min(avail64, (uint64_t)count);
+  mStatus = mPipeIn->ReadSegments(writer, closure, avail, result);
+  return mStatus;
+}
+
+NS_IMETHODIMP
+nsSyncStreamListener::IsNonBlocking(bool* result) {
+  *result = false;
+  return NS_OK;
+}
diff --git a/netwerk/base/nsSyncStreamListener.h b/netwerk/base/nsSyncStreamListener.h
new file mode 100644
index 0000000000..9bd9908535
--- /dev/null
+++ b/netwerk/base/nsSyncStreamListener.h
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsSyncStreamListener_h__
+#define nsSyncStreamListener_h__
+
+#include "nsISyncStreamListener.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+
+//-----------------------------------------------------------------------------
+
+class nsSyncStreamListener final : public nsISyncStreamListener,
+                                   public nsIInputStream {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSISYNCSTREAMLISTENER
+  NS_DECL_NSIINPUTSTREAM
+
+ private:
+  // Factory method:
+  friend nsresult NS_NewSyncStreamListener(nsIStreamListener** result,
+                                           nsIInputStream** stream);
+  nsSyncStreamListener();
+  ~nsSyncStreamListener() = default;
+
+  nsresult Init();
+
+  nsresult WaitForData();
+
+  nsCOMPtr<nsIInputStream> mPipeIn;
+  nsCOMPtr<nsIOutputStream> mPipeOut;
+  nsresult mStatus{NS_OK};
+  bool mKeepWaiting{false};
+  bool mDone{false};
+};
+
+#endif  // nsSyncStreamListener_h__
diff --git a/netwerk/base/nsTransportUtils.cpp b/netwerk/base/nsTransportUtils.cpp
new file mode 100644
index 0000000000..df53ead198
--- /dev/null
+++ b/netwerk/base/nsTransportUtils.cpp
@@ -0,0 +1,133 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Mutex.h"
+#include "nsCOMPtr.h"
+#include "nsITransport.h"
+#include "nsProxyRelease.h"
+#include "nsSocketTransportService2.h"
+#include "nsThreadUtils.h"
+#include "nsTransportUtils.h"
+
+using namespace mozilla;
+
+//-----------------------------------------------------------------------------
+
+class nsTransportStatusEvent;
+
+class nsTransportEventSinkProxy : public nsITransportEventSink {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITRANSPORTEVENTSINK
+
+  nsTransportEventSinkProxy(nsITransportEventSink* sink, nsIEventTarget* target)
+      : mSink(sink),
+        mTarget(target),
+        mLock("nsTransportEventSinkProxy.mLock"),
+        mLastEvent(nullptr) {
+    NS_ADDREF(mSink);
+  }
+
+ private:
+  virtual ~nsTransportEventSinkProxy() {
+    // our reference to mSink could be the last, so be sure to release
+    // it on the target thread.  otherwise, we could get into trouble.
+    NS_ProxyRelease("nsTransportEventSinkProxy::mSink", mTarget,
+                    dont_AddRef(mSink));
+  }
+
+ public:
+  nsITransportEventSink* mSink;
+  nsCOMPtr<nsIEventTarget> mTarget;
+  Mutex mLock MOZ_UNANNOTATED;
+  nsTransportStatusEvent* mLastEvent;
+};
+
+class nsTransportStatusEvent : public Runnable {
+ public:
+  nsTransportStatusEvent(nsTransportEventSinkProxy* proxy,
+                         nsITransport* transport, nsresult status,
+                         int64_t progress, int64_t progressMax)
+      : Runnable("nsTransportStatusEvent"),
+        mProxy(proxy),
+        mTransport(transport),
+        mStatus(status),
+        mProgress(progress),
+        mProgressMax(progressMax) {}
+
+  ~nsTransportStatusEvent() {
+    auto ReleaseTransport = [transport(std::move(mTransport))]() mutable {};
+    if (!net::OnSocketThread()) {
+      net::gSocketTransportService->Dispatch(NS_NewRunnableFunction(
+          "nsHttpConnection::~nsHttpConnection", std::move(ReleaseTransport)));
+    }
+  }
+
+  NS_IMETHOD Run() override {
+    // since this event is being handled, we need to clear the proxy's ref.
+    // if not coalescing all, then last event may not equal self!
+    {
+      MutexAutoLock lock(mProxy->mLock);
+      if (mProxy->mLastEvent == this) mProxy->mLastEvent = nullptr;
+    }
+
+    mProxy->mSink->OnTransportStatus(mTransport, mStatus, mProgress,
+                                     mProgressMax);
+    return NS_OK;
+  }
+
+  RefPtr<nsTransportEventSinkProxy> mProxy;
+
+  // parameters to OnTransportStatus
+  nsCOMPtr<nsITransport> mTransport;
+  nsresult mStatus;
+  int64_t mProgress;
+  int64_t mProgressMax;
+};
+
+NS_IMPL_ISUPPORTS(nsTransportEventSinkProxy, nsITransportEventSink)
+
+NS_IMETHODIMP
+nsTransportEventSinkProxy::OnTransportStatus(nsITransport* transport,
+                                             nsresult status, int64_t progress,
+                                             int64_t progressMax) {
+  nsresult rv = NS_OK;
+  RefPtr<nsTransportStatusEvent> event;
+  {
+    MutexAutoLock lock(mLock);
+
+    // try to coalesce events! ;-)
+    if (mLastEvent && (mLastEvent->mStatus == status)) {
+      mLastEvent->mStatus = status;
+      mLastEvent->mProgress = progress;
+      mLastEvent->mProgressMax = progressMax;
+    } else {
+      event = new nsTransportStatusEvent(this, transport, status, progress,
+                                         progressMax);
+      if (!event) rv = NS_ERROR_OUT_OF_MEMORY;
+      mLastEvent = event;  // weak ref
+    }
+  }
+  if (event) {
+    rv = mTarget->Dispatch(event, NS_DISPATCH_NORMAL);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("unable to post transport status event");
+
+      MutexAutoLock lock(mLock);  // cleanup.. don't reference anymore!
+      mLastEvent = nullptr;
+    }
+  }
+  return rv;
+}
+
+//-----------------------------------------------------------------------------
+
+nsresult net_NewTransportEventSinkProxy(nsITransportEventSink** result,
+                                        nsITransportEventSink* sink,
+                                        nsIEventTarget* target) {
+  RefPtr<nsTransportEventSinkProxy> res =
+      new nsTransportEventSinkProxy(sink, target);
+  res.forget(result);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsTransportUtils.h b/netwerk/base/nsTransportUtils.h
new file mode 100644
index 0000000000..141b9e4eda
--- /dev/null
+++ b/netwerk/base/nsTransportUtils.h
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsTransportUtils_h__
+#define nsTransportUtils_h__
+
+#include "nsITransport.h"
+
+/**
+ * This function returns a proxy object for a transport event sink instance.
+ * The transport event sink will be called on the thread indicated by the
+ * given event target.  Like events are automatically coalesced.  This means
+ * that for example if the status value is the same from event to event, and
+ * the previous event has not yet been delivered, then only one event will
+ * be delivered.  The progress reported will be that from the second event.
+
+ * Coalescing events can help prevent a backlog of unprocessed transport
+ * events in the case that the target thread is overworked.
+ */
+nsresult net_NewTransportEventSinkProxy(nsITransportEventSink** aResult,
+                                        nsITransportEventSink* aSink,
+                                        nsIEventTarget* aTarget);
+
+#endif  // nsTransportUtils_h__
diff --git a/netwerk/base/nsUDPSocket.cpp b/netwerk/base/nsUDPSocket.cpp
new file mode 100644
index 0000000000..fa74a53f3c
--- /dev/null
+++ b/netwerk/base/nsUDPSocket.cpp
@@ -0,0 +1,1545 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Attributes.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/Telemetry.h"
+
+#include "nsQueryObject.h"
+#include "nsSocketTransport2.h"
+#include "nsUDPSocket.h"
+#include "nsProxyRelease.h"
+#include "nsError.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsIOService.h"
+#include "prnetdb.h"
+#include "prio.h"
+#include "nsNetAddr.h"
+#include "nsNetSegmentUtils.h"
+#include "IOActivityMonitor.h"
+#include "nsServiceManagerUtils.h"
+#include "nsStreamUtils.h"
+#include "prerror.h"
+#include "nsThreadUtils.h"
+#include "nsIDNSRecord.h"
+#include "nsIDNSService.h"
+#include "nsICancelable.h"
+#include "nsIPipe.h"
+#include "nsWrapperCacheInlines.h"
+#include "HttpConnectionUDP.h"
+#include "mozilla/StaticPrefs_network.h"
+
+#if defined(FUZZING)
+#  include "FuzzyLayer.h"
+#  include "mozilla/StaticPrefs_fuzzing.h"
+#endif
+
+namespace mozilla {
+namespace net {
+
+static const uint32_t UDP_PACKET_CHUNK_SIZE = 1400;
+
+//-----------------------------------------------------------------------------
+
+using nsUDPSocketFunc = void (nsUDPSocket::*)();
+
+static nsresult PostEvent(nsUDPSocket* s, nsUDPSocketFunc func) {
+  if (!gSocketTransportService) return NS_ERROR_FAILURE;
+
+  return gSocketTransportService->Dispatch(
+      NewRunnableMethod("net::PostEvent", s, func), NS_DISPATCH_NORMAL);
+}
+
+static nsresult ResolveHost(const nsACString& host,
+                            const OriginAttributes& aOriginAttributes,
+                            nsIDNSListener* listener) {
+  nsresult rv;
+
+  nsCOMPtr<nsIDNSService> dns =
+      do_GetService("@mozilla.org/network/dns-service;1", &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsICancelable> tmpOutstanding;
+  return dns->AsyncResolveNative(host, nsIDNSService::RESOLVE_TYPE_DEFAULT,
+                                 nsIDNSService::RESOLVE_DEFAULT_FLAGS, nullptr,
+                                 listener, nullptr, aOriginAttributes,
+                                 getter_AddRefs(tmpOutstanding));
+}
+
+static nsresult CheckIOStatus(const NetAddr* aAddr) {
+  MOZ_ASSERT(gIOService);
+
+  if (gIOService->IsNetTearingDown()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (gIOService->IsOffline() &&
+      (StaticPrefs::network_disable_localhost_when_offline() ||
+       !aAddr->IsLoopbackAddr())) {
+    return NS_ERROR_OFFLINE;
+  }
+
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+class SetSocketOptionRunnable : public Runnable {
+ public:
+  SetSocketOptionRunnable(nsUDPSocket* aSocket, const PRSocketOptionData& aOpt)
+      : Runnable("net::SetSocketOptionRunnable"),
+        mSocket(aSocket),
+        mOpt(aOpt) {}
+
+  NS_IMETHOD Run() override { return mSocket->SetSocketOption(mOpt); }
+
+ private:
+  RefPtr<nsUDPSocket> mSocket;
+  PRSocketOptionData mOpt;
+};
+
+//-----------------------------------------------------------------------------
+// nsUDPOutputStream impl
+//-----------------------------------------------------------------------------
+NS_IMPL_ISUPPORTS(nsUDPOutputStream, nsIOutputStream)
+
+nsUDPOutputStream::nsUDPOutputStream(nsUDPSocket* aSocket, PRFileDesc* aFD,
+                                     PRNetAddr& aPrClientAddr)
+    : mSocket(aSocket),
+      mFD(aFD),
+      mPrClientAddr(aPrClientAddr),
+      mIsClosed(false) {}
+
+NS_IMETHODIMP nsUDPOutputStream::Close() {
+  if (mIsClosed) return NS_BASE_STREAM_CLOSED;
+
+  mIsClosed = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsUDPOutputStream::Flush() { return NS_OK; }
+
+NS_IMETHODIMP nsUDPOutputStream::StreamStatus() {
+  return mIsClosed ? NS_BASE_STREAM_CLOSED : NS_OK;
+}
+
+NS_IMETHODIMP nsUDPOutputStream::Write(const char* aBuf, uint32_t aCount,
+                                       uint32_t* _retval) {
+  if (mIsClosed) return NS_BASE_STREAM_CLOSED;
+
+  *_retval = 0;
+  int32_t count =
+      PR_SendTo(mFD, aBuf, aCount, 0, &mPrClientAddr, PR_INTERVAL_NO_WAIT);
+  if (count < 0) {
+    PRErrorCode code = PR_GetError();
+    return ErrorAccordingToNSPR(code);
+  }
+
+  *_retval = count;
+
+  mSocket->AddOutputBytes(count);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsUDPOutputStream::WriteFrom(nsIInputStream* aFromStream,
+                                           uint32_t aCount, uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP nsUDPOutputStream::WriteSegments(nsReadSegmentFun aReader,
+                                               void* aClosure, uint32_t aCount,
+                                               uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP nsUDPOutputStream::IsNonBlocking(bool* _retval) {
+  *_retval = true;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// nsUDPMessage impl
+//-----------------------------------------------------------------------------
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsUDPMessage)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsUDPMessage)
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsUDPMessage)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsUDPMessage)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsIUDPMessage)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsUDPMessage)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mJsobj)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsUDPMessage)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsUDPMessage)
+  tmp->mJsobj = nullptr;
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+nsUDPMessage::nsUDPMessage(NetAddr* aAddr, nsIOutputStream* aOutputStream,
+                           FallibleTArray<uint8_t>&& aData)
+    : mOutputStream(aOutputStream), mData(std::move(aData)) {
+  memcpy(&mAddr, aAddr, sizeof(NetAddr));
+}
+
+nsUDPMessage::~nsUDPMessage() { DropJSObjects(this); }
+
+NS_IMETHODIMP
+nsUDPMessage::GetFromAddr(nsINetAddr** aFromAddr) {
+  NS_ENSURE_ARG_POINTER(aFromAddr);
+
+  nsCOMPtr<nsINetAddr> result = new nsNetAddr(&mAddr);
+  result.forget(aFromAddr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPMessage::GetData(nsACString& aData) {
+  aData.Assign(reinterpret_cast<const char*>(mData.Elements()), mData.Length());
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPMessage::GetOutputStream(nsIOutputStream** aOutputStream) {
+  NS_ENSURE_ARG_POINTER(aOutputStream);
+  *aOutputStream = do_AddRef(mOutputStream).take();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPMessage::GetRawData(JSContext* cx, JS::MutableHandle<JS::Value> aRawData) {
+  if (!mJsobj) {
+    mJsobj =
+        dom::Uint8Array::Create(cx, nullptr, mData.Length(), mData.Elements());
+    HoldJSObjects(this);
+  }
+  aRawData.setObject(*mJsobj);
+  return NS_OK;
+}
+
+FallibleTArray<uint8_t>& nsUDPMessage::GetDataAsTArray() { return mData; }
+
+//-----------------------------------------------------------------------------
+// nsUDPSocket
+//-----------------------------------------------------------------------------
+
+nsUDPSocket::nsUDPSocket() {
+  // we want to be able to access the STS directly, and it may not have been
+  // constructed yet.  the STS constructor sets gSocketTransportService.
+  if (!gSocketTransportService) {
+    // This call can fail if we're offline, for example.
+    nsCOMPtr<nsISocketTransportService> sts =
+        do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID);
+  }
+
+  mSts = gSocketTransportService;
+}
+
+nsUDPSocket::~nsUDPSocket() { CloseSocket(); }
+
+void nsUDPSocket::AddOutputBytes(uint64_t aBytes) { mByteWriteCount += aBytes; }
+
+void nsUDPSocket::OnMsgClose() {
+  UDPSOCKET_LOG(("nsUDPSocket::OnMsgClose [this=%p]\n", this));
+
+  if (NS_FAILED(mCondition)) return;
+
+  // tear down socket.  this signals the STS to detach our socket handler.
+  mCondition = NS_BINDING_ABORTED;
+
+  // if we are attached, then socket transport service will call our
+  // OnSocketDetached method automatically. Otherwise, we have to call it
+  // (and thus close the socket) manually.
+  if (!mAttached) OnSocketDetached(mFD);
+}
+
+void nsUDPSocket::OnMsgAttach() {
+  UDPSOCKET_LOG(("nsUDPSocket::OnMsgAttach [this=%p]\n", this));
+
+  if (NS_FAILED(mCondition)) return;
+
+  mCondition = TryAttach();
+
+  // if we hit an error while trying to attach then bail...
+  if (NS_FAILED(mCondition)) {
+    UDPSOCKET_LOG(("nsUDPSocket::OnMsgAttach: TryAttach FAILED err=0x%" PRIx32
+                   " [this=%p]\n",
+                   static_cast<uint32_t>(mCondition), this));
+    NS_ASSERTION(!mAttached, "should not be attached already");
+    OnSocketDetached(mFD);
+  }
+}
+
+nsresult nsUDPSocket::TryAttach() {
+  nsresult rv;
+
+  if (!gSocketTransportService) return NS_ERROR_FAILURE;
+
+  rv = CheckIOStatus(&mAddr);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  //
+  // find out if it is going to be ok to attach another socket to the STS.
+  // if not then we have to wait for the STS to tell us that it is ok.
+  // the notification is asynchronous, which means that when we could be
+  // in a race to call AttachSocket once notified.  for this reason, when
+  // we get notified, we just re-enter this function.  as a result, we are
+  // sure to ask again before calling AttachSocket.  in this way we deal
+  // with the race condition.  though it isn't the most elegant solution,
+  // it is far simpler than trying to build a system that would guarantee
+  // FIFO ordering (which wouldn't even be that valuable IMO).  see bug
+  // 194402 for more info.
+  //
+  if (!gSocketTransportService->CanAttachSocket()) {
+    nsCOMPtr<nsIRunnable> event = NewRunnableMethod(
+        "net::nsUDPSocket::OnMsgAttach", this, &nsUDPSocket::OnMsgAttach);
+
+    nsresult rv = gSocketTransportService->NotifyWhenCanAttachSocket(event);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  //
+  // ok, we can now attach our socket to the STS for polling
+  //
+  rv = gSocketTransportService->AttachSocket(mFD, this);
+  if (NS_FAILED(rv)) return rv;
+
+  mAttached = true;
+
+  //
+  // now, configure our poll flags for listening...
+  //
+  mPollFlags = (PR_POLL_READ | PR_POLL_EXCEPT);
+  return NS_OK;
+}
+
+namespace {
+//-----------------------------------------------------------------------------
+// UDPMessageProxy
+//-----------------------------------------------------------------------------
+class UDPMessageProxy final : public nsIUDPMessage {
+ public:
+  UDPMessageProxy(NetAddr* aAddr, nsIOutputStream* aOutputStream,
+                  FallibleTArray<uint8_t>&& aData)
+      : mOutputStream(aOutputStream), mData(std::move(aData)) {
+    memcpy(&mAddr, aAddr, sizeof(mAddr));
+  }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIUDPMESSAGE
+
+ private:
+  ~UDPMessageProxy() = default;
+
+  NetAddr mAddr;
+  nsCOMPtr<nsIOutputStream> mOutputStream;
+  FallibleTArray<uint8_t> mData;
+};
+
+NS_IMPL_ISUPPORTS(UDPMessageProxy, nsIUDPMessage)
+
+NS_IMETHODIMP
+UDPMessageProxy::GetFromAddr(nsINetAddr** aFromAddr) {
+  NS_ENSURE_ARG_POINTER(aFromAddr);
+
+  nsCOMPtr<nsINetAddr> result = new nsNetAddr(&mAddr);
+  result.forget(aFromAddr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPMessageProxy::GetData(nsACString& aData) {
+  aData.Assign(reinterpret_cast<const char*>(mData.Elements()), mData.Length());
+  return NS_OK;
+}
+
+FallibleTArray<uint8_t>& UDPMessageProxy::GetDataAsTArray() { return mData; }
+
+NS_IMETHODIMP
+UDPMessageProxy::GetRawData(JSContext* cx,
+                            JS::MutableHandle<JS::Value> aRawData) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+UDPMessageProxy::GetOutputStream(nsIOutputStream** aOutputStream) {
+  NS_ENSURE_ARG_POINTER(aOutputStream);
+  *aOutputStream = do_AddRef(mOutputStream).take();
+  return NS_OK;
+}
+
+}  // anonymous namespace
+
+//-----------------------------------------------------------------------------
+// nsUDPSocket::nsASocketHandler
+//-----------------------------------------------------------------------------
+
+void nsUDPSocket::OnSocketReady(PRFileDesc* fd, int16_t outFlags) {
+  UDPSOCKET_LOG(
+      ("nsUDPSocket::OnSocketReady: flags=%d [this=%p]\n", outFlags, this));
+  NS_ASSERTION(NS_SUCCEEDED(mCondition), "oops");
+  NS_ASSERTION(mFD == fd, "wrong file descriptor");
+  NS_ASSERTION(outFlags != -1, "unexpected timeout condition reached");
+
+  if (outFlags & (PR_POLL_HUP | PR_POLL_NVAL)) {
+    NS_WARNING("error polling on listening socket");
+    mCondition = NS_ERROR_UNEXPECTED;
+    return;
+  }
+
+  if (mSyncListener) {
+    mSyncListener->OnPacketReceived(this);
+    return;
+  }
+
+  PRNetAddr prClientAddr;
+  int32_t count;
+  // Bug 1252755 - use 9216 bytes to allign with nICEr and transportlayer to
+  // support the maximum size of jumbo frames
+  char buff[9216];
+  count = PR_RecvFrom(mFD, buff, sizeof(buff), 0, &prClientAddr,
+                      PR_INTERVAL_NO_WAIT);
+  if (count < 0) {
+    UDPSOCKET_LOG(
+        ("nsUDPSocket::OnSocketReady: PR_RecvFrom failed [this=%p]\n", this));
+    return;
+  }
+  mByteReadCount += count;
+
+  FallibleTArray<uint8_t> data;
+  if (!data.AppendElements(buff, count, fallible)) {
+    UDPSOCKET_LOG((
+        "nsUDPSocket::OnSocketReady: AppendElements FAILED [this=%p]\n", this));
+    mCondition = NS_ERROR_UNEXPECTED;
+    return;
+  }
+
+  nsCOMPtr<nsIAsyncInputStream> pipeIn;
+  nsCOMPtr<nsIAsyncOutputStream> pipeOut;
+
+  uint32_t segsize = UDP_PACKET_CHUNK_SIZE;
+  uint32_t segcount = 0;
+  net_ResolveSegmentParams(segsize, segcount);
+  NS_NewPipe2(getter_AddRefs(pipeIn), getter_AddRefs(pipeOut), true, true,
+              segsize, segcount);
+
+  RefPtr<nsUDPOutputStream> os = new nsUDPOutputStream(this, mFD, prClientAddr);
+  nsresult rv = NS_AsyncCopy(pipeIn, os, mSts, NS_ASYNCCOPY_VIA_READSEGMENTS,
+                             UDP_PACKET_CHUNK_SIZE);
+
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  NetAddr netAddr(&prClientAddr);
+  nsCOMPtr<nsIUDPMessage> message =
+      new UDPMessageProxy(&netAddr, pipeOut, std::move(data));
+  mListener->OnPacketReceived(this, message);
+}
+
+void nsUDPSocket::OnSocketDetached(PRFileDesc* fd) {
+  UDPSOCKET_LOG(("nsUDPSocket::OnSocketDetached [this=%p]\n", this));
+  // force a failure condition if none set; maybe the STS is shutting down :-/
+  if (NS_SUCCEEDED(mCondition)) mCondition = NS_ERROR_ABORT;
+
+  if (mFD) {
+    NS_ASSERTION(mFD == fd, "wrong file descriptor");
+    CloseSocket();
+  }
+
+  if (mSyncListener) {
+    mSyncListener->OnStopListening(this, mCondition);
+    mSyncListener = nullptr;
+  } else if (mListener) {
+    // need to atomically clear mListener.  see our Close() method.
+    RefPtr<nsIUDPSocketListener> listener = nullptr;
+    {
+      MutexAutoLock lock(mLock);
+      listener = ToRefPtr(std::move(mListener));
+    }
+
+    if (listener) {
+      listener->OnStopListening(this, mCondition);
+      NS_ProxyRelease("nsUDPSocket::mListener", mListenerTarget,
+                      listener.forget());
+    }
+  }
+}
+
+void nsUDPSocket::IsLocal(bool* aIsLocal) {
+  // If bound to loopback, this UDP socket only accepts local connections.
+  *aIsLocal = mAddr.IsLoopbackAddr();
+}
+
+nsresult nsUDPSocket::GetRemoteAddr(NetAddr* addr) {
+  if (!mSyncListener) {
+    return NS_ERROR_FAILURE;
+  }
+  RefPtr<HttpConnectionUDP> connUDP = do_QueryObject(mSyncListener);
+  if (!connUDP) {
+    return NS_ERROR_FAILURE;
+  }
+  return connUDP->GetPeerAddr(addr);
+}
+
+//-----------------------------------------------------------------------------
+// nsSocket::nsISupports
+//-----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsUDPSocket, nsIUDPSocket)
+
+//-----------------------------------------------------------------------------
+// nsSocket::nsISocket
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsUDPSocket::Init(int32_t aPort, bool aLoopbackOnly, nsIPrincipal* aPrincipal,
+                  bool aAddressReuse, uint8_t aOptionalArgc) {
+  NetAddr addr;
+
+  if (aPort < 0) aPort = 0;
+
+  addr.raw.family = AF_INET;
+  addr.inet.port = htons(aPort);
+
+  if (aLoopbackOnly) {
+    addr.inet.ip = htonl(INADDR_LOOPBACK);
+  } else {
+    addr.inet.ip = htonl(INADDR_ANY);
+  }
+
+  return InitWithAddress(&addr, aPrincipal, aAddressReuse, aOptionalArgc);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::Init2(const nsACString& aAddr, int32_t aPort,
+                   nsIPrincipal* aPrincipal, bool aAddressReuse,
+                   uint8_t aOptionalArgc) {
+  if (NS_WARN_IF(aAddr.IsEmpty())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (aPort < 0) {
+    aPort = 0;
+  }
+
+  NetAddr addr;
+  if (NS_FAILED(addr.InitFromString(aAddr, uint16_t(aPort)))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (addr.raw.family != PR_AF_INET && addr.raw.family != PR_AF_INET6) {
+    MOZ_ASSERT_UNREACHABLE("Dont accept address other than IPv4 and IPv6");
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+
+  return InitWithAddress(&addr, aPrincipal, aAddressReuse, aOptionalArgc);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::InitWithAddress(const NetAddr* aAddr, nsIPrincipal* aPrincipal,
+                             bool aAddressReuse, uint8_t aOptionalArgc) {
+  NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
+
+  nsresult rv;
+
+  rv = CheckIOStatus(aAddr);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  bool addressReuse = (aOptionalArgc == 1) ? aAddressReuse : true;
+
+  if (aPrincipal) {
+    mOriginAttributes = aPrincipal->OriginAttributesRef();
+  }
+  //
+  // configure listening socket...
+  //
+
+  mFD = PR_OpenUDPSocket(aAddr->raw.family);
+  if (!mFD) {
+    NS_WARNING("unable to create UDP socket");
+    return NS_ERROR_FAILURE;
+  }
+
+#ifdef FUZZING
+  if (StaticPrefs::fuzzing_necko_enabled()) {
+    rv = AttachFuzzyIOLayer(mFD);
+    if (NS_FAILED(rv)) {
+      UDPSOCKET_LOG(("Failed to attach fuzzing IOLayer [rv=%" PRIx32 "].\n",
+                     static_cast<uint32_t>(rv)));
+      return rv;
+    }
+    UDPSOCKET_LOG(("Successfully attached fuzzing IOLayer.\n"));
+  }
+#endif
+
+  uint16_t port;
+  if (NS_FAILED(aAddr->GetPort(&port))) {
+    NS_WARNING("invalid bind address");
+    goto fail;
+  }
+
+  PRSocketOptionData opt;
+
+  // Linux kernel will sometimes hand out a used port if we bind
+  // to port 0 with SO_REUSEADDR
+  if (port) {
+    opt.option = PR_SockOpt_Reuseaddr;
+    opt.value.reuse_addr = addressReuse;
+    PR_SetSocketOption(mFD, &opt);
+  }
+
+  opt.option = PR_SockOpt_Nonblocking;
+  opt.value.non_blocking = true;
+  PR_SetSocketOption(mFD, &opt);
+
+  PRNetAddr addr;
+  // Temporary work around for IPv6 until bug 1330490 is fixed
+  memset(&addr, 0, sizeof(addr));
+  NetAddrToPRNetAddr(aAddr, &addr);
+
+  if (PR_Bind(mFD, &addr) != PR_SUCCESS) {
+    NS_WARNING("failed to bind socket");
+    goto fail;
+  }
+
+  // get the resulting socket address, which may be different than what
+  // we passed to bind.
+  if (PR_GetSockName(mFD, &addr) != PR_SUCCESS) {
+    NS_WARNING("cannot get socket name");
+    goto fail;
+  }
+
+  PRNetAddrToNetAddr(&addr, &mAddr);
+
+  // create proxy via IOActivityMonitor
+  IOActivityMonitor::MonitorSocket(mFD);
+
+  // wait until AsyncListen is called before polling the socket for
+  // client connections.
+  return NS_OK;
+
+fail:
+  Close();
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::Connect(const NetAddr* aAddr) {
+  UDPSOCKET_LOG(("nsUDPSocket::Connect [this=%p]\n", this));
+
+  NS_ENSURE_ARG(aAddr);
+
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+
+  rv = CheckIOStatus(aAddr);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  bool onSTSThread = false;
+  mSts->IsOnCurrentThread(&onSTSThread);
+  NS_ASSERTION(onSTSThread, "NOT ON STS THREAD");
+  if (!onSTSThread) {
+    return NS_ERROR_FAILURE;
+  }
+
+  PRNetAddr prAddr;
+  memset(&prAddr, 0, sizeof(prAddr));
+  NetAddrToPRNetAddr(aAddr, &prAddr);
+
+  if (PR_Connect(mFD, &prAddr, PR_INTERVAL_NO_WAIT) != PR_SUCCESS) {
+    NS_WARNING("Cannot PR_Connect");
+    return NS_ERROR_FAILURE;
+  }
+  PR_SetFDInheritable(mFD, false);
+
+  // get the resulting socket address, which may have been updated.
+  PRNetAddr addr;
+  if (PR_GetSockName(mFD, &addr) != PR_SUCCESS) {
+    NS_WARNING("cannot get socket name");
+    return NS_ERROR_FAILURE;
+  }
+
+  PRNetAddrToNetAddr(&addr, &mAddr);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::Close() {
+  {
+    MutexAutoLock lock(mLock);
+    // we want to proxy the close operation to the socket thread if a listener
+    // has been set.  otherwise, we should just close the socket here...
+    if (!mListener && !mSyncListener) {
+      // Here we want to go directly with closing the socket since some tests
+      // expects this happen synchronously.
+      CloseSocket();
+
+      return NS_OK;
+    }
+  }
+  return PostEvent(this, &nsUDPSocket::OnMsgClose);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetPort(int32_t* aResult) {
+  // no need to enter the lock here
+  uint16_t result;
+  nsresult rv = mAddr.GetPort(&result);
+  *aResult = static_cast<int32_t>(result);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetLocalAddr(nsINetAddr** aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+
+  nsCOMPtr<nsINetAddr> result = new nsNetAddr(&mAddr);
+  result.forget(aResult);
+
+  return NS_OK;
+}
+
+void nsUDPSocket::CloseSocket() {
+  if (mFD) {
+    if (gIOService->IsNetTearingDown() &&
+        ((PR_IntervalNow() - gIOService->NetTearingDownStarted()) >
+         gSocketTransportService->MaxTimeForPrClosePref())) {
+      // If shutdown last to long, let the socket leak and do not close it.
+      UDPSOCKET_LOG(("Intentional leak"));
+    } else {
+      PRIntervalTime closeStarted = 0;
+      if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+        closeStarted = PR_IntervalNow();
+      }
+
+      PR_Close(mFD);
+
+      if (gSocketTransportService->IsTelemetryEnabledAndNotSleepPhase()) {
+        PRIntervalTime now = PR_IntervalNow();
+        if (gIOService->IsNetTearingDown()) {
+          Telemetry::Accumulate(Telemetry::PRCLOSE_UDP_BLOCKING_TIME_SHUTDOWN,
+                                PR_IntervalToMilliseconds(now - closeStarted));
+
+        } else if (PR_IntervalToSeconds(
+                       now - gIOService->LastConnectivityChange()) < 60) {
+          Telemetry::Accumulate(
+              Telemetry::PRCLOSE_UDP_BLOCKING_TIME_CONNECTIVITY_CHANGE,
+              PR_IntervalToMilliseconds(now - closeStarted));
+
+        } else if (PR_IntervalToSeconds(
+                       now - gIOService->LastNetworkLinkChange()) < 60) {
+          Telemetry::Accumulate(
+              Telemetry::PRCLOSE_UDP_BLOCKING_TIME_LINK_CHANGE,
+              PR_IntervalToMilliseconds(now - closeStarted));
+
+        } else if (PR_IntervalToSeconds(
+                       now - gIOService->LastOfflineStateChange()) < 60) {
+          Telemetry::Accumulate(Telemetry::PRCLOSE_UDP_BLOCKING_TIME_OFFLINE,
+                                PR_IntervalToMilliseconds(now - closeStarted));
+
+        } else {
+          Telemetry::Accumulate(Telemetry::PRCLOSE_UDP_BLOCKING_TIME_NORMAL,
+                                PR_IntervalToMilliseconds(now - closeStarted));
+        }
+      }
+    }
+    mFD = nullptr;
+  }
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetAddress(NetAddr* aResult) {
+  // no need to enter the lock here
+  memcpy(aResult, &mAddr, sizeof(mAddr));
+  return NS_OK;
+}
+
+namespace {
+//-----------------------------------------------------------------------------
+// SocketListenerProxy
+//-----------------------------------------------------------------------------
+class SocketListenerProxy final : public nsIUDPSocketListener {
+  ~SocketListenerProxy() = default;
+
+ public:
+  explicit SocketListenerProxy(nsIUDPSocketListener* aListener)
+      : mListener(new nsMainThreadPtrHolder<nsIUDPSocketListener>(
+            "SocketListenerProxy::mListener", aListener)),
+        mTarget(GetCurrentSerialEventTarget()) {}
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIUDPSOCKETLISTENER
+
+  class OnPacketReceivedRunnable : public Runnable {
+   public:
+    OnPacketReceivedRunnable(
+        const nsMainThreadPtrHandle<nsIUDPSocketListener>& aListener,
+        nsIUDPSocket* aSocket, nsIUDPMessage* aMessage)
+        : Runnable("net::SocketListenerProxy::OnPacketReceivedRunnable"),
+          mListener(aListener),
+          mSocket(aSocket),
+          mMessage(aMessage) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsMainThreadPtrHandle<nsIUDPSocketListener> mListener;
+    nsCOMPtr<nsIUDPSocket> mSocket;
+    nsCOMPtr<nsIUDPMessage> mMessage;
+  };
+
+  class OnStopListeningRunnable : public Runnable {
+   public:
+    OnStopListeningRunnable(
+        const nsMainThreadPtrHandle<nsIUDPSocketListener>& aListener,
+        nsIUDPSocket* aSocket, nsresult aStatus)
+        : Runnable("net::SocketListenerProxy::OnStopListeningRunnable"),
+          mListener(aListener),
+          mSocket(aSocket),
+          mStatus(aStatus) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsMainThreadPtrHandle<nsIUDPSocketListener> mListener;
+    nsCOMPtr<nsIUDPSocket> mSocket;
+    nsresult mStatus;
+  };
+
+ private:
+  nsMainThreadPtrHandle<nsIUDPSocketListener> mListener;
+  nsCOMPtr<nsIEventTarget> mTarget;
+};
+
+NS_IMPL_ISUPPORTS(SocketListenerProxy, nsIUDPSocketListener)
+
+NS_IMETHODIMP
+SocketListenerProxy::OnPacketReceived(nsIUDPSocket* aSocket,
+                                      nsIUDPMessage* aMessage) {
+  RefPtr<OnPacketReceivedRunnable> r =
+      new OnPacketReceivedRunnable(mListener, aSocket, aMessage);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+SocketListenerProxy::OnStopListening(nsIUDPSocket* aSocket, nsresult aStatus) {
+  RefPtr<OnStopListeningRunnable> r =
+      new OnStopListeningRunnable(mListener, aSocket, aStatus);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+SocketListenerProxy::OnPacketReceivedRunnable::Run() {
+  NetAddr netAddr;
+  nsCOMPtr<nsINetAddr> nsAddr;
+  mMessage->GetFromAddr(getter_AddRefs(nsAddr));
+  nsAddr->GetNetAddr(&netAddr);
+
+  nsCOMPtr<nsIOutputStream> outputStream;
+  mMessage->GetOutputStream(getter_AddRefs(outputStream));
+
+  FallibleTArray<uint8_t>& data = mMessage->GetDataAsTArray();
+
+  nsCOMPtr<nsIUDPMessage> message =
+      new nsUDPMessage(&netAddr, outputStream, std::move(data));
+  mListener->OnPacketReceived(mSocket, message);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SocketListenerProxy::OnStopListeningRunnable::Run() {
+  mListener->OnStopListening(mSocket, mStatus);
+  return NS_OK;
+}
+
+class SocketListenerProxyBackground final : public nsIUDPSocketListener {
+  ~SocketListenerProxyBackground() = default;
+
+ public:
+  explicit SocketListenerProxyBackground(nsIUDPSocketListener* aListener)
+      : mListener(aListener), mTarget(GetCurrentSerialEventTarget()) {}
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIUDPSOCKETLISTENER
+
+  class OnPacketReceivedRunnable : public Runnable {
+   public:
+    OnPacketReceivedRunnable(const nsCOMPtr<nsIUDPSocketListener>& aListener,
+                             nsIUDPSocket* aSocket, nsIUDPMessage* aMessage)
+        : Runnable(
+              "net::SocketListenerProxyBackground::OnPacketReceivedRunnable"),
+          mListener(aListener),
+          mSocket(aSocket),
+          mMessage(aMessage) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsCOMPtr<nsIUDPSocketListener> mListener;
+    nsCOMPtr<nsIUDPSocket> mSocket;
+    nsCOMPtr<nsIUDPMessage> mMessage;
+  };
+
+  class OnStopListeningRunnable : public Runnable {
+   public:
+    OnStopListeningRunnable(const nsCOMPtr<nsIUDPSocketListener>& aListener,
+                            nsIUDPSocket* aSocket, nsresult aStatus)
+        : Runnable(
+              "net::SocketListenerProxyBackground::OnStopListeningRunnable"),
+          mListener(aListener),
+          mSocket(aSocket),
+          mStatus(aStatus) {}
+
+    NS_DECL_NSIRUNNABLE
+
+   private:
+    nsCOMPtr<nsIUDPSocketListener> mListener;
+    nsCOMPtr<nsIUDPSocket> mSocket;
+    nsresult mStatus;
+  };
+
+ private:
+  nsCOMPtr<nsIUDPSocketListener> mListener;
+  nsCOMPtr<nsIEventTarget> mTarget;
+};
+
+NS_IMPL_ISUPPORTS(SocketListenerProxyBackground, nsIUDPSocketListener)
+
+NS_IMETHODIMP
+SocketListenerProxyBackground::OnPacketReceived(nsIUDPSocket* aSocket,
+                                                nsIUDPMessage* aMessage) {
+  RefPtr<OnPacketReceivedRunnable> r =
+      new OnPacketReceivedRunnable(mListener, aSocket, aMessage);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+SocketListenerProxyBackground::OnStopListening(nsIUDPSocket* aSocket,
+                                               nsresult aStatus) {
+  RefPtr<OnStopListeningRunnable> r =
+      new OnStopListeningRunnable(mListener, aSocket, aStatus);
+  return mTarget->Dispatch(r, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+SocketListenerProxyBackground::OnPacketReceivedRunnable::Run() {
+  NetAddr netAddr;
+  nsCOMPtr<nsINetAddr> nsAddr;
+  mMessage->GetFromAddr(getter_AddRefs(nsAddr));
+  nsAddr->GetNetAddr(&netAddr);
+
+  nsCOMPtr<nsIOutputStream> outputStream;
+  mMessage->GetOutputStream(getter_AddRefs(outputStream));
+
+  FallibleTArray<uint8_t>& data = mMessage->GetDataAsTArray();
+
+  UDPSOCKET_LOG(("%s [this=%p], len %zu", __FUNCTION__, this, data.Length()));
+  nsCOMPtr<nsIUDPMessage> message =
+      new UDPMessageProxy(&netAddr, outputStream, std::move(data));
+  mListener->OnPacketReceived(mSocket, message);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SocketListenerProxyBackground::OnStopListeningRunnable::Run() {
+  mListener->OnStopListening(mSocket, mStatus);
+  return NS_OK;
+}
+
+class PendingSend : public nsIDNSListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSLISTENER
+
+  PendingSend(nsUDPSocket* aSocket, uint16_t aPort,
+              FallibleTArray<uint8_t>&& aData)
+      : mSocket(aSocket), mPort(aPort), mData(std::move(aData)) {}
+
+ private:
+  virtual ~PendingSend() = default;
+
+  RefPtr<nsUDPSocket> mSocket;
+  uint16_t mPort;
+  FallibleTArray<uint8_t> mData;
+};
+
+NS_IMPL_ISUPPORTS(PendingSend, nsIDNSListener)
+
+NS_IMETHODIMP
+PendingSend::OnLookupComplete(nsICancelable* request, nsIDNSRecord* aRecord,
+                              nsresult status) {
+  if (NS_FAILED(status)) {
+    NS_WARNING("Failed to send UDP packet due to DNS lookup failure");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDNSAddrRecord> rec = do_QueryInterface(aRecord);
+  MOZ_ASSERT(rec);
+  NetAddr addr;
+  if (NS_SUCCEEDED(rec->GetNextAddr(mPort, &addr))) {
+    uint32_t count;
+    nsresult rv = mSocket->SendWithAddress(&addr, mData, &count);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+class PendingSendStream : public nsIDNSListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSLISTENER
+
+  PendingSendStream(nsUDPSocket* aSocket, uint16_t aPort,
+                    nsIInputStream* aStream)
+      : mSocket(aSocket), mPort(aPort), mStream(aStream) {}
+
+ private:
+  virtual ~PendingSendStream() = default;
+
+  RefPtr<nsUDPSocket> mSocket;
+  uint16_t mPort;
+  nsCOMPtr<nsIInputStream> mStream;
+};
+
+NS_IMPL_ISUPPORTS(PendingSendStream, nsIDNSListener)
+
+NS_IMETHODIMP
+PendingSendStream::OnLookupComplete(nsICancelable* request,
+                                    nsIDNSRecord* aRecord, nsresult status) {
+  if (NS_FAILED(status)) {
+    NS_WARNING("Failed to send UDP packet due to DNS lookup failure");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDNSAddrRecord> rec = do_QueryInterface(aRecord);
+  MOZ_ASSERT(rec);
+  NetAddr addr;
+  if (NS_SUCCEEDED(rec->GetNextAddr(mPort, &addr))) {
+    nsresult rv = mSocket->SendBinaryStreamWithAddress(&addr, mStream);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+class SendRequestRunnable : public Runnable {
+ public:
+  SendRequestRunnable(nsUDPSocket* aSocket, const NetAddr& aAddr,
+                      FallibleTArray<uint8_t>&& aData)
+      : Runnable("net::SendRequestRunnable"),
+        mSocket(aSocket),
+        mAddr(aAddr),
+        mData(std::move(aData)) {}
+
+  NS_DECL_NSIRUNNABLE
+
+ private:
+  RefPtr<nsUDPSocket> mSocket;
+  const NetAddr mAddr;
+  FallibleTArray<uint8_t> mData;
+};
+
+NS_IMETHODIMP
+SendRequestRunnable::Run() {
+  uint32_t count;
+  mSocket->SendWithAddress(&mAddr, mData, &count);
+  return NS_OK;
+}
+
+}  // namespace
+
+NS_IMETHODIMP
+nsUDPSocket::AsyncListen(nsIUDPSocketListener* aListener) {
+  // ensuring mFD implies ensuring mLock
+  NS_ENSURE_TRUE(mFD, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mListener == nullptr, NS_ERROR_IN_PROGRESS);
+  NS_ENSURE_TRUE(mSyncListener == nullptr, NS_ERROR_IN_PROGRESS);
+  {
+    MutexAutoLock lock(mLock);
+    mListenerTarget = GetCurrentSerialEventTarget();
+    if (NS_IsMainThread()) {
+      // PNecko usage
+      mListener = new SocketListenerProxy(aListener);
+    } else {
+      // PBackground usage from dom/media/webrtc/transport
+      mListener = new SocketListenerProxyBackground(aListener);
+    }
+  }
+  return PostEvent(this, &nsUDPSocket::OnMsgAttach);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SyncListen(nsIUDPSocketSyncListener* aListener) {
+  // ensuring mFD implies ensuring mLock
+  NS_ENSURE_TRUE(mFD, NS_ERROR_NOT_INITIALIZED);
+  NS_ENSURE_TRUE(mListener == nullptr, NS_ERROR_IN_PROGRESS);
+  NS_ENSURE_TRUE(mSyncListener == nullptr, NS_ERROR_IN_PROGRESS);
+
+  mSyncListener = aListener;
+
+  return PostEvent(this, &nsUDPSocket::OnMsgAttach);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::Send(const nsACString& aHost, uint16_t aPort,
+                  const nsTArray<uint8_t>& aData, uint32_t* _retval) {
+  NS_ENSURE_ARG_POINTER(_retval);
+
+  *_retval = 0;
+
+  FallibleTArray<uint8_t> fallibleArray;
+  if (!fallibleArray.InsertElementsAt(0, aData, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  nsCOMPtr<nsIDNSListener> listener =
+      new PendingSend(this, aPort, std::move(fallibleArray));
+
+  nsresult rv = ResolveHost(aHost, mOriginAttributes, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *_retval = aData.Length();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SendWithAddr(nsINetAddr* aAddr, const nsTArray<uint8_t>& aData,
+                          uint32_t* _retval) {
+  NS_ENSURE_ARG(aAddr);
+  NS_ENSURE_ARG_POINTER(_retval);
+
+  NetAddr netAddr;
+  aAddr->GetNetAddr(&netAddr);
+  return SendWithAddress(&netAddr, aData, _retval);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SendWithAddress(const NetAddr* aAddr,
+                             const nsTArray<uint8_t>& aData,
+                             uint32_t* _retval) {
+  NS_ENSURE_ARG(aAddr);
+  NS_ENSURE_ARG_POINTER(_retval);
+
+  if (StaticPrefs::network_http_http3_block_loopback_ipv6_addr() &&
+      aAddr->raw.family == AF_INET6 && aAddr->IsLoopbackAddr()) {
+    return NS_ERROR_CONNECTION_REFUSED;
+  }
+
+  *_retval = 0;
+
+  PRNetAddr prAddr;
+  NetAddrToPRNetAddr(aAddr, &prAddr);
+
+  bool onSTSThread = false;
+  mSts->IsOnCurrentThread(&onSTSThread);
+
+  if (onSTSThread) {
+    MutexAutoLock lock(mLock);
+    if (!mFD) {
+      // socket is not initialized or has been closed
+      return NS_ERROR_FAILURE;
+    }
+    int32_t count =
+        PR_SendTo(mFD, aData.Elements(), sizeof(uint8_t) * aData.Length(), 0,
+                  &prAddr, PR_INTERVAL_NO_WAIT);
+    if (count < 0) {
+      PRErrorCode code = PR_GetError();
+      return ErrorAccordingToNSPR(code);
+    }
+    this->AddOutputBytes(count);
+    *_retval = count;
+  } else {
+    FallibleTArray<uint8_t> fallibleArray;
+    if (!fallibleArray.InsertElementsAt(0, aData, fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    nsresult rv = mSts->Dispatch(
+        new SendRequestRunnable(this, *aAddr, std::move(fallibleArray)),
+        NS_DISPATCH_NORMAL);
+    NS_ENSURE_SUCCESS(rv, rv);
+    *_retval = aData.Length();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SendBinaryStream(const nsACString& aHost, uint16_t aPort,
+                              nsIInputStream* aStream) {
+  NS_ENSURE_ARG(aStream);
+
+  nsCOMPtr<nsIDNSListener> listener =
+      new PendingSendStream(this, aPort, aStream);
+
+  return ResolveHost(aHost, mOriginAttributes, listener);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SendBinaryStreamWithAddress(const NetAddr* aAddr,
+                                         nsIInputStream* aStream) {
+  NS_ENSURE_ARG(aAddr);
+  NS_ENSURE_ARG(aStream);
+
+  PRNetAddr prAddr;
+  PR_InitializeNetAddr(PR_IpAddrAny, 0, &prAddr);
+  NetAddrToPRNetAddr(aAddr, &prAddr);
+
+  RefPtr<nsUDPOutputStream> os = new nsUDPOutputStream(this, mFD, prAddr);
+  return NS_AsyncCopy(aStream, os, mSts, NS_ASYNCCOPY_VIA_READSEGMENTS,
+                      UDP_PACKET_CHUNK_SIZE);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::RecvWithAddr(NetAddr* addr, nsTArray<uint8_t>& aData) {
+  MOZ_ASSERT(OnSocketThread(), "not on socket thread");
+  PRNetAddr prAddr;
+  int32_t count;
+  char buff[9216];
+  count = PR_RecvFrom(mFD, buff, sizeof(buff), 0, &prAddr, PR_INTERVAL_NO_WAIT);
+  if (count < 0) {
+    UDPSOCKET_LOG(
+        ("nsUDPSocket::RecvWithAddr: PR_RecvFrom failed [this=%p]\n", this));
+    return NS_OK;
+  }
+  mByteReadCount += count;
+  PRNetAddrToNetAddr(&prAddr, addr);
+
+  if (!aData.AppendElements(buff, count, fallible)) {
+    UDPSOCKET_LOG((
+        "nsUDPSocket::OnSocketReady: AppendElements FAILED [this=%p]\n", this));
+    mCondition = NS_ERROR_UNEXPECTED;
+  }
+  return NS_OK;
+}
+
+nsresult nsUDPSocket::SetSocketOption(const PRSocketOptionData& aOpt) {
+  bool onSTSThread = false;
+  mSts->IsOnCurrentThread(&onSTSThread);
+
+  if (!onSTSThread) {
+    // Dispatch to STS thread and re-enter this method there
+    nsCOMPtr<nsIRunnable> runnable = new SetSocketOptionRunnable(this, aOpt);
+    nsresult rv = mSts->Dispatch(runnable, NS_DISPATCH_NORMAL);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    return NS_OK;
+  }
+
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (PR_SetSocketOption(mFD, &aOpt) != PR_SUCCESS) {
+    UDPSOCKET_LOG(
+        ("nsUDPSocket::SetSocketOption [this=%p] failed for type %d, "
+         "error %d\n",
+         this, aOpt.option, PR_GetError()));
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::JoinMulticast(const nsACString& aAddr, const nsACString& aIface) {
+  if (NS_WARN_IF(aAddr.IsEmpty())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prAddr;
+  if (PR_StringToNetAddr(aAddr.BeginReading(), &prAddr) != PR_SUCCESS) {
+    return NS_ERROR_FAILURE;
+  }
+
+  PRNetAddr prIface;
+  if (aIface.IsEmpty()) {
+    PR_InitializeNetAddr(PR_IpAddrAny, 0, &prIface);
+  } else {
+    if (PR_StringToNetAddr(aIface.BeginReading(), &prIface) != PR_SUCCESS) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  return JoinMulticastInternal(prAddr, prIface);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::JoinMulticastAddr(const NetAddr aAddr, const NetAddr* aIface) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prAddr;
+  NetAddrToPRNetAddr(&aAddr, &prAddr);
+
+  PRNetAddr prIface;
+  if (!aIface) {
+    PR_InitializeNetAddr(PR_IpAddrAny, 0, &prIface);
+  } else {
+    NetAddrToPRNetAddr(aIface, &prIface);
+  }
+
+  return JoinMulticastInternal(prAddr, prIface);
+}
+
+nsresult nsUDPSocket::JoinMulticastInternal(const PRNetAddr& aAddr,
+                                            const PRNetAddr& aIface) {
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_AddMember;
+  opt.value.add_member.mcaddr = aAddr;
+  opt.value.add_member.ifaddr = aIface;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::LeaveMulticast(const nsACString& aAddr, const nsACString& aIface) {
+  if (NS_WARN_IF(aAddr.IsEmpty())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prAddr;
+  if (PR_StringToNetAddr(aAddr.BeginReading(), &prAddr) != PR_SUCCESS) {
+    return NS_ERROR_FAILURE;
+  }
+
+  PRNetAddr prIface;
+  if (aIface.IsEmpty()) {
+    PR_InitializeNetAddr(PR_IpAddrAny, 0, &prIface);
+  } else {
+    if (PR_StringToNetAddr(aIface.BeginReading(), &prIface) != PR_SUCCESS) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  return LeaveMulticastInternal(prAddr, prIface);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::LeaveMulticastAddr(const NetAddr aAddr, const NetAddr* aIface) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prAddr;
+  NetAddrToPRNetAddr(&aAddr, &prAddr);
+
+  PRNetAddr prIface;
+  if (!aIface) {
+    PR_InitializeNetAddr(PR_IpAddrAny, 0, &prIface);
+  } else {
+    NetAddrToPRNetAddr(aIface, &prIface);
+  }
+
+  return LeaveMulticastInternal(prAddr, prIface);
+}
+
+nsresult nsUDPSocket::LeaveMulticastInternal(const PRNetAddr& aAddr,
+                                             const PRNetAddr& aIface) {
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_DropMember;
+  opt.value.drop_member.mcaddr = aAddr;
+  opt.value.drop_member.ifaddr = aIface;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetMulticastLoopback(bool* aLoopback) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetMulticastLoopback(bool aLoopback) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_McastLoopback;
+  opt.value.mcast_loopback = aLoopback;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetRecvBufferSize(int* size) {
+  // Bug 1252759 - missing support for GetSocketOption
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetRecvBufferSize(int size) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_RecvBufferSize;
+  opt.value.recv_buffer_size = size;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetDontFragment(bool* dontFragment) {
+  // Bug 1252759 - missing support for GetSocketOption
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetDontFragment(bool dontFragment) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRSocketOptionData opt;
+  opt.option = PR_SockOpt_DontFrag;
+  opt.value.dont_fragment = dontFragment;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetSendBufferSize(int* size) {
+  // Bug 1252759 - missing support for GetSocketOption
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetSendBufferSize(int size) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_SendBufferSize;
+  opt.value.send_buffer_size = size;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetMulticastInterface(nsACString& aIface) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::GetMulticastInterfaceAddr(NetAddr* aIface) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetMulticastInterface(const nsACString& aIface) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prIface;
+  if (aIface.IsEmpty()) {
+    PR_InitializeNetAddr(PR_IpAddrAny, 0, &prIface);
+  } else {
+    if (PR_StringToNetAddr(aIface.BeginReading(), &prIface) != PR_SUCCESS) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  return SetMulticastInterfaceInternal(prIface);
+}
+
+NS_IMETHODIMP
+nsUDPSocket::SetMulticastInterfaceAddr(NetAddr aIface) {
+  if (NS_WARN_IF(!mFD)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  PRNetAddr prIface;
+  NetAddrToPRNetAddr(&aIface, &prIface);
+
+  return SetMulticastInterfaceInternal(prIface);
+}
+
+nsresult nsUDPSocket::SetMulticastInterfaceInternal(const PRNetAddr& aIface) {
+  PRSocketOptionData opt;
+
+  opt.option = PR_SockOpt_McastInterface;
+  opt.value.mcast_if = aIface;
+
+  nsresult rv = SetSocketOption(opt);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsUDPSocket.h b/netwerk/base/nsUDPSocket.h
new file mode 100644
index 0000000000..7736d5f995
--- /dev/null
+++ b/netwerk/base/nsUDPSocket.h
@@ -0,0 +1,118 @@
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsUDPSocket_h__
+#define nsUDPSocket_h__
+
+#include "nsIUDPSocket.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/net/DNS.h"
+#include "nsIOutputStream.h"
+#include "nsASocketHandler.h"
+#include "nsCycleCollectionParticipant.h"
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+class nsSocketTransportService;
+
+class nsUDPSocket final : public nsASocketHandler, public nsIUDPSocket {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIUDPSOCKET
+
+  // nsASocketHandler methods:
+  virtual void OnSocketReady(PRFileDesc* fd, int16_t outFlags) override;
+  virtual void OnSocketDetached(PRFileDesc* fd) override;
+  virtual void IsLocal(bool* aIsLocal) override;
+  virtual nsresult GetRemoteAddr(NetAddr* addr) override;
+
+  uint64_t ByteCountSent() override { return mByteWriteCount; }
+  uint64_t ByteCountReceived() override { return mByteReadCount; }
+
+  void AddOutputBytes(uint64_t aBytes);
+
+  nsUDPSocket();
+
+ private:
+  virtual ~nsUDPSocket();
+
+  void OnMsgClose();
+  void OnMsgAttach();
+
+  // try attaching our socket (mFD) to the STS's poll list.
+  nsresult TryAttach();
+
+  friend class SetSocketOptionRunnable;
+  nsresult SetSocketOption(const PRSocketOptionData& aOpt);
+  nsresult JoinMulticastInternal(const PRNetAddr& aAddr,
+                                 const PRNetAddr& aIface);
+  nsresult LeaveMulticastInternal(const PRNetAddr& aAddr,
+                                  const PRNetAddr& aIface);
+  nsresult SetMulticastInterfaceInternal(const PRNetAddr& aIface);
+
+  void CloseSocket();
+
+  // lock protects access to mListener;
+  // so mListener is not cleared while being used/locked.
+  Mutex mLock MOZ_UNANNOTATED{"nsUDPSocket.mLock"};
+  PRFileDesc* mFD{nullptr};
+  NetAddr mAddr;
+  OriginAttributes mOriginAttributes;
+  nsCOMPtr<nsIUDPSocketListener> mListener;
+  nsCOMPtr<nsIUDPSocketSyncListener> mSyncListener;
+  nsCOMPtr<nsIEventTarget> mListenerTarget;
+  bool mAttached{false};
+  RefPtr<nsSocketTransportService> mSts;
+
+  uint64_t mByteReadCount{0};
+  uint64_t mByteWriteCount{0};
+};
+
+//-----------------------------------------------------------------------------
+
+class nsUDPMessage : public nsIUDPMessage {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsUDPMessage)
+  NS_DECL_NSIUDPMESSAGE
+
+  nsUDPMessage(NetAddr* aAddr, nsIOutputStream* aOutputStream,
+               FallibleTArray<uint8_t>&& aData);
+
+ private:
+  virtual ~nsUDPMessage();
+
+  NetAddr mAddr;
+  nsCOMPtr<nsIOutputStream> mOutputStream;
+  FallibleTArray<uint8_t> mData;
+  JS::Heap<JSObject*> mJsobj;
+};
+
+//-----------------------------------------------------------------------------
+
+class nsUDPOutputStream : public nsIOutputStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+
+  nsUDPOutputStream(nsUDPSocket* aSocket, PRFileDesc* aFD,
+                    PRNetAddr& aPrClientAddr);
+
+ private:
+  virtual ~nsUDPOutputStream() = default;
+
+  RefPtr<nsUDPSocket> mSocket;
+  PRFileDesc* mFD;
+  PRNetAddr mPrClientAddr;
+  bool mIsClosed;
+};
+
+}  // namespace net
+}  // namespace mozilla
+
+#endif  // nsUDPSocket_h__
diff --git a/netwerk/base/nsURIHashKey.h b/netwerk/base/nsURIHashKey.h
new file mode 100644
index 0000000000..fb98ae0d21
--- /dev/null
+++ b/netwerk/base/nsURIHashKey.h
@@ -0,0 +1,71 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef nsURIHashKey_h__
+#define nsURIHashKey_h__
+
+#include <utility>
+
+#include "PLDHashTable.h"
+#include "mozilla/Unused.h"
+#include "nsCOMPtr.h"
+#include "nsHashKeys.h"
+#include "nsIURI.h"
+
+/**
+ * Hashtable key class to use with nsTHashtable/nsBaseHashtable
+ */
+class nsURIHashKey : public PLDHashEntryHdr {
+ public:
+  typedef nsIURI* KeyType;
+  typedef const nsIURI* KeyTypePointer;
+
+  nsURIHashKey() { MOZ_COUNT_CTOR(nsURIHashKey); }
+  explicit nsURIHashKey(const nsIURI* aKey) : mKey(const_cast<nsIURI*>(aKey)) {
+    MOZ_COUNT_CTOR(nsURIHashKey);
+  }
+  nsURIHashKey(nsURIHashKey&& toMove)
+      : PLDHashEntryHdr(std::move(toMove)), mKey(std::move(toMove.mKey)) {
+    MOZ_COUNT_CTOR(nsURIHashKey);
+  }
+  MOZ_COUNTED_DTOR(nsURIHashKey)
+
+  nsURIHashKey& operator=(const nsURIHashKey& aOther) {
+    mKey = aOther.mKey;
+    return *this;
+  }
+
+  nsIURI* GetKey() const { return mKey; }
+
+  bool KeyEquals(const nsIURI* aKey) const {
+    bool eq;
+    if (!mKey) {
+      return !aKey;
+    }
+    if (NS_SUCCEEDED(mKey->Equals(const_cast<nsIURI*>(aKey), &eq))) {
+      return eq;
+    }
+    return false;
+  }
+
+  static const nsIURI* KeyToPointer(nsIURI* aKey) { return aKey; }
+  static PLDHashNumber HashKey(const nsIURI* aKey) {
+    if (!aKey) {
+      // If the key is null, return hash for empty string.
+      return mozilla::HashString(""_ns);
+    }
+    nsAutoCString spec;
+    // If GetSpec() fails, ignoring the failure and proceeding with an
+    // empty |spec| seems like the best thing to do.
+    mozilla::Unused << const_cast<nsIURI*>(aKey)->GetSpec(spec);
+    return mozilla::HashString(spec);
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+ protected:
+  nsCOMPtr<nsIURI> mKey;
+};
+
+#endif  // nsURIHashKey_h__
diff --git a/netwerk/base/nsURLHelper.cpp b/netwerk/base/nsURLHelper.cpp
new file mode 100644
index 0000000000..31eb5851a2
--- /dev/null
+++ b/netwerk/base/nsURLHelper.cpp
@@ -0,0 +1,1167 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsURLHelper.h"
+
+#include "mozilla/Encoding.h"
+#include "mozilla/RangedPtr.h"
+#include "mozilla/TextUtils.h"
+
+#include <algorithm>
+#include <iterator>
+
+#include "nsASCIIMask.h"
+#include "nsIFile.h"
+#include "nsIURLParser.h"
+#include "nsCOMPtr.h"
+#include "nsCRT.h"
+#include "nsNetCID.h"
+#include "mozilla/Preferences.h"
+#include "prnetdb.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Tokenizer.h"
+#include "nsEscape.h"
+#include "nsDOMString.h"
+#include "mozilla/net/rust_helper.h"
+#include "mozilla/net/DNS.h"
+
+using namespace mozilla;
+
+//----------------------------------------------------------------------------
+// Init/Shutdown
+//----------------------------------------------------------------------------
+
+static bool gInitialized = false;
+static StaticRefPtr<nsIURLParser> gNoAuthURLParser;
+static StaticRefPtr<nsIURLParser> gAuthURLParser;
+static StaticRefPtr<nsIURLParser> gStdURLParser;
+
+static void InitGlobals() {
+  nsCOMPtr<nsIURLParser> parser;
+
+  parser = do_GetService(NS_NOAUTHURLPARSER_CONTRACTID);
+  NS_ASSERTION(parser, "failed getting 'noauth' url parser");
+  if (parser) {
+    gNoAuthURLParser = parser;
+  }
+
+  parser = do_GetService(NS_AUTHURLPARSER_CONTRACTID);
+  NS_ASSERTION(parser, "failed getting 'auth' url parser");
+  if (parser) {
+    gAuthURLParser = parser;
+  }
+
+  parser = do_GetService(NS_STDURLPARSER_CONTRACTID);
+  NS_ASSERTION(parser, "failed getting 'std' url parser");
+  if (parser) {
+    gStdURLParser = parser;
+  }
+
+  gInitialized = true;
+}
+
+void net_ShutdownURLHelper() {
+  if (gInitialized) {
+    gInitialized = false;
+  }
+  gNoAuthURLParser = nullptr;
+  gAuthURLParser = nullptr;
+  gStdURLParser = nullptr;
+}
+
+//----------------------------------------------------------------------------
+// nsIURLParser getters
+//----------------------------------------------------------------------------
+
+nsIURLParser* net_GetAuthURLParser() {
+  if (!gInitialized) InitGlobals();
+  return gAuthURLParser;
+}
+
+nsIURLParser* net_GetNoAuthURLParser() {
+  if (!gInitialized) InitGlobals();
+  return gNoAuthURLParser;
+}
+
+nsIURLParser* net_GetStdURLParser() {
+  if (!gInitialized) InitGlobals();
+  return gStdURLParser;
+}
+
+//---------------------------------------------------------------------------
+// GetFileFromURLSpec implementations
+//---------------------------------------------------------------------------
+nsresult net_GetURLSpecFromDir(nsIFile* aFile, nsACString& result) {
+  nsAutoCString escPath;
+  nsresult rv = net_GetURLSpecFromActualFile(aFile, escPath);
+  if (NS_FAILED(rv)) return rv;
+
+  if (escPath.Last() != '/') {
+    escPath += '/';
+  }
+
+  result = escPath;
+  return NS_OK;
+}
+
+nsresult net_GetURLSpecFromFile(nsIFile* aFile, nsACString& result) {
+  nsAutoCString escPath;
+  nsresult rv = net_GetURLSpecFromActualFile(aFile, escPath);
+  if (NS_FAILED(rv)) return rv;
+
+  // if this file references a directory, then we need to ensure that the
+  // URL ends with a slash.  this is important since it affects the rules
+  // for relative URL resolution when this URL is used as a base URL.
+  // if the file does not exist, then we make no assumption about its type,
+  // and simply leave the URL unmodified.
+  if (escPath.Last() != '/') {
+    bool dir;
+    rv = aFile->IsDirectory(&dir);
+    if (NS_SUCCEEDED(rv) && dir) escPath += '/';
+  }
+
+  result = escPath;
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// file:// URL parsing
+//----------------------------------------------------------------------------
+
+nsresult net_ParseFileURL(const nsACString& inURL, nsACString& outDirectory,
+                          nsACString& outFileBaseName,
+                          nsACString& outFileExtension) {
+  nsresult rv;
+
+  if (inURL.Length() >
+      (uint32_t)StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  outDirectory.Truncate();
+  outFileBaseName.Truncate();
+  outFileExtension.Truncate();
+
+  const nsPromiseFlatCString& flatURL = PromiseFlatCString(inURL);
+  const char* url = flatURL.get();
+
+  nsAutoCString scheme;
+  rv = net_ExtractURLScheme(flatURL, scheme);
+  if (NS_FAILED(rv)) return rv;
+
+  if (!scheme.EqualsLiteral("file")) {
+    NS_ERROR("must be a file:// url");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsIURLParser* parser = net_GetNoAuthURLParser();
+  NS_ENSURE_TRUE(parser, NS_ERROR_UNEXPECTED);
+
+  uint32_t pathPos, filepathPos, directoryPos, basenamePos, extensionPos;
+  int32_t pathLen, filepathLen, directoryLen, basenameLen, extensionLen;
+
+  // invoke the parser to extract the URL path
+  rv = parser->ParseURL(url, flatURL.Length(), nullptr,
+                        nullptr,           // don't care about scheme
+                        nullptr, nullptr,  // don't care about authority
+                        &pathPos, &pathLen);
+  if (NS_FAILED(rv)) return rv;
+
+  // invoke the parser to extract filepath from the path
+  rv = parser->ParsePath(url + pathPos, pathLen, &filepathPos, &filepathLen,
+                         nullptr, nullptr,   // don't care about query
+                         nullptr, nullptr);  // don't care about ref
+  if (NS_FAILED(rv)) return rv;
+
+  filepathPos += pathPos;
+
+  // invoke the parser to extract the directory and filename from filepath
+  rv = parser->ParseFilePath(url + filepathPos, filepathLen, &directoryPos,
+                             &directoryLen, &basenamePos, &basenameLen,
+                             &extensionPos, &extensionLen);
+  if (NS_FAILED(rv)) return rv;
+
+  if (directoryLen > 0) {
+    outDirectory = Substring(inURL, filepathPos + directoryPos, directoryLen);
+  }
+  if (basenameLen > 0) {
+    outFileBaseName = Substring(inURL, filepathPos + basenamePos, basenameLen);
+  }
+  if (extensionLen > 0) {
+    outFileExtension =
+        Substring(inURL, filepathPos + extensionPos, extensionLen);
+  }
+  // since we are using a no-auth url parser, there will never be a host
+  // XXX not strictly true... file://localhost/foo/bar.html is a valid URL
+
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// path manipulation functions
+//----------------------------------------------------------------------------
+
+// Replace all /./ with a / while resolving URLs
+// But only till #?
+void net_CoalesceDirs(netCoalesceFlags flags, char* path) {
+  /* Stolen from the old netlib's mkparse.c.
+   *
+   * modifies a url of the form   /foo/../foo1  ->  /foo1
+   *                       and    /foo/./foo1   ->  /foo/foo1
+   *                       and    /foo/foo1/..  ->  /foo/
+   */
+  char* fwdPtr = path;
+  char* urlPtr = path;
+  char* lastslash = path;
+  uint32_t traversal = 0;
+  uint32_t special_ftp_len = 0;
+
+  /* Remember if this url is a special ftp one: */
+  if (flags & NET_COALESCE_DOUBLE_SLASH_IS_ROOT) {
+    /* some schemes (for example ftp) have the speciality that
+       the path can begin // or /%2F to mark the root of the
+       servers filesystem, a simple / only marks the root relative
+       to the user loging in. We remember the length of the marker */
+    if (nsCRT::strncasecmp(path, "/%2F", 4) == 0) {
+      special_ftp_len = 4;
+    } else if (strncmp(path, "//", 2) == 0) {
+      special_ftp_len = 2;
+    }
+  }
+
+  /* find the last slash before # or ? */
+  for (; (*fwdPtr != '\0') && (*fwdPtr != '?') && (*fwdPtr != '#'); ++fwdPtr) {
+  }
+
+  /* found nothing, but go back one only */
+  /* if there is something to go back to */
+  if (fwdPtr != path && *fwdPtr == '\0') {
+    --fwdPtr;
+  }
+
+  /* search the slash */
+  for (; (fwdPtr != path) && (*fwdPtr != '/'); --fwdPtr) {
+  }
+  lastslash = fwdPtr;
+  fwdPtr = path;
+
+  /* replace all %2E or %2e with . in the path */
+  /* but stop at lastchar if non null */
+  for (; (*fwdPtr != '\0') && (*fwdPtr != '?') && (*fwdPtr != '#') &&
+         (*lastslash == '\0' || fwdPtr != lastslash);
+       ++fwdPtr) {
+    if (*fwdPtr == '%' && *(fwdPtr + 1) == '2' &&
+        (*(fwdPtr + 2) == 'E' || *(fwdPtr + 2) == 'e')) {
+      *urlPtr++ = '.';
+      ++fwdPtr;
+      ++fwdPtr;
+    } else {
+      *urlPtr++ = *fwdPtr;
+    }
+  }
+  // Copy remaining stuff past the #?;
+  for (; *fwdPtr != '\0'; ++fwdPtr) {
+    *urlPtr++ = *fwdPtr;
+  }
+  *urlPtr = '\0';  // terminate the url
+
+  // start again, this time for real
+  fwdPtr = path;
+  urlPtr = path;
+
+  for (; (*fwdPtr != '\0') && (*fwdPtr != '?') && (*fwdPtr != '#'); ++fwdPtr) {
+    if (*fwdPtr == '/' && *(fwdPtr + 1) == '.' && *(fwdPtr + 2) == '/') {
+      // remove . followed by slash
+      ++fwdPtr;
+    } else if (*fwdPtr == '/' && *(fwdPtr + 1) == '.' && *(fwdPtr + 2) == '.' &&
+               (*(fwdPtr + 3) == '/' ||
+                *(fwdPtr + 3) == '\0' ||  // This will take care of
+                *(fwdPtr + 3) == '?' ||   // something like foo/bar/..#sometag
+                *(fwdPtr + 3) == '#')) {
+      // remove foo/..
+      // reverse the urlPtr to the previous slash if possible
+      // if url does not allow relative root then drop .. above root
+      // otherwise retain them in the path
+      if (traversal > 0 || !(flags & NET_COALESCE_ALLOW_RELATIVE_ROOT)) {
+        if (urlPtr != path) urlPtr--;  // we must be going back at least by one
+        for (; *urlPtr != '/' && urlPtr != path; urlPtr--) {
+          ;  // null body
+        }
+        --traversal;  // count back
+        // forward the fwdPtr past the ../
+        fwdPtr += 2;
+        // if we have reached the beginning of the path
+        // while searching for the previous / and we remember
+        // that it is an url that begins with /%2F then
+        // advance urlPtr again by 3 chars because /%2F already
+        // marks the root of the path
+        if (urlPtr == path && special_ftp_len > 3) {
+          ++urlPtr;
+          ++urlPtr;
+          ++urlPtr;
+        }
+        // special case if we have reached the end
+        // to preserve the last /
+        if (*fwdPtr == '.' && *(fwdPtr + 1) == '\0') ++urlPtr;
+      } else {
+        // there are to much /.. in this path, just copy them instead.
+        // forward the urlPtr past the /.. and copying it
+
+        // However if we remember it is an url that starts with
+        // /%2F and urlPtr just points at the "F" of "/%2F" then do
+        // not overwrite it with the /, just copy .. and move forward
+        // urlPtr.
+        if (special_ftp_len > 3 && urlPtr == path + special_ftp_len - 1) {
+          ++urlPtr;
+        } else {
+          *urlPtr++ = *fwdPtr;
+        }
+        ++fwdPtr;
+        *urlPtr++ = *fwdPtr;
+        ++fwdPtr;
+        *urlPtr++ = *fwdPtr;
+      }
+    } else {
+      // count the hierachie, but only if we do not have reached
+      // the root of some special urls with a special root marker
+      if (*fwdPtr == '/' && *(fwdPtr + 1) != '.' &&
+          (special_ftp_len != 2 || *(fwdPtr + 1) != '/')) {
+        traversal++;
+      }
+      // copy the url incrementaly
+      *urlPtr++ = *fwdPtr;
+    }
+  }
+
+  /*
+   *  Now lets remove trailing . case
+   *     /foo/foo1/.   ->  /foo/foo1/
+   */
+
+  if ((urlPtr > (path + 1)) && (*(urlPtr - 1) == '.') &&
+      (*(urlPtr - 2) == '/')) {
+    urlPtr--;
+  }
+
+  // Copy remaining stuff past the #?;
+  for (; *fwdPtr != '\0'; ++fwdPtr) {
+    *urlPtr++ = *fwdPtr;
+  }
+  *urlPtr = '\0';  // terminate the url
+}
+
+//----------------------------------------------------------------------------
+// scheme fu
+//----------------------------------------------------------------------------
+
+static bool net_IsValidSchemeChar(const char aChar) {
+  return mozilla::net::rust_net_is_valid_scheme_char(aChar);
+}
+
+/* Extract URI-Scheme if possible */
+nsresult net_ExtractURLScheme(const nsACString& inURI, nsACString& scheme) {
+  nsACString::const_iterator start, end;
+  inURI.BeginReading(start);
+  inURI.EndReading(end);
+
+  // Strip C0 and space from begining
+  while (start != end) {
+    if ((uint8_t)*start > 0x20) {
+      break;
+    }
+    start++;
+  }
+
+  Tokenizer p(Substring(start, end), "\r\n\t");
+  p.Record();
+  if (!p.CheckChar(IsAsciiAlpha)) {
+    // First char must be alpha
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  while (p.CheckChar(net_IsValidSchemeChar) || p.CheckWhite()) {
+    // Skip valid scheme characters or \r\n\t
+  }
+
+  if (!p.CheckChar(':')) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  p.Claim(scheme);
+  scheme.StripTaggedASCII(ASCIIMask::MaskCRLFTab());
+  ToLowerCase(scheme);
+  return NS_OK;
+}
+
+bool net_IsValidScheme(const nsACString& scheme) {
+  return mozilla::net::rust_net_is_valid_scheme(&scheme);
+}
+
+bool net_IsAbsoluteURL(const nsACString& uri) {
+  nsACString::const_iterator start, end;
+  uri.BeginReading(start);
+  uri.EndReading(end);
+
+  // Strip C0 and space from begining
+  while (start != end) {
+    if ((uint8_t)*start > 0x20) {
+      break;
+    }
+    start++;
+  }
+
+  Tokenizer p(Substring(start, end), "\r\n\t");
+
+  // First char must be alpha
+  if (!p.CheckChar(IsAsciiAlpha)) {
+    return false;
+  }
+
+  while (p.CheckChar(net_IsValidSchemeChar) || p.CheckWhite()) {
+    // Skip valid scheme characters or \r\n\t
+  }
+  if (!p.CheckChar(':')) {
+    return false;
+  }
+  p.SkipWhites();
+
+  if (!p.CheckChar('/')) {
+    return false;
+  }
+  p.SkipWhites();
+
+  if (p.CheckChar('/')) {
+    // aSpec is really absolute. Ignore aBaseURI in this case
+    return true;
+  }
+  return false;
+}
+
+void net_FilterURIString(const nsACString& input, nsACString& result) {
+  result.Truncate();
+
+  const auto* start = input.BeginReading();
+  const auto* end = input.EndReading();
+
+  // Trim off leading and trailing invalid chars.
+  auto charFilter = [](char c) { return static_cast<uint8_t>(c) > 0x20; };
+  const auto* newStart = std::find_if(start, end, charFilter);
+  const auto* newEnd =
+      std::find_if(std::reverse_iterator<decltype(end)>(end),
+                   std::reverse_iterator<decltype(newStart)>(newStart),
+                   charFilter)
+          .base();
+
+  // Check if chars need to be stripped.
+  bool needsStrip = false;
+  const ASCIIMaskArray& mask = ASCIIMask::MaskCRLFTab();
+  for (const auto* itr = start; itr != end; ++itr) {
+    if (ASCIIMask::IsMasked(mask, *itr)) {
+      needsStrip = true;
+      break;
+    }
+  }
+
+  // Just use the passed in string rather than creating new copies if no
+  // changes are necessary.
+  if (newStart == start && newEnd == end && !needsStrip) {
+    result = input;
+    return;
+  }
+
+  result.Assign(Substring(newStart, newEnd));
+  if (needsStrip) {
+    result.StripTaggedASCII(mask);
+  }
+}
+
+nsresult net_FilterAndEscapeURI(const nsACString& aInput, uint32_t aFlags,
+                                const ASCIIMaskArray& aFilterMask,
+                                nsACString& aResult) {
+  aResult.Truncate();
+
+  const auto* start = aInput.BeginReading();
+  const auto* end = aInput.EndReading();
+
+  // Trim off leading and trailing invalid chars.
+  auto charFilter = [](char c) { return static_cast<uint8_t>(c) > 0x20; };
+  const auto* newStart = std::find_if(start, end, charFilter);
+  const auto* newEnd =
+      std::find_if(std::reverse_iterator<decltype(end)>(end),
+                   std::reverse_iterator<decltype(newStart)>(newStart),
+                   charFilter)
+          .base();
+
+  return NS_EscapeAndFilterURL(Substring(newStart, newEnd), aFlags,
+                               &aFilterMask, aResult, fallible);
+}
+
+#if defined(XP_WIN)
+bool net_NormalizeFileURL(const nsACString& aURL, nsCString& aResultBuf) {
+  bool writing = false;
+
+  nsACString::const_iterator beginIter, endIter;
+  aURL.BeginReading(beginIter);
+  aURL.EndReading(endIter);
+
+  const char *s, *begin = beginIter.get();
+
+  for (s = begin; s != endIter.get(); ++s) {
+    if (*s == '\\') {
+      writing = true;
+      if (s > begin) aResultBuf.Append(begin, s - begin);
+      aResultBuf += '/';
+      begin = s + 1;
+    }
+  }
+  if (writing && s > begin) aResultBuf.Append(begin, s - begin);
+
+  return writing;
+}
+#endif
+
+//----------------------------------------------------------------------------
+// miscellaneous (i.e., stuff that should really be elsewhere)
+//----------------------------------------------------------------------------
+
+static inline void ToLower(char& c) {
+  if ((unsigned)(c - 'A') <= (unsigned)('Z' - 'A')) c += 'a' - 'A';
+}
+
+void net_ToLowerCase(char* str, uint32_t length) {
+  for (char* end = str + length; str < end; ++str) ToLower(*str);
+}
+
+void net_ToLowerCase(char* str) {
+  for (; *str; ++str) ToLower(*str);
+}
+
+char* net_FindCharInSet(const char* iter, const char* stop, const char* set) {
+  for (; iter != stop && *iter; ++iter) {
+    for (const char* s = set; *s; ++s) {
+      if (*iter == *s) return (char*)iter;
+    }
+  }
+  return (char*)iter;
+}
+
+char* net_FindCharNotInSet(const char* iter, const char* stop,
+                           const char* set) {
+repeat:
+  for (const char* s = set; *s; ++s) {
+    if (*iter == *s) {
+      if (++iter == stop) break;
+      goto repeat;
+    }
+  }
+  return (char*)iter;
+}
+
+char* net_RFindCharNotInSet(const char* stop, const char* iter,
+                            const char* set) {
+  --iter;
+  --stop;
+
+  if (iter == stop) return (char*)iter;
+
+repeat:
+  for (const char* s = set; *s; ++s) {
+    if (*iter == *s) {
+      if (--iter == stop) break;
+      goto repeat;
+    }
+  }
+  return (char*)iter;
+}
+
+#define HTTP_LWS " \t"
+
+// Return the index of the closing quote of the string, if any
+static uint32_t net_FindStringEnd(const nsCString& flatStr,
+                                  uint32_t stringStart, char stringDelim) {
+  NS_ASSERTION(stringStart < flatStr.Length() &&
+                   flatStr.CharAt(stringStart) == stringDelim &&
+                   (stringDelim == '"' || stringDelim == '\''),
+               "Invalid stringStart");
+
+  const char set[] = {stringDelim, '\\', '\0'};
+  do {
+    // stringStart points to either the start quote or the last
+    // escaped char (the char following a '\\')
+
+    // Write to searchStart here, so that when we get back to the
+    // top of the loop right outside this one we search from the
+    // right place.
+    uint32_t stringEnd = flatStr.FindCharInSet(set, stringStart + 1);
+    if (stringEnd == uint32_t(kNotFound)) return flatStr.Length();
+
+    if (flatStr.CharAt(stringEnd) == '\\') {
+      // Hit a backslash-escaped char.  Need to skip over it.
+      stringStart = stringEnd + 1;
+      if (stringStart == flatStr.Length()) return stringStart;
+
+      // Go back to looking for the next escape or the string end
+      continue;
+    }
+
+    return stringEnd;
+
+  } while (true);
+
+  MOZ_ASSERT_UNREACHABLE("How did we get here?");
+  return flatStr.Length();
+}
+
+static uint32_t net_FindMediaDelimiter(const nsCString& flatStr,
+                                       uint32_t searchStart, char delimiter) {
+  do {
+    // searchStart points to the spot from which we should start looking
+    // for the delimiter.
+    const char delimStr[] = {delimiter, '"', '\0'};
+    uint32_t curDelimPos = flatStr.FindCharInSet(delimStr, searchStart);
+    if (curDelimPos == uint32_t(kNotFound)) return flatStr.Length();
+
+    char ch = flatStr.CharAt(curDelimPos);
+    if (ch == delimiter) {
+      // Found delimiter
+      return curDelimPos;
+    }
+
+    // We hit the start of a quoted string.  Look for its end.
+    searchStart = net_FindStringEnd(flatStr, curDelimPos, ch);
+    if (searchStart == flatStr.Length()) return searchStart;
+
+    ++searchStart;
+
+    // searchStart now points to the first char after the end of the
+    // string, so just go back to the top of the loop and look for
+    // |delimiter| again.
+  } while (true);
+
+  MOZ_ASSERT_UNREACHABLE("How did we get here?");
+  return flatStr.Length();
+}
+
+// aOffset should be added to aCharsetStart and aCharsetEnd if this
+// function sets them.
+static void net_ParseMediaType(const nsACString& aMediaTypeStr,
+                               nsACString& aContentType,
+                               nsACString& aContentCharset, int32_t aOffset,
+                               bool* aHadCharset, int32_t* aCharsetStart,
+                               int32_t* aCharsetEnd, bool aStrict) {
+  const nsCString& flatStr = PromiseFlatCString(aMediaTypeStr);
+  const char* start = flatStr.get();
+  const char* end = start + flatStr.Length();
+
+  // Trim LWS leading and trailing whitespace from type.  We include '(' in
+  // the trailing trim set to catch media-type comments, which are not at all
+  // standard, but may occur in rare cases.
+  const char* type = net_FindCharNotInSet(start, end, HTTP_LWS);
+  const char* typeEnd = net_FindCharInSet(type, end, HTTP_LWS ";(");
+
+  const char* charset = "";
+  const char* charsetEnd = charset;
+  int32_t charsetParamStart = 0;
+  int32_t charsetParamEnd = 0;
+
+  uint32_t consumed = typeEnd - type;
+
+  // Iterate over parameters
+  bool typeHasCharset = false;
+  uint32_t paramStart = flatStr.FindChar(';', typeEnd - start);
+  if (paramStart != uint32_t(kNotFound)) {
+    // We have parameters.  Iterate over them.
+    uint32_t curParamStart = paramStart + 1;
+    do {
+      uint32_t curParamEnd =
+          net_FindMediaDelimiter(flatStr, curParamStart, ';');
+
+      const char* paramName = net_FindCharNotInSet(
+          start + curParamStart, start + curParamEnd, HTTP_LWS);
+      static const char charsetStr[] = "charset=";
+      if (nsCRT::strncasecmp(paramName, charsetStr, sizeof(charsetStr) - 1) ==
+          0) {
+        charset = paramName + sizeof(charsetStr) - 1;
+        charsetEnd = start + curParamEnd;
+        typeHasCharset = true;
+        charsetParamStart = curParamStart - 1;
+        charsetParamEnd = curParamEnd;
+      }
+
+      consumed = curParamEnd;
+      curParamStart = curParamEnd + 1;
+    } while (curParamStart < flatStr.Length());
+  }
+
+  bool charsetNeedsQuotedStringUnescaping = false;
+  if (typeHasCharset) {
+    // Trim LWS leading and trailing whitespace from charset.  We include
+    // '(' in the trailing trim set to catch media-type comments, which are
+    // not at all standard, but may occur in rare cases.
+    charset = net_FindCharNotInSet(charset, charsetEnd, HTTP_LWS);
+    if (*charset == '"') {
+      charsetNeedsQuotedStringUnescaping = true;
+      charsetEnd =
+          start + net_FindStringEnd(flatStr, charset - start, *charset);
+      charset++;
+      NS_ASSERTION(charsetEnd >= charset, "Bad charset parsing");
+    } else {
+      charsetEnd = net_FindCharInSet(charset, charsetEnd, HTTP_LWS ";(");
+    }
+  }
+
+  // if the server sent "*/*", it is meaningless, so do not store it.
+  // also, if type is the same as aContentType, then just update the
+  // charset.  however, if charset is empty and aContentType hasn't
+  // changed, then don't wipe-out an existing aContentCharset.  We
+  // also want to reject a mime-type if it does not include a slash.
+  // some servers give junk after the charset parameter, which may
+  // include a comma, so this check makes us a bit more tolerant.
+
+  if (type != typeEnd && memchr(type, '/', typeEnd - type) != nullptr &&
+      (aStrict ? (net_FindCharNotInSet(start + consumed, end, HTTP_LWS) == end)
+               : (strncmp(type, "*/*", typeEnd - type) != 0))) {
+    // Common case here is that aContentType is empty
+    bool eq = !aContentType.IsEmpty() &&
+              aContentType.Equals(Substring(type, typeEnd),
+                                  nsCaseInsensitiveCStringComparator);
+    if (!eq) {
+      aContentType.Assign(type, typeEnd - type);
+      ToLowerCase(aContentType);
+    }
+
+    if ((!eq && *aHadCharset) || typeHasCharset) {
+      *aHadCharset = true;
+      if (charsetNeedsQuotedStringUnescaping) {
+        // parameters using the "quoted-string" syntax need
+        // backslash-escapes to be unescaped (see RFC 2616 Section 2.2)
+        aContentCharset.Truncate();
+        for (const char* c = charset; c != charsetEnd; c++) {
+          if (*c == '\\' && c + 1 != charsetEnd) {
+            // eat escape
+            c++;
+          }
+          aContentCharset.Append(*c);
+        }
+      } else {
+        aContentCharset.Assign(charset, charsetEnd - charset);
+      }
+      if (typeHasCharset) {
+        *aCharsetStart = charsetParamStart + aOffset;
+        *aCharsetEnd = charsetParamEnd + aOffset;
+      }
+    }
+    // Only set a new charset position if this is a different type
+    // from the last one we had and it doesn't already have a
+    // charset param.  If this is the same type, we probably want
+    // to leave the charset position on its first occurrence.
+    if (!eq && !typeHasCharset) {
+      int32_t charsetStart = int32_t(paramStart);
+      if (charsetStart == kNotFound) charsetStart = flatStr.Length();
+
+      *aCharsetEnd = *aCharsetStart = charsetStart + aOffset;
+    }
+  }
+}
+
+#undef HTTP_LWS
+
+void net_ParseContentType(const nsACString& aHeaderStr,
+                          nsACString& aContentType, nsACString& aContentCharset,
+                          bool* aHadCharset) {
+  int32_t dummy1, dummy2;
+  net_ParseContentType(aHeaderStr, aContentType, aContentCharset, aHadCharset,
+                       &dummy1, &dummy2);
+}
+
+void net_ParseContentType(const nsACString& aHeaderStr,
+                          nsACString& aContentType, nsACString& aContentCharset,
+                          bool* aHadCharset, int32_t* aCharsetStart,
+                          int32_t* aCharsetEnd) {
+  //
+  // Augmented BNF (from RFC 2616 section 3.7):
+  //
+  //   header-value = media-type *( LWS "," LWS media-type )
+  //   media-type   = type "/" subtype *( LWS ";" LWS parameter )
+  //   type         = token
+  //   subtype      = token
+  //   parameter    = attribute "=" value
+  //   attribute    = token
+  //   value        = token | quoted-string
+  //
+  //
+  // Examples:
+  //
+  //   text/html
+  //   text/html, text/html
+  //   text/html,text/html; charset=ISO-8859-1
+  //   text/html,text/html; charset="ISO-8859-1"
+  //   text/html;charset=ISO-8859-1, text/html
+  //   text/html;charset='ISO-8859-1', text/html
+  //   application/octet-stream
+  //
+
+  *aHadCharset = false;
+  const nsCString& flatStr = PromiseFlatCString(aHeaderStr);
+
+  // iterate over media-types.  Note that ',' characters can happen
+  // inside quoted strings, so we need to watch out for that.
+  uint32_t curTypeStart = 0;
+  do {
+    // curTypeStart points to the start of the current media-type.  We want
+    // to look for its end.
+    uint32_t curTypeEnd = net_FindMediaDelimiter(flatStr, curTypeStart, ',');
+
+    // At this point curTypeEnd points to the spot where the media-type
+    // starting at curTypeEnd ends.  Time to parse that!
+    net_ParseMediaType(
+        Substring(flatStr, curTypeStart, curTypeEnd - curTypeStart),
+        aContentType, aContentCharset, curTypeStart, aHadCharset, aCharsetStart,
+        aCharsetEnd, false);
+
+    // And let's move on to the next media-type
+    curTypeStart = curTypeEnd + 1;
+  } while (curTypeStart < flatStr.Length());
+}
+
+void net_ParseRequestContentType(const nsACString& aHeaderStr,
+                                 nsACString& aContentType,
+                                 nsACString& aContentCharset,
+                                 bool* aHadCharset) {
+  //
+  // Augmented BNF (from RFC 7231 section 3.1.1.1):
+  //
+  //   media-type   = type "/" subtype *( OWS ";" OWS parameter )
+  //   type         = token
+  //   subtype      = token
+  //   parameter    = token "=" ( token / quoted-string )
+  //
+  // Examples:
+  //
+  //   text/html
+  //   text/html; charset=ISO-8859-1
+  //   text/html; charset="ISO-8859-1"
+  //   application/octet-stream
+  //
+
+  aContentType.Truncate();
+  aContentCharset.Truncate();
+  *aHadCharset = false;
+  const nsCString& flatStr = PromiseFlatCString(aHeaderStr);
+
+  // At this point curTypeEnd points to the spot where the media-type
+  // starting at curTypeEnd ends.  Time to parse that!
+  nsAutoCString contentType, contentCharset;
+  bool hadCharset = false;
+  int32_t dummy1, dummy2;
+  uint32_t typeEnd = net_FindMediaDelimiter(flatStr, 0, ',');
+  if (typeEnd != flatStr.Length()) {
+    // We have some stuff left at the end, so this is not a valid
+    // request Content-Type header.
+    return;
+  }
+  net_ParseMediaType(flatStr, contentType, contentCharset, 0, &hadCharset,
+                     &dummy1, &dummy2, true);
+
+  aContentType = contentType;
+  aContentCharset = contentCharset;
+  *aHadCharset = hadCharset;
+}
+
+bool net_IsValidHostName(const nsACString& host) {
+  // A DNS name is limited to 255 bytes on the wire.
+  // In practice this means the host name is limited to 253 ascii characters.
+  if (StaticPrefs::network_dns_limit_253_chars() && host.Length() > 253) {
+    return false;
+  }
+
+  const char* end = host.EndReading();
+  // Use explicit whitelists to select which characters we are
+  // willing to send to lower-level DNS logic. This is more
+  // self-documenting, and can also be slightly faster than the
+  // blacklist approach, since DNS names are the common case, and
+  // the commonest characters will tend to be near the start of
+  // the list.
+
+  // Whitelist for DNS names (RFC 1035) with extra characters added
+  // for pragmatic reasons "$+_"
+  // see https://bugzilla.mozilla.org/show_bug.cgi?id=355181#c2
+  if (net_FindCharNotInSet(host.BeginReading(), end,
+                           "abcdefghijklmnopqrstuvwxyz"
+                           ".-0123456789"
+                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ$+_") == end) {
+    return true;
+  }
+
+  // Might be a valid IPv6 link-local address containing a percent sign
+  return mozilla::net::HostIsIPLiteral(host);
+}
+
+bool net_IsValidIPv4Addr(const nsACString& aAddr) {
+  return mozilla::net::rust_net_is_valid_ipv4_addr(&aAddr);
+}
+
+bool net_IsValidIPv6Addr(const nsACString& aAddr) {
+  return mozilla::net::rust_net_is_valid_ipv6_addr(&aAddr);
+}
+
+namespace mozilla {
+static auto MakeNameMatcher(const nsAString& aName) {
+  return [&aName](const auto& param) { return param.mKey.Equals(aName); };
+}
+
+bool URLParams::Has(const nsAString& aName) {
+  return std::any_of(mParams.cbegin(), mParams.cend(), MakeNameMatcher(aName));
+}
+
+bool URLParams::Has(const nsAString& aName, const nsAString& aValue) {
+  return std::any_of(
+      mParams.cbegin(), mParams.cend(), [&aName, &aValue](const auto& param) {
+        return param.mKey.Equals(aName) && param.mValue.Equals(aValue);
+      });
+}
+
+void URLParams::Get(const nsAString& aName, nsString& aRetval) {
+  SetDOMStringToNull(aRetval);
+
+  const auto end = mParams.cend();
+  const auto it = std::find_if(mParams.cbegin(), end, MakeNameMatcher(aName));
+  if (it != end) {
+    aRetval.Assign(it->mValue);
+  }
+}
+
+void URLParams::GetAll(const nsAString& aName, nsTArray<nsString>& aRetval) {
+  aRetval.Clear();
+
+  for (uint32_t i = 0, len = mParams.Length(); i < len; ++i) {
+    if (mParams[i].mKey.Equals(aName)) {
+      aRetval.AppendElement(mParams[i].mValue);
+    }
+  }
+}
+
+void URLParams::Append(const nsAString& aName, const nsAString& aValue) {
+  Param* param = mParams.AppendElement();
+  param->mKey = aName;
+  param->mValue = aValue;
+}
+
+void URLParams::Set(const nsAString& aName, const nsAString& aValue) {
+  Param* param = nullptr;
+  for (uint32_t i = 0, len = mParams.Length(); i < len;) {
+    if (!mParams[i].mKey.Equals(aName)) {
+      ++i;
+      continue;
+    }
+    if (!param) {
+      param = &mParams[i];
+      ++i;
+      continue;
+    }
+    // Remove duplicates.
+    mParams.RemoveElementAt(i);
+    --len;
+  }
+
+  if (!param) {
+    param = mParams.AppendElement();
+    param->mKey = aName;
+  }
+
+  param->mValue = aValue;
+}
+
+void URLParams::Delete(const nsAString& aName) {
+  mParams.RemoveElementsBy(
+      [&aName](const auto& param) { return param.mKey.Equals(aName); });
+}
+
+void URLParams::Delete(const nsAString& aName, const nsAString& aValue) {
+  mParams.RemoveElementsBy([&aName, &aValue](const auto& param) {
+    return param.mKey.Equals(aName) && param.mValue.Equals(aValue);
+  });
+}
+
+/* static */
+void URLParams::ConvertString(const nsACString& aInput, nsAString& aOutput) {
+  if (NS_FAILED(UTF_8_ENCODING->DecodeWithoutBOMHandling(aInput, aOutput))) {
+    MOZ_CRASH("Out of memory when converting URL params.");
+  }
+}
+
+/* static */
+void URLParams::DecodeString(const nsACString& aInput, nsAString& aOutput) {
+  const char* const end = aInput.EndReading();
+
+  nsAutoCString unescaped;
+
+  for (const char* iter = aInput.BeginReading(); iter != end;) {
+    // replace '+' with U+0020
+    if (*iter == '+') {
+      unescaped.Append(' ');
+      ++iter;
+      continue;
+    }
+
+    // Percent decode algorithm
+    if (*iter == '%') {
+      const char* const first = iter + 1;
+      const char* const second = first + 1;
+
+      const auto asciiHexDigit = [](char x) {
+        return (x >= 0x41 && x <= 0x46) || (x >= 0x61 && x <= 0x66) ||
+               (x >= 0x30 && x <= 0x39);
+      };
+
+      const auto hexDigit = [](char x) {
+        return x >= 0x30 && x <= 0x39
+                   ? x - 0x30
+                   : (x >= 0x41 && x <= 0x46 ? x - 0x37 : x - 0x57);
+      };
+
+      if (first != end && second != end && asciiHexDigit(*first) &&
+          asciiHexDigit(*second)) {
+        unescaped.Append(hexDigit(*first) * 16 + hexDigit(*second));
+        iter = second + 1;
+      } else {
+        unescaped.Append('%');
+        ++iter;
+      }
+
+      continue;
+    }
+
+    unescaped.Append(*iter);
+    ++iter;
+  }
+
+  // XXX It seems rather wasteful to first decode into a UTF-8 nsCString and
+  // then convert the whole string to UTF-16, at least if we exceed the inline
+  // storage size.
+  ConvertString(unescaped, aOutput);
+}
+
+/* static */
+bool URLParams::ParseNextInternal(const char*& aStart, const char* const aEnd,
+                                  nsAString* aOutDecodedName,
+                                  nsAString* aOutDecodedValue) {
+  nsDependentCSubstring string;
+
+  const char* const iter = std::find(aStart, aEnd, '&');
+  if (iter != aEnd) {
+    string.Rebind(aStart, iter);
+    aStart = iter + 1;
+  } else {
+    string.Rebind(aStart, aEnd);
+    aStart = aEnd;
+  }
+
+  if (string.IsEmpty()) {
+    return false;
+  }
+
+  const auto* const eqStart = string.BeginReading();
+  const auto* const eqEnd = string.EndReading();
+  const auto* const eqIter = std::find(eqStart, eqEnd, '=');
+
+  nsDependentCSubstring name;
+  nsDependentCSubstring value;
+
+  if (eqIter != eqEnd) {
+    name.Rebind(eqStart, eqIter);
+    value.Rebind(eqIter + 1, eqEnd);
+  } else {
+    name.Rebind(string, 0);
+  }
+
+  DecodeString(name, *aOutDecodedName);
+  DecodeString(value, *aOutDecodedValue);
+
+  return true;
+}
+
+/* static */
+bool URLParams::Extract(const nsACString& aInput, const nsAString& aName,
+                        nsAString& aValue) {
+  aValue.SetIsVoid(true);
+  return !URLParams::Parse(
+      aInput, [&aName, &aValue](const nsAString& name, nsString&& value) {
+        if (aName == name) {
+          aValue = std::move(value);
+          return false;
+        }
+        return true;
+      });
+}
+
+void URLParams::ParseInput(const nsACString& aInput) {
+  // Remove all the existing data before parsing a new input.
+  DeleteAll();
+
+  URLParams::Parse(aInput, [this](nsString&& name, nsString&& value) {
+    mParams.AppendElement(Param{std::move(name), std::move(value)});
+    return true;
+  });
+}
+
+namespace {
+
+void SerializeString(const nsCString& aInput, nsAString& aValue) {
+  const unsigned char* p = (const unsigned char*)aInput.get();
+  const unsigned char* end = p + aInput.Length();
+
+  while (p != end) {
+    // ' ' to '+'
+    if (*p == 0x20) {
+      aValue.Append(0x2B);
+      // Percent Encode algorithm
+    } else if (*p == 0x2A || *p == 0x2D || *p == 0x2E ||
+               (*p >= 0x30 && *p <= 0x39) || (*p >= 0x41 && *p <= 0x5A) ||
+               *p == 0x5F || (*p >= 0x61 && *p <= 0x7A)) {
+      aValue.Append(*p);
+    } else {
+      aValue.AppendPrintf("%%%.2X", *p);
+    }
+
+    ++p;
+  }
+}
+
+}  // namespace
+
+void URLParams::Serialize(nsAString& aValue, bool aEncode) const {
+  aValue.Truncate();
+  bool first = true;
+
+  for (uint32_t i = 0, len = mParams.Length(); i < len; ++i) {
+    if (first) {
+      first = false;
+    } else {
+      aValue.Append('&');
+    }
+
+    // XXX Actually, it's not necessary to build a new string object. Generally,
+    // such cases could just convert each codepoint one-by-one.
+    if (aEncode) {
+      SerializeString(NS_ConvertUTF16toUTF8(mParams[i].mKey), aValue);
+      aValue.Append('=');
+      SerializeString(NS_ConvertUTF16toUTF8(mParams[i].mValue), aValue);
+    } else {
+      aValue.Append(mParams[i].mKey);
+      aValue.Append('=');
+      aValue.Append(mParams[i].mValue);
+    }
+  }
+}
+
+void URLParams::Sort() {
+  mParams.StableSort([](const Param& lhs, const Param& rhs) {
+    return Compare(lhs.mKey, rhs.mKey);
+  });
+}
+
+}  // namespace mozilla
diff --git a/netwerk/base/nsURLHelper.h b/netwerk/base/nsURLHelper.h
new file mode 100644
index 0000000000..f97d947652
--- /dev/null
+++ b/netwerk/base/nsURLHelper.h
@@ -0,0 +1,366 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsURLHelper_h__
+#define nsURLHelper_h__
+
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsASCIIMask.h"
+
+class nsIFile;
+class nsIURLParser;
+
+enum netCoalesceFlags {
+  NET_COALESCE_NORMAL = 0,
+
+  /**
+   * retains /../ that reach above dir root (useful for FTP
+   * servers in which the root of the FTP URL is not necessarily
+   * the root of the FTP filesystem).
+   */
+  NET_COALESCE_ALLOW_RELATIVE_ROOT = 1 << 0,
+
+  /**
+   * recognizes /%2F and // as markers for the root directory
+   * and handles them properly.
+   */
+  NET_COALESCE_DOUBLE_SLASH_IS_ROOT = 1 << 1
+};
+
+//----------------------------------------------------------------------------
+// This module contains some private helper functions related to URL parsing.
+//----------------------------------------------------------------------------
+
+/* shutdown frees URL parser */
+void net_ShutdownURLHelper();
+#ifdef XP_MACOSX
+void net_ShutdownURLHelperOSX();
+#endif
+
+/* access URL parsers */
+nsIURLParser* net_GetAuthURLParser();
+nsIURLParser* net_GetNoAuthURLParser();
+nsIURLParser* net_GetStdURLParser();
+
+/* convert between nsIFile and file:// URL spec
+ * net_GetURLSpecFromFile does an extra stat, so callers should
+ * avoid it if possible in favor of net_GetURLSpecFromActualFile
+ * and net_GetURLSpecFromDir */
+nsresult net_GetURLSpecFromFile(nsIFile*, nsACString&);
+nsresult net_GetURLSpecFromDir(nsIFile*, nsACString&);
+nsresult net_GetURLSpecFromActualFile(nsIFile*, nsACString&);
+nsresult net_GetFileFromURLSpec(const nsACString&, nsIFile**);
+
+/* extract file path components from file:// URL */
+nsresult net_ParseFileURL(const nsACString& inURL, nsACString& outDirectory,
+                          nsACString& outFileBaseName,
+                          nsACString& outFileExtension);
+
+/* handle .. in dirs while resolving URLs (path is UTF-8) */
+void net_CoalesceDirs(netCoalesceFlags flags, char* path);
+
+/**
+ * Check if a URL is absolute
+ *
+ * @param inURL     URL spec
+ * @return true if the given spec represents an absolute URL
+ */
+bool net_IsAbsoluteURL(const nsACString& uri);
+
+/**
+ * Extract URI-Scheme if possible
+ *
+ * @param inURI     URI spec
+ * @param scheme    scheme copied to this buffer on return. Is lowercase.
+ */
+nsresult net_ExtractURLScheme(const nsACString& inURI, nsACString& scheme);
+
+/* check that the given scheme conforms to RFC 2396 */
+bool net_IsValidScheme(const nsACString& scheme);
+
+/**
+ * This function strips out all C0 controls and space at the beginning and end
+ * of the URL and filters out \r, \n, \t from the middle of the URL.  This makes
+ * it safe to call on things like javascript: urls or data: urls, where we may
+ * in fact run into whitespace that is not properly encoded.
+ *
+ * @param input the URL spec we want to filter
+ * @param result the out param to write to if filtering happens
+ */
+void net_FilterURIString(const nsACString& input, nsACString& result);
+
+/**
+ * This function performs character stripping just like net_FilterURIString,
+ * with the added benefit of also performing percent escaping of dissallowed
+ * characters, all in one pass. Saving one pass is very important when operating
+ * on really large strings.
+ *
+ * @param aInput the URL spec we want to filter
+ * @param aFlags the flags which control which characters we escape
+ * @param aFilterMask a mask of characters that should excluded from the result
+ * @param aResult the out param to write to if filtering happens
+ */
+nsresult net_FilterAndEscapeURI(const nsACString& aInput, uint32_t aFlags,
+                                const ASCIIMaskArray& aFilterMask,
+                                nsACString& aResult);
+
+#if defined(XP_WIN)
+/**
+ * On Win32 and OS/2 system's a back-slash in a file:// URL is equivalent to a
+ * forward-slash.  This function maps any back-slashes to forward-slashes.
+ *
+ * @param aURL
+ *        The URL string to normalize (UTF-8 encoded).  This can be a
+ *        relative URL segment.
+ * @param aResultBuf
+ *        The resulting string is appended to this string.  If the input URL
+ *        is already normalized, then aResultBuf is unchanged.
+ *
+ * @returns false if aURL is already normalized.  Otherwise, returns true.
+ */
+bool net_NormalizeFileURL(const nsACString& aURL, nsCString& aResultBuf);
+#endif
+
+/*****************************************************************************
+ * generic string routines follow (XXX move to someplace more generic).
+ */
+
+/* convert to lower case */
+void net_ToLowerCase(char* str, uint32_t length);
+void net_ToLowerCase(char* str);
+
+/**
+ * returns pointer to first character of |str| in the given set.  if not found,
+ * then |end| is returned.  stops prematurely if a null byte is encountered,
+ * and returns the address of the null byte.
+ */
+char* net_FindCharInSet(const char* iter, const char* stop, const char* set);
+
+/**
+ * returns pointer to first character of |str| NOT in the given set.  if all
+ * characters are in the given set, then |end| is returned.  if '\0' is not
+ * included in |set|, then stops prematurely if a null byte is encountered,
+ * and returns the address of the null byte.
+ */
+char* net_FindCharNotInSet(const char* iter, const char* stop, const char* set);
+
+/**
+ * returns pointer to last character of |str| NOT in the given set.  if all
+ * characters are in the given set, then |str - 1| is returned.
+ */
+char* net_RFindCharNotInSet(const char* stop, const char* iter,
+                            const char* set);
+
+/**
+ * Parses a content-type header and returns the content type and
+ * charset (if any).  aCharset is not modified if no charset is
+ * specified in anywhere in aHeaderStr.  In that case (no charset
+ * specified), aHadCharset is set to false.  Otherwise, it's set to
+ * true.  Note that aContentCharset can be empty even if aHadCharset
+ * is true.
+ *
+ * This parsing is suitable for HTTP request.  Use net_ParseContentType
+ * for parsing this header in HTTP responses.
+ */
+void net_ParseRequestContentType(const nsACString& aHeaderStr,
+                                 nsACString& aContentType,
+                                 nsACString& aContentCharset,
+                                 bool* aHadCharset);
+
+/**
+ * Parses a content-type header and returns the content type and
+ * charset (if any).  aCharset is not modified if no charset is
+ * specified in anywhere in aHeaderStr.  In that case (no charset
+ * specified), aHadCharset is set to false.  Otherwise, it's set to
+ * true.  Note that aContentCharset can be empty even if aHadCharset
+ * is true.
+ */
+void net_ParseContentType(const nsACString& aHeaderStr,
+                          nsACString& aContentType, nsACString& aContentCharset,
+                          bool* aHadCharset);
+/**
+ * As above, but also returns the start and end indexes for the charset
+ * parameter in aHeaderStr.  These are indices for the entire parameter, NOT
+ * just the value.  If there is "effectively" no charset parameter (e.g. if an
+ * earlier type with one is overridden by a later type without one),
+ * *aHadCharset will be true but *aCharsetStart will be set to -1.  Note that
+ * it's possible to have aContentCharset empty and *aHadCharset true when
+ * *aCharsetStart is nonnegative; this corresponds to charset="".
+ */
+void net_ParseContentType(const nsACString& aHeaderStr,
+                          nsACString& aContentType, nsACString& aContentCharset,
+                          bool* aHadCharset, int32_t* aCharsetStart,
+                          int32_t* aCharsetEnd);
+
+/* inline versions */
+
+/* remember the 64-bit platforms ;-) */
+#define NET_MAX_ADDRESS ((char*)UINTPTR_MAX)
+
+inline char* net_FindCharInSet(const char* str, const char* set) {
+  return net_FindCharInSet(str, NET_MAX_ADDRESS, set);
+}
+inline char* net_FindCharNotInSet(const char* str, const char* set) {
+  return net_FindCharNotInSet(str, NET_MAX_ADDRESS, set);
+}
+inline char* net_RFindCharNotInSet(const char* str, const char* set) {
+  return net_RFindCharNotInSet(str, str + strlen(str), set);
+}
+
+/**
+ * This function returns true if the given hostname does not include any
+ * restricted characters.  Otherwise, false is returned.
+ */
+bool net_IsValidHostName(const nsACString& host);
+
+/**
+ * Checks whether the IPv4 address is valid according to RFC 3986 section 3.2.2.
+ */
+bool net_IsValidIPv4Addr(const nsACString& aAddr);
+
+/**
+ * Checks whether the IPv6 address is valid according to RFC 3986 section 3.2.2.
+ */
+bool net_IsValidIPv6Addr(const nsACString& aAddr);
+
+namespace mozilla {
+/**
+ * A class for handling form-urlencoded query strings.
+ *
+ * Manages an ordered list of name-value pairs, and allows conversion from and
+ * to the string representation.
+ *
+ * In addition, there are static functions for handling one-shot use cases.
+ */
+class URLParams final {
+ public:
+  /**
+   * \brief Parses a query string and calls a parameter handler for each
+   * name/value pair. The parameter handler can stop processing early by
+   * returning false.
+   *
+   * \param aInput the query string to parse
+   * \param aParamHandler the parameter handler as desribed above
+   * \tparam ParamHandler a function type compatible with signature
+   * bool(nsString, nsString)
+   *
+   * \return false if the parameter handler returned false for any parameter,
+   * true otherwise
+   */
+  template <typename ParamHandler>
+  static bool Parse(const nsACString& aInput, ParamHandler aParamHandler) {
+    const char* start = aInput.BeginReading();
+    const char* const end = aInput.EndReading();
+
+    while (start != end) {
+      nsAutoString decodedName;
+      nsAutoString decodedValue;
+
+      if (!ParseNextInternal(start, end, &decodedName, &decodedValue)) {
+        continue;
+      }
+
+      if (!aParamHandler(std::move(decodedName), std::move(decodedValue))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * \brief Parses a query string and returns the value of a single parameter
+   * specified by name.
+   *
+   * If there are multiple parameters with the same name, the value of the first
+   * is returned.
+   *
+   * \param aInput the query string to parse
+   * \param aName the name of the parameter to extract
+   * \param[out] aValue will be assigned the parameter value, set to void if
+   * there is no match \return true iff there was a parameter with with name
+   * \paramref aName
+   */
+  static bool Extract(const nsACString& aInput, const nsAString& aName,
+                      nsAString& aValue);
+
+  /**
+   * \brief Resets the state of this instance and parses a new query string.
+   *
+   * \param aInput the query string to parse
+   */
+  void ParseInput(const nsACString& aInput);
+
+  /**
+   * Serializes the current state to a query string.
+   *
+   * \param[out] aValue will be assigned the result of the serialization
+   * \param aEncode If this is true, the serialization will encode the string.
+   */
+  void Serialize(nsAString& aValue, bool aEncode) const;
+
+  void Get(const nsAString& aName, nsString& aRetval);
+
+  void GetAll(const nsAString& aName, nsTArray<nsString>& aRetval);
+
+  /**
+   * \brief Sets the value of a given parameter.
+   *
+   * If one or more parameters of the name exist, the value of the first is
+   * replaced, and all further parameters of the name are deleted. Otherwise,
+   * the behaviour is the same as \ref Append.
+   */
+  void Set(const nsAString& aName, const nsAString& aValue);
+
+  void Append(const nsAString& aName, const nsAString& aValue);
+
+  bool Has(const nsAString& aName);
+
+  bool Has(const nsAString& aName, const nsAString& aValue);
+
+  /**
+   * \brief Deletes all parameters with the given name.
+   */
+  void Delete(const nsAString& aName);
+
+  void Delete(const nsAString& aName, const nsAString& aValue);
+
+  void DeleteAll() { mParams.Clear(); }
+
+  uint32_t Length() const { return mParams.Length(); }
+
+  const nsAString& GetKeyAtIndex(uint32_t aIndex) const {
+    MOZ_ASSERT(aIndex < mParams.Length());
+    return mParams[aIndex].mKey;
+  }
+
+  const nsAString& GetValueAtIndex(uint32_t aIndex) const {
+    MOZ_ASSERT(aIndex < mParams.Length());
+    return mParams[aIndex].mValue;
+  }
+
+  /**
+   * \brief Performs a stable sort of the parameters, maintaining the order of
+   * multiple parameters with the same name.
+   */
+  void Sort();
+
+ private:
+  static void DecodeString(const nsACString& aInput, nsAString& aOutput);
+  static void ConvertString(const nsACString& aInput, nsAString& aOutput);
+  static bool ParseNextInternal(const char*& aStart, const char* aEnd,
+                                nsAString* aOutDecodedName,
+                                nsAString* aOutDecodedValue);
+
+  struct Param {
+    nsString mKey;
+    nsString mValue;
+  };
+
+  nsTArray<Param> mParams;
+};
+}  // namespace mozilla
+
+#endif  // !nsURLHelper_h__
diff --git a/netwerk/base/nsURLHelperOSX.cpp b/netwerk/base/nsURLHelperOSX.cpp
new file mode 100644
index 0000000000..9a8fbad9a2
--- /dev/null
+++ b/netwerk/base/nsURLHelperOSX.cpp
@@ -0,0 +1,205 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Mac OS X-specific local file uri parsing */
+#include "nsURLHelper.h"
+#include "nsEscape.h"
+#include "nsIFile.h"
+#include "nsTArray.h"
+#include "nsReadableUtils.h"
+#include <Carbon/Carbon.h>
+
+static nsTArray<nsCString>* gVolumeList = nullptr;
+
+static bool pathBeginsWithVolName(const nsACString& path,
+                                  nsACString& firstPathComponent) {
+  // Return whether the 1st path component in path (escaped) is equal to the
+  // name of a mounted volume. Return the 1st path component (unescaped) in any
+  // case. This needs to be done as quickly as possible, so we cache a list of
+  // volume names.
+  // XXX Register an event handler to detect drives being mounted/unmounted?
+
+  if (!gVolumeList) {
+    gVolumeList = new nsTArray<nsCString>;
+    if (!gVolumeList) {
+      return false;  // out of memory
+    }
+  }
+
+  // Cache a list of volume names
+  if (!gVolumeList->Length()) {
+    OSErr err;
+    ItemCount volumeIndex = 1;
+
+    do {
+      HFSUniStr255 volName;
+      FSRef rootDirectory;
+      err = ::FSGetVolumeInfo(0, volumeIndex, nullptr, kFSVolInfoNone, nullptr,
+                              &volName, &rootDirectory);
+      if (err == noErr) {
+        NS_ConvertUTF16toUTF8 volNameStr(
+            Substring((char16_t*)volName.unicode,
+                      (char16_t*)volName.unicode + volName.length));
+        gVolumeList->AppendElement(volNameStr);
+        volumeIndex++;
+      }
+    } while (err == noErr);
+  }
+
+  // Extract the first component of the path
+  nsACString::const_iterator start;
+  path.BeginReading(start);
+  start.advance(1);  // path begins with '/'
+  nsACString::const_iterator directory_end;
+  path.EndReading(directory_end);
+  nsACString::const_iterator component_end(start);
+  FindCharInReadable('/', component_end, directory_end);
+
+  nsAutoCString flatComponent((Substring(start, component_end)));
+  NS_UnescapeURL(flatComponent);
+  int32_t foundIndex = gVolumeList->IndexOf(flatComponent);
+  firstPathComponent = flatComponent;
+  return (foundIndex != -1);
+}
+
+void net_ShutdownURLHelperOSX() {
+  delete gVolumeList;
+  gVolumeList = nullptr;
+}
+
+static nsresult convertHFSPathtoPOSIX(const nsACString& hfsPath,
+                                      nsACString& posixPath) {
+  // Use CFURL to do the conversion. We don't want to do this by simply
+  // using SwapSlashColon - we need the charset mapped from MacRoman
+  // to UTF-8, and we need "/Volumes" (or whatever - Apple says this is subject
+  // to change) prepended if the path is not on the boot drive.
+
+  CFStringRef pathStrRef = CFStringCreateWithCString(
+      nullptr, PromiseFlatCString(hfsPath).get(), kCFStringEncodingMacRoman);
+  if (!pathStrRef) return NS_ERROR_FAILURE;
+
+  nsresult rv = NS_ERROR_FAILURE;
+  CFURLRef urlRef = CFURLCreateWithFileSystemPath(nullptr, pathStrRef,
+                                                  kCFURLHFSPathStyle, true);
+  if (urlRef) {
+    UInt8 pathBuf[PATH_MAX];
+    if (CFURLGetFileSystemRepresentation(urlRef, true, pathBuf,
+                                         sizeof(pathBuf))) {
+      posixPath = (char*)pathBuf;
+      rv = NS_OK;
+    }
+  }
+  CFRelease(pathStrRef);
+  if (urlRef) CFRelease(urlRef);
+  return rv;
+}
+
+static void SwapSlashColon(char* s) {
+  while (*s) {
+    if (*s == '/')
+      *s = ':';
+    else if (*s == ':')
+      *s = '/';
+    s++;
+  }
+}
+
+nsresult net_GetURLSpecFromActualFile(nsIFile* aFile, nsACString& result) {
+  // NOTE: This is identical to the implementation in nsURLHelperUnix.cpp
+
+  nsresult rv;
+  nsAutoCString ePath;
+
+  // construct URL spec from native file path
+  rv = aFile->GetNativePath(ePath);
+  if (NS_FAILED(rv)) return rv;
+
+  nsAutoCString escPath;
+  constexpr auto prefix = "file://"_ns;
+
+  // Escape the path with the directory mask
+  if (NS_EscapeURL(ePath.get(), ePath.Length(), esc_Directory + esc_Forced,
+                   escPath))
+    escPath.Insert(prefix, 0);
+  else
+    escPath.Assign(prefix + ePath);
+
+  // esc_Directory does not escape the semicolons, so if a filename
+  // contains semicolons we need to manually escape them.
+  // This replacement should be removed in bug #473280
+  escPath.ReplaceSubstring(";", "%3b");
+
+  result = escPath;
+  return NS_OK;
+}
+
+nsresult net_GetFileFromURLSpec(const nsACString& aURL, nsIFile** result) {
+  // NOTE: See also the implementation in nsURLHelperUnix.cpp
+  // This matches it except for the HFS path handling.
+
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> localFile;
+  rv = NS_NewNativeLocalFile(""_ns, true, getter_AddRefs(localFile));
+  if (NS_FAILED(rv)) return rv;
+
+  nsAutoCString directory, fileBaseName, fileExtension, path;
+  bool bHFSPath = false;
+
+  rv = net_ParseFileURL(aURL, directory, fileBaseName, fileExtension);
+  if (NS_FAILED(rv)) return rv;
+
+  if (!directory.IsEmpty()) {
+    NS_EscapeURL(directory, esc_Directory | esc_AlwaysCopy, path);
+
+    // The canonical form of file URLs on OSX use POSIX paths:
+    //   file:///path-name.
+    // But, we still encounter file URLs that use HFS paths:
+    //   file:///volume-name/path-name
+    // Determine that here and normalize HFS paths to POSIX.
+    nsAutoCString possibleVolName;
+    if (pathBeginsWithVolName(directory, possibleVolName)) {
+      // Though we know it begins with a volume name, it could still
+      // be a valid POSIX path if the boot drive is named "Mac HD"
+      // and there is a directory "Mac HD" at its root. If such a
+      // directory doesn't exist, we'll assume this is an HFS path.
+      FSRef testRef;
+      possibleVolName.InsertLiteral("/", 0);
+      if (::FSPathMakeRef((UInt8*)possibleVolName.get(), &testRef, nullptr) !=
+          noErr)
+        bHFSPath = true;
+    }
+
+    if (bHFSPath) {
+      // "%2F"s need to become slashes, while all other slashes need to
+      // become colons. If we start out by changing "%2F"s to colons, we
+      // can reply on SwapSlashColon() to do what we need
+      path.ReplaceSubstring("%2F", ":");
+      path.Cut(0, 1);  // directory begins with '/'
+      SwapSlashColon((char*)path.get());
+      // At this point, path is an HFS path made using the same
+      // algorithm as nsURLHelperMac. We'll convert to POSIX below.
+    }
+  }
+  if (!fileBaseName.IsEmpty())
+    NS_EscapeURL(fileBaseName, esc_FileBaseName | esc_AlwaysCopy, path);
+  if (!fileExtension.IsEmpty()) {
+    path += '.';
+    NS_EscapeURL(fileExtension, esc_FileExtension | esc_AlwaysCopy, path);
+  }
+
+  NS_UnescapeURL(path);
+  if (path.Length() != strlen(path.get())) return NS_ERROR_FILE_INVALID_PATH;
+
+  if (bHFSPath) convertHFSPathtoPOSIX(path, path);
+
+  // assuming path is encoded in the native charset
+  rv = localFile->InitWithNativePath(path);
+  if (NS_FAILED(rv)) return rv;
+
+  localFile.forget(result);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsURLHelperUnix.cpp b/netwerk/base/nsURLHelperUnix.cpp
new file mode 100644
index 0000000000..abb8b0cfeb
--- /dev/null
+++ b/netwerk/base/nsURLHelperUnix.cpp
@@ -0,0 +1,109 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Unix-specific local file uri parsing */
+#include "nsURLHelper.h"
+#include "nsEscape.h"
+#include "nsIFile.h"
+#include "nsNativeCharsetUtils.h"
+#include "mozilla/Utf8.h"
+
+using mozilla::IsUtf8;
+
+nsresult net_GetURLSpecFromActualFile(nsIFile* aFile, nsACString& result) {
+  nsresult rv;
+  nsAutoCString nativePath, ePath;
+  nsAutoString path;
+
+  rv = aFile->GetNativePath(nativePath);
+  if (NS_FAILED(rv)) return rv;
+
+  // Convert to unicode and back to check correct conversion to native charset
+  NS_CopyNativeToUnicode(nativePath, path);
+  NS_CopyUnicodeToNative(path, ePath);
+
+  // Use UTF8 version if conversion was successful
+  if (nativePath == ePath) {
+    CopyUTF16toUTF8(path, ePath);
+  } else {
+    ePath = nativePath;
+  }
+
+  nsAutoCString escPath;
+  constexpr auto prefix = "file://"_ns;
+
+  // Escape the path with the directory mask
+  if (NS_EscapeURL(ePath.get(), -1, esc_Directory + esc_Forced, escPath)) {
+    escPath.Insert(prefix, 0);
+  } else {
+    escPath.Assign(prefix + ePath);
+  }
+
+  // esc_Directory does not escape the semicolons, so if a filename
+  // contains semicolons we need to manually escape them.
+  // This replacement should be removed in bug #473280
+  escPath.ReplaceSubstring(";", "%3b");
+  result = escPath;
+  return NS_OK;
+}
+
+nsresult net_GetFileFromURLSpec(const nsACString& aURL, nsIFile** result) {
+  // NOTE: See also the implementation in nsURLHelperOSX.cpp,
+  // which is based on this.
+
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> localFile;
+  rv = NS_NewNativeLocalFile(""_ns, true, getter_AddRefs(localFile));
+  if (NS_FAILED(rv)) return rv;
+
+  nsAutoCString directory, fileBaseName, fileExtension, path;
+
+  rv = net_ParseFileURL(aURL, directory, fileBaseName, fileExtension);
+  if (NS_FAILED(rv)) return rv;
+
+  if (!directory.IsEmpty()) {
+    rv = NS_EscapeURL(directory, esc_Directory | esc_AlwaysCopy, path,
+                      mozilla::fallible);
+    if (NS_FAILED(rv)) return rv;
+  }
+  if (!fileBaseName.IsEmpty()) {
+    rv = NS_EscapeURL(fileBaseName, esc_FileBaseName | esc_AlwaysCopy, path,
+                      mozilla::fallible);
+    if (NS_FAILED(rv)) return rv;
+  }
+  if (!fileExtension.IsEmpty()) {
+    path += '.';
+    rv = NS_EscapeURL(fileExtension, esc_FileExtension | esc_AlwaysCopy, path,
+                      mozilla::fallible);
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  NS_UnescapeURL(path);
+  if (path.Length() != strlen(path.get())) return NS_ERROR_FILE_INVALID_PATH;
+
+  if (IsUtf8(path)) {
+    // speed up the start-up where UTF-8 is the native charset
+    // (e.g. on recent Linux distributions)
+    if (NS_IsNativeUTF8()) {
+      rv = localFile->InitWithNativePath(path);
+    } else {
+      rv = localFile->InitWithPath(NS_ConvertUTF8toUTF16(path));
+    }
+    // XXX In rare cases, a valid UTF-8 string can be valid as a native
+    // encoding (e.g. 0xC5 0x83 is valid both as UTF-8 and Windows-125x).
+    // However, the chance is very low that a meaningful word in a legacy
+    // encoding is valid as UTF-8.
+  } else {
+    // if path is not in UTF-8, assume it is encoded in the native charset
+    rv = localFile->InitWithNativePath(path);
+  }
+
+  if (NS_FAILED(rv)) return rv;
+
+  localFile.forget(result);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsURLHelperWin.cpp b/netwerk/base/nsURLHelperWin.cpp
new file mode 100644
index 0000000000..7a4f53978e
--- /dev/null
+++ b/netwerk/base/nsURLHelperWin.cpp
@@ -0,0 +1,111 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=4 sw=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Windows-specific local file uri parsing */
+#include "nsComponentManagerUtils.h"
+#include "nsURLHelper.h"
+#include "nsEscape.h"
+#include "nsIFile.h"
+#include <windows.h>
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/Utf8.h"
+
+using namespace mozilla;
+
+nsresult net_GetURLSpecFromActualFile(nsIFile* aFile, nsACString& result) {
+  nsresult rv;
+  nsAutoString path;
+
+  // construct URL spec from file path
+  rv = aFile->GetPath(path);
+  if (NS_FAILED(rv)) return rv;
+
+  // Replace \ with / to convert to an url
+  path.ReplaceChar(char16_t(0x5Cu), char16_t(0x2Fu));
+
+  nsAutoCString escPath;
+
+  // Windows Desktop paths begin with a drive letter, so need an 'extra'
+  // slash at the begining
+  // C:\Windows =>  file:///C:/Windows
+  constexpr auto prefix = "file:///"_ns;
+
+  // Escape the path with the directory mask
+  NS_ConvertUTF16toUTF8 ePath(path);
+  if (NS_EscapeURL(ePath.get(), -1, esc_Directory + esc_Forced, escPath))
+    escPath.Insert(prefix, 0);
+  else
+    escPath.Assign(prefix + ePath);
+
+  // esc_Directory does not escape the semicolons, so if a filename
+  // contains semicolons we need to manually escape them.
+  // This replacement should be removed in bug #473280
+  escPath.ReplaceSubstring(";", "%3b");
+
+  result = escPath;
+  return NS_OK;
+}
+
+nsresult net_GetFileFromURLSpec(const nsACString& aURL, nsIFile** result) {
+  nsresult rv;
+
+  if (aURL.Length() > StaticPrefs::network_standard_url_max_length()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsCOMPtr<nsIFile> localFile(do_CreateInstance(NS_LOCAL_FILE_CONTRACTID, &rv));
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Only nsIFile supported right now");
+    return rv;
+  }
+
+  const nsACString* specPtr;
+
+  nsAutoCString buf;
+  if (net_NormalizeFileURL(aURL, buf))
+    specPtr = &buf;
+  else
+    specPtr = &aURL;
+
+  nsAutoCString directory, fileBaseName, fileExtension;
+
+  rv = net_ParseFileURL(*specPtr, directory, fileBaseName, fileExtension);
+  if (NS_FAILED(rv)) return rv;
+
+  nsAutoCString path;
+
+  if (!directory.IsEmpty()) {
+    NS_EscapeURL(directory, esc_Directory | esc_AlwaysCopy, path);
+    if (path.Length() > 2 && path.CharAt(2) == '|') path.SetCharAt(':', 2);
+    path.ReplaceChar('/', '\\');
+  }
+  if (!fileBaseName.IsEmpty())
+    NS_EscapeURL(fileBaseName, esc_FileBaseName | esc_AlwaysCopy, path);
+  if (!fileExtension.IsEmpty()) {
+    path += '.';
+    NS_EscapeURL(fileExtension, esc_FileExtension | esc_AlwaysCopy, path);
+  }
+
+  NS_UnescapeURL(path);
+  if (path.Length() != strlen(path.get())) return NS_ERROR_FILE_INVALID_PATH;
+
+  // remove leading '\'
+  if (path.CharAt(0) == '\\') path.Cut(0, 1);
+
+  if (IsUtf8(path)) rv = localFile->InitWithPath(NS_ConvertUTF8toUTF16(path));
+  // XXX In rare cases, a valid UTF-8 string can be valid as a native
+  // encoding (e.g. 0xC5 0x83 is valid both as UTF-8 and Windows-125x).
+  // However, the chance is very low that a meaningful word in a legacy
+  // encoding is valid as UTF-8.
+  else
+    // if path is not in UTF-8, assume it is encoded in the native charset
+    rv = localFile->InitWithNativePath(path);
+
+  if (NS_FAILED(rv)) return rv;
+
+  localFile.forget(result);
+  return NS_OK;
+}
diff --git a/netwerk/base/nsURLParsers.cpp b/netwerk/base/nsURLParsers.cpp
new file mode 100644
index 0000000000..7dc6567d84
--- /dev/null
+++ b/netwerk/base/nsURLParsers.cpp
@@ -0,0 +1,644 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <string.h>
+
+#include "mozilla/RangedPtr.h"
+#include "mozilla/TextUtils.h"
+
+#include "nsCRTGlue.h"
+#include "nsURLParsers.h"
+#include "nsURLHelper.h"
+#include "nsString.h"
+
+using namespace mozilla;
+
+//----------------------------------------------------------------------------
+
+static uint32_t CountConsecutiveSlashes(const char* str, int32_t len) {
+  RangedPtr<const char> p(str, len);
+  uint32_t count = 0;
+  while (len-- && *p++ == '/') ++count;
+  return count;
+}
+
+//----------------------------------------------------------------------------
+// nsBaseURLParser implementation
+//----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(nsAuthURLParser, nsIURLParser)
+NS_IMPL_ISUPPORTS(nsNoAuthURLParser, nsIURLParser)
+
+#define SET_RESULT(component, pos, len)                \
+  PR_BEGIN_MACRO                                       \
+  if (component##Pos) *component##Pos = uint32_t(pos); \
+  if (component##Len) *component##Len = int32_t(len);  \
+  PR_END_MACRO
+
+#define OFFSET_RESULT(component, offset)           \
+  PR_BEGIN_MACRO                                   \
+  if (component##Pos) *component##Pos += (offset); \
+  PR_END_MACRO
+
+NS_IMETHODIMP
+nsBaseURLParser::ParseURL(const char* spec, int32_t specLen,
+                          uint32_t* schemePos, int32_t* schemeLen,
+                          uint32_t* authorityPos, int32_t* authorityLen,
+                          uint32_t* pathPos, int32_t* pathLen) {
+  if (NS_WARN_IF(!spec)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (specLen < 0) specLen = strlen(spec);
+
+  const char* stop = nullptr;
+  const char* colon = nullptr;
+  const char* slash = nullptr;
+  const char* p = spec;
+  uint32_t offset = 0;
+  int32_t len = specLen;
+
+  // skip leading whitespace
+  while (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t') {
+    spec++;
+    specLen--;
+    offset++;
+
+    p++;
+    len--;
+  }
+
+  for (; len && *p && !colon && !slash; ++p, --len) {
+    switch (*p) {
+      case ':':
+        if (!colon) colon = p;
+        break;
+      case '/':  // start of filepath
+      case '?':  // start of query
+      case '#':  // start of ref
+        if (!slash) slash = p;
+        break;
+      case '@':  // username@hostname
+      case '[':  // start of IPv6 address literal
+        if (!stop) stop = p;
+        break;
+    }
+  }
+  // disregard the first colon if it follows an '@' or a '['
+  if (colon && stop && colon > stop) colon = nullptr;
+
+  // if the spec only contained whitespace ...
+  if (specLen == 0) {
+    SET_RESULT(scheme, 0, -1);
+    SET_RESULT(authority, 0, 0);
+    SET_RESULT(path, 0, 0);
+    return NS_OK;
+  }
+
+  // ignore trailing whitespace and control characters
+  for (p = spec + specLen - 1; ((unsigned char)*p <= ' ') && (p != spec); --p) {
+    ;
+  }
+
+  specLen = p - spec + 1;
+
+  if (colon && (colon < slash || !slash)) {
+    //
+    // spec = <scheme>:/<the-rest>
+    //
+    // or
+    //
+    // spec = <scheme>:<authority>
+    // spec = <scheme>:<path-no-slashes>
+    //
+    if (!net_IsValidScheme(nsDependentCSubstring(spec, colon - spec))) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    SET_RESULT(scheme, offset, colon - spec);
+    if (authorityLen || pathLen) {
+      uint32_t schemeLen = colon + 1 - spec;
+      offset += schemeLen;
+      ParseAfterScheme(colon + 1, specLen - schemeLen, authorityPos,
+                       authorityLen, pathPos, pathLen);
+      OFFSET_RESULT(authority, offset);
+      OFFSET_RESULT(path, offset);
+    }
+  } else {
+    //
+    // spec = <authority-no-port-or-password>/<path>
+    // spec = <path>
+    //
+    // or
+    //
+    // spec = <authority-no-port-or-password>/<path-with-colon>
+    // spec = <path-with-colon>
+    //
+    // or
+    //
+    // spec = <authority-no-port-or-password>
+    // spec = <path-no-slashes-or-colon>
+    //
+    SET_RESULT(scheme, 0, -1);
+    if (authorityLen || pathLen) {
+      ParseAfterScheme(spec, specLen, authorityPos, authorityLen, pathPos,
+                       pathLen);
+      OFFSET_RESULT(authority, offset);
+      OFFSET_RESULT(path, offset);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseURLParser::ParseAuthority(const char* auth, int32_t authLen,
+                                uint32_t* usernamePos, int32_t* usernameLen,
+                                uint32_t* passwordPos, int32_t* passwordLen,
+                                uint32_t* hostnamePos, int32_t* hostnameLen,
+                                int32_t* port) {
+  if (NS_WARN_IF(!auth)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (authLen < 0) authLen = strlen(auth);
+
+  SET_RESULT(username, 0, -1);
+  SET_RESULT(password, 0, -1);
+  SET_RESULT(hostname, 0, authLen);
+  if (port) *port = -1;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseURLParser::ParseUserInfo(const char* userinfo, int32_t userinfoLen,
+                               uint32_t* usernamePos, int32_t* usernameLen,
+                               uint32_t* passwordPos, int32_t* passwordLen) {
+  SET_RESULT(username, 0, -1);
+  SET_RESULT(password, 0, -1);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseURLParser::ParseServerInfo(const char* serverinfo, int32_t serverinfoLen,
+                                 uint32_t* hostnamePos, int32_t* hostnameLen,
+                                 int32_t* port) {
+  SET_RESULT(hostname, 0, -1);
+  if (port) *port = -1;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseURLParser::ParsePath(const char* path, int32_t pathLen,
+                           uint32_t* filepathPos, int32_t* filepathLen,
+                           uint32_t* queryPos, int32_t* queryLen,
+                           uint32_t* refPos, int32_t* refLen) {
+  if (NS_WARN_IF(!path)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (pathLen < 0) pathLen = strlen(path);
+
+  // path = [/]<segment1>/<segment2>/<...>/<segmentN>?<query>#<ref>
+
+  // XXX PL_strnpbrk would be nice, but it's buggy
+
+  // search for first occurrence of either ? or #
+  const char *query_beg = nullptr, *query_end = nullptr;
+  const char* ref_beg = nullptr;
+  const char* p = nullptr;
+  for (p = path; p < path + pathLen; ++p) {
+    // only match the query string if it precedes the reference fragment
+    if (!ref_beg && !query_beg && *p == '?') {
+      query_beg = p + 1;
+    } else if (*p == '#') {
+      ref_beg = p + 1;
+      if (query_beg) query_end = p;
+      break;
+    }
+  }
+
+  if (query_beg) {
+    if (query_end) {
+      SET_RESULT(query, query_beg - path, query_end - query_beg);
+    } else {
+      SET_RESULT(query, query_beg - path, pathLen - (query_beg - path));
+    }
+  } else {
+    SET_RESULT(query, 0, -1);
+  }
+
+  if (ref_beg) {
+    SET_RESULT(ref, ref_beg - path, pathLen - (ref_beg - path));
+  } else {
+    SET_RESULT(ref, 0, -1);
+  }
+
+  const char* end;
+  if (query_beg) {
+    end = query_beg - 1;
+  } else if (ref_beg) {
+    end = ref_beg - 1;
+  } else {
+    end = path + pathLen;
+  }
+
+  // an empty file path is no file path
+  if (end != path) {
+    SET_RESULT(filepath, 0, end - path);
+  } else {
+    SET_RESULT(filepath, 0, -1);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBaseURLParser::ParseFilePath(const char* filepath, int32_t filepathLen,
+                               uint32_t* directoryPos, int32_t* directoryLen,
+                               uint32_t* basenamePos, int32_t* basenameLen,
+                               uint32_t* extensionPos, int32_t* extensionLen) {
+  if (NS_WARN_IF(!filepath)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (filepathLen < 0) filepathLen = strlen(filepath);
+
+  if (filepathLen == 0) {
+    SET_RESULT(directory, 0, -1);
+    SET_RESULT(basename, 0, 0);  // assume a zero length file basename
+    SET_RESULT(extension, 0, -1);
+    return NS_OK;
+  }
+
+  const char* p;
+  const char* end = filepath + filepathLen;
+
+  // search backwards for filename
+  for (p = end - 1; *p != '/' && p > filepath; --p) {
+    ;
+  }
+  if (*p == '/') {
+    // catch /.. and /.
+    if ((p + 1 < end && *(p + 1) == '.') &&
+        (p + 2 == end || (*(p + 2) == '.' && p + 3 == end))) {
+      p = end - 1;
+    }
+    // filepath = <directory><filename>.<extension>
+    SET_RESULT(directory, 0, p - filepath + 1);
+    ParseFileName(p + 1, end - (p + 1), basenamePos, basenameLen, extensionPos,
+                  extensionLen);
+    OFFSET_RESULT(basename, p + 1 - filepath);
+    OFFSET_RESULT(extension, p + 1 - filepath);
+  } else {
+    // filepath = <filename>.<extension>
+    SET_RESULT(directory, 0, -1);
+    ParseFileName(filepath, filepathLen, basenamePos, basenameLen, extensionPos,
+                  extensionLen);
+  }
+  return NS_OK;
+}
+
+nsresult nsBaseURLParser::ParseFileName(
+    const char* filename, int32_t filenameLen, uint32_t* basenamePos,
+    int32_t* basenameLen, uint32_t* extensionPos, int32_t* extensionLen) {
+  if (NS_WARN_IF(!filename)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (filenameLen < 0) filenameLen = strlen(filename);
+
+  // no extension if filename ends with a '.'
+  if (filename[filenameLen - 1] != '.') {
+    // ignore '.' at the beginning
+    for (const char* p = filename + filenameLen - 1; p > filename; --p) {
+      if (*p == '.') {
+        // filename = <basename.extension>
+        SET_RESULT(basename, 0, p - filename);
+        SET_RESULT(extension, p + 1 - filename,
+                   filenameLen - (p - filename + 1));
+        return NS_OK;
+      }
+    }
+  }
+  // filename = <basename>
+  SET_RESULT(basename, 0, filenameLen);
+  SET_RESULT(extension, 0, -1);
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------------
+// nsNoAuthURLParser implementation
+//----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsNoAuthURLParser::ParseAuthority(const char* auth, int32_t authLen,
+                                  uint32_t* usernamePos, int32_t* usernameLen,
+                                  uint32_t* passwordPos, int32_t* passwordLen,
+                                  uint32_t* hostnamePos, int32_t* hostnameLen,
+                                  int32_t* port) {
+  MOZ_ASSERT_UNREACHABLE("Shouldn't parse auth in a NoAuthURL!");
+  return NS_ERROR_UNEXPECTED;
+}
+
+void nsNoAuthURLParser::ParseAfterScheme(const char* spec, int32_t specLen,
+                                         uint32_t* authPos, int32_t* authLen,
+                                         uint32_t* pathPos, int32_t* pathLen) {
+  MOZ_ASSERT(specLen >= 0, "unexpected");
+
+  // everything is the path
+  uint32_t pos = 0;
+  switch (CountConsecutiveSlashes(spec, specLen)) {
+    case 0:
+    case 1:
+      break;
+    case 2: {
+      const char* p = nullptr;
+      if (specLen > 2) {
+        // looks like there is an authority section
+
+        // if the authority looks like a drive number then we
+        // really want to treat it as part of the path
+        // [a-zA-Z][:|]{/\}
+        // i.e one of:   c:   c:\foo  c:/foo  c|  c|\foo  c|/foo
+        if ((specLen > 3) && (spec[3] == ':' || spec[3] == '|') &&
+            IsAsciiAlpha(spec[2]) &&
+            ((specLen == 4) || (spec[4] == '/') || (spec[4] == '\\'))) {
+          pos = 1;
+          break;
+        }
+        // Ignore apparent authority; path is everything after it
+        for (p = spec + 2; p < spec + specLen; ++p) {
+          if (*p == '/' || *p == '?' || *p == '#') break;
+        }
+      }
+      SET_RESULT(auth, 0, -1);
+      if (p && p != spec + specLen) {
+        SET_RESULT(path, p - spec, specLen - (p - spec));
+      } else {
+        SET_RESULT(path, 0, -1);
+      }
+      return;
+    }
+    default:
+      pos = 2;
+      break;
+  }
+  SET_RESULT(auth, pos, 0);
+  SET_RESULT(path, pos, specLen - pos);
+}
+
+#if defined(XP_WIN)
+NS_IMETHODIMP
+nsNoAuthURLParser::ParseFilePath(const char* filepath, int32_t filepathLen,
+                                 uint32_t* directoryPos, int32_t* directoryLen,
+                                 uint32_t* basenamePos, int32_t* basenameLen,
+                                 uint32_t* extensionPos,
+                                 int32_t* extensionLen) {
+  if (NS_WARN_IF(!filepath)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (filepathLen < 0) filepathLen = strlen(filepath);
+
+  // look for a filepath consisting of only a drive number, which may or
+  // may not have a leading slash.
+  if (filepathLen > 1 && filepathLen < 4) {
+    const char* end = filepath + filepathLen;
+    const char* p = filepath;
+    if (*p == '/') p++;
+    if ((end - p == 2) && (p[1] == ':' || p[1] == '|') && IsAsciiAlpha(*p)) {
+      // filepath = <drive-number>:
+      SET_RESULT(directory, 0, filepathLen);
+      SET_RESULT(basename, 0, -1);
+      SET_RESULT(extension, 0, -1);
+      return NS_OK;
+    }
+  }
+
+  // otherwise fallback on common implementation
+  return nsBaseURLParser::ParseFilePath(filepath, filepathLen, directoryPos,
+                                        directoryLen, basenamePos, basenameLen,
+                                        extensionPos, extensionLen);
+}
+#endif
+
+//----------------------------------------------------------------------------
+// nsAuthURLParser implementation
+//----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+nsAuthURLParser::ParseAuthority(const char* auth, int32_t authLen,
+                                uint32_t* usernamePos, int32_t* usernameLen,
+                                uint32_t* passwordPos, int32_t* passwordLen,
+                                uint32_t* hostnamePos, int32_t* hostnameLen,
+                                int32_t* port) {
+  nsresult rv;
+
+  if (NS_WARN_IF(!auth)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (authLen < 0) authLen = strlen(auth);
+
+  if (authLen == 0) {
+    SET_RESULT(username, 0, -1);
+    SET_RESULT(password, 0, -1);
+    SET_RESULT(hostname, 0, 0);
+    if (port) *port = -1;
+    return NS_OK;
+  }
+
+  // search backwards for @
+  const char* p = auth + authLen - 1;
+  for (; (*p != '@') && (p > auth); --p) {
+  }
+  if (*p == '@') {
+    // auth = <user-info@server-info>
+    rv = ParseUserInfo(auth, p - auth, usernamePos, usernameLen, passwordPos,
+                       passwordLen);
+    if (NS_FAILED(rv)) return rv;
+    rv = ParseServerInfo(p + 1, authLen - (p - auth + 1), hostnamePos,
+                         hostnameLen, port);
+    if (NS_FAILED(rv)) return rv;
+    OFFSET_RESULT(hostname, p + 1 - auth);
+
+    // malformed if has a username or password
+    // but no host info, such as: http://u:p@/
+    if ((usernamePos || passwordPos) && (!hostnamePos || !*hostnameLen)) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+  } else {
+    // auth = <server-info>
+    SET_RESULT(username, 0, -1);
+    SET_RESULT(password, 0, -1);
+    rv = ParseServerInfo(auth, authLen, hostnamePos, hostnameLen, port);
+    if (NS_FAILED(rv)) return rv;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthURLParser::ParseUserInfo(const char* userinfo, int32_t userinfoLen,
+                               uint32_t* usernamePos, int32_t* usernameLen,
+                               uint32_t* passwordPos, int32_t* passwordLen) {
+  if (NS_WARN_IF(!userinfo)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (userinfoLen < 0) userinfoLen = strlen(userinfo);
+
+  if (userinfoLen == 0) {
+    SET_RESULT(username, 0, -1);
+    SET_RESULT(password, 0, -1);
+    return NS_OK;
+  }
+
+  const char* p = (const char*)memchr(userinfo, ':', userinfoLen);
+  if (p) {
+    // userinfo = <username:password>
+    SET_RESULT(username, 0, p - userinfo);
+    SET_RESULT(password, p - userinfo + 1, userinfoLen - (p - userinfo + 1));
+  } else {
+    // userinfo = <username>
+    SET_RESULT(username, 0, userinfoLen);
+    SET_RESULT(password, 0, -1);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAuthURLParser::ParseServerInfo(const char* serverinfo, int32_t serverinfoLen,
+                                 uint32_t* hostnamePos, int32_t* hostnameLen,
+                                 int32_t* port) {
+  if (NS_WARN_IF(!serverinfo)) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  if (serverinfoLen < 0) serverinfoLen = strlen(serverinfo);
+
+  if (serverinfoLen == 0) {
+    SET_RESULT(hostname, 0, 0);
+    if (port) *port = -1;
+    return NS_OK;
+  }
+
+  // search backwards for a ':' but stop on ']' (IPv6 address literal
+  // delimiter).  check for illegal characters in the hostname.
+  const char* p = serverinfo + serverinfoLen - 1;
+  const char *colon = nullptr, *bracket = nullptr;
+  for (; p > serverinfo; --p) {
+    switch (*p) {
+      case ']':
+        bracket = p;
+        break;
+      case ':':
+        if (bracket == nullptr) colon = p;
+        break;
+      case ' ':
+        // hostname must not contain a space
+        return NS_ERROR_MALFORMED_URI;
+    }
+  }
+
+  if (colon) {
+    // serverinfo = <hostname:port>
+    SET_RESULT(hostname, 0, colon - serverinfo);
+    if (port) {
+      // XXX unfortunately ToInteger is not defined for substrings
+      nsAutoCString buf(colon + 1, serverinfoLen - (colon + 1 - serverinfo));
+      if (buf.Length() == 0) {
+        *port = -1;
+      } else {
+        const char* nondigit = NS_strspnp("0123456789", buf.get());
+        if (nondigit && *nondigit) return NS_ERROR_MALFORMED_URI;
+
+        nsresult err;
+        *port = buf.ToInteger(&err);
+        if (NS_FAILED(err) || *port < 0 ||
+            *port > std::numeric_limits<uint16_t>::max()) {
+          return NS_ERROR_MALFORMED_URI;
+        }
+      }
+    }
+  } else {
+    // serverinfo = <hostname>
+    SET_RESULT(hostname, 0, serverinfoLen);
+    if (port) *port = -1;
+  }
+
+  // In case of IPv6 address check its validity
+  if (*hostnameLen > 1 && *(serverinfo + *hostnamePos) == '[' &&
+      *(serverinfo + *hostnamePos + *hostnameLen - 1) == ']' &&
+      !net_IsValidIPv6Addr(
+          Substring(serverinfo + *hostnamePos + 1, *hostnameLen - 2))) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  return NS_OK;
+}
+
+void nsAuthURLParser::ParseAfterScheme(const char* spec, int32_t specLen,
+                                       uint32_t* authPos, int32_t* authLen,
+                                       uint32_t* pathPos, int32_t* pathLen) {
+  MOZ_ASSERT(specLen >= 0, "unexpected");
+
+  uint32_t nslash = CountConsecutiveSlashes(spec, specLen);
+
+  // search for the end of the authority section
+  const char* end = spec + specLen;
+  const char* p;
+  for (p = spec + nslash; p < end; ++p) {
+    if (*p == '/' || *p == '?' || *p == '#') break;
+  }
+  if (p < end) {
+    // spec = [/]<auth><path>
+    SET_RESULT(auth, nslash, p - (spec + nslash));
+    SET_RESULT(path, p - spec, specLen - (p - spec));
+  } else {
+    // spec = [/]<auth>
+    SET_RESULT(auth, nslash, specLen - nslash);
+    SET_RESULT(path, 0, -1);
+  }
+}
+
+//----------------------------------------------------------------------------
+// nsStdURLParser implementation
+//----------------------------------------------------------------------------
+
+void nsStdURLParser::ParseAfterScheme(const char* spec, int32_t specLen,
+                                      uint32_t* authPos, int32_t* authLen,
+                                      uint32_t* pathPos, int32_t* pathLen) {
+  MOZ_ASSERT(specLen >= 0, "unexpected");
+
+  uint32_t nslash = CountConsecutiveSlashes(spec, specLen);
+
+  // search for the end of the authority section
+  const char* end = spec + specLen;
+  const char* p;
+  for (p = spec + nslash; p < end; ++p) {
+    if (strchr("/?#;", *p)) break;
+  }
+  switch (nslash) {
+    case 0:
+    case 2:
+      if (p < end) {
+        // spec = (//)<auth><path>
+        SET_RESULT(auth, nslash, p - (spec + nslash));
+        SET_RESULT(path, p - spec, specLen - (p - spec));
+      } else {
+        // spec = (//)<auth>
+        SET_RESULT(auth, nslash, specLen - nslash);
+        SET_RESULT(path, 0, -1);
+      }
+      break;
+    case 1:
+      // spec = /<path>
+      SET_RESULT(auth, 0, -1);
+      SET_RESULT(path, 0, specLen);
+      break;
+    default:
+      // spec = ///[/]<path>
+      SET_RESULT(auth, 2, 0);
+      SET_RESULT(path, 2, specLen - 2);
+  }
+}
diff --git a/netwerk/base/nsURLParsers.h b/netwerk/base/nsURLParsers.h
new file mode 100644
index 0000000000..3143022b90
--- /dev/null
+++ b/netwerk/base/nsURLParsers.h
@@ -0,0 +1,119 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsURLParsers_h__
+#define nsURLParsers_h__
+
+#include "nsIURLParser.h"
+#include "mozilla/Attributes.h"
+
+//----------------------------------------------------------------------------
+// base class for url parsers
+//----------------------------------------------------------------------------
+
+class nsBaseURLParser : public nsIURLParser {
+ public:
+  NS_DECL_NSIURLPARSER
+
+  nsBaseURLParser() = default;
+
+ protected:
+  // implemented by subclasses
+  virtual void ParseAfterScheme(const char* spec, int32_t specLen,
+                                uint32_t* authPos, int32_t* authLen,
+                                uint32_t* pathPos, int32_t* pathLen) = 0;
+};
+
+//----------------------------------------------------------------------------
+// an url parser for urls that do not have an authority section
+//
+// eg. file:foo/bar.txt
+//     file:/foo/bar.txt      (treated equivalently)
+//     file:///foo/bar.txt
+//
+// eg. file:////foo/bar.txt   (UNC-filepath = \\foo\bar.txt)
+//
+// XXX except in this case:
+//     file://foo/bar.txt     (the authority "foo"  is ignored)
+//----------------------------------------------------------------------------
+
+class nsNoAuthURLParser final : public nsBaseURLParser {
+  ~nsNoAuthURLParser() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+#if defined(XP_WIN)
+  NS_IMETHOD ParseFilePath(const char*, int32_t, uint32_t*, int32_t*, uint32_t*,
+                           int32_t*, uint32_t*, int32_t*) override;
+#endif
+
+  NS_IMETHOD ParseAuthority(const char* auth, int32_t authLen,
+                            uint32_t* usernamePos, int32_t* usernameLen,
+                            uint32_t* passwordPos, int32_t* passwordLen,
+                            uint32_t* hostnamePos, int32_t* hostnameLen,
+                            int32_t* port) override;
+
+  void ParseAfterScheme(const char* spec, int32_t specLen, uint32_t* authPos,
+                        int32_t* authLen, uint32_t* pathPos,
+                        int32_t* pathLen) override;
+};
+
+//----------------------------------------------------------------------------
+// an url parser for urls that must have an authority section
+//
+// eg. http:www.foo.com/bar.html
+//     http:/www.foo.com/bar.html
+//     http://www.foo.com/bar.html    (treated equivalently)
+//     http:///www.foo.com/bar.html
+//----------------------------------------------------------------------------
+
+class nsAuthURLParser : public nsBaseURLParser {
+ protected:
+  virtual ~nsAuthURLParser() = default;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  NS_IMETHOD ParseAuthority(const char* auth, int32_t authLen,
+                            uint32_t* usernamePos, int32_t* usernameLen,
+                            uint32_t* passwordPos, int32_t* passwordLen,
+                            uint32_t* hostnamePos, int32_t* hostnameLen,
+                            int32_t* port) override;
+
+  NS_IMETHOD ParseUserInfo(const char* userinfo, int32_t userinfoLen,
+                           uint32_t* usernamePos, int32_t* usernameLen,
+                           uint32_t* passwordPos,
+                           int32_t* passwordLen) override;
+
+  NS_IMETHOD ParseServerInfo(const char* serverinfo, int32_t serverinfoLen,
+                             uint32_t* hostnamePos, int32_t* hostnameLen,
+                             int32_t* port) override;
+
+  void ParseAfterScheme(const char* spec, int32_t specLen, uint32_t* authPos,
+                        int32_t* authLen, uint32_t* pathPos,
+                        int32_t* pathLen) override;
+};
+
+//----------------------------------------------------------------------------
+// an url parser for urls that may or may not have an authority section
+//
+// eg. http:www.foo.com              (www.foo.com is authority)
+//     http:www.foo.com/bar.html     (www.foo.com is authority)
+//     http:/www.foo.com/bar.html    (www.foo.com is part of file path)
+//     http://www.foo.com/bar.html   (www.foo.com is authority)
+//     http:///www.foo.com/bar.html  (www.foo.com is part of file path)
+//----------------------------------------------------------------------------
+
+class nsStdURLParser : public nsAuthURLParser {
+  virtual ~nsStdURLParser() = default;
+
+ public:
+  void ParseAfterScheme(const char* spec, int32_t specLen, uint32_t* authPos,
+                        int32_t* authLen, uint32_t* pathPos,
+                        int32_t* pathLen) override;
+};
+
+#endif  // nsURLParsers_h__
diff --git a/netwerk/base/rust-helper/Cargo.toml b/netwerk/base/rust-helper/Cargo.toml
new file mode 100644
index 0000000000..370d420182
--- /dev/null
+++ b/netwerk/base/rust-helper/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "netwerk_helper"
+version = "0.0.1"
+authors = ["Jeff Hemphill <jthemphill@mozilla.com>"]
+license = "MPL-2.0"
+
+[dependencies]
+nserror = { path = "../../../xpcom/rust/nserror" }
+nsstring = { path = "../../../xpcom/rust/nsstring" }
+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }
diff --git a/netwerk/base/rust-helper/cbindgen.toml b/netwerk/base/rust-helper/cbindgen.toml
new file mode 100644
index 0000000000..1e5e235576
--- /dev/null
+++ b/netwerk/base/rust-helper/cbindgen.toml
@@ -0,0 +1,18 @@
+header = """/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */"""
+autogen_warning = """/* DO NOT MODIFY THIS MANUALLY! This file was generated using cbindgen. */"""
+include_guard = "mozilla_net_rustHelper_h"
+include_version = true
+braces = "SameLine"
+line_length = 100
+tab_width = 2
+language = "C++"
+namespaces = ["mozilla", "net"]
+includes = ["nsError.h", "nsString.h"]
+
+[export]
+item_types = ["globals", "enums", "structs", "unions", "typedefs", "opaque", "functions", "constants"]
+
+[export.rename]
+"ThinVec" = "nsTArray"
diff --git a/netwerk/base/rust-helper/moz.build b/netwerk/base/rust-helper/moz.build
new file mode 100644
index 0000000000..1f7512ecf9
--- /dev/null
+++ b/netwerk/base/rust-helper/moz.build
@@ -0,0 +1,12 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+if CONFIG["COMPILE_ENVIRONMENT"]:
+    CbindgenHeader("rust_helper.h", inputs=["/netwerk/base/rust-helper"])
+
+    EXPORTS.mozilla.net += [
+        "!rust_helper.h",
+    ]
diff --git a/netwerk/base/rust-helper/src/lib.rs b/netwerk/base/rust-helper/src/lib.rs
new file mode 100644
index 0000000000..7a97736e50
--- /dev/null
+++ b/netwerk/base/rust-helper/src/lib.rs
@@ -0,0 +1,360 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+extern crate nserror;
+use self::nserror::*;
+
+extern crate nsstring;
+use self::nsstring::{nsACString, nsCString};
+
+extern crate thin_vec;
+use self::thin_vec::ThinVec;
+
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::net::Ipv4Addr;
+
+/// HTTP leading whitespace, defined in netwerk/protocol/http/nsHttp.h
+static HTTP_LWS: &'static [u8] = &[' ' as u8, '\t' as u8];
+
+/// Trim leading whitespace, trailing whitespace, and quality-value
+/// from a token.
+fn trim_token(token: &[u8]) -> &[u8] {
+    // Trim left whitespace
+    let ltrim = token
+        .iter()
+        .take_while(|c| HTTP_LWS.iter().any(|ws| &ws == c))
+        .count();
+
+    // Trim right whitespace
+    // remove "; q=..." if present
+    let rtrim = token[ltrim..]
+        .iter()
+        .take_while(|c| **c != (';' as u8) && HTTP_LWS.iter().all(|ws| ws != *c))
+        .count();
+
+    &token[ltrim..ltrim + rtrim]
+}
+
+#[no_mangle]
+/// Allocates an nsACString that contains a ISO 639 language list
+/// notated with HTTP "q" values for output with an HTTP Accept-Language
+/// header. Previous q values will be stripped because the order of
+/// the langs implies the q value. The q values are calculated by dividing
+/// 1.0 amongst the number of languages present.
+///
+/// Ex: passing: "en, ja"
+///     returns: "en,ja;q=0.5"
+///
+///     passing: "en, ja, fr_CA"
+///     returns: "en,ja;q=0.7,fr_CA;q=0.3"
+pub extern "C" fn rust_prepare_accept_languages<'a, 'b>(
+    i_accept_languages: &'a nsACString,
+    o_accept_languages: &'b mut nsACString,
+) -> nsresult {
+    if i_accept_languages.is_empty() {
+        return NS_OK;
+    }
+
+    let make_tokens = || {
+        i_accept_languages
+            .split(|c| *c == (',' as u8))
+            .map(|token| trim_token(token))
+            .filter(|token| token.len() != 0)
+    };
+
+    let n = make_tokens().count();
+
+    for (count_n, i_token) in make_tokens().enumerate() {
+        // delimiter if not first item
+        if count_n != 0 {
+            o_accept_languages.append(",");
+        }
+
+        let token_pos = o_accept_languages.len();
+        o_accept_languages.append(&i_token as &[u8]);
+
+        {
+            let o_token = o_accept_languages.to_mut();
+            canonicalize_language_tag(&mut o_token[token_pos..]);
+        }
+
+        // Divide the quality-values evenly among the languages.
+        let q = 1.0 - count_n as f32 / n as f32;
+
+        let u: u32 = ((q + 0.005) * 100.0) as u32;
+        // Only display q-value if less than 1.00.
+        if u < 100 {
+            // With a small number of languages, one decimal place is
+            // enough to prevent duplicate q-values.
+            // Also, trailing zeroes do not add any information, so
+            // they can be removed.
+            if n < 10 || u % 10 == 0 {
+                let u = (u + 5) / 10;
+                o_accept_languages.append(&format!(";q=0.{}", u));
+            } else {
+                // Values below 10 require zero padding.
+                o_accept_languages.append(&format!(";q=0.{:02}", u));
+            }
+        }
+    }
+
+    NS_OK
+}
+
+/// Defines a consistent capitalization for a given language string.
+///
+/// # Arguments
+/// * `token` - a narrow char slice describing a language.
+///
+/// Valid language tags are of the form
+/// "*", "fr", "en-US", "es-419", "az-Arab", "x-pig-latin", "man-Nkoo-GN"
+///
+/// Language tags are defined in the
+/// [rfc5646](https://tools.ietf.org/html/rfc5646) spec. According to
+/// the spec:
+///
+/// > At all times, language tags and their subtags, including private
+/// > use and extensions, are to be treated as case insensitive: there
+/// > exist conventions for the capitalization of some of the subtags,
+/// > but these MUST NOT be taken to carry meaning.
+///
+/// So why is this code even here? See bug 1108183, I guess.
+fn canonicalize_language_tag(token: &mut [u8]) {
+    for c in token.iter_mut() {
+        *c = c.to_ascii_lowercase();
+    }
+
+    let sub_tags = token.split_mut(|c| *c == ('-' as u8));
+    for (i, sub_tag) in sub_tags.enumerate() {
+        if i == 0 {
+            // ISO 639-1 language code, like the "en" in "en-US"
+            continue;
+        }
+
+        match sub_tag.len() {
+            // Singleton tag, like "x" or "i". These signify a
+            // non-standard language, so we stop capitalizing after
+            // these.
+            1 => break,
+            // ISO 3166-1 Country code, like "US"
+            2 => {
+                sub_tag[0] = sub_tag[0].to_ascii_uppercase();
+                sub_tag[1] = sub_tag[1].to_ascii_uppercase();
+            }
+            // ISO 15924 script code, like "Nkoo"
+            4 => {
+                sub_tag[0] = sub_tag[0].to_ascii_uppercase();
+            }
+            _ => {}
+        };
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn rust_net_is_valid_ipv4_addr<'a>(addr: &'a nsACString) -> bool {
+    is_valid_ipv4_addr(addr)
+}
+
+#[inline]
+fn try_apply_digit(current_octet: u8, digit_to_apply: u8) -> Option<u8> {
+    current_octet.checked_mul(10)?.checked_add(digit_to_apply)
+}
+
+pub fn is_valid_ipv4_addr<'a>(addr: &'a [u8]) -> bool {
+    let mut current_octet: Option<u8> = None;
+    let mut dots: u8 = 0;
+    for c in addr {
+        let c = *c as char;
+        match c {
+            '.' => {
+                match current_octet {
+                    None => {
+                        // starting an octet with a . is not allowed
+                        return false;
+                    }
+                    Some(_) => {
+                        dots = dots + 1;
+                        current_octet = None;
+                    }
+                }
+            }
+            // The character is not a digit
+            no_digit if no_digit.to_digit(10).is_none() => {
+                return false;
+            }
+            digit => {
+                match current_octet {
+                    None => {
+                        // Unwrap is sound because it has been checked in the previous arm
+                        current_octet = Some(digit.to_digit(10).unwrap() as u8);
+                    }
+                    Some(octet) => {
+                        if let Some(0) = current_octet {
+                            // Leading 0 is not allowed
+                            return false;
+                        }
+                        if let Some(applied) =
+                            try_apply_digit(octet, digit.to_digit(10).unwrap() as u8)
+                        {
+                            current_octet = Some(applied);
+                        } else {
+                            // Multiplication or Addition overflowed
+                            return false;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    dots == 3 && current_octet.is_some()
+}
+
+#[no_mangle]
+pub extern "C" fn rust_net_is_valid_ipv6_addr<'a>(addr: &'a nsACString) -> bool {
+    is_valid_ipv6_addr(addr)
+}
+
+#[inline(always)]
+fn fast_is_hex_digit(c: u8) -> bool {
+    match c {
+        b'0'..=b'9' => true,
+        b'a'..=b'f' => true,
+        b'A'..=b'F' => true,
+        _ => false,
+    }
+}
+
+pub fn is_valid_ipv6_addr<'a>(addr: &'a [u8]) -> bool {
+    let mut double_colon = false;
+    let mut colon_before = false;
+    let mut digits: u8 = 0;
+    let mut blocks: u8 = 0;
+
+    // The smallest ipv6 is unspecified (::)
+    // The IP starts with a single colon
+    if addr.len() < 2 || addr[0] == b':' && addr[1] != b':' {
+        return false;
+    }
+    //Enumerate with an u8 for cache locality
+    for (i, c) in (0u8..).zip(addr) {
+        match c {
+            maybe_digit if fast_is_hex_digit(*maybe_digit) => {
+                // Too many digits in the block
+                if digits == 4 {
+                    return false;
+                }
+                colon_before = false;
+                digits += 1;
+            }
+            b':' => {
+                // Too many columns
+                if double_colon && colon_before || blocks == 8 {
+                    return false;
+                }
+                if !colon_before {
+                    if digits != 0 {
+                        blocks += 1;
+                    }
+                    digits = 0;
+                    colon_before = true;
+                } else if !double_colon {
+                    double_colon = true;
+                }
+            }
+            b'.' => {
+                // IPv4 from the last block
+                if is_valid_ipv4_addr(&addr[(i - digits) as usize..]) {
+                    return double_colon && blocks < 6 || !double_colon && blocks == 6;
+                }
+                return false;
+            }
+            _ => {
+                // Invalid character
+                return false;
+            }
+        }
+    }
+    if colon_before && !double_colon {
+        // The IP ends with a single colon
+        return false;
+    }
+    if digits != 0 {
+        blocks += 1;
+    }
+
+    double_colon && blocks < 8 || !double_colon && blocks == 8
+}
+
+#[no_mangle]
+pub extern "C" fn rust_net_is_valid_scheme_char(a_char: u8) -> bool {
+    is_valid_scheme_char(a_char)
+}
+
+#[no_mangle]
+pub extern "C" fn rust_net_is_valid_scheme<'a>(scheme: &'a nsACString) -> bool {
+    if scheme.is_empty() {
+        return false;
+    }
+
+    // first char must be alpha
+    if !scheme[0].is_ascii_alphabetic() {
+        return false;
+    }
+
+    scheme[1..]
+        .iter()
+        .all(|a_char| is_valid_scheme_char(*a_char))
+}
+
+fn is_valid_scheme_char(a_char: u8) -> bool {
+    a_char.is_ascii_alphanumeric() || a_char == b'+' || a_char == b'.' || a_char == b'-'
+}
+
+pub type ParsingCallback = extern "C" fn(&ThinVec<nsCString>) -> bool;
+
+#[no_mangle]
+pub extern "C" fn rust_parse_etc_hosts<'a>(path: &'a nsACString, callback: ParsingCallback) {
+    let file = match File::open(&*path.to_utf8()) {
+        Ok(file) => io::BufReader::new(file),
+        Err(..) => return,
+    };
+
+    let mut array = ThinVec::new();
+    for line in file.lines() {
+        let line = match line {
+            Ok(l) => l,
+            Err(..) => continue,
+        };
+
+        let mut iter = line.split('#').next().unwrap().split_whitespace();
+        iter.next(); // skip the IP
+
+        array.extend(
+            iter.filter(|host| {
+                // Make sure it's a valid domain
+                let invalid = [
+                    '\0', '\t', '\n', '\r', ' ', '#', '%', '/', ':', '?', '@', '[', '\\', ']',
+                ];
+                host.parse::<Ipv4Addr>().is_err() && !host.contains(&invalid[..])
+            })
+            .map(nsCString::from),
+        );
+
+        // /etc/hosts files can be huge. To make sure we don't block shutdown
+        // for every 100 domains that we parse we call the callback passing the
+        // domains and see if we should keep parsing.
+        if array.len() > 100 {
+            let keep_going = callback(&array);
+            array.clear();
+            if !keep_going {
+                break;
+            }
+        }
+    }
+
+    if !array.is_empty() {
+        callback(&array);
+    }
+}