Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 13877 insertions, 0 deletions

diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
new file mode 100644
index 0000000000..57ee34cad0
--- /dev/null
+++ b/docshell/base/nsDocShell.cpp
@@ -0,0 +1,13877 @@
+/* -*- 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 "nsDocShell.h"
+
+#include <algorithm>
+
+#ifdef XP_WIN
+#  include <process.h>
+#  define getpid _getpid
+#else
+#  include <unistd.h>  // for getpid()
+#endif
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/AutoRestore.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/Casting.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/Components.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/EventStateManager.h"
+#include "mozilla/HTMLEditor.h"
+#include "mozilla/InputTaskManager.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/Logging.h"
+#include "mozilla/MediaFeatureChange.h"
+#include "mozilla/ObservedDocShell.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/SchedulerGroup.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/ScrollTypes.h"
+#include "mozilla/SimpleEnumerator.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPrefs_docshell.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/StaticPrefs_extensions.h"
+#include "mozilla/StaticPrefs_privacy.h"
+#include "mozilla/StaticPrefs_security.h"
+#include "mozilla/StaticPrefs_ui.h"
+#include "mozilla/StaticPrefs_fission.h"
+#include "mozilla/StartupTimeline.h"
+#include "mozilla/StorageAccess.h"
+#include "mozilla/StoragePrincipalHelper.h"
+#include "mozilla/Telemetry.h"
+
+#include "mozilla/Unused.h"
+#include "mozilla/WidgetUtils.h"
+
+#include "mozilla/dom/AutoEntryScript.h"
+#include "mozilla/dom/ChildProcessChannelListener.h"
+#include "mozilla/dom/ClientChannelHelper.h"
+#include "mozilla/dom/ClientHandle.h"
+#include "mozilla/dom/ClientInfo.h"
+#include "mozilla/dom/ClientManager.h"
+#include "mozilla/dom/ClientSource.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/ContentFrameMessageManager.h"
+#include "mozilla/dom/DocGroup.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLAnchorElement.h"
+#include "mozilla/dom/HTMLIFrameElement.h"
+#include "mozilla/dom/PerformanceNavigation.h"
+#include "mozilla/dom/PermissionMessageUtils.h"
+#include "mozilla/dom/PopupBlocker.h"
+#include "mozilla/dom/ProfileTimelineMarkerBinding.h"
+#include "mozilla/dom/ScreenOrientation.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/ServiceWorkerInterceptController.h"
+#include "mozilla/dom/ServiceWorkerUtils.h"
+#include "mozilla/dom/SessionHistoryEntry.h"
+#include "mozilla/dom/SessionStorageManager.h"
+#include "mozilla/dom/SessionStoreChangeListener.h"
+#include "mozilla/dom/SessionStoreChild.h"
+#include "mozilla/dom/SessionStoreUtils.h"
+#include "mozilla/dom/BrowserChild.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "mozilla/dom/UserActivation.h"
+#include "mozilla/dom/ChildSHistory.h"
+#include "mozilla/dom/nsCSPContext.h"
+#include "mozilla/dom/nsHTTPSOnlyUtils.h"
+#include "mozilla/dom/LoadURIOptionsBinding.h"
+#include "mozilla/dom/JSWindowActorChild.h"
+#include "mozilla/dom/DocumentBinding.h"
+#include "mozilla/ipc/ProtocolUtils.h"
+#include "mozilla/net/DocumentChannel.h"
+#include "mozilla/net/DocumentChannelChild.h"
+#include "mozilla/net/ParentChannelWrapper.h"
+#include "mozilla/net/UrlClassifierFeatureFactory.h"
+#include "ReferrerInfo.h"
+
+#include "nsIAuthPrompt.h"
+#include "nsIAuthPrompt2.h"
+#include "nsICachingChannel.h"
+#include "nsICaptivePortalService.h"
+#include "nsIChannel.h"
+#include "nsIChannelEventSink.h"
+#include "nsIClassOfService.h"
+#include "nsIConsoleReportCollector.h"
+#include "nsIContent.h"
+#include "nsIContentInlines.h"
+#include "nsIContentSecurityPolicy.h"
+#include "nsIContentViewer.h"
+#include "nsIController.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "mozilla/dom/Document.h"
+#include "nsHTMLDocument.h"
+#include "nsIDocumentLoaderFactory.h"
+#include "nsIDOMWindow.h"
+#include "nsIEditingSession.h"
+#include "nsIEffectiveTLDService.h"
+#include "nsIExternalProtocolService.h"
+#include "nsIFormPOSTActionChannel.h"
+#include "nsIFrame.h"
+#include "nsIGlobalObject.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsIIDNService.h"
+#include "nsIInputStreamChannel.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsILayoutHistoryState.h"
+#include "nsILoadInfo.h"
+#include "nsILoadURIDelegate.h"
+#include "nsIMultiPartChannel.h"
+#include "nsINestedURI.h"
+#include "nsINetworkPredictor.h"
+#include "nsINode.h"
+#include "nsINSSErrorsService.h"
+#include "nsIObserverService.h"
+#include "nsIOService.h"
+#include "nsIPrincipal.h"
+#include "nsIPrivacyTransitionObserver.h"
+#include "nsIPrompt.h"
+#include "nsIPromptCollection.h"
+#include "nsIPromptFactory.h"
+#include "nsIPublicKeyPinningService.h"
+#include "nsIReflowObserver.h"
+#include "nsIScriptChannel.h"
+#include "nsIScriptObjectPrincipal.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsIScrollableFrame.h"
+#include "nsIScrollObserver.h"
+#include "nsISupportsPrimitives.h"
+#include "nsISecureBrowserUI.h"
+#include "nsISeekableStream.h"
+#include "nsISelectionDisplay.h"
+#include "nsISHEntry.h"
+#include "nsISiteSecurityService.h"
+#include "nsISocketProvider.h"
+#include "nsIStringBundle.h"
+#include "nsIStructuredCloneContainer.h"
+#include "nsIBrowserChild.h"
+#include "nsITextToSubURI.h"
+#include "nsITimedChannel.h"
+#include "nsITimer.h"
+#include "nsITransportSecurityInfo.h"
+#include "nsIUploadChannel.h"
+#include "nsIURIFixup.h"
+#include "nsIURIMutator.h"
+#include "nsIURILoader.h"
+#include "nsIViewSourceChannel.h"
+#include "nsIWebBrowserChrome.h"
+#include "nsIWebBrowserChromeFocus.h"
+#include "nsIWebBrowserFind.h"
+#include "nsIWebProgress.h"
+#include "nsIWidget.h"
+#include "nsIWindowWatcher.h"
+#include "nsIWritablePropertyBag2.h"
+#include "nsIX509Cert.h"
+#include "nsIXULRuntime.h"
+
+#include "nsCommandManager.h"
+#include "nsPIDOMWindow.h"
+#include "nsPIWindowRoot.h"
+
+#include "IHistory.h"
+#include "IUrlClassifierUITelemetry.h"
+
+#include "nsArray.h"
+#include "nsArrayUtils.h"
+#include "nsCExternalHandlerService.h"
+#include "nsContentDLF.h"
+#include "nsContentPolicyUtils.h"  // NS_CheckContentLoadPolicy(...)
+#include "nsContentSecurityManager.h"
+#include "nsContentSecurityUtils.h"
+#include "nsContentUtils.h"
+#include "nsCURILoader.h"
+#include "nsDocShellCID.h"
+#include "nsDocShellEditorData.h"
+#include "nsDocShellEnumerator.h"
+#include "nsDocShellLoadState.h"
+#include "nsDocShellLoadTypes.h"
+#include "nsDOMCID.h"
+#include "nsDOMNavigationTiming.h"
+#include "nsDSURIContentListener.h"
+#include "nsEditingSession.h"
+#include "nsError.h"
+#include "nsEscape.h"
+#include "nsFocusManager.h"
+#include "nsGlobalWindow.h"
+#include "nsJSEnvironment.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsObjectLoadingContent.h"
+#include "nsPingListener.h"
+#include "nsPoint.h"
+#include "nsQueryObject.h"
+#include "nsQueryActor.h"
+#include "nsRect.h"
+#include "nsRefreshTimer.h"
+#include "nsSandboxFlags.h"
+#include "nsSHEntry.h"
+#include "nsSHistory.h"
+#include "nsSHEntry.h"
+#include "nsStructuredCloneContainer.h"
+#include "nsSubDocumentFrame.h"
+#include "nsURILoader.h"
+#include "nsURLHelper.h"
+#include "nsView.h"
+#include "nsViewManager.h"
+#include "nsViewSourceHandler.h"
+#include "nsWebBrowserFind.h"
+#include "nsWhitespaceTokenizer.h"
+#include "nsWidgetsCID.h"
+#include "nsXULAppAPI.h"
+
+#include "ThirdPartyUtil.h"
+#include "GeckoProfiler.h"
+#include "mozilla/NullPrincipal.h"
+#include "Navigator.h"
+#include "prenv.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "sslerr.h"
+#include "mozpkix/pkix.h"
+#include "NSSErrorsService.h"
+
+#include "timeline/JavascriptTimelineMarker.h"
+#include "nsDocShellTelemetryUtils.h"
+
+#ifdef MOZ_PLACES
+#  include "nsIFaviconService.h"
+#  include "mozIPlacesPendingOperation.h"
+#endif
+
+#if NS_PRINT_PREVIEW
+#  include "nsIDocumentViewerPrint.h"
+#  include "nsIWebBrowserPrint.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::net;
+
+using mozilla::ipc::Endpoint;
+
+// Threshold value in ms for META refresh based redirects
+#define REFRESH_REDIRECT_TIMER 15000
+
+static mozilla::LazyLogModule gCharsetMenuLog("CharsetMenu");
+
+#define LOGCHARSETMENU(args) \
+  MOZ_LOG(gCharsetMenuLog, mozilla::LogLevel::Debug, args)
+
+#ifdef DEBUG
+unsigned long nsDocShell::gNumberOfDocShells = 0;
+static uint64_t gDocshellIDCounter = 0;
+
+static mozilla::LazyLogModule gDocShellLog("nsDocShell");
+static mozilla::LazyLogModule gDocShellAndDOMWindowLeakLogging(
+    "DocShellAndDOMWindowLeak");
+#endif
+static mozilla::LazyLogModule gDocShellLeakLog("nsDocShellLeak");
+extern mozilla::LazyLogModule gPageCacheLog;
+mozilla::LazyLogModule gSHLog("SessionHistory");
+extern mozilla::LazyLogModule gSHIPBFCacheLog;
+
+const char kAppstringsBundleURL[] =
+    "chrome://global/locale/appstrings.properties";
+
+static bool IsTopLevelDoc(BrowsingContext* aBrowsingContext,
+                          nsILoadInfo* aLoadInfo) {
+  MOZ_ASSERT(aBrowsingContext);
+  MOZ_ASSERT(aLoadInfo);
+
+  if (aLoadInfo->GetExternalContentPolicyType() !=
+      ExtContentPolicy::TYPE_DOCUMENT) {
+    return false;
+  }
+
+  return aBrowsingContext->IsTopContent();
+}
+
+// True if loading for top level document loading in active tab.
+static bool IsUrgentStart(BrowsingContext* aBrowsingContext,
+                          nsILoadInfo* aLoadInfo, uint32_t aLoadType) {
+  MOZ_ASSERT(aBrowsingContext);
+  MOZ_ASSERT(aLoadInfo);
+
+  if (!IsTopLevelDoc(aBrowsingContext, aLoadInfo)) {
+    return false;
+  }
+
+  if (aLoadType &
+      (nsIDocShell::LOAD_CMD_NORMAL | nsIDocShell::LOAD_CMD_HISTORY)) {
+    return true;
+  }
+
+  return aBrowsingContext->IsActive();
+}
+
+nsDocShell::nsDocShell(BrowsingContext* aBrowsingContext,
+                       uint64_t aContentWindowID)
+    : nsDocLoader(true),
+      mContentWindowID(aContentWindowID),
+      mBrowsingContext(aBrowsingContext),
+      mParentCharset(nullptr),
+      mTreeOwner(nullptr),
+      mScrollbarPref(ScrollbarPreference::Auto),
+      mCharsetReloadState(eCharsetReloadInit),
+      mParentCharsetSource(0),
+      mFrameMargins(-1, -1),
+      mItemType(aBrowsingContext->IsContent() ? typeContent : typeChrome),
+      mPreviousEntryIndex(-1),
+      mLoadedEntryIndex(-1),
+      mBusyFlags(BUSY_FLAGS_NONE),
+      mAppType(nsIDocShell::APP_TYPE_UNKNOWN),
+      mLoadType(0),
+      mFailedLoadType(0),
+      mJSRunToCompletionDepth(0),
+      mMetaViewportOverride(nsIDocShell::META_VIEWPORT_OVERRIDE_NONE),
+      mChannelToDisconnectOnPageHide(0),
+      mCreatingDocument(false),
+#ifdef DEBUG
+      mInEnsureScriptEnv(false),
+#endif
+      mInitialized(false),
+      mAllowSubframes(true),
+      mAllowMetaRedirects(true),
+      mAllowImages(true),
+      mAllowMedia(true),
+      mAllowDNSPrefetch(true),
+      mAllowWindowControl(true),
+      mCSSErrorReportingEnabled(false),
+      mAllowAuth(mItemType == typeContent),
+      mAllowKeywordFixup(false),
+      mDisableMetaRefreshWhenInactive(false),
+      mWindowDraggingAllowed(false),
+      mInFrameSwap(false),
+      mFiredUnloadEvent(false),
+      mEODForCurrentDocument(false),
+      mURIResultedInDocument(false),
+      mIsBeingDestroyed(false),
+      mIsExecutingOnLoadHandler(false),
+      mSavingOldViewer(false),
+      mInvisible(false),
+      mHasLoadedNonBlankURI(false),
+      mBlankTiming(false),
+      mTitleValidForCurrentURI(false),
+      mWillChangeProcess(false),
+      mIsNavigating(false),
+      mForcedAutodetection(false),
+      mCheckingSessionHistory(false),
+      mNeedToReportActiveAfterLoadingBecomesActive(false) {
+  // If no outer window ID was provided, generate a new one.
+  if (aContentWindowID == 0) {
+    mContentWindowID = nsContentUtils::GenerateWindowId();
+  }
+
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug, ("DOCSHELL %p created\n", this));
+
+#ifdef DEBUG
+  mDocShellID = gDocshellIDCounter++;
+  // We're counting the number of |nsDocShells| to help find leaks
+  ++gNumberOfDocShells;
+  MOZ_LOG(gDocShellAndDOMWindowLeakLogging, LogLevel::Info,
+          ("++DOCSHELL %p == %ld [pid = %d] [id = %" PRIu64 "]\n", (void*)this,
+           gNumberOfDocShells, getpid(), mDocShellID));
+#endif
+}
+
+nsDocShell::~nsDocShell() {
+  MOZ_ASSERT(!mObserved);
+
+  // Avoid notifying observers while we're in the dtor.
+  mIsBeingDestroyed = true;
+
+  Destroy();
+
+  if (mContentViewer) {
+    mContentViewer->Close(nullptr);
+    mContentViewer->Destroy();
+    mContentViewer = nullptr;
+  }
+
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug, ("DOCSHELL %p destroyed\n", this));
+
+#ifdef DEBUG
+  if (MOZ_LOG_TEST(gDocShellAndDOMWindowLeakLogging, LogLevel::Info)) {
+    nsAutoCString url;
+    if (mLastOpenedURI) {
+      url = mLastOpenedURI->GetSpecOrDefault();
+
+      // Data URLs can be very long, so truncate to avoid flooding the log.
+      const uint32_t maxURLLength = 1000;
+      if (url.Length() > maxURLLength) {
+        url.Truncate(maxURLLength);
+      }
+    }
+
+    // We're counting the number of |nsDocShells| to help find leaks
+    --gNumberOfDocShells;
+    MOZ_LOG(
+        gDocShellAndDOMWindowLeakLogging, LogLevel::Info,
+        ("--DOCSHELL %p == %ld [pid = %d] [id = %" PRIu64 "] [url = %s]\n",
+         (void*)this, gNumberOfDocShells, getpid(), mDocShellID, url.get()));
+  }
+#endif
+}
+
+bool nsDocShell::Initialize() {
+  if (mInitialized) {
+    // We've already been initialized.
+    return true;
+  }
+
+  NS_ASSERTION(mItemType == typeContent || mItemType == typeChrome,
+               "Unexpected item type in docshell");
+
+  NS_ENSURE_TRUE(Preferences::GetRootBranch(), false);
+  mInitialized = true;
+
+  mDisableMetaRefreshWhenInactive =
+      Preferences::GetBool("browser.meta_refresh_when_inactive.disabled",
+                           mDisableMetaRefreshWhenInactive);
+
+  if (nsCOMPtr<nsIObserverService> serv = services::GetObserverService()) {
+    const char* msg = mItemType == typeContent ? NS_WEBNAVIGATION_CREATE
+                                               : NS_CHROME_WEBNAVIGATION_CREATE;
+    serv->NotifyWhenScriptSafe(GetAsSupports(this), msg, nullptr);
+  }
+
+  return true;
+}
+
+/* static */
+already_AddRefed<nsDocShell> nsDocShell::Create(
+    BrowsingContext* aBrowsingContext, uint64_t aContentWindowID) {
+  MOZ_ASSERT(aBrowsingContext, "DocShell without a BrowsingContext!");
+
+  nsresult rv;
+  RefPtr<nsDocShell> ds = new nsDocShell(aBrowsingContext, aContentWindowID);
+
+  // Initialize the underlying nsDocLoader.
+  rv = ds->nsDocLoader::InitWithBrowsingContext(aBrowsingContext);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // Create our ContentListener
+  ds->mContentListener = new nsDSURIContentListener(ds);
+
+  // We enable if we're in the parent process in order to support non-e10s
+  // configurations.
+  // Note: This check is duplicated in SharedWorkerInterfaceRequestor's
+  // constructor.
+  if (XRE_IsParentProcess()) {
+    ds->mInterceptController = new ServiceWorkerInterceptController();
+  }
+
+  // We want to hold a strong ref to the loadgroup, so it better hold a weak
+  // ref to us...  use an InterfaceRequestorProxy to do this.
+  nsCOMPtr<nsIInterfaceRequestor> proxy = new InterfaceRequestorProxy(ds);
+  ds->mLoadGroup->SetNotificationCallbacks(proxy);
+
+  // XXX(nika): We have our BrowsingContext, so we might be able to skip this.
+  // It could be nice to directly set up our DocLoader tree?
+  rv = nsDocLoader::AddDocLoaderAsChildOfRoot(ds);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // Add |ds| as a progress listener to itself.  A little weird, but simpler
+  // than reproducing all the listener-notification logic in overrides of the
+  // various methods via which nsDocLoader can be notified.   Note that this
+  // holds an nsWeakPtr to |ds|, so it's ok.
+  rv = ds->AddProgressListener(ds, nsIWebProgress::NOTIFY_STATE_DOCUMENT |
+                                       nsIWebProgress::NOTIFY_STATE_NETWORK |
+                                       nsIWebProgress::NOTIFY_LOCATION);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // If our BrowsingContext has private browsing enabled, update the number of
+  // private browsing docshells.
+  if (aBrowsingContext->UsePrivateBrowsing()) {
+    ds->NotifyPrivateBrowsingChanged();
+  }
+
+  // If our parent window is present in this process, set up our parent now.
+  RefPtr<WindowContext> parentWC = aBrowsingContext->GetParentWindowContext();
+  if (parentWC && parentWC->IsInProcess()) {
+    // If we don't have a parent element anymore, we can't finish this load!
+    // How'd we get here?
+    RefPtr<Element> parentElement = aBrowsingContext->GetEmbedderElement();
+    if (!parentElement) {
+      MOZ_ASSERT_UNREACHABLE("nsDocShell::Create() - !parentElement");
+      return nullptr;
+    }
+
+    // We have an in-process parent window, but don't have a parent nsDocShell?
+    // How'd we get here!
+    nsCOMPtr<nsIDocShell> parentShell =
+        parentElement->OwnerDoc()->GetDocShell();
+    if (!parentShell) {
+      MOZ_ASSERT_UNREACHABLE("nsDocShell::Create() - !parentShell");
+      return nullptr;
+    }
+    parentShell->AddChild(ds);
+  }
+
+  // Make |ds| the primary DocShell for the given context.
+  aBrowsingContext->SetDocShell(ds);
+
+  // Set |ds| default load flags on load group.
+  ds->SetLoadGroupDefaultLoadFlags(aBrowsingContext->GetDefaultLoadFlags());
+
+  if (XRE_IsParentProcess()) {
+    aBrowsingContext->Canonical()->MaybeAddAsProgressListener(ds);
+  }
+
+  return ds.forget();
+}
+
+void nsDocShell::DestroyChildren() {
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShellTreeItem> shell = do_QueryObject(child);
+    NS_ASSERTION(shell, "docshell has null child");
+
+    if (shell) {
+      shell->SetTreeOwner(nullptr);
+    }
+  }
+
+  nsDocLoader::DestroyChildren();
+}
+
+NS_IMPL_CYCLE_COLLECTION_WEAK_PTR_INHERITED(nsDocShell, nsDocLoader,
+                                            mScriptGlobal, mInitialClientSource,
+                                            mBrowsingContext,
+                                            mChromeEventHandler)
+
+NS_IMPL_ADDREF_INHERITED(nsDocShell, nsDocLoader)
+NS_IMPL_RELEASE_INHERITED(nsDocShell, nsDocLoader)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDocShell)
+  NS_INTERFACE_MAP_ENTRY(nsIDocShell)
+  NS_INTERFACE_MAP_ENTRY(nsIDocShellTreeItem)
+  NS_INTERFACE_MAP_ENTRY(nsIWebNavigation)
+  NS_INTERFACE_MAP_ENTRY(nsIBaseWindow)
+  NS_INTERFACE_MAP_ENTRY(nsIRefreshURI)
+  NS_INTERFACE_MAP_ENTRY(nsIWebProgressListener)
+  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+  NS_INTERFACE_MAP_ENTRY(nsIWebPageDescriptor)
+  NS_INTERFACE_MAP_ENTRY(nsIAuthPromptProvider)
+  NS_INTERFACE_MAP_ENTRY(nsILoadContext)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsINetworkInterceptController,
+                                     mInterceptController)
+NS_INTERFACE_MAP_END_INHERITING(nsDocLoader)
+
+NS_IMETHODIMP
+nsDocShell::GetInterface(const nsIID& aIID, void** aSink) {
+  MOZ_ASSERT(aSink, "null out param");
+
+  *aSink = nullptr;
+
+  if (aIID.Equals(NS_GET_IID(nsICommandManager))) {
+    NS_ENSURE_SUCCESS(EnsureCommandHandler(), NS_ERROR_FAILURE);
+    *aSink = static_cast<nsICommandManager*>(mCommandManager.get());
+  } else if (aIID.Equals(NS_GET_IID(nsIURIContentListener))) {
+    *aSink = mContentListener;
+  } else if ((aIID.Equals(NS_GET_IID(nsIScriptGlobalObject)) ||
+              aIID.Equals(NS_GET_IID(nsIGlobalObject)) ||
+              aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter)) ||
+              aIID.Equals(NS_GET_IID(mozIDOMWindowProxy)) ||
+              aIID.Equals(NS_GET_IID(nsIDOMWindow))) &&
+             NS_SUCCEEDED(EnsureScriptEnvironment())) {
+    return mScriptGlobal->QueryInterface(aIID, aSink);
+  } else if (aIID.Equals(NS_GET_IID(Document)) &&
+             NS_SUCCEEDED(EnsureContentViewer())) {
+    RefPtr<Document> doc = mContentViewer->GetDocument();
+    doc.forget(aSink);
+    return *aSink ? NS_OK : NS_NOINTERFACE;
+  } else if (aIID.Equals(NS_GET_IID(nsIPrompt)) &&
+             NS_SUCCEEDED(EnsureScriptEnvironment())) {
+    nsresult rv;
+    nsCOMPtr<nsIWindowWatcher> wwatch =
+        do_GetService(NS_WINDOWWATCHER_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Get the an auth prompter for our window so that the parenting
+    // of the dialogs works as it should when using tabs.
+    nsIPrompt* prompt;
+    rv = wwatch->GetNewPrompter(mScriptGlobal, &prompt);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    *aSink = prompt;
+    return NS_OK;
+  } else if (aIID.Equals(NS_GET_IID(nsIAuthPrompt)) ||
+             aIID.Equals(NS_GET_IID(nsIAuthPrompt2))) {
+    return NS_SUCCEEDED(GetAuthPrompt(PROMPT_NORMAL, aIID, aSink))
+               ? NS_OK
+               : NS_NOINTERFACE;
+  } else if (aIID.Equals(NS_GET_IID(nsISHistory))) {
+    // This is deprecated, you should instead directly get
+    // ChildSHistory from the browsing context.
+    MOZ_DIAGNOSTIC_ASSERT(
+        false, "Do not try to get a nsISHistory interface from nsIDocShell");
+    return NS_NOINTERFACE;
+  } else if (aIID.Equals(NS_GET_IID(nsIWebBrowserFind))) {
+    nsresult rv = EnsureFind();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    *aSink = mFind;
+    NS_ADDREF((nsISupports*)*aSink);
+    return NS_OK;
+  } else if (aIID.Equals(NS_GET_IID(nsISelectionDisplay))) {
+    if (PresShell* presShell = GetPresShell()) {
+      return presShell->QueryInterface(aIID, aSink);
+    }
+  } else if (aIID.Equals(NS_GET_IID(nsIDocShellTreeOwner))) {
+    nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
+    nsresult rv = GetTreeOwner(getter_AddRefs(treeOwner));
+    if (NS_SUCCEEDED(rv) && treeOwner) {
+      return treeOwner->QueryInterface(aIID, aSink);
+    }
+  } else if (aIID.Equals(NS_GET_IID(nsIBrowserChild))) {
+    *aSink = GetBrowserChild().take();
+    return *aSink ? NS_OK : NS_ERROR_FAILURE;
+  } else {
+    return nsDocLoader::GetInterface(aIID, aSink);
+  }
+
+  NS_IF_ADDREF(((nsISupports*)*aSink));
+  return *aSink ? NS_OK : NS_NOINTERFACE;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetCancelContentJSEpoch(int32_t aEpoch) {
+  // Note: this gets called fairly early (before a pageload actually starts).
+  // We could probably defer this even longer.
+  nsCOMPtr<nsIBrowserChild> browserChild = GetBrowserChild();
+  static_cast<BrowserChild*>(browserChild.get())
+      ->SetCancelContentJSEpoch(aEpoch);
+  return NS_OK;
+}
+
+nsresult nsDocShell::CheckDisallowedJavascriptLoad(
+    nsDocShellLoadState* aLoadState) {
+  if (!net::SchemeIsJavascript(aLoadState->URI())) {
+    return NS_OK;
+  }
+
+  if (nsCOMPtr<nsIPrincipal> targetPrincipal =
+          GetInheritedPrincipal(/* aConsiderCurrentDocument */ true)) {
+    if (!aLoadState->TriggeringPrincipal()->Subsumes(targetPrincipal)) {
+      return NS_ERROR_DOM_BAD_CROSS_ORIGIN_URI;
+    }
+    return NS_OK;
+  }
+  return NS_ERROR_DOM_BAD_CROSS_ORIGIN_URI;
+}
+
+NS_IMETHODIMP
+nsDocShell::LoadURI(nsDocShellLoadState* aLoadState, bool aSetNavigating) {
+  return LoadURI(aLoadState, aSetNavigating, false);
+}
+
+nsresult nsDocShell::LoadURI(nsDocShellLoadState* aLoadState,
+                             bool aSetNavigating,
+                             bool aContinueHandlingSubframeHistory) {
+  MOZ_ASSERT(aLoadState, "Must have a valid load state!");
+  // NOTE: This comparison between what appears to be internal/external load
+  // flags is intentional, as it's ensuring that the caller isn't using any of
+  // the flags reserved for implementations by the `nsIWebNavigation` interface.
+  // In the future, this check may be dropped.
+  MOZ_ASSERT(
+      (aLoadState->LoadFlags() & INTERNAL_LOAD_FLAGS_LOADURI_SETUP_FLAGS) == 0,
+      "Should not have these flags set");
+  MOZ_ASSERT(aLoadState->TargetBrowsingContext().IsNull(),
+             "Targeting doesn't occur until InternalLoad");
+
+  if (!aLoadState->TriggeringPrincipal()) {
+    MOZ_ASSERT(false, "LoadURI must have a triggering principal");
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_TRY(CheckDisallowedJavascriptLoad(aLoadState));
+
+  bool oldIsNavigating = mIsNavigating;
+  auto cleanupIsNavigating =
+      MakeScopeExit([&]() { mIsNavigating = oldIsNavigating; });
+  if (aSetNavigating) {
+    mIsNavigating = true;
+  }
+
+  PopupBlocker::PopupControlState popupState = PopupBlocker::openOverridden;
+  if (aLoadState->HasLoadFlags(LOAD_FLAGS_ALLOW_POPUPS)) {
+    popupState = PopupBlocker::openAllowed;
+    // If we allow popups as part of the navigation, ensure we fake a user
+    // interaction, so that popups can, in fact, be allowed to open.
+    if (WindowContext* wc = mBrowsingContext->GetCurrentWindowContext()) {
+      wc->NotifyUserGestureActivation();
+    }
+  }
+
+  AutoPopupStatePusher statePusher(popupState);
+
+  if (aLoadState->GetCancelContentJSEpoch().isSome()) {
+    SetCancelContentJSEpoch(*aLoadState->GetCancelContentJSEpoch());
+  }
+
+  // Note: we allow loads to get through here even if mFiredUnloadEvent is
+  // true; that case will get handled in LoadInternal or LoadHistoryEntry,
+  // so we pass false as the second parameter to IsNavigationAllowed.
+  // However, we don't allow the page to change location *in the middle of*
+  // firing beforeunload, so we do need to check if *beforeunload* is currently
+  // firing, so we call IsNavigationAllowed rather than just IsPrintingOrPP.
+  if (!IsNavigationAllowed(true, false)) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  nsLoadFlags defaultLoadFlags = mBrowsingContext->GetDefaultLoadFlags();
+  if (aLoadState->HasLoadFlags(LOAD_FLAGS_FORCE_TRR)) {
+    defaultLoadFlags |= nsIRequest::LOAD_TRR_ONLY_MODE;
+  } else if (aLoadState->HasLoadFlags(LOAD_FLAGS_DISABLE_TRR)) {
+    defaultLoadFlags |= nsIRequest::LOAD_TRR_DISABLED_MODE;
+  }
+
+  MOZ_ALWAYS_SUCCEEDS(mBrowsingContext->SetDefaultLoadFlags(defaultLoadFlags));
+
+  if (!StartupTimeline::HasRecord(StartupTimeline::FIRST_LOAD_URI) &&
+      mItemType == typeContent && !NS_IsAboutBlank(aLoadState->URI())) {
+    StartupTimeline::RecordOnce(StartupTimeline::FIRST_LOAD_URI);
+  }
+
+  // LoadType used to be set to a default value here, if no LoadInfo/LoadState
+  // object was passed in. That functionality has been removed as of bug
+  // 1492648. LoadType should now be set up by the caller at the time they
+  // create their nsDocShellLoadState object to pass into LoadURI.
+
+  MOZ_LOG(
+      gDocShellLeakLog, LogLevel::Debug,
+      ("nsDocShell[%p]: loading %s with flags 0x%08x", this,
+       aLoadState->URI()->GetSpecOrDefault().get(), aLoadState->LoadFlags()));
+
+  if ((!aLoadState->LoadIsFromSessionHistory() &&
+       !LOAD_TYPE_HAS_FLAGS(aLoadState->LoadType(),
+                            LOAD_FLAGS_REPLACE_HISTORY)) ||
+      aContinueHandlingSubframeHistory) {
+    // This is possibly a subframe, so handle it accordingly.
+    //
+    // If history exists, it will be loaded into the aLoadState object, and the
+    // LoadType will be changed.
+    if (MaybeHandleSubframeHistory(aLoadState,
+                                   aContinueHandlingSubframeHistory)) {
+      // MaybeHandleSubframeHistory returns true if we need to continue loading
+      // asynchronously.
+      return NS_OK;
+    }
+  }
+
+  if (aLoadState->LoadIsFromSessionHistory()) {
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("nsDocShell[%p]: loading from session history", this));
+
+    if (!mozilla::SessionHistoryInParent()) {
+      nsCOMPtr<nsISHEntry> entry = aLoadState->SHEntry();
+      return LoadHistoryEntry(entry, aLoadState->LoadType(),
+                              aLoadState->HasValidUserGestureActivation());
+    }
+
+    // FIXME Null check aLoadState->GetLoadingSessionHistoryInfo()?
+    return LoadHistoryEntry(*aLoadState->GetLoadingSessionHistoryInfo(),
+                            aLoadState->LoadType(),
+                            aLoadState->HasValidUserGestureActivation());
+  }
+
+  // On history navigation via Back/Forward buttons, don't execute
+  // automatic JavaScript redirection such as |location.href = ...| or
+  // |window.open()|
+  //
+  // LOAD_NORMAL:        window.open(...) etc.
+  // LOAD_STOP_CONTENT:  location.href = ..., location.assign(...)
+  if ((aLoadState->LoadType() == LOAD_NORMAL ||
+       aLoadState->LoadType() == LOAD_STOP_CONTENT) &&
+      ShouldBlockLoadingForBackButton()) {
+    return NS_OK;
+  }
+
+  BrowsingContext::Type bcType = mBrowsingContext->GetType();
+
+  // Set up the inheriting principal in LoadState.
+  nsresult rv = aLoadState->SetupInheritingPrincipal(
+      bcType, mBrowsingContext->OriginAttributesRef());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aLoadState->SetupTriggeringPrincipal(
+      mBrowsingContext->OriginAttributesRef());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aLoadState->CalculateLoadURIFlags();
+
+  MOZ_ASSERT(aLoadState->TypeHint().IsVoid(),
+             "Typehint should be null when calling InternalLoad from LoadURI");
+  MOZ_ASSERT(aLoadState->FileName().IsVoid(),
+             "FileName should be null when calling InternalLoad from LoadURI");
+  MOZ_ASSERT(!aLoadState->LoadIsFromSessionHistory(),
+             "Shouldn't be loading from an entry when calling InternalLoad "
+             "from LoadURI");
+
+  // If we have a system triggering principal, we can assume that this load was
+  // triggered by some UI in the browser chrome, such as the URL bar or
+  // bookmark bar. This should count as a user interaction for the current sh
+  // entry, so that the user may navigate back to the current entry, from the
+  // entry that is going to be added as part of this load.
+  nsCOMPtr<nsIPrincipal> triggeringPrincipal =
+      aLoadState->TriggeringPrincipal();
+  if (triggeringPrincipal && triggeringPrincipal->IsSystemPrincipal()) {
+    if (mozilla::SessionHistoryInParent()) {
+      WindowContext* topWc = mBrowsingContext->GetTopWindowContext();
+      if (topWc && !topWc->IsDiscarded()) {
+        MOZ_ALWAYS_SUCCEEDS(topWc->SetSHEntryHasUserInteraction(true));
+      }
+    } else {
+      bool oshe = false;
+      nsCOMPtr<nsISHEntry> currentSHEntry;
+      GetCurrentSHEntry(getter_AddRefs(currentSHEntry), &oshe);
+      if (currentSHEntry) {
+        currentSHEntry->SetHasUserInteraction(true);
+      }
+    }
+  }
+
+  rv = InternalLoad(aLoadState);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aLoadState->GetOriginalURIString().isSome()) {
+    // Save URI string in case it's needed later when
+    // sending to search engine service in EndPageLoad()
+    mOriginalUriString = *aLoadState->GetOriginalURIString();
+  }
+
+  return NS_OK;
+}
+
+bool nsDocShell::IsLoadingFromSessionHistory() {
+  return mActiveEntryIsLoadingFromSessionHistory;
+}
+
+// StopDetector is modeled similarly to OnloadBlocker; it is a rather
+// dummy nsIRequest implementation which can be added to an nsILoadGroup to
+// detect Cancel calls.
+class StopDetector final : public nsIRequest {
+ public:
+  StopDetector() = default;
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUEST
+
+  bool Canceled() { return mCanceled; }
+
+ private:
+  ~StopDetector() = default;
+
+  bool mCanceled = false;
+};
+
+NS_IMPL_ISUPPORTS(StopDetector, nsIRequest)
+
+NS_IMETHODIMP
+StopDetector::GetName(nsACString& aResult) {
+  aResult.AssignLiteral("about:stop-detector");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StopDetector::IsPending(bool* aRetVal) {
+  *aRetVal = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StopDetector::GetStatus(nsresult* aStatus) {
+  *aStatus = NS_OK;
+  return NS_OK;
+}
+
+NS_IMETHODIMP StopDetector::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP StopDetector::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP StopDetector::CancelWithReason(nsresult aStatus,
+                                             const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+StopDetector::Cancel(nsresult aStatus) {
+  mCanceled = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StopDetector::Suspend(void) { return NS_OK; }
+NS_IMETHODIMP
+StopDetector::Resume(void) { return NS_OK; }
+
+NS_IMETHODIMP
+StopDetector::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  *aLoadGroup = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StopDetector::SetLoadGroup(nsILoadGroup* aLoadGroup) { return NS_OK; }
+
+NS_IMETHODIMP
+StopDetector::GetLoadFlags(nsLoadFlags* aLoadFlags) {
+  *aLoadFlags = nsIRequest::LOAD_NORMAL;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+StopDetector::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+StopDetector::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+StopDetector::SetLoadFlags(nsLoadFlags aLoadFlags) { return NS_OK; }
+
+bool nsDocShell::MaybeHandleSubframeHistory(
+    nsDocShellLoadState* aLoadState, bool aContinueHandlingSubframeHistory) {
+  // First, verify if this is a subframe.
+  // Note, it is ok to rely on docshell here and not browsing context since when
+  // an iframe is created, it has first in-process docshell.
+  nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
+  GetInProcessSameTypeParent(getter_AddRefs(parentAsItem));
+  nsCOMPtr<nsIDocShell> parentDS(do_QueryInterface(parentAsItem));
+
+  if (!parentDS || parentDS == static_cast<nsIDocShell*>(this)) {
+    if (mBrowsingContext && mBrowsingContext->IsTop()) {
+      // This is the root docshell. If we got here while
+      // executing an onLoad Handler,this load will not go
+      // into session history.
+      // XXX Why is this code in a method which deals with iframes!
+      bool inOnLoadHandler = false;
+      GetIsExecutingOnLoadHandler(&inOnLoadHandler);
+      if (inOnLoadHandler) {
+        aLoadState->SetLoadType(LOAD_NORMAL_REPLACE);
+      }
+    }
+    return false;
+  }
+
+  /* OK. It is a subframe. Checkout the parent's loadtype. If the parent was
+   * loaded through a history mechanism, then get the SH entry for the child
+   * from the parent. This is done to restore frameset navigation while going
+   * back/forward. If the parent was loaded through any other loadType, set the
+   * child's loadType too accordingly, so that session history does not get
+   * confused.
+   */
+
+  // Get the parent's load type
+  uint32_t parentLoadType;
+  parentDS->GetLoadType(&parentLoadType);
+
+  if (!aContinueHandlingSubframeHistory) {
+    if (mozilla::SessionHistoryInParent()) {
+      if (nsDocShell::Cast(parentDS.get())->IsLoadingFromSessionHistory() &&
+          !GetCreatedDynamically()) {
+        if (XRE_IsContentProcess()) {
+          dom::ContentChild* contentChild = dom::ContentChild::GetSingleton();
+          nsCOMPtr<nsILoadGroup> loadGroup;
+          GetLoadGroup(getter_AddRefs(loadGroup));
+          if (contentChild && loadGroup && !mCheckingSessionHistory) {
+            RefPtr<Document> parentDoc = parentDS->GetDocument();
+            parentDoc->BlockOnload();
+            RefPtr<BrowsingContext> browsingContext = mBrowsingContext;
+            Maybe<uint64_t> currentLoadIdentifier =
+                mBrowsingContext->GetCurrentLoadIdentifier();
+            RefPtr<nsDocShellLoadState> loadState = aLoadState;
+            bool isNavigating = mIsNavigating;
+            RefPtr<StopDetector> stopDetector = new StopDetector();
+            loadGroup->AddRequest(stopDetector, nullptr);
+            // Need to set mCheckingSessionHistory so that
+            // GetIsAttemptingToNavigate() returns true.
+            mCheckingSessionHistory = true;
+
+            auto resolve =
+                [currentLoadIdentifier, browsingContext, parentDoc, loadState,
+                 isNavigating, loadGroup, stopDetector](
+                    mozilla::Maybe<LoadingSessionHistoryInfo>&& aResult) {
+                  RefPtr<nsDocShell> docShell =
+                      static_cast<nsDocShell*>(browsingContext->GetDocShell());
+                  auto unblockParent = MakeScopeExit(
+                      [loadGroup, stopDetector, parentDoc, docShell]() {
+                        if (docShell) {
+                          docShell->mCheckingSessionHistory = false;
+                        }
+                        loadGroup->RemoveRequest(stopDetector, nullptr, NS_OK);
+                        parentDoc->UnblockOnload(false);
+                      });
+
+                  if (!docShell || !docShell->mCheckingSessionHistory) {
+                    return;
+                  }
+
+                  if (stopDetector->Canceled()) {
+                    return;
+                  }
+                  if (currentLoadIdentifier ==
+                          browsingContext->GetCurrentLoadIdentifier() &&
+                      aResult.isSome()) {
+                    loadState->SetLoadingSessionHistoryInfo(aResult.value());
+                    // This is an initial subframe load from the session
+                    // history, index doesn't need to be updated.
+                    loadState->SetLoadIsFromSessionHistory(0, false);
+                  }
+
+                  // We got the results back from the parent process, call
+                  // LoadURI again with the possibly updated data.
+                  docShell->LoadURI(loadState, isNavigating, true);
+                };
+            auto reject = [loadGroup, stopDetector, browsingContext,
+                           parentDoc](mozilla::ipc::ResponseRejectReason) {
+              RefPtr<nsDocShell> docShell =
+                  static_cast<nsDocShell*>(browsingContext->GetDocShell());
+              if (docShell) {
+                docShell->mCheckingSessionHistory = false;
+              }
+              // In practise reject shouldn't be called ever.
+              loadGroup->RemoveRequest(stopDetector, nullptr, NS_OK);
+              parentDoc->UnblockOnload(false);
+            };
+            contentChild->SendGetLoadingSessionHistoryInfoFromParent(
+                mBrowsingContext, std::move(resolve), std::move(reject));
+            return true;
+          }
+        } else {
+          Maybe<LoadingSessionHistoryInfo> info;
+          mBrowsingContext->Canonical()->GetLoadingSessionHistoryInfoFromParent(
+              info);
+          if (info.isSome()) {
+            aLoadState->SetLoadingSessionHistoryInfo(info.value());
+            // This is an initial subframe load from the session
+            // history, index doesn't need to be updated.
+            aLoadState->SetLoadIsFromSessionHistory(0, false);
+          }
+        }
+      }
+    } else {
+      // Get the ShEntry for the child from the parent
+      nsCOMPtr<nsISHEntry> currentSH;
+      bool oshe = false;
+      parentDS->GetCurrentSHEntry(getter_AddRefs(currentSH), &oshe);
+      bool dynamicallyAddedChild = GetCreatedDynamically();
+
+      if (!dynamicallyAddedChild && !oshe && currentSH) {
+        // Only use the old SHEntry, if we're sure enough that
+        // it wasn't originally for some other frame.
+        nsCOMPtr<nsISHEntry> shEntry;
+        currentSH->GetChildSHEntryIfHasNoDynamicallyAddedChild(
+            mBrowsingContext->ChildOffset(), getter_AddRefs(shEntry));
+        if (shEntry) {
+          aLoadState->SetSHEntry(shEntry);
+        }
+      }
+    }
+  }
+
+  // Make some decisions on the child frame's loadType based on the
+  // parent's loadType, if the subframe hasn't loaded anything into it.
+  //
+  // In some cases privileged scripts may try to get the DOMWindow
+  // reference of this docshell before the loading starts, causing the
+  // initial about:blank content viewer being created and mCurrentURI being
+  // set. To handle this case we check if mCurrentURI is about:blank and
+  // currentSHEntry is null.
+  bool oshe = false;
+  nsCOMPtr<nsISHEntry> currentChildEntry;
+  GetCurrentSHEntry(getter_AddRefs(currentChildEntry), &oshe);
+
+  if (mCurrentURI && (!NS_IsAboutBlank(mCurrentURI) || currentChildEntry ||
+                      mLoadingEntry || mActiveEntry)) {
+    // This is a pre-existing subframe. If
+    // 1. The load of this frame was not originally initiated by session
+    //    history directly (i.e. (!shEntry) condition succeeded, but it can
+    //    still be a history load on parent which causes this frame being
+    //    loaded), which we checked with the above assert, and
+    // 2. mCurrentURI is not null, nor the initial about:blank,
+    // it is possible that a parent's onLoadHandler or even self's
+    // onLoadHandler is loading a new page in this child. Check parent's and
+    // self's busy flag and if it is set, we don't want this onLoadHandler
+    // load to get in to session history.
+    BusyFlags parentBusy = parentDS->GetBusyFlags();
+    BusyFlags selfBusy = GetBusyFlags();
+
+    if (parentBusy & BUSY_FLAGS_BUSY || selfBusy & BUSY_FLAGS_BUSY) {
+      aLoadState->SetLoadType(LOAD_NORMAL_REPLACE);
+      aLoadState->ClearLoadIsFromSessionHistory();
+    }
+    return false;
+  }
+
+  // This is a newly created frame. Check for exception cases first.
+  // By default the subframe will inherit the parent's loadType.
+  if (aLoadState->LoadIsFromSessionHistory() &&
+      (parentLoadType == LOAD_NORMAL || parentLoadType == LOAD_LINK)) {
+    // The parent was loaded normally. In this case, this *brand new*
+    // child really shouldn't have a SHEntry. If it does, it could be
+    // because the parent is replacing an existing frame with a new frame,
+    // in the onLoadHandler. We don't want this url to get into session
+    // history. Clear off shEntry, and set load type to
+    // LOAD_BYPASS_HISTORY.
+    bool inOnLoadHandler = false;
+    parentDS->GetIsExecutingOnLoadHandler(&inOnLoadHandler);
+    if (inOnLoadHandler) {
+      aLoadState->SetLoadType(LOAD_NORMAL_REPLACE);
+      aLoadState->ClearLoadIsFromSessionHistory();
+    }
+  } else if (parentLoadType == LOAD_REFRESH) {
+    // Clear shEntry. For refresh loads, we have to load
+    // what comes through the pipe, not what's in history.
+    aLoadState->ClearLoadIsFromSessionHistory();
+  } else if ((parentLoadType == LOAD_BYPASS_HISTORY) ||
+             (aLoadState->LoadIsFromSessionHistory() &&
+              ((parentLoadType & LOAD_CMD_HISTORY) ||
+               (parentLoadType == LOAD_RELOAD_NORMAL) ||
+               (parentLoadType == LOAD_RELOAD_CHARSET_CHANGE) ||
+               (parentLoadType == LOAD_RELOAD_CHARSET_CHANGE_BYPASS_CACHE) ||
+               (parentLoadType ==
+                LOAD_RELOAD_CHARSET_CHANGE_BYPASS_PROXY_AND_CACHE)))) {
+    // If the parent url, bypassed history or was loaded from
+    // history, pass on the parent's loadType to the new child
+    // frame too, so that the child frame will also
+    // avoid getting into history.
+    aLoadState->SetLoadType(parentLoadType);
+  } else if (parentLoadType == LOAD_ERROR_PAGE) {
+    // If the parent document is an error page, we don't
+    // want to update global/session history. However,
+    // this child frame is not an error page.
+    aLoadState->SetLoadType(LOAD_BYPASS_HISTORY);
+  } else if ((parentLoadType == LOAD_RELOAD_BYPASS_CACHE) ||
+             (parentLoadType == LOAD_RELOAD_BYPASS_PROXY) ||
+             (parentLoadType == LOAD_RELOAD_BYPASS_PROXY_AND_CACHE)) {
+    // the new frame should inherit the parent's load type so that it also
+    // bypasses the cache and/or proxy
+    aLoadState->SetLoadType(parentLoadType);
+  }
+
+  return false;
+}
+
+/*
+ * Reset state to a new content model within the current document and the
+ * document viewer. Called by the document before initiating an out of band
+ * document.write().
+ */
+NS_IMETHODIMP
+nsDocShell::PrepareForNewContentModel() {
+  // Clear out our form control state, because the state of controls
+  // in the pre-open() document should not affect the state of
+  // controls that are now going to be written.
+  SetLayoutHistoryState(nullptr);
+  mEODForCurrentDocument = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::FirePageHideNotification(bool aIsUnload) {
+  FirePageHideNotificationInternal(aIsUnload, false);
+  return NS_OK;
+}
+
+void nsDocShell::FirePageHideNotificationInternal(
+    bool aIsUnload, bool aSkipCheckingDynEntries) {
+  if (mContentViewer && !mFiredUnloadEvent) {
+    // Keep an explicit reference since calling PageHide could release
+    // mContentViewer
+    nsCOMPtr<nsIContentViewer> contentViewer(mContentViewer);
+    mFiredUnloadEvent = true;
+
+    if (mTiming) {
+      mTiming->NotifyUnloadEventStart();
+    }
+
+    contentViewer->PageHide(aIsUnload);
+
+    if (mTiming) {
+      mTiming->NotifyUnloadEventEnd();
+    }
+
+    AutoTArray<nsCOMPtr<nsIDocShell>, 8> kids;
+    uint32_t n = mChildList.Length();
+    kids.SetCapacity(n);
+    for (uint32_t i = 0; i < n; i++) {
+      kids.AppendElement(do_QueryInterface(ChildAt(i)));
+    }
+
+    n = kids.Length();
+    for (uint32_t i = 0; i < n; ++i) {
+      RefPtr<nsDocShell> child = static_cast<nsDocShell*>(kids[i].get());
+      if (child) {
+        // Skip checking dynamic subframe entries in our children.
+        child->FirePageHideNotificationInternal(aIsUnload, true);
+      }
+    }
+
+    // If the document is unloading, remove all dynamic subframe entries.
+    if (aIsUnload && !aSkipCheckingDynEntries) {
+      RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+      if (rootSH) {
+        MOZ_LOG(
+            gSHLog, LogLevel::Debug,
+            ("nsDocShell %p unloading, remove dynamic subframe entries", this));
+        if (mozilla::SessionHistoryInParent()) {
+          if (mActiveEntry) {
+            mBrowsingContext->RemoveDynEntriesFromActiveSessionHistoryEntry();
+          }
+          MOZ_LOG(gSHLog, LogLevel::Debug,
+                  ("nsDocShell %p unloading, no active entries", this));
+        } else if (mOSHE) {
+          int32_t index = rootSH->Index();
+          rootSH->LegacySHistory()->RemoveDynEntries(index, mOSHE);
+        }
+      }
+    }
+
+    // Now make sure our editor, if any, is detached before we go
+    // any farther.
+    DetachEditorFromWindow();
+  }
+}
+
+void nsDocShell::ThawFreezeNonRecursive(bool aThaw) {
+  MOZ_ASSERT(mozilla::BFCacheInParent());
+
+  if (!mScriptGlobal) {
+    return;
+  }
+
+  RefPtr<nsGlobalWindowInner> inner =
+      mScriptGlobal->GetCurrentInnerWindowInternal();
+  if (inner) {
+    if (aThaw) {
+      inner->Thaw(false);
+    } else {
+      inner->Freeze(false);
+    }
+  }
+}
+
+void nsDocShell::FirePageHideShowNonRecursive(bool aShow) {
+  MOZ_ASSERT(mozilla::BFCacheInParent());
+
+  if (!mContentViewer) {
+    return;
+  }
+
+  // Emulate what non-SHIP BFCache does too. In pageshow case
+  // add and remove a request and before that call SetCurrentURI to get
+  // the location change notification.
+  // For pagehide, set mFiredUnloadEvent to true, so that unload doesn't fire.
+  nsCOMPtr<nsIContentViewer> contentViewer(mContentViewer);
+  if (aShow) {
+    contentViewer->SetIsHidden(false);
+    mRefreshURIList = std::move(mBFCachedRefreshURIList);
+    RefreshURIFromQueue();
+    mFiredUnloadEvent = false;
+    RefPtr<Document> doc = contentViewer->GetDocument();
+    if (doc) {
+      doc->NotifyActivityChanged();
+      RefPtr<nsGlobalWindowInner> inner =
+          mScriptGlobal ? mScriptGlobal->GetCurrentInnerWindowInternal()
+                        : nullptr;
+      if (mBrowsingContext->IsTop()) {
+        doc->NotifyPossibleTitleChange(false);
+        doc->SetLoadingOrRestoredFromBFCacheTimeStampToNow();
+        if (inner) {
+          // Now that we have found the inner window of the page restored
+          // from the history, we have to make sure that
+          // performance.navigation.type is 2.
+          // Traditionally this type change has been done to the top level page
+          // only.
+          Performance* performance = inner->GetPerformance();
+          if (performance) {
+            performance->GetDOMTiming()->NotifyRestoreStart();
+          }
+        }
+      }
+
+      nsCOMPtr<nsIChannel> channel = doc->GetChannel();
+      if (channel) {
+        SetLoadType(LOAD_HISTORY);
+        mEODForCurrentDocument = false;
+        mIsRestoringDocument = true;
+        mLoadGroup->AddRequest(channel, nullptr);
+        SetCurrentURI(doc->GetDocumentURI(), channel,
+                      /* aFireOnLocationChange */ true,
+                      /* aIsInitialAboutBlank */ false,
+                      /* aLocationFlags */ 0);
+        mLoadGroup->RemoveRequest(channel, nullptr, NS_OK);
+        mIsRestoringDocument = false;
+      }
+      RefPtr<PresShell> presShell = GetPresShell();
+      if (presShell) {
+        presShell->Thaw(false);
+      }
+
+      if (inner) {
+        inner->FireDelayedDOMEvents(false);
+      }
+    }
+  } else if (!mFiredUnloadEvent) {
+    // XXXBFCache check again that the page can enter bfcache.
+    // XXXBFCache should mTiming->NotifyUnloadEventStart()/End() be called here?
+
+    if (mRefreshURIList) {
+      RefreshURIToQueue();
+      mBFCachedRefreshURIList = std::move(mRefreshURIList);
+    } else {
+      // If Stop was called, the list was moved to mSavedRefreshURIList after
+      // calling SuspendRefreshURIs, which calls RefreshURIToQueue.
+      mBFCachedRefreshURIList = std::move(mSavedRefreshURIList);
+    }
+
+    mFiredUnloadEvent = true;
+    contentViewer->PageHide(false);
+
+    RefPtr<PresShell> presShell = GetPresShell();
+    if (presShell) {
+      presShell->Freeze(false);
+    }
+  }
+}
+
+nsresult nsDocShell::Dispatch(TaskCategory aCategory,
+                              already_AddRefed<nsIRunnable>&& aRunnable) {
+  nsCOMPtr<nsIRunnable> runnable(aRunnable);
+  nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+  if (NS_WARN_IF(!win)) {
+    // Window should only be unavailable after destroyed.
+    MOZ_ASSERT(mIsBeingDestroyed);
+    return NS_ERROR_FAILURE;
+  }
+
+  if (win->GetDocGroup()) {
+    return win->GetDocGroup()->Dispatch(aCategory, runnable.forget());
+  }
+
+  return SchedulerGroup::Dispatch(aCategory, runnable.forget());
+}
+
+NS_IMETHODIMP
+nsDocShell::DispatchLocationChangeEvent() {
+  return Dispatch(
+      TaskCategory::Other,
+      NewRunnableMethod("nsDocShell::FireDummyOnLocationChange", this,
+                        &nsDocShell::FireDummyOnLocationChange));
+}
+
+NS_IMETHODIMP
+nsDocShell::StartDelayedAutoplayMediaComponents() {
+  RefPtr<nsPIDOMWindowOuter> outerWindow = GetWindow();
+  if (outerWindow) {
+    outerWindow->ActivateMediaComponents();
+  }
+  return NS_OK;
+}
+
+bool nsDocShell::MaybeInitTiming() {
+  if (mTiming && !mBlankTiming) {
+    return false;
+  }
+
+  bool canBeReset = false;
+
+  if (mScriptGlobal && mBlankTiming) {
+    nsPIDOMWindowInner* innerWin = mScriptGlobal->GetCurrentInnerWindow();
+    if (innerWin && innerWin->GetPerformance()) {
+      mTiming = innerWin->GetPerformance()->GetDOMTiming();
+      mBlankTiming = false;
+    }
+  }
+
+  if (!mTiming) {
+    mTiming = new nsDOMNavigationTiming(this);
+    canBeReset = true;
+  }
+
+  mTiming->NotifyNavigationStart(
+      mBrowsingContext->IsActive()
+          ? nsDOMNavigationTiming::DocShellState::eActive
+          : nsDOMNavigationTiming::DocShellState::eInactive);
+
+  return canBeReset;
+}
+
+void nsDocShell::MaybeResetInitTiming(bool aReset) {
+  if (aReset) {
+    mTiming = nullptr;
+  }
+}
+
+nsDOMNavigationTiming* nsDocShell::GetNavigationTiming() const {
+  return mTiming;
+}
+
+nsPresContext* nsDocShell::GetEldestPresContext() {
+  nsIContentViewer* viewer = mContentViewer;
+  while (viewer) {
+    nsIContentViewer* prevViewer = viewer->GetPreviousViewer();
+    if (!prevViewer) {
+      return viewer->GetPresContext();
+    }
+    viewer = prevViewer;
+  }
+
+  return nullptr;
+}
+
+nsPresContext* nsDocShell::GetPresContext() {
+  if (!mContentViewer) {
+    return nullptr;
+  }
+
+  return mContentViewer->GetPresContext();
+}
+
+PresShell* nsDocShell::GetPresShell() {
+  nsPresContext* presContext = GetPresContext();
+  return presContext ? presContext->GetPresShell() : nullptr;
+}
+
+PresShell* nsDocShell::GetEldestPresShell() {
+  nsPresContext* presContext = GetEldestPresContext();
+
+  if (presContext) {
+    return presContext->GetPresShell();
+  }
+
+  return nullptr;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetContentViewer(nsIContentViewer** aContentViewer) {
+  NS_ENSURE_ARG_POINTER(aContentViewer);
+
+  *aContentViewer = mContentViewer;
+  NS_IF_ADDREF(*aContentViewer);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetOuterWindowID(uint64_t* aWindowID) {
+  *aWindowID = mContentWindowID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetChromeEventHandler(EventTarget* aChromeEventHandler) {
+  mChromeEventHandler = aChromeEventHandler;
+
+  if (mScriptGlobal) {
+    mScriptGlobal->SetChromeEventHandler(mChromeEventHandler);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetChromeEventHandler(EventTarget** aChromeEventHandler) {
+  NS_ENSURE_ARG_POINTER(aChromeEventHandler);
+  RefPtr<EventTarget> handler = mChromeEventHandler;
+  handler.forget(aChromeEventHandler);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetCurrentURIForSessionStore(nsIURI* aURI) {
+  // Note that securityUI will set STATE_IS_INSECURE, even if
+  // the scheme of |aURI| is "https".
+  SetCurrentURI(aURI, nullptr,
+                /* aFireOnLocationChange */
+                true,
+                /* aIsInitialAboutBlank */
+                false,
+                /* aLocationFlags */
+                nsIWebProgressListener::LOCATION_CHANGE_SESSION_STORE);
+  return NS_OK;
+}
+
+bool nsDocShell::SetCurrentURI(nsIURI* aURI, nsIRequest* aRequest,
+                               bool aFireOnLocationChange,
+                               bool aIsInitialAboutBlank,
+                               uint32_t aLocationFlags) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug,
+          ("DOCSHELL %p SetCurrentURI %s\n", this,
+           aURI ? aURI->GetSpecOrDefault().get() : ""));
+
+  // We don't want to send a location change when we're displaying an error
+  // page, and we don't want to change our idea of "current URI" either
+  if (mLoadType == LOAD_ERROR_PAGE) {
+    return false;
+  }
+
+  bool uriIsEqual = false;
+  if (!mCurrentURI || !aURI ||
+      NS_FAILED(mCurrentURI->Equals(aURI, &uriIsEqual)) || !uriIsEqual) {
+    mTitleValidForCurrentURI = false;
+  }
+
+  mCurrentURI = aURI;
+
+#ifdef DEBUG
+  mLastOpenedURI = aURI;
+#endif
+
+  if (!NS_IsAboutBlank(mCurrentURI)) {
+    mHasLoadedNonBlankURI = true;
+  }
+
+  // Don't fire onLocationChange when creating a subframe's initial about:blank
+  // document, as this can happen when it's not safe for us to run script.
+  if (aIsInitialAboutBlank && !mHasLoadedNonBlankURI &&
+      !mBrowsingContext->IsTop()) {
+    MOZ_ASSERT(!aRequest && aLocationFlags == 0);
+    return false;
+  }
+
+  MOZ_ASSERT(nsContentUtils::IsSafeToRunScript());
+
+  if (aFireOnLocationChange) {
+    FireOnLocationChange(this, aRequest, aURI, aLocationFlags);
+  }
+  return !aFireOnLocationChange;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCharset(nsACString& aCharset) {
+  aCharset.Truncate();
+
+  PresShell* presShell = GetPresShell();
+  NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
+  Document* doc = presShell->GetDocument();
+  NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
+  doc->GetDocumentCharacterSet()->Name(aCharset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::ForceEncodingDetection() {
+  nsCOMPtr<nsIContentViewer> viewer;
+  GetContentViewer(getter_AddRefs(viewer));
+  if (!viewer) {
+    return NS_OK;
+  }
+
+  Document* doc = viewer->GetDocument();
+  if (!doc || doc->WillIgnoreCharsetOverride()) {
+    return NS_OK;
+  }
+
+  mForcedAutodetection = true;
+
+  nsIURI* url = doc->GetOriginalURI();
+  bool isFileURL = url && SchemeIsFile(url);
+
+  int32_t charsetSource = doc->GetDocumentCharacterSetSource();
+  auto encoding = doc->GetDocumentCharacterSet();
+  // AsHTMLDocument is valid, because we called
+  // WillIgnoreCharsetOverride() above.
+  if (doc->AsHTMLDocument()->IsPlainText()) {
+    switch (charsetSource) {
+      case kCharsetFromInitialAutoDetectionASCII:
+        // Deliberately no final version
+        LOGCHARSETMENU(("TEXT:UnlabeledAscii"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::UnlabeledAscii);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8Generic:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8Generic:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8GenericInitialWasASCII:
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8Content:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8Content:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8ContentInitialWasASCII:
+        LOGCHARSETMENU(("TEXT:UnlabeledNonUtf8"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::
+                UnlabeledNonUtf8);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8DependedOnTLD:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8DependedOnTLD:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8DependedOnTLDInitialWasASCII:
+        LOGCHARSETMENU(("TEXT:UnlabeledNonUtf8TLD"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::
+                UnlabeledNonUtf8TLD);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldHaveBeenUTF8:
+      case kCharsetFromFinalAutoDetectionWouldHaveBeenUTF8InitialWasASCII:
+        LOGCHARSETMENU(("TEXT:UnlabeledUtf8"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::UnlabeledUtf8);
+        break;
+      case kCharsetFromChannel:
+        if (encoding == UTF_8_ENCODING) {
+          LOGCHARSETMENU(("TEXT:ChannelUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::ChannelUtf8);
+        } else {
+          LOGCHARSETMENU(("TEXT:ChannelNonUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::
+                  ChannelNonUtf8);
+        }
+        break;
+      default:
+        LOGCHARSETMENU(("TEXT:Bug"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_TEXT::Bug);
+        break;
+    }
+  } else {
+    switch (charsetSource) {
+      case kCharsetFromInitialAutoDetectionASCII:
+        // Deliberately no final version
+        LOGCHARSETMENU(("HTML:UnlabeledAscii"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::UnlabeledAscii);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8Generic:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8Generic:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8GenericInitialWasASCII:
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8Content:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8Content:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8ContentInitialWasASCII:
+        LOGCHARSETMENU(("HTML:UnlabeledNonUtf8"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::
+                UnlabeledNonUtf8);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldNotHaveBeenUTF8DependedOnTLD:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8DependedOnTLD:
+      case kCharsetFromFinalAutoDetectionWouldNotHaveBeenUTF8DependedOnTLDInitialWasASCII:
+        LOGCHARSETMENU(("HTML:UnlabeledNonUtf8TLD"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::
+                UnlabeledNonUtf8TLD);
+        break;
+      case kCharsetFromInitialAutoDetectionWouldHaveBeenUTF8:
+      case kCharsetFromFinalAutoDetectionWouldHaveBeenUTF8InitialWasASCII:
+        LOGCHARSETMENU(("HTML:UnlabeledUtf8"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::UnlabeledUtf8);
+        break;
+      case kCharsetFromChannel:
+        if (encoding == UTF_8_ENCODING) {
+          LOGCHARSETMENU(("HTML:ChannelUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::ChannelUtf8);
+        } else {
+          LOGCHARSETMENU(("HTML:ChannelNonUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::
+                  ChannelNonUtf8);
+        }
+        break;
+      case kCharsetFromXmlDeclaration:
+      case kCharsetFromMetaTag:
+        if (isFileURL) {
+          LOGCHARSETMENU(("HTML:LocalLabeled"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::LocalLabeled);
+        } else if (encoding == UTF_8_ENCODING) {
+          LOGCHARSETMENU(("HTML:MetaUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::InternalUtf8);
+        } else {
+          LOGCHARSETMENU(("HTML:MetaNonUtf8"));
+          Telemetry::AccumulateCategorical(
+              Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::
+                  InternalNonUtf8);
+        }
+        break;
+      default:
+        LOGCHARSETMENU(("HTML:Bug"));
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_ENCODING_OVERRIDE_SITUATION_HTML::Bug);
+        break;
+    }
+  }
+  return NS_OK;
+}
+
+void nsDocShell::SetParentCharset(const Encoding*& aCharset,
+                                  int32_t aCharsetSource,
+                                  nsIPrincipal* aPrincipal) {
+  mParentCharset = aCharset;
+  mParentCharsetSource = aCharsetSource;
+  mParentCharsetPrincipal = aPrincipal;
+}
+
+void nsDocShell::GetParentCharset(const Encoding*& aCharset,
+                                  int32_t* aCharsetSource,
+                                  nsIPrincipal** aPrincipal) {
+  aCharset = mParentCharset;
+  *aCharsetSource = mParentCharsetSource;
+  NS_IF_ADDREF(*aPrincipal = mParentCharsetPrincipal);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetHasTrackingContentBlocked(Promise** aPromise) {
+  MOZ_ASSERT(aPromise);
+
+  ErrorResult rv;
+  RefPtr<Document> doc(GetDocument());
+  RefPtr<Promise> retPromise = Promise::Create(doc->GetOwnerGlobal(), rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return rv.StealNSResult();
+  }
+
+  // Retrieve the document's content blocking events from the parent process.
+  RefPtr<Document::GetContentBlockingEventsPromise> promise =
+      doc->GetContentBlockingEvents();
+  if (promise) {
+    promise->Then(
+        GetCurrentSerialEventTarget(), __func__,
+        [retPromise](const Document::GetContentBlockingEventsPromise::
+                         ResolveOrRejectValue& aValue) {
+          if (aValue.IsResolve()) {
+            bool has = aValue.ResolveValue() &
+                       nsIWebProgressListener::STATE_BLOCKED_TRACKING_CONTENT;
+            retPromise->MaybeResolve(has);
+          } else {
+            retPromise->MaybeResolve(false);
+          }
+        });
+  } else {
+    retPromise->MaybeResolve(false);
+  }
+
+  retPromise.forget(aPromise);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowPlugins(bool* aAllowPlugins) {
+  NS_ENSURE_ARG_POINTER(aAllowPlugins);
+
+  *aAllowPlugins = mBrowsingContext->GetAllowPlugins();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowPlugins(bool aAllowPlugins) {
+  // XXX should enable or disable a plugin host
+  return mBrowsingContext->SetAllowPlugins(aAllowPlugins);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCssErrorReportingEnabled(bool* aEnabled) {
+  MOZ_ASSERT(aEnabled);
+  *aEnabled = mCSSErrorReportingEnabled;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetCssErrorReportingEnabled(bool aEnabled) {
+  mCSSErrorReportingEnabled = aEnabled;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetUsePrivateBrowsing(bool* aUsePrivateBrowsing) {
+  NS_ENSURE_ARG_POINTER(aUsePrivateBrowsing);
+  return mBrowsingContext->GetUsePrivateBrowsing(aUsePrivateBrowsing);
+}
+
+void nsDocShell::NotifyPrivateBrowsingChanged() {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mPrivacyObservers);
+  while (iter.HasMore()) {
+    nsWeakPtr ref = iter.GetNext();
+    nsCOMPtr<nsIPrivacyTransitionObserver> obs = do_QueryReferent(ref);
+    if (!obs) {
+      iter.Remove();
+    } else {
+      obs->PrivateModeChanged(UsePrivateBrowsing());
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::SetUsePrivateBrowsing(bool aUsePrivateBrowsing) {
+  return mBrowsingContext->SetUsePrivateBrowsing(aUsePrivateBrowsing);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetPrivateBrowsing(bool aUsePrivateBrowsing) {
+  return mBrowsingContext->SetPrivateBrowsing(aUsePrivateBrowsing);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetHasLoadedNonBlankURI(bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+
+  *aResult = mHasLoadedNonBlankURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetUseRemoteTabs(bool* aUseRemoteTabs) {
+  NS_ENSURE_ARG_POINTER(aUseRemoteTabs);
+  return mBrowsingContext->GetUseRemoteTabs(aUseRemoteTabs);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetRemoteTabs(bool aUseRemoteTabs) {
+  return mBrowsingContext->SetRemoteTabs(aUseRemoteTabs);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetUseRemoteSubframes(bool* aUseRemoteSubframes) {
+  NS_ENSURE_ARG_POINTER(aUseRemoteSubframes);
+  return mBrowsingContext->GetUseRemoteSubframes(aUseRemoteSubframes);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetRemoteSubframes(bool aUseRemoteSubframes) {
+  return mBrowsingContext->SetRemoteSubframes(aUseRemoteSubframes);
+}
+
+NS_IMETHODIMP
+nsDocShell::AddWeakPrivacyTransitionObserver(
+    nsIPrivacyTransitionObserver* aObserver) {
+  nsWeakPtr weakObs = do_GetWeakReference(aObserver);
+  if (!weakObs) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  mPrivacyObservers.AppendElement(weakObs);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::AddWeakReflowObserver(nsIReflowObserver* aObserver) {
+  nsWeakPtr weakObs = do_GetWeakReference(aObserver);
+  if (!weakObs) {
+    return NS_ERROR_FAILURE;
+  }
+  mReflowObservers.AppendElement(weakObs);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::RemoveWeakReflowObserver(nsIReflowObserver* aObserver) {
+  nsWeakPtr obs = do_GetWeakReference(aObserver);
+  return mReflowObservers.RemoveElement(obs) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsDocShell::NotifyReflowObservers(bool aInterruptible,
+                                  DOMHighResTimeStamp aStart,
+                                  DOMHighResTimeStamp aEnd) {
+  nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mReflowObservers);
+  while (iter.HasMore()) {
+    nsWeakPtr ref = iter.GetNext();
+    nsCOMPtr<nsIReflowObserver> obs = do_QueryReferent(ref);
+    if (!obs) {
+      iter.Remove();
+    } else if (aInterruptible) {
+      obs->ReflowInterruptible(aStart, aEnd);
+    } else {
+      obs->Reflow(aStart, aEnd);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowMetaRedirects(bool* aReturn) {
+  NS_ENSURE_ARG_POINTER(aReturn);
+
+  *aReturn = mAllowMetaRedirects;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowMetaRedirects(bool aValue) {
+  mAllowMetaRedirects = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowSubframes(bool* aAllowSubframes) {
+  NS_ENSURE_ARG_POINTER(aAllowSubframes);
+
+  *aAllowSubframes = mAllowSubframes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowSubframes(bool aAllowSubframes) {
+  mAllowSubframes = aAllowSubframes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowImages(bool* aAllowImages) {
+  NS_ENSURE_ARG_POINTER(aAllowImages);
+
+  *aAllowImages = mAllowImages;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowImages(bool aAllowImages) {
+  mAllowImages = aAllowImages;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowMedia(bool* aAllowMedia) {
+  *aAllowMedia = mAllowMedia;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowMedia(bool aAllowMedia) {
+  mAllowMedia = aAllowMedia;
+
+  // Mute or unmute audio contexts attached to the inner window.
+  if (mScriptGlobal) {
+    if (nsPIDOMWindowInner* innerWin = mScriptGlobal->GetCurrentInnerWindow()) {
+      if (aAllowMedia) {
+        innerWin->UnmuteAudioContexts();
+      } else {
+        innerWin->MuteAudioContexts();
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowDNSPrefetch(bool* aAllowDNSPrefetch) {
+  *aAllowDNSPrefetch = mAllowDNSPrefetch;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowDNSPrefetch(bool aAllowDNSPrefetch) {
+  mAllowDNSPrefetch = aAllowDNSPrefetch;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowWindowControl(bool* aAllowWindowControl) {
+  *aAllowWindowControl = mAllowWindowControl;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowWindowControl(bool aAllowWindowControl) {
+  mAllowWindowControl = aAllowWindowControl;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowContentRetargeting(bool* aAllowContentRetargeting) {
+  *aAllowContentRetargeting = mBrowsingContext->GetAllowContentRetargeting();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowContentRetargeting(bool aAllowContentRetargeting) {
+  BrowsingContext::Transaction txn;
+  txn.SetAllowContentRetargeting(aAllowContentRetargeting);
+  txn.SetAllowContentRetargetingOnChildren(aAllowContentRetargeting);
+  return txn.Commit(mBrowsingContext);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowContentRetargetingOnChildren(
+    bool* aAllowContentRetargetingOnChildren) {
+  *aAllowContentRetargetingOnChildren =
+      mBrowsingContext->GetAllowContentRetargetingOnChildren();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowContentRetargetingOnChildren(
+    bool aAllowContentRetargetingOnChildren) {
+  return mBrowsingContext->SetAllowContentRetargetingOnChildren(
+      aAllowContentRetargetingOnChildren);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetMayEnableCharacterEncodingMenu(
+    bool* aMayEnableCharacterEncodingMenu) {
+  *aMayEnableCharacterEncodingMenu = false;
+  if (!mContentViewer) {
+    return NS_OK;
+  }
+  Document* doc = mContentViewer->GetDocument();
+  if (!doc) {
+    return NS_OK;
+  }
+  if (doc->WillIgnoreCharsetOverride()) {
+    return NS_OK;
+  }
+
+  *aMayEnableCharacterEncodingMenu = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllDocShellsInSubtree(int32_t aItemType,
+                                     DocShellEnumeratorDirection aDirection,
+                                     nsTArray<RefPtr<nsIDocShell>>& aResult) {
+  aResult.Clear();
+
+  nsDocShellEnumerator docShellEnum(
+      (aDirection == ENUMERATE_FORWARDS)
+          ? nsDocShellEnumerator::EnumerationDirection::Forwards
+          : nsDocShellEnumerator::EnumerationDirection::Backwards,
+      aItemType, *this);
+
+  nsresult rv = docShellEnum.BuildDocShellArray(aResult);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAppType(AppType* aAppType) {
+  *aAppType = mAppType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAppType(AppType aAppType) {
+  mAppType = aAppType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAllowAuth(bool* aAllowAuth) {
+  *aAllowAuth = mAllowAuth;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetAllowAuth(bool aAllowAuth) {
+  mAllowAuth = aAllowAuth;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetZoom(float* aZoom) {
+  NS_ENSURE_ARG_POINTER(aZoom);
+  *aZoom = 1.0f;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetZoom(float aZoom) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsDocShell::GetBusyFlags(BusyFlags* aBusyFlags) {
+  NS_ENSURE_ARG_POINTER(aBusyFlags);
+
+  *aBusyFlags = mBusyFlags;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::TabToTreeOwner(bool aForward, bool aForDocumentNavigation,
+                           bool* aTookFocus) {
+  NS_ENSURE_ARG_POINTER(aTookFocus);
+
+  nsCOMPtr<nsIWebBrowserChromeFocus> chromeFocus = do_GetInterface(mTreeOwner);
+  if (chromeFocus) {
+    if (aForward) {
+      *aTookFocus =
+          NS_SUCCEEDED(chromeFocus->FocusNextElement(aForDocumentNavigation));
+    } else {
+      *aTookFocus =
+          NS_SUCCEEDED(chromeFocus->FocusPrevElement(aForDocumentNavigation));
+    }
+  } else {
+    *aTookFocus = false;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetLoadURIDelegate(nsILoadURIDelegate** aLoadURIDelegate) {
+  nsCOMPtr<nsILoadURIDelegate> delegate = GetLoadURIDelegate();
+  delegate.forget(aLoadURIDelegate);
+  return NS_OK;
+}
+
+already_AddRefed<nsILoadURIDelegate> nsDocShell::GetLoadURIDelegate() {
+  if (nsCOMPtr<nsILoadURIDelegate> result =
+          do_QueryActor("LoadURIDelegate", GetDocument())) {
+    return result.forget();
+  }
+
+  return nullptr;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetUseErrorPages(bool* aUseErrorPages) {
+  *aUseErrorPages = mBrowsingContext->GetUseErrorPages();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetUseErrorPages(bool aUseErrorPages) {
+  return mBrowsingContext->SetUseErrorPages(aUseErrorPages);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetPreviousEntryIndex(int32_t* aPreviousEntryIndex) {
+  *aPreviousEntryIndex = mPreviousEntryIndex;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetLoadedEntryIndex(int32_t* aLoadedEntryIndex) {
+  *aLoadedEntryIndex = mLoadedEntryIndex;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::HistoryPurged(int32_t aNumEntries) {
+  // These indices are used for fastback cache eviction, to determine
+  // which session history entries are candidates for content viewer
+  // eviction.  We need to adjust by the number of entries that we
+  // just purged from history, so that we look at the right session history
+  // entries during eviction.
+  mPreviousEntryIndex = std::max(-1, mPreviousEntryIndex - aNumEntries);
+  mLoadedEntryIndex = std::max(0, mLoadedEntryIndex - aNumEntries);
+
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> shell = do_QueryObject(child);
+    if (shell) {
+      shell->HistoryPurged(aNumEntries);
+    }
+  }
+
+  return NS_OK;
+}
+
+void nsDocShell::TriggerParentCheckDocShellIsEmpty() {
+  if (RefPtr<nsDocShell> parent = GetInProcessParentDocshell()) {
+    parent->DocLoaderIsEmpty(true);
+  }
+  if (GetBrowsingContext()->IsContentSubframe() &&
+      !GetBrowsingContext()->GetParent()->IsInProcess()) {
+    if (BrowserChild* browserChild = BrowserChild::GetFrom(this)) {
+      mozilla::Unused << browserChild->SendMaybeFireEmbedderLoadEvents(
+          EmbedderElementEventType::NoEvent);
+    }
+  }
+}
+
+nsresult nsDocShell::HistoryEntryRemoved(int32_t aIndex) {
+  // These indices are used for fastback cache eviction, to determine
+  // which session history entries are candidates for content viewer
+  // eviction.  We need to adjust by the number of entries that we
+  // just purged from history, so that we look at the right session history
+  // entries during eviction.
+  if (aIndex == mPreviousEntryIndex) {
+    mPreviousEntryIndex = -1;
+  } else if (aIndex < mPreviousEntryIndex) {
+    --mPreviousEntryIndex;
+  }
+  if (mLoadedEntryIndex == aIndex) {
+    mLoadedEntryIndex = 0;
+  } else if (aIndex < mLoadedEntryIndex) {
+    --mLoadedEntryIndex;
+  }
+
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> shell = do_QueryObject(child);
+    if (shell) {
+      static_cast<nsDocShell*>(shell.get())->HistoryEntryRemoved(aIndex);
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetRecordProfileTimelineMarkers(bool aValue) {
+  bool currentValue = nsIDocShell::GetRecordProfileTimelineMarkers();
+  if (currentValue == aValue) {
+    return NS_OK;
+  }
+
+  if (aValue) {
+    MOZ_ASSERT(!TimelineConsumers::HasConsumer(this));
+    TimelineConsumers::AddConsumer(this);
+    MOZ_ASSERT(TimelineConsumers::HasConsumer(this));
+    UseEntryScriptProfiling();
+  } else {
+    MOZ_ASSERT(TimelineConsumers::HasConsumer(this));
+    TimelineConsumers::RemoveConsumer(this);
+    MOZ_ASSERT(!TimelineConsumers::HasConsumer(this));
+    UnuseEntryScriptProfiling();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetRecordProfileTimelineMarkers(bool* aValue) {
+  *aValue = !!mObserved;
+  return NS_OK;
+}
+
+nsresult nsDocShell::PopProfileTimelineMarkers(
+    JSContext* aCx, JS::MutableHandle<JS::Value> aOut) {
+  nsTArray<dom::ProfileTimelineMarker> store;
+  SequenceRooter<dom::ProfileTimelineMarker> rooter(aCx, &store);
+
+  TimelineConsumers::PopMarkers(this, aCx, store);
+
+  if (!ToJSValue(aCx, store, aOut)) {
+    JS_ClearPendingException(aCx);
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::Now(DOMHighResTimeStamp* aWhen) {
+  *aWhen = (TimeStamp::Now() - TimeStamp::ProcessCreation()).ToMilliseconds();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetWindowDraggingAllowed(bool aValue) {
+  RefPtr<nsDocShell> parent = GetInProcessParentDocshell();
+  if (!aValue && mItemType == typeChrome && !parent) {
+    // Window dragging is always allowed for top level
+    // chrome docshells.
+    return NS_ERROR_FAILURE;
+  }
+  mWindowDraggingAllowed = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetWindowDraggingAllowed(bool* aValue) {
+  // window dragging regions in CSS (-moz-window-drag:drag)
+  // can be slow. Default behavior is to only allow it for
+  // chrome top level windows.
+  RefPtr<nsDocShell> parent = GetInProcessParentDocshell();
+  if (mItemType == typeChrome && !parent) {
+    // Top level chrome window
+    *aValue = true;
+  } else {
+    *aValue = mWindowDraggingAllowed;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCurrentDocumentChannel(nsIChannel** aResult) {
+  NS_IF_ADDREF(*aResult = GetCurrentDocChannel());
+  return NS_OK;
+}
+
+nsIChannel* nsDocShell::GetCurrentDocChannel() {
+  if (mContentViewer) {
+    Document* doc = mContentViewer->GetDocument();
+    if (doc) {
+      return doc->GetChannel();
+    }
+  }
+  return nullptr;
+}
+
+NS_IMETHODIMP
+nsDocShell::AddWeakScrollObserver(nsIScrollObserver* aObserver) {
+  nsWeakPtr weakObs = do_GetWeakReference(aObserver);
+  if (!weakObs) {
+    return NS_ERROR_FAILURE;
+  }
+  mScrollObservers.AppendElement(weakObs);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::RemoveWeakScrollObserver(nsIScrollObserver* aObserver) {
+  nsWeakPtr obs = do_GetWeakReference(aObserver);
+  return mScrollObservers.RemoveElement(obs) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+void nsDocShell::NotifyAsyncPanZoomStarted() {
+  nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mScrollObservers);
+  while (iter.HasMore()) {
+    nsWeakPtr ref = iter.GetNext();
+    nsCOMPtr<nsIScrollObserver> obs = do_QueryReferent(ref);
+    if (obs) {
+      obs->AsyncPanZoomStarted();
+    } else {
+      iter.Remove();
+    }
+  }
+}
+
+void nsDocShell::NotifyAsyncPanZoomStopped() {
+  nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mScrollObservers);
+  while (iter.HasMore()) {
+    nsWeakPtr ref = iter.GetNext();
+    nsCOMPtr<nsIScrollObserver> obs = do_QueryReferent(ref);
+    if (obs) {
+      obs->AsyncPanZoomStopped();
+    } else {
+      iter.Remove();
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::NotifyScrollObservers() {
+  nsTObserverArray<nsWeakPtr>::ForwardIterator iter(mScrollObservers);
+  while (iter.HasMore()) {
+    nsWeakPtr ref = iter.GetNext();
+    nsCOMPtr<nsIScrollObserver> obs = do_QueryReferent(ref);
+    if (obs) {
+      obs->ScrollPositionChanged();
+    } else {
+      iter.Remove();
+    }
+  }
+  return NS_OK;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIDocShellTreeItem
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::GetName(nsAString& aName) {
+  aName = mBrowsingContext->Name();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetName(const nsAString& aName) {
+  return mBrowsingContext->SetName(aName);
+}
+
+NS_IMETHODIMP
+nsDocShell::NameEquals(const nsAString& aName, bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = mBrowsingContext->NameEquals(aName);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCustomUserAgent(nsAString& aCustomUserAgent) {
+  mBrowsingContext->GetCustomUserAgent(aCustomUserAgent);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetCustomUserAgent(const nsAString& aCustomUserAgent) {
+  if (mWillChangeProcess) {
+    NS_WARNING("SetCustomUserAgent: Process is changing. Ignoring set");
+    return NS_ERROR_FAILURE;
+  }
+
+  return mBrowsingContext->SetCustomUserAgent(aCustomUserAgent);
+}
+
+NS_IMETHODIMP
+nsDocShell::ClearCachedPlatform() {
+  RefPtr<nsGlobalWindowInner> win =
+      mScriptGlobal ? mScriptGlobal->GetCurrentInnerWindowInternal() : nullptr;
+  if (win) {
+    Navigator* navigator = win->Navigator();
+    if (navigator) {
+      navigator->ClearPlatformCache();
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::ClearCachedUserAgent() {
+  RefPtr<nsGlobalWindowInner> win =
+      mScriptGlobal ? mScriptGlobal->GetCurrentInnerWindowInternal() : nullptr;
+  if (win) {
+    Navigator* navigator = win->Navigator();
+    if (navigator) {
+      navigator->ClearUserAgentCache();
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetMetaViewportOverride(
+    MetaViewportOverride* aMetaViewportOverride) {
+  NS_ENSURE_ARG_POINTER(aMetaViewportOverride);
+
+  *aMetaViewportOverride = mMetaViewportOverride;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetMetaViewportOverride(
+    MetaViewportOverride aMetaViewportOverride) {
+  // We don't have a way to verify this coming from Javascript, so this check is
+  // still needed.
+  if (!(aMetaViewportOverride == META_VIEWPORT_OVERRIDE_NONE ||
+        aMetaViewportOverride == META_VIEWPORT_OVERRIDE_ENABLED ||
+        aMetaViewportOverride == META_VIEWPORT_OVERRIDE_DISABLED)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mMetaViewportOverride = aMetaViewportOverride;
+
+  // Inform our presShell that it needs to re-check its need for a viewport
+  // override.
+  if (RefPtr<PresShell> presShell = GetPresShell()) {
+    presShell->MaybeRecreateMobileViewportManager(true);
+  }
+
+  return NS_OK;
+}
+
+/* virtual */
+int32_t nsDocShell::ItemType() { return mItemType; }
+
+NS_IMETHODIMP
+nsDocShell::GetItemType(int32_t* aItemType) {
+  NS_ENSURE_ARG_POINTER(aItemType);
+
+  MOZ_DIAGNOSTIC_ASSERT(
+      (mBrowsingContext->IsContent() ? typeContent : typeChrome) == mItemType);
+  *aItemType = mItemType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessParent(nsIDocShellTreeItem** aParent) {
+  if (!mParent) {
+    *aParent = nullptr;
+  } else {
+    CallQueryInterface(mParent, aParent);
+  }
+  // Note that in the case when the parent is not an nsIDocShellTreeItem we
+  // don't want to throw; we just want to return null.
+  return NS_OK;
+}
+
+// With Fission, related nsDocShell objects may exist in a different process. In
+// that case, this method will return `nullptr`, despite a parent nsDocShell
+// object existing.
+//
+// Prefer using `BrowsingContext::Parent()`, which will succeed even if the
+// parent entry is not in the current process, and handle the case where the
+// parent nsDocShell is inaccessible.
+already_AddRefed<nsDocShell> nsDocShell::GetInProcessParentDocshell() {
+  nsCOMPtr<nsIDocShell> docshell = do_QueryInterface(GetAsSupports(mParent));
+  return docshell.forget().downcast<nsDocShell>();
+}
+
+void nsDocShell::MaybeCreateInitialClientSource(nsIPrincipal* aPrincipal) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  // If there is an existing document then there is no need to create
+  // a client for a future initial about:blank document.
+  if (mScriptGlobal && mScriptGlobal->GetCurrentInnerWindowInternal() &&
+      mScriptGlobal->GetCurrentInnerWindowInternal()->GetExtantDoc()) {
+    MOZ_DIAGNOSTIC_ASSERT(mScriptGlobal->GetCurrentInnerWindowInternal()
+                              ->GetClientInfo()
+                              .isSome());
+    MOZ_DIAGNOSTIC_ASSERT(!mInitialClientSource);
+    return;
+  }
+
+  // Don't recreate the initial client source.  We call this multiple times
+  // when DoChannelLoad() is called before CreateAboutBlankContentViewer.
+  if (mInitialClientSource) {
+    return;
+  }
+
+  // Don't pre-allocate the client when we are sandboxed.  The inherited
+  // principal does not take sandboxing into account.
+  // TODO: Refactor sandboxing principal code out so we can use it here.
+  if (!aPrincipal && mBrowsingContext->GetSandboxFlags()) {
+    return;
+  }
+
+  // We cannot get inherited foreign partitioned principal here. Instead, we
+  // directly check which principal we want to inherit for the service worker.
+  nsIPrincipal* principal =
+      aPrincipal
+          ? aPrincipal
+          : GetInheritedPrincipal(
+                false, StoragePrincipalHelper::
+                           ShouldUsePartitionPrincipalForServiceWorker(this));
+
+  // Sometimes there is no principal available when we are called from
+  // CreateAboutBlankContentViewer.  For example, sometimes the principal
+  // is only extracted from the load context after the document is created
+  // in Document::ResetToURI().  Ideally we would do something similar
+  // here, but for now lets just avoid the issue by not preallocating the
+  // client.
+  if (!principal) {
+    return;
+  }
+
+  nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+  if (!win) {
+    return;
+  }
+
+  mInitialClientSource = ClientManager::CreateSource(
+      ClientType::Window, win->EventTargetFor(TaskCategory::Other), principal);
+  MOZ_DIAGNOSTIC_ASSERT(mInitialClientSource);
+
+  // Mark the initial client as execution ready, but owned by the docshell.
+  // If the client is actually used this will cause ClientSource to force
+  // the creation of the initial about:blank by calling
+  // nsDocShell::GetDocument().
+  mInitialClientSource->DocShellExecutionReady(this);
+
+  // Next, check to see if the parent is controlled.
+  nsCOMPtr<nsIDocShell> parent = GetInProcessParentDocshell();
+  nsPIDOMWindowOuter* parentOuter = parent ? parent->GetWindow() : nullptr;
+  nsPIDOMWindowInner* parentInner =
+      parentOuter ? parentOuter->GetCurrentInnerWindow() : nullptr;
+  if (!parentInner) {
+    return;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  MOZ_ALWAYS_SUCCEEDS(NS_NewURI(getter_AddRefs(uri), "about:blank"_ns));
+
+  // We're done if there is no parent controller or if this docshell
+  // is not permitted to control for some reason.
+  Maybe<ServiceWorkerDescriptor> controller(parentInner->GetController());
+  if (controller.isNothing() ||
+      !ServiceWorkerAllowedToControlWindow(principal, uri)) {
+    return;
+  }
+
+  mInitialClientSource->InheritController(controller.ref());
+}
+
+Maybe<ClientInfo> nsDocShell::GetInitialClientInfo() const {
+  if (mInitialClientSource) {
+    Maybe<ClientInfo> result;
+    result.emplace(mInitialClientSource->Info());
+    return result;
+  }
+
+  nsGlobalWindowInner* innerWindow =
+      mScriptGlobal ? mScriptGlobal->GetCurrentInnerWindowInternal() : nullptr;
+  Document* doc = innerWindow ? innerWindow->GetExtantDoc() : nullptr;
+
+  if (!doc || !doc->IsInitialDocument()) {
+    return Maybe<ClientInfo>();
+  }
+
+  return innerWindow->GetClientInfo();
+}
+
+nsresult nsDocShell::SetDocLoaderParent(nsDocLoader* aParent) {
+  bool wasFrame = IsSubframe();
+
+  nsresult rv = nsDocLoader::SetDocLoaderParent(aParent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsISupportsPriority> priorityGroup = do_QueryInterface(mLoadGroup);
+  if (wasFrame != IsSubframe() && priorityGroup) {
+    priorityGroup->AdjustPriority(wasFrame ? -1 : 1);
+  }
+
+  // Curse ambiguous nsISupports inheritance!
+  nsISupports* parent = GetAsSupports(aParent);
+
+  // If parent is another docshell, we inherit all their flags for
+  // allowing plugins, scripting etc.
+  bool value;
+  nsCOMPtr<nsIDocShell> parentAsDocShell(do_QueryInterface(parent));
+
+  if (parentAsDocShell) {
+    if (mAllowMetaRedirects &&
+        NS_SUCCEEDED(parentAsDocShell->GetAllowMetaRedirects(&value))) {
+      SetAllowMetaRedirects(value);
+    }
+    if (mAllowSubframes &&
+        NS_SUCCEEDED(parentAsDocShell->GetAllowSubframes(&value))) {
+      SetAllowSubframes(value);
+    }
+    if (mAllowImages &&
+        NS_SUCCEEDED(parentAsDocShell->GetAllowImages(&value))) {
+      SetAllowImages(value);
+    }
+    SetAllowMedia(parentAsDocShell->GetAllowMedia() && mAllowMedia);
+    if (mAllowWindowControl &&
+        NS_SUCCEEDED(parentAsDocShell->GetAllowWindowControl(&value))) {
+      SetAllowWindowControl(value);
+    }
+    if (NS_FAILED(parentAsDocShell->GetAllowDNSPrefetch(&value))) {
+      value = false;
+    }
+    SetAllowDNSPrefetch(mAllowDNSPrefetch && value);
+
+    // We don't need to inherit metaViewportOverride, because the viewport
+    // is only relevant for the outermost nsDocShell, not for any iframes
+    // like this that might be embedded within it.
+  }
+
+  nsCOMPtr<nsIURIContentListener> parentURIListener(do_GetInterface(parent));
+  if (parentURIListener) {
+    mContentListener->SetParentContentListener(parentURIListener);
+  }
+
+  return NS_OK;
+}
+
+void nsDocShell::MaybeRestoreWindowName() {
+  if (!StaticPrefs::privacy_window_name_update_enabled()) {
+    return;
+  }
+
+  // We only restore window.name for the top-level content.
+  if (!mBrowsingContext->IsTopContent()) {
+    return;
+  }
+
+  nsAutoString name;
+
+  // Following implements https://html.spec.whatwg.org/#history-traversal:
+  // Step 4.4. Check if the loading entry has a name.
+
+  if (mLSHE) {
+    mLSHE->GetName(name);
+  }
+
+  if (mLoadingEntry) {
+    name = mLoadingEntry->mInfo.GetName();
+  }
+
+  if (name.IsEmpty()) {
+    return;
+  }
+
+  // Step 4.4.1. Set the name to the browsing context.
+  Unused << mBrowsingContext->SetName(name);
+
+  // Step 4.4.2. Clear the name of all entries that are contiguous and
+  // same-origin with the loading entry.
+  if (mLSHE) {
+    nsSHistory::WalkContiguousEntries(
+        mLSHE, [](nsISHEntry* aEntry) { aEntry->SetName(EmptyString()); });
+  }
+
+  if (mLoadingEntry) {
+    // Clear the name of the session entry in the child side. For parent side,
+    // the clearing will be done when we commit the history to the parent.
+    mLoadingEntry->mInfo.SetName(EmptyString());
+  }
+}
+
+void nsDocShell::StoreWindowNameToSHEntries() {
+  MOZ_ASSERT(mBrowsingContext->IsTopContent());
+
+  nsAutoString name;
+  mBrowsingContext->GetName(name);
+
+  if (mOSHE) {
+    nsSHistory::WalkContiguousEntries(
+        mOSHE, [&](nsISHEntry* aEntry) { aEntry->SetName(name); });
+  }
+
+  if (mozilla::SessionHistoryInParent()) {
+    if (XRE_IsParentProcess()) {
+      SessionHistoryEntry* entry =
+          mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+      if (entry) {
+        nsSHistory::WalkContiguousEntries(
+            entry, [&](nsISHEntry* aEntry) { aEntry->SetName(name); });
+      }
+    } else {
+      // Ask parent process to store the name in entries.
+      mozilla::Unused
+          << ContentChild::GetSingleton()
+                 ->SendSessionHistoryEntryStoreWindowNameInContiguousEntries(
+                     mBrowsingContext, name);
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessSameTypeParent(nsIDocShellTreeItem** aParent) {
+  if (BrowsingContext* parentBC = mBrowsingContext->GetParent()) {
+    *aParent = do_AddRef(parentBC->GetDocShell()).take();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetSameTypeInProcessParentIgnoreBrowserBoundaries(
+    nsIDocShell** aParent) {
+  NS_ENSURE_ARG_POINTER(aParent);
+  *aParent = nullptr;
+
+  nsCOMPtr<nsIDocShellTreeItem> parent =
+      do_QueryInterface(GetAsSupports(mParent));
+  if (!parent) {
+    return NS_OK;
+  }
+
+  if (parent->ItemType() == mItemType) {
+    nsCOMPtr<nsIDocShell> parentDS = do_QueryInterface(parent);
+    parentDS.forget(aParent);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessRootTreeItem(nsIDocShellTreeItem** aRootTreeItem) {
+  NS_ENSURE_ARG_POINTER(aRootTreeItem);
+
+  RefPtr<nsDocShell> root = this;
+  RefPtr<nsDocShell> parent = root->GetInProcessParentDocshell();
+  while (parent) {
+    root = parent;
+    parent = root->GetInProcessParentDocshell();
+  }
+
+  root.forget(aRootTreeItem);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessSameTypeRootTreeItem(
+    nsIDocShellTreeItem** aRootTreeItem) {
+  NS_ENSURE_ARG_POINTER(aRootTreeItem);
+  *aRootTreeItem = static_cast<nsIDocShellTreeItem*>(this);
+
+  nsCOMPtr<nsIDocShellTreeItem> parent;
+  NS_ENSURE_SUCCESS(GetInProcessSameTypeParent(getter_AddRefs(parent)),
+                    NS_ERROR_FAILURE);
+  while (parent) {
+    *aRootTreeItem = parent;
+    NS_ENSURE_SUCCESS(
+        (*aRootTreeItem)->GetInProcessSameTypeParent(getter_AddRefs(parent)),
+        NS_ERROR_FAILURE);
+  }
+  NS_ADDREF(*aRootTreeItem);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetTreeOwner(nsIDocShellTreeOwner** aTreeOwner) {
+  NS_ENSURE_ARG_POINTER(aTreeOwner);
+
+  *aTreeOwner = mTreeOwner;
+  NS_IF_ADDREF(*aTreeOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetTreeOwner(nsIDocShellTreeOwner* aTreeOwner) {
+  if (mIsBeingDestroyed && aTreeOwner) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Don't automatically set the progress based on the tree owner for frames
+  if (!IsSubframe()) {
+    nsCOMPtr<nsIWebProgress> webProgress =
+        do_QueryInterface(GetAsSupports(this));
+
+    if (webProgress) {
+      nsCOMPtr<nsIWebProgressListener> oldListener =
+          do_QueryInterface(mTreeOwner);
+      nsCOMPtr<nsIWebProgressListener> newListener =
+          do_QueryInterface(aTreeOwner);
+
+      if (oldListener) {
+        webProgress->RemoveProgressListener(oldListener);
+      }
+
+      if (newListener) {
+        webProgress->AddProgressListener(newListener,
+                                         nsIWebProgress::NOTIFY_ALL);
+      }
+    }
+  }
+
+  mTreeOwner = aTreeOwner;  // Weak reference per API
+
+  for (auto* childDocLoader : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShellTreeItem> child = do_QueryObject(childDocLoader);
+    NS_ENSURE_TRUE(child, NS_ERROR_FAILURE);
+
+    if (child->ItemType() == mItemType) {
+      child->SetTreeOwner(aTreeOwner);
+    }
+  }
+
+  // If we're in the content process and have had a TreeOwner set on us, extract
+  // our BrowserChild actor. If we've already had our BrowserChild set, assert
+  // that it hasn't changed.
+  if (mTreeOwner && XRE_IsContentProcess()) {
+    nsCOMPtr<nsIBrowserChild> newBrowserChild = do_GetInterface(mTreeOwner);
+    MOZ_ASSERT(newBrowserChild,
+               "No BrowserChild actor for tree owner in Content!");
+
+    if (mBrowserChild) {
+      nsCOMPtr<nsIBrowserChild> oldBrowserChild =
+          do_QueryReferent(mBrowserChild);
+      MOZ_RELEASE_ASSERT(
+          oldBrowserChild == newBrowserChild,
+          "Cannot change BrowserChild during nsDocShell lifetime!");
+    } else {
+      mBrowserChild = do_GetWeakReference(newBrowserChild);
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetHistoryID(nsID& aID) {
+  aID = mBrowsingContext->GetHistoryID();
+  return NS_OK;
+}
+
+const nsID& nsDocShell::HistoryID() { return mBrowsingContext->GetHistoryID(); }
+
+NS_IMETHODIMP
+nsDocShell::GetIsInUnload(bool* aIsInUnload) {
+  *aIsInUnload = mFiredUnloadEvent;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessChildCount(int32_t* aChildCount) {
+  NS_ENSURE_ARG_POINTER(aChildCount);
+  *aChildCount = mChildList.Length();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::AddChild(nsIDocShellTreeItem* aChild) {
+  NS_ENSURE_ARG_POINTER(aChild);
+
+  RefPtr<nsDocLoader> childAsDocLoader = GetAsDocLoader(aChild);
+  NS_ENSURE_TRUE(childAsDocLoader, NS_ERROR_UNEXPECTED);
+
+  // Make sure we're not creating a loop in the docshell tree
+  nsDocLoader* ancestor = this;
+  do {
+    if (childAsDocLoader == ancestor) {
+      return NS_ERROR_ILLEGAL_VALUE;
+    }
+    ancestor = ancestor->GetParent();
+  } while (ancestor);
+
+  // Make sure to remove the child from its current parent.
+  nsDocLoader* childsParent = childAsDocLoader->GetParent();
+  if (childsParent) {
+    nsresult rv = childsParent->RemoveChildLoader(childAsDocLoader);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // Make sure to clear the treeowner in case this child is a different type
+  // from us.
+  aChild->SetTreeOwner(nullptr);
+
+  nsresult res = AddChildLoader(childAsDocLoader);
+  NS_ENSURE_SUCCESS(res, res);
+  NS_ASSERTION(!mChildList.IsEmpty(),
+               "child list must not be empty after a successful add");
+
+  /* Set the child's global history if the parent has one */
+  if (mBrowsingContext->GetUseGlobalHistory()) {
+    // childDocShell->SetUseGlobalHistory(true);
+    // this should be set through BC inherit
+    MOZ_ASSERT(aChild->GetBrowsingContext()->GetUseGlobalHistory());
+  }
+
+  if (aChild->ItemType() != mItemType) {
+    return NS_OK;
+  }
+
+  aChild->SetTreeOwner(mTreeOwner);
+
+  nsCOMPtr<nsIDocShell> childAsDocShell(do_QueryInterface(aChild));
+  if (!childAsDocShell) {
+    return NS_OK;
+  }
+
+  // charset, style-disabling, and zoom will be inherited in SetupNewViewer()
+
+  // Now take this document's charset and set the child's parentCharset field
+  // to it. We'll later use that field, in the loading process, for the
+  // charset choosing algorithm.
+  // If we fail, at any point, we just return NS_OK.
+  // This code has some performance impact. But this will be reduced when
+  // the current charset will finally be stored as an Atom, avoiding the
+  // alias resolution extra look-up.
+
+  // we are NOT going to propagate the charset is this Chrome's docshell
+  if (mItemType == nsIDocShellTreeItem::typeChrome) {
+    return NS_OK;
+  }
+
+  // get the parent's current charset
+  if (!mContentViewer) {
+    return NS_OK;
+  }
+  Document* doc = mContentViewer->GetDocument();
+  if (!doc) {
+    return NS_OK;
+  }
+
+  const Encoding* parentCS = doc->GetDocumentCharacterSet();
+  int32_t charsetSource = doc->GetDocumentCharacterSetSource();
+  // set the child's parentCharset
+  childAsDocShell->SetParentCharset(parentCS, charsetSource,
+                                    doc->NodePrincipal());
+
+  // printf("### 1 >>> Adding child. Parent CS = %s. ItemType = %d.\n",
+  //        NS_LossyConvertUTF16toASCII(parentCS).get(), mItemType);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::RemoveChild(nsIDocShellTreeItem* aChild) {
+  NS_ENSURE_ARG_POINTER(aChild);
+
+  RefPtr<nsDocLoader> childAsDocLoader = GetAsDocLoader(aChild);
+  NS_ENSURE_TRUE(childAsDocLoader, NS_ERROR_UNEXPECTED);
+
+  nsresult rv = RemoveChildLoader(childAsDocLoader);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aChild->SetTreeOwner(nullptr);
+
+  return nsDocLoader::AddDocLoaderAsChildOfRoot(childAsDocLoader);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetInProcessChildAt(int32_t aIndex, nsIDocShellTreeItem** aChild) {
+  NS_ENSURE_ARG_POINTER(aChild);
+
+  RefPtr<nsDocShell> child = GetInProcessChildAt(aIndex);
+  NS_ENSURE_TRUE(child, NS_ERROR_UNEXPECTED);
+
+  child.forget(aChild);
+
+  return NS_OK;
+}
+
+nsDocShell* nsDocShell::GetInProcessChildAt(int32_t aIndex) {
+#ifdef DEBUG
+  if (aIndex < 0) {
+    NS_WARNING("Negative index passed to GetChildAt");
+  } else if (static_cast<uint32_t>(aIndex) >= mChildList.Length()) {
+    NS_WARNING("Too large an index passed to GetChildAt");
+  }
+#endif
+
+  nsIDocumentLoader* child = ChildAt(aIndex);
+
+  // child may be nullptr here.
+  return static_cast<nsDocShell*>(child);
+}
+
+nsresult nsDocShell::AddChildSHEntry(nsISHEntry* aCloneRef,
+                                     nsISHEntry* aNewEntry,
+                                     int32_t aChildOffset, uint32_t aLoadType,
+                                     bool aCloneChildren) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  nsresult rv = NS_OK;
+
+  if (mLSHE && aLoadType != LOAD_PUSHSTATE) {
+    /* You get here if you are currently building a
+     * hierarchy ie.,you just visited a frameset page
+     */
+    if (NS_FAILED(mLSHE->ReplaceChild(aNewEntry))) {
+      rv = mLSHE->AddChild(aNewEntry, aChildOffset);
+    }
+  } else if (!aCloneRef) {
+    /* This is an initial load in some subframe.  Just append it if we can */
+    if (mOSHE) {
+      rv = mOSHE->AddChild(aNewEntry, aChildOffset, UseRemoteSubframes());
+    }
+  } else {
+    RefPtr<ChildSHistory> shistory = GetRootSessionHistory();
+    if (shistory) {
+      rv = shistory->LegacySHistory()->AddChildSHEntryHelper(
+          aCloneRef, aNewEntry, mBrowsingContext->Top(), aCloneChildren);
+    }
+  }
+  return rv;
+}
+
+nsresult nsDocShell::AddChildSHEntryToParent(nsISHEntry* aNewEntry,
+                                             int32_t aChildOffset,
+                                             bool aCloneChildren) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  /* You will get here when you are in a subframe and
+   * a new url has been loaded on you.
+   * The mOSHE in this subframe will be the previous url's
+   * mOSHE. This mOSHE will be used as the identification
+   * for this subframe in the  CloneAndReplace function.
+   */
+
+  // In this case, we will end up calling AddEntry, which increases the
+  // current index by 1
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (rootSH) {
+    mPreviousEntryIndex = rootSH->Index();
+  }
+
+  nsresult rv;
+  // XXX(farre): this is not Fission safe, expect errors. This never
+  // get's executed once session history in the parent is enabled.
+  nsCOMPtr<nsIDocShell> parent = do_QueryInterface(GetAsSupports(mParent), &rv);
+  NS_WARNING_ASSERTION(
+      parent || !UseRemoteSubframes(),
+      "Failed to add child session history entry! This will be resolved once "
+      "session history in the parent is enabled.");
+  if (parent) {
+    rv = nsDocShell::Cast(parent)->AddChildSHEntry(
+        mOSHE, aNewEntry, aChildOffset, mLoadType, aCloneChildren);
+  }
+
+  if (rootSH) {
+    mLoadedEntryIndex = rootSH->Index();
+
+    if (MOZ_UNLIKELY(MOZ_LOG_TEST(gPageCacheLog, LogLevel::Verbose))) {
+      MOZ_LOG(gPageCacheLog, LogLevel::Verbose,
+              ("Previous index: %d, Loaded index: %d", mPreviousEntryIndex,
+               mLoadedEntryIndex));
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCurrentSHEntry(nsISHEntry** aEntry, bool* aOSHE) {
+  *aOSHE = false;
+  *aEntry = nullptr;
+  if (mLSHE) {
+    NS_ADDREF(*aEntry = mLSHE);
+  } else if (mOSHE) {
+    NS_ADDREF(*aEntry = mOSHE);
+    *aOSHE = true;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsDocShell::SynchronizeLayoutHistoryState() {
+  if (mActiveEntry && mActiveEntry->GetLayoutHistoryState() &&
+      mBrowsingContext) {
+    if (XRE_IsContentProcess()) {
+      dom::ContentChild* contentChild = dom::ContentChild::GetSingleton();
+      if (contentChild) {
+        contentChild->SendSynchronizeLayoutHistoryState(
+            mBrowsingContext, mActiveEntry->GetLayoutHistoryState());
+      }
+    } else {
+      SessionHistoryEntry* entry =
+          mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+      if (entry) {
+        entry->SetLayoutHistoryState(mActiveEntry->GetLayoutHistoryState());
+      }
+    }
+    if (mLoadingEntry &&
+        mLoadingEntry->mInfo.SharedId() == mActiveEntry->SharedId()) {
+      mLoadingEntry->mInfo.SetLayoutHistoryState(
+          mActiveEntry->GetLayoutHistoryState());
+    }
+  }
+
+  return NS_OK;
+}
+
+void nsDocShell::SetLoadGroupDefaultLoadFlags(nsLoadFlags aLoadFlags) {
+  if (mLoadGroup) {
+    mLoadGroup->SetDefaultLoadFlags(aLoadFlags);
+  } else {
+    NS_WARNING(
+        "nsDocShell::SetLoadGroupDefaultLoadFlags has no loadGroup to "
+        "propagate the mode to");
+  }
+}
+
+nsIScriptGlobalObject* nsDocShell::GetScriptGlobalObject() {
+  NS_ENSURE_SUCCESS(EnsureScriptEnvironment(), nullptr);
+  return mScriptGlobal;
+}
+
+Document* nsDocShell::GetDocument() {
+  NS_ENSURE_SUCCESS(EnsureContentViewer(), nullptr);
+  return mContentViewer->GetDocument();
+}
+
+Document* nsDocShell::GetExtantDocument() {
+  return mContentViewer ? mContentViewer->GetDocument() : nullptr;
+}
+
+nsPIDOMWindowOuter* nsDocShell::GetWindow() {
+  if (NS_FAILED(EnsureScriptEnvironment())) {
+    return nullptr;
+  }
+  return mScriptGlobal;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDomWindow(mozIDOMWindowProxy** aWindow) {
+  NS_ENSURE_ARG_POINTER(aWindow);
+
+  nsresult rv = EnsureScriptEnvironment();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<nsGlobalWindowOuter> window = mScriptGlobal;
+  window.forget(aWindow);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetMessageManager(ContentFrameMessageManager** aMessageManager) {
+  RefPtr<ContentFrameMessageManager> mm;
+  if (RefPtr<BrowserChild> browserChild = BrowserChild::GetFrom(this)) {
+    mm = browserChild->GetMessageManager();
+  } else if (nsPIDOMWindowOuter* win = GetWindow()) {
+    mm = win->GetMessageManager();
+  }
+  mm.forget(aMessageManager);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetIsNavigating(bool* aOut) {
+  *aOut = mIsNavigating;
+  return NS_OK;
+}
+
+void nsDocShell::ClearFrameHistory(nsISHEntry* aEntry) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (!rootSH || !aEntry) {
+    return;
+  }
+
+  rootSH->LegacySHistory()->RemoveFrameEntries(aEntry);
+}
+
+//-------------------------------------
+//-- Helper Method for Print discovery
+//-------------------------------------
+bool nsDocShell::NavigationBlockedByPrinting(bool aDisplayErrorDialog) {
+  if (!mBrowsingContext->Top()->GetIsPrinting()) {
+    return false;
+  }
+  if (aDisplayErrorDialog) {
+    DisplayLoadError(NS_ERROR_DOCUMENT_IS_PRINTMODE, nullptr, nullptr, nullptr);
+  }
+  return true;
+}
+
+bool nsDocShell::IsNavigationAllowed(bool aDisplayPrintErrorDialog,
+                                     bool aCheckIfUnloadFired) {
+  bool isAllowed = !NavigationBlockedByPrinting(aDisplayPrintErrorDialog) &&
+                   (!aCheckIfUnloadFired || !mFiredUnloadEvent);
+  if (!isAllowed) {
+    return false;
+  }
+  if (!mContentViewer) {
+    return true;
+  }
+  bool firingBeforeUnload;
+  mContentViewer->GetBeforeUnloadFiring(&firingBeforeUnload);
+  return !firingBeforeUnload;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIWebNavigation
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::GetCanGoBack(bool* aCanGoBack) {
+  *aCanGoBack = false;
+  if (!IsNavigationAllowed(false)) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (rootSH) {
+    *aCanGoBack = rootSH->CanGo(-1);
+    MOZ_LOG(gSHLog, LogLevel::Verbose,
+            ("nsDocShell %p CanGoBack()->%d", this, *aCanGoBack));
+
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCanGoForward(bool* aCanGoForward) {
+  *aCanGoForward = false;
+  if (!IsNavigationAllowed(false)) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (rootSH) {
+    *aCanGoForward = rootSH->CanGo(1);
+    MOZ_LOG(gSHLog, LogLevel::Verbose,
+            ("nsDocShell %p CanGoForward()->%d", this, *aCanGoForward));
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsDocShell::GoBack(bool aRequireUserInteraction, bool aUserActivation) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  auto cleanupIsNavigating = MakeScopeExit([&]() { mIsNavigating = false; });
+  mIsNavigating = true;
+
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
+  ErrorResult rv;
+  rootSH->Go(-1, aRequireUserInteraction, aUserActivation, rv);
+  return rv.StealNSResult();
+}
+
+NS_IMETHODIMP
+nsDocShell::GoForward(bool aRequireUserInteraction, bool aUserActivation) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  auto cleanupIsNavigating = MakeScopeExit([&]() { mIsNavigating = false; });
+  mIsNavigating = true;
+
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
+  ErrorResult rv;
+  rootSH->Go(1, aRequireUserInteraction, aUserActivation, rv);
+  return rv.StealNSResult();
+}
+
+// XXX(nika): We may want to stop exposing this API in the child process? Going
+// to a specific index from multiple different processes could definitely race.
+NS_IMETHODIMP
+nsDocShell::GotoIndex(int32_t aIndex, bool aUserActivation) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  auto cleanupIsNavigating = MakeScopeExit([&]() { mIsNavigating = false; });
+  mIsNavigating = true;
+
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  NS_ENSURE_TRUE(rootSH, NS_ERROR_FAILURE);
+
+  ErrorResult rv;
+  rootSH->GotoIndex(aIndex, aIndex - rootSH->Index(), false, aUserActivation,
+                    rv);
+  return rv.StealNSResult();
+}
+
+nsresult nsDocShell::LoadURI(nsIURI* aURI,
+                             const LoadURIOptions& aLoadURIOptions) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+  RefPtr<nsDocShellLoadState> loadState;
+  nsresult rv = nsDocShellLoadState::CreateFromLoadURIOptions(
+      mBrowsingContext, aURI, aLoadURIOptions, getter_AddRefs(loadState));
+  MOZ_ASSERT(rv != NS_ERROR_MALFORMED_URI);
+  if (NS_FAILED(rv) || !loadState) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return LoadURI(loadState, true);
+}
+
+NS_IMETHODIMP
+nsDocShell::LoadURIFromScript(nsIURI* aURI,
+                              JS::Handle<JS::Value> aLoadURIOptions,
+                              JSContext* aCx) {
+  // generate dictionary for aLoadURIOptions and forward call
+  LoadURIOptions loadURIOptions;
+  if (!loadURIOptions.Init(aCx, aLoadURIOptions)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  return LoadURI(aURI, loadURIOptions);
+}
+
+nsresult nsDocShell::FixupAndLoadURIString(
+    const nsAString& aURIString, const LoadURIOptions& aLoadURIOptions) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  RefPtr<nsDocShellLoadState> loadState;
+  nsresult rv = nsDocShellLoadState::CreateFromLoadURIOptions(
+      mBrowsingContext, aURIString, aLoadURIOptions, getter_AddRefs(loadState));
+
+  uint32_t loadFlags = aLoadURIOptions.mLoadFlags;
+  if (NS_ERROR_MALFORMED_URI == rv) {
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("Creating an active entry on nsDocShell %p to %s (because "
+             "we're showing an error page)",
+             this, NS_ConvertUTF16toUTF8(aURIString).get()));
+
+    // We need to store a session history entry. We don't have a valid URI, so
+    // we use about:blank instead.
+    nsCOMPtr<nsIURI> uri;
+    MOZ_ALWAYS_SUCCEEDS(NS_NewURI(getter_AddRefs(uri), "about:blank"_ns));
+    nsCOMPtr<nsIPrincipal> triggeringPrincipal;
+    if (aLoadURIOptions.mTriggeringPrincipal) {
+      triggeringPrincipal = aLoadURIOptions.mTriggeringPrincipal;
+    } else {
+      triggeringPrincipal = nsContentUtils::GetSystemPrincipal();
+    }
+    if (mozilla::SessionHistoryInParent()) {
+      mActiveEntry = MakeUnique<SessionHistoryInfo>(
+          uri, triggeringPrincipal, nullptr, nullptr, nullptr,
+          nsLiteralCString("text/html"));
+      mBrowsingContext->SetActiveSessionHistoryEntry(
+          Nothing(), mActiveEntry.get(), MAKE_LOAD_TYPE(LOAD_NORMAL, loadFlags),
+          /* aUpdatedCacheKey = */ 0);
+    }
+    if (DisplayLoadError(rv, nullptr, PromiseFlatString(aURIString).get(),
+                         nullptr) &&
+        (loadFlags & LOAD_FLAGS_ERROR_LOAD_CHANGES_RV) != 0) {
+      return NS_ERROR_LOAD_SHOWED_ERRORPAGE;
+    }
+  }
+
+  if (NS_FAILED(rv) || !loadState) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return LoadURI(loadState, true);
+}
+
+NS_IMETHODIMP
+nsDocShell::FixupAndLoadURIStringFromScript(
+    const nsAString& aURIString, JS::Handle<JS::Value> aLoadURIOptions,
+    JSContext* aCx) {
+  // generate dictionary for aLoadURIOptions and forward call
+  LoadURIOptions loadURIOptions;
+  if (!loadURIOptions.Init(aCx, aLoadURIOptions)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  return FixupAndLoadURIString(aURIString, loadURIOptions);
+}
+
+void nsDocShell::UnblockEmbedderLoadEventForFailure(bool aFireFrameErrorEvent) {
+  // If we're not in a content frame, or are at a BrowsingContext tree boundary,
+  // such as the content-chrome boundary, don't fire the error event.
+  if (mBrowsingContext->IsTopContent() || mBrowsingContext->IsChrome()) {
+    return;
+  }
+
+  // If embedder is same-process, then unblocking the load event is already
+  // handled by nsDocLoader. Fire the error event on our embedder element if
+  // requested.
+  //
+  // XXX: Bug 1440212 is looking into potentially changing this behaviour to act
+  // more like the remote case when in-process.
+  RefPtr<Element> element = mBrowsingContext->GetEmbedderElement();
+  if (element) {
+    if (aFireFrameErrorEvent) {
+      if (RefPtr<nsFrameLoaderOwner> flo = do_QueryObject(element)) {
+        if (RefPtr<nsFrameLoader> fl = flo->GetFrameLoader()) {
+          fl->FireErrorEvent();
+        }
+      }
+    }
+    return;
+  }
+
+  // If we have a cross-process parent document, we must notify it that we no
+  // longer block its load event.  This is necessary for OOP sub-documents
+  // because error documents do not result in a call to
+  // SendMaybeFireEmbedderLoadEvents via any of the normal call paths.
+  // (Obviously, we must do this before any of the returns below.)
+  RefPtr<BrowserChild> browserChild = BrowserChild::GetFrom(this);
+  if (browserChild) {
+    mozilla::Unused << browserChild->SendMaybeFireEmbedderLoadEvents(
+        aFireFrameErrorEvent ? EmbedderElementEventType::ErrorEvent
+                             : EmbedderElementEventType::NoEvent);
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::DisplayLoadError(nsresult aError, nsIURI* aURI,
+                             const char16_t* aURL, nsIChannel* aFailedChannel,
+                             bool* aDisplayedErrorPage) {
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug,
+          ("DOCSHELL %p DisplayLoadError %s\n", this,
+           aURI ? aURI->GetSpecOrDefault().get() : ""));
+
+  *aDisplayedErrorPage = false;
+  // Get prompt and string bundle services
+  nsCOMPtr<nsIPrompt> prompter;
+  nsCOMPtr<nsIStringBundle> stringBundle;
+  GetPromptAndStringBundle(getter_AddRefs(prompter),
+                           getter_AddRefs(stringBundle));
+
+  NS_ENSURE_TRUE(stringBundle, NS_ERROR_FAILURE);
+  NS_ENSURE_TRUE(prompter, NS_ERROR_FAILURE);
+
+  const char* error = nullptr;
+  // The key used to select the appropriate error message from the properties
+  // file.
+  const char* errorDescriptionID = nullptr;
+  AutoTArray<nsString, 3> formatStrs;
+  bool addHostPort = false;
+  bool isBadStsCertError = false;
+  nsresult rv = NS_OK;
+  nsAutoString messageStr;
+  nsAutoCString cssClass;
+  nsAutoCString errorPage;
+
+  errorPage.AssignLiteral("neterror");
+
+  // Turn the error code into a human readable error message.
+  if (NS_ERROR_UNKNOWN_PROTOCOL == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    // Extract the schemes into a comma delimited list.
+    nsAutoCString scheme;
+    aURI->GetScheme(scheme);
+    CopyASCIItoUTF16(scheme, *formatStrs.AppendElement());
+    nsCOMPtr<nsINestedURI> nestedURI = do_QueryInterface(aURI);
+    while (nestedURI) {
+      nsCOMPtr<nsIURI> tempURI;
+      nsresult rv2;
+      rv2 = nestedURI->GetInnerURI(getter_AddRefs(tempURI));
+      if (NS_SUCCEEDED(rv2) && tempURI) {
+        tempURI->GetScheme(scheme);
+        formatStrs[0].AppendLiteral(", ");
+        AppendASCIItoUTF16(scheme, formatStrs[0]);
+      }
+      nestedURI = do_QueryInterface(tempURI);
+    }
+    error = "unknownProtocolFound";
+  } else if (NS_ERROR_FILE_NOT_FOUND == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    error = "fileNotFound";
+  } else if (NS_ERROR_FILE_ACCESS_DENIED == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    error = "fileAccessDenied";
+  } else if (NS_ERROR_UNKNOWN_HOST == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    // Get the host
+    nsAutoCString host;
+    nsCOMPtr<nsIURI> innermostURI = NS_GetInnermostURI(aURI);
+    innermostURI->GetHost(host);
+    CopyUTF8toUTF16(host, *formatStrs.AppendElement());
+    errorDescriptionID = "dnsNotFound2";
+    error = "dnsNotFound";
+  } else if (NS_ERROR_CONNECTION_REFUSED == aError ||
+             NS_ERROR_PROXY_BAD_GATEWAY == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    addHostPort = true;
+    error = "connectionFailure";
+  } else if (NS_ERROR_NET_INTERRUPT == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    addHostPort = true;
+    error = "netInterrupt";
+  } else if (NS_ERROR_NET_TIMEOUT == aError ||
+             NS_ERROR_PROXY_GATEWAY_TIMEOUT == aError ||
+             NS_ERROR_NET_TIMEOUT_EXTERNAL == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    // Get the host
+    nsAutoCString host;
+    aURI->GetHost(host);
+    CopyUTF8toUTF16(host, *formatStrs.AppendElement());
+    error = "netTimeout";
+  } else if (NS_ERROR_CSP_FRAME_ANCESTOR_VIOLATION == aError ||
+             NS_ERROR_CSP_FORM_ACTION_VIOLATION == aError ||
+             NS_ERROR_CSP_NAVIGATE_TO_VIOLATION == aError) {
+    // CSP error
+    cssClass.AssignLiteral("neterror");
+    error = "cspBlocked";
+  } else if (NS_ERROR_XFO_VIOLATION == aError) {
+    // XFO error
+    cssClass.AssignLiteral("neterror");
+    error = "xfoBlocked";
+  } else if (NS_ERROR_GET_MODULE(aError) == NS_ERROR_MODULE_SECURITY) {
+    nsCOMPtr<nsINSSErrorsService> nsserr =
+        do_GetService(NS_NSS_ERRORS_SERVICE_CONTRACTID);
+
+    uint32_t errorClass;
+    if (!nsserr || NS_FAILED(nsserr->GetErrorClass(aError, &errorClass))) {
+      errorClass = nsINSSErrorsService::ERROR_CLASS_SSL_PROTOCOL;
+    }
+
+    nsCOMPtr<nsITransportSecurityInfo> tsi;
+    if (aFailedChannel) {
+      aFailedChannel->GetSecurityInfo(getter_AddRefs(tsi));
+    }
+    if (tsi) {
+      uint32_t securityState;
+      tsi->GetSecurityState(&securityState);
+      if (securityState & nsIWebProgressListener::STATE_USES_SSL_3) {
+        error = "sslv3Used";
+        addHostPort = true;
+      } else if (securityState &
+                 nsIWebProgressListener::STATE_USES_WEAK_CRYPTO) {
+        error = "weakCryptoUsed";
+        addHostPort = true;
+      }
+    } else {
+      // No channel, let's obtain the generic error message
+      if (nsserr) {
+        nsserr->GetErrorMessage(aError, messageStr);
+      }
+    }
+    // We don't have a message string here anymore but DisplayLoadError
+    // requires a non-empty messageStr.
+    messageStr.Truncate();
+    messageStr.AssignLiteral(u" ");
+    if (errorClass == nsINSSErrorsService::ERROR_CLASS_BAD_CERT) {
+      error = "nssBadCert";
+
+      // If this is an HTTP Strict Transport Security host or a pinned host
+      // and the certificate is bad, don't allow overrides (RFC 6797 section
+      // 12.1).
+      bool isStsHost = false;
+      bool isPinnedHost = false;
+      OriginAttributes attrsForHSTS;
+      if (aFailedChannel) {
+        StoragePrincipalHelper::GetOriginAttributesForHSTS(aFailedChannel,
+                                                           attrsForHSTS);
+      } else {
+        attrsForHSTS = GetOriginAttributes();
+      }
+
+      if (XRE_IsParentProcess()) {
+        nsCOMPtr<nsISiteSecurityService> sss =
+            do_GetService(NS_SSSERVICE_CONTRACTID, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+        rv = sss->IsSecureURI(aURI, attrsForHSTS, &isStsHost);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } else {
+        mozilla::dom::ContentChild* cc =
+            mozilla::dom::ContentChild::GetSingleton();
+        cc->SendIsSecureURI(aURI, attrsForHSTS, &isStsHost);
+      }
+      nsCOMPtr<nsIPublicKeyPinningService> pkps =
+          do_GetService(NS_PKPSERVICE_CONTRACTID, &rv);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = pkps->HostHasPins(aURI, &isPinnedHost);
+
+      if (Preferences::GetBool("browser.xul.error_pages.expert_bad_cert",
+                               false)) {
+        cssClass.AssignLiteral("expertBadCert");
+      }
+
+      // HSTS/pinning takes precedence over the expert bad cert pref. We
+      // never want to show the "Add Exception" button for these sites.
+      // In the future we should differentiate between an HSTS host and a
+      // pinned host and display a more informative message to the user.
+      if (isStsHost || isPinnedHost) {
+        isBadStsCertError = true;
+        cssClass.AssignLiteral("badStsCert");
+      }
+
+      // See if an alternate cert error page is registered
+      nsAutoCString alternateErrorPage;
+      nsresult rv = Preferences::GetCString(
+          "security.alternate_certificate_error_page", alternateErrorPage);
+      if (NS_SUCCEEDED(rv)) {
+        errorPage.Assign(alternateErrorPage);
+      }
+    } else {
+      error = "nssFailure2";
+    }
+  } else if (NS_ERROR_PHISHING_URI == aError ||
+             NS_ERROR_MALWARE_URI == aError ||
+             NS_ERROR_UNWANTED_URI == aError ||
+             NS_ERROR_HARMFUL_URI == aError) {
+    nsAutoCString host;
+    aURI->GetHost(host);
+    CopyUTF8toUTF16(host, *formatStrs.AppendElement());
+
+    // Malware and phishing detectors may want to use an alternate error
+    // page, but if the pref's not set, we'll fall back on the standard page
+    nsAutoCString alternateErrorPage;
+    nsresult rv = Preferences::GetCString("urlclassifier.alternate_error_page",
+                                          alternateErrorPage);
+    if (NS_SUCCEEDED(rv)) {
+      errorPage.Assign(alternateErrorPage);
+    }
+
+    if (NS_ERROR_PHISHING_URI == aError) {
+      error = "deceptiveBlocked";
+    } else if (NS_ERROR_MALWARE_URI == aError) {
+      error = "malwareBlocked";
+    } else if (NS_ERROR_UNWANTED_URI == aError) {
+      error = "unwantedBlocked";
+    } else if (NS_ERROR_HARMFUL_URI == aError) {
+      error = "harmfulBlocked";
+    }
+
+    cssClass.AssignLiteral("blacklist");
+  } else if (NS_ERROR_CONTENT_CRASHED == aError) {
+    errorPage.AssignLiteral("tabcrashed");
+    error = "tabcrashed";
+
+    RefPtr<EventTarget> handler = mChromeEventHandler;
+    if (handler) {
+      nsCOMPtr<Element> element = do_QueryInterface(handler);
+      element->GetAttribute(u"crashedPageTitle"_ns, messageStr);
+    }
+
+    // DisplayLoadError requires a non-empty messageStr to proceed and call
+    // LoadErrorPage. If the page doesn't have a title, we will use a blank
+    // space which will be trimmed and thus treated as empty by the front-end.
+    if (messageStr.IsEmpty()) {
+      messageStr.AssignLiteral(u" ");
+    }
+  } else if (NS_ERROR_FRAME_CRASHED == aError) {
+    errorPage.AssignLiteral("framecrashed");
+    error = "framecrashed";
+    messageStr.AssignLiteral(u" ");
+  } else if (NS_ERROR_BUILDID_MISMATCH == aError) {
+    errorPage.AssignLiteral("restartrequired");
+    error = "restartrequired";
+
+    // DisplayLoadError requires a non-empty messageStr to proceed and call
+    // LoadErrorPage. If the page doesn't have a title, we will use a blank
+    // space which will be trimmed and thus treated as empty by the front-end.
+    if (messageStr.IsEmpty()) {
+      messageStr.AssignLiteral(u" ");
+    }
+  } else {
+    // Errors requiring simple formatting
+    switch (aError) {
+      case NS_ERROR_MALFORMED_URI:
+        // URI is malformed
+        error = "malformedURI";
+        errorDescriptionID = "malformedURI2";
+        break;
+      case NS_ERROR_REDIRECT_LOOP:
+        // Doc failed to load because the server generated too many redirects
+        error = "redirectLoop";
+        break;
+      case NS_ERROR_UNKNOWN_SOCKET_TYPE:
+        // Doc failed to load because PSM is not installed
+        error = "unknownSocketType";
+        break;
+      case NS_ERROR_NET_RESET:
+        // Doc failed to load because the server kept reseting the connection
+        // before we could read any data from it
+        error = "netReset";
+        break;
+      case NS_ERROR_DOCUMENT_NOT_CACHED:
+        // Doc failed to load because the cache does not contain a copy of
+        // the document.
+        error = "notCached";
+        break;
+      case NS_ERROR_OFFLINE:
+        // Doc failed to load because we are offline.
+        error = "netOffline";
+        break;
+      case NS_ERROR_DOCUMENT_IS_PRINTMODE:
+        // Doc navigation attempted while Printing or Print Preview
+        error = "isprinting";
+        break;
+      case NS_ERROR_PORT_ACCESS_NOT_ALLOWED:
+        // Port blocked for security reasons
+        addHostPort = true;
+        error = "deniedPortAccess";
+        break;
+      case NS_ERROR_UNKNOWN_PROXY_HOST:
+        // Proxy hostname could not be resolved.
+        error = "proxyResolveFailure";
+        break;
+      case NS_ERROR_PROXY_CONNECTION_REFUSED:
+      case NS_ERROR_PROXY_FORBIDDEN:
+      case NS_ERROR_PROXY_NOT_IMPLEMENTED:
+      case NS_ERROR_PROXY_AUTHENTICATION_FAILED:
+      case NS_ERROR_PROXY_TOO_MANY_REQUESTS:
+        // Proxy connection was refused.
+        error = "proxyConnectFailure";
+        break;
+      case NS_ERROR_INVALID_CONTENT_ENCODING:
+        // Bad Content Encoding.
+        error = "contentEncodingError";
+        break;
+      case NS_ERROR_UNSAFE_CONTENT_TYPE:
+        // Channel refused to load from an unrecognized content type.
+        error = "unsafeContentType";
+        break;
+      case NS_ERROR_CORRUPTED_CONTENT:
+        // Broken Content Detected. e.g. Content-MD5 check failure.
+        error = "corruptedContentErrorv2";
+        break;
+      case NS_ERROR_INTERCEPTION_FAILED:
+        // ServiceWorker intercepted request, but something went wrong.
+        error = "corruptedContentErrorv2";
+        break;
+      case NS_ERROR_NET_INADEQUATE_SECURITY:
+        // Server negotiated bad TLS for HTTP/2.
+        error = "inadequateSecurityError";
+        addHostPort = true;
+        break;
+      case NS_ERROR_BLOCKED_BY_POLICY:
+      case NS_ERROR_DOM_COOP_FAILED:
+      case NS_ERROR_DOM_COEP_FAILED:
+        // Page blocked by policy
+        error = "blockedByPolicy";
+        break;
+      case NS_ERROR_NET_HTTP2_SENT_GOAWAY:
+      case NS_ERROR_NET_HTTP3_PROTOCOL_ERROR:
+        // HTTP/2 or HTTP/3 stack detected a protocol error
+        error = "networkProtocolError";
+        break;
+
+      default:
+        break;
+    }
+  }
+
+  nsresult delegateErrorCode = aError;
+  // If the HTTPS-Only Mode upgraded this request and the upgrade might have
+  // caused this error, we replace the error-page with about:httpsonlyerror
+  if (nsHTTPSOnlyUtils::CouldBeHttpsOnlyError(aFailedChannel, aError)) {
+    errorPage.AssignLiteral("httpsonlyerror");
+    delegateErrorCode = NS_ERROR_HTTPS_ONLY;
+  } else if (isBadStsCertError) {
+    delegateErrorCode = NS_ERROR_BAD_HSTS_CERT;
+  }
+
+  if (nsCOMPtr<nsILoadURIDelegate> loadURIDelegate = GetLoadURIDelegate()) {
+    nsCOMPtr<nsIURI> errorPageURI;
+    rv = loadURIDelegate->HandleLoadError(
+        aURI, delegateErrorCode, NS_ERROR_GET_MODULE(delegateErrorCode),
+        getter_AddRefs(errorPageURI));
+    // If the docshell is going away there's no point in showing an error page.
+    if (NS_FAILED(rv) || mIsBeingDestroyed) {
+      *aDisplayedErrorPage = false;
+      return NS_OK;
+    }
+
+    if (errorPageURI) {
+      *aDisplayedErrorPage =
+          NS_SUCCEEDED(LoadErrorPage(errorPageURI, aURI, aFailedChannel));
+      return NS_OK;
+    }
+  }
+
+  // Test if the error should be displayed
+  if (!error) {
+    return NS_OK;
+  }
+
+  if (!errorDescriptionID) {
+    errorDescriptionID = error;
+  }
+
+  Telemetry::AccumulateCategoricalKeyed(
+      IsSubframe() ? "frame"_ns : "top"_ns,
+      mozilla::dom::LoadErrorToTelemetryLabel(aError));
+
+  // Test if the error needs to be formatted
+  if (!messageStr.IsEmpty()) {
+    // already obtained message
+  } else {
+    if (addHostPort) {
+      // Build up the host:port string.
+      nsAutoCString hostport;
+      if (aURI) {
+        aURI->GetHostPort(hostport);
+      } else {
+        hostport.Assign('?');
+      }
+      CopyUTF8toUTF16(hostport, *formatStrs.AppendElement());
+    }
+
+    nsAutoCString spec;
+    rv = NS_ERROR_NOT_AVAILABLE;
+    auto& nextFormatStr = *formatStrs.AppendElement();
+    if (aURI) {
+      // displaying "file://" is aesthetically unpleasing and could even be
+      // confusing to the user
+      if (SchemeIsFile(aURI)) {
+        aURI->GetPathQueryRef(spec);
+      } else {
+        aURI->GetSpec(spec);
+      }
+
+      nsCOMPtr<nsITextToSubURI> textToSubURI(
+          do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv));
+      if (NS_SUCCEEDED(rv)) {
+        rv = textToSubURI->UnEscapeURIForUI(spec, nextFormatStr);
+      }
+    } else {
+      spec.Assign('?');
+    }
+    if (NS_FAILED(rv)) {
+      CopyUTF8toUTF16(spec, nextFormatStr);
+    }
+    rv = NS_OK;
+
+    nsAutoString str;
+    rv =
+        stringBundle->FormatStringFromName(errorDescriptionID, formatStrs, str);
+    NS_ENSURE_SUCCESS(rv, rv);
+    messageStr.Assign(str);
+  }
+
+  // Display the error as a page or an alert prompt
+  NS_ENSURE_FALSE(messageStr.IsEmpty(), NS_ERROR_FAILURE);
+
+  if ((NS_ERROR_NET_INTERRUPT == aError || NS_ERROR_NET_RESET == aError) &&
+      SchemeIsHTTPS(aURI)) {
+    // Maybe TLS intolerant. Treat this as an SSL error.
+    error = "nssFailure2";
+  }
+
+  if (mBrowsingContext->GetUseErrorPages()) {
+    // Display an error page
+    nsresult loadedPage =
+        LoadErrorPage(aURI, aURL, errorPage.get(), error, messageStr.get(),
+                      cssClass.get(), aFailedChannel);
+    *aDisplayedErrorPage = NS_SUCCEEDED(loadedPage);
+  } else {
+    // The prompter reqires that our private window has a document (or it
+    // asserts). Satisfy that assertion now since GetDoc will force
+    // creation of one if it hasn't already been created.
+    if (mScriptGlobal) {
+      Unused << mScriptGlobal->GetDoc();
+    }
+
+    // Display a message box
+    prompter->Alert(nullptr, messageStr.get());
+  }
+
+  return NS_OK;
+}
+
+#define PREF_SAFEBROWSING_ALLOWOVERRIDE "browser.safebrowsing.allowOverride"
+
+nsresult nsDocShell::LoadErrorPage(nsIURI* aURI, const char16_t* aURL,
+                                   const char* aErrorPage,
+                                   const char* aErrorType,
+                                   const char16_t* aDescription,
+                                   const char* aCSSClass,
+                                   nsIChannel* aFailedChannel) {
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+#if defined(DEBUG)
+  if (MOZ_LOG_TEST(gDocShellLog, LogLevel::Debug)) {
+    nsAutoCString chanName;
+    if (aFailedChannel) {
+      aFailedChannel->GetName(chanName);
+    } else {
+      chanName.AssignLiteral("<no channel>");
+    }
+
+    MOZ_LOG(gDocShellLog, LogLevel::Debug,
+            ("nsDocShell[%p]::LoadErrorPage(\"%s\", \"%s\", {...}, [%s])\n",
+             this, aURI ? aURI->GetSpecOrDefault().get() : "",
+             NS_ConvertUTF16toUTF8(aURL).get(), chanName.get()));
+  }
+#endif
+
+  nsAutoCString url;
+  if (aURI) {
+    nsresult rv = aURI->GetSpec(url);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else if (aURL) {
+    CopyUTF16toUTF8(MakeStringSpan(aURL), url);
+  } else {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
+  // Create a URL to pass all the error information through to the page.
+
+#undef SAFE_ESCAPE
+#define SAFE_ESCAPE(output, input, params)             \
+  if (NS_WARN_IF(!NS_Escape(input, output, params))) { \
+    return NS_ERROR_OUT_OF_MEMORY;                     \
+  }
+
+  nsCString escapedUrl, escapedError, escapedDescription, escapedCSSClass;
+  SAFE_ESCAPE(escapedUrl, url, url_Path);
+  SAFE_ESCAPE(escapedError, nsDependentCString(aErrorType), url_Path);
+  SAFE_ESCAPE(escapedDescription, NS_ConvertUTF16toUTF8(aDescription),
+              url_Path);
+  if (aCSSClass) {
+    nsCString cssClass(aCSSClass);
+    SAFE_ESCAPE(escapedCSSClass, cssClass, url_Path);
+  }
+  nsCString errorPageUrl("about:");
+  errorPageUrl.AppendASCII(aErrorPage);
+  errorPageUrl.AppendLiteral("?e=");
+
+  errorPageUrl.AppendASCII(escapedError.get());
+  errorPageUrl.AppendLiteral("&u=");
+  errorPageUrl.AppendASCII(escapedUrl.get());
+  if ((strcmp(aErrorPage, "blocked") == 0) &&
+      Preferences::GetBool(PREF_SAFEBROWSING_ALLOWOVERRIDE, true)) {
+    errorPageUrl.AppendLiteral("&o=1");
+  }
+  if (!escapedCSSClass.IsEmpty()) {
+    errorPageUrl.AppendLiteral("&s=");
+    errorPageUrl.AppendASCII(escapedCSSClass.get());
+  }
+  errorPageUrl.AppendLiteral("&c=UTF-8");
+
+  nsCOMPtr<nsICaptivePortalService> cps = do_GetService(NS_CAPTIVEPORTAL_CID);
+  int32_t cpsState;
+  if (cps && NS_SUCCEEDED(cps->GetState(&cpsState)) &&
+      cpsState == nsICaptivePortalService::LOCKED_PORTAL) {
+    errorPageUrl.AppendLiteral("&captive=true");
+  }
+
+  errorPageUrl.AppendLiteral("&d=");
+  errorPageUrl.AppendASCII(escapedDescription.get());
+
+  nsCOMPtr<nsIURI> errorPageURI;
+  nsresult rv = NS_NewURI(getter_AddRefs(errorPageURI), errorPageUrl);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return LoadErrorPage(errorPageURI, aURI, aFailedChannel);
+}
+
+nsresult nsDocShell::LoadErrorPage(nsIURI* aErrorURI, nsIURI* aFailedURI,
+                                   nsIChannel* aFailedChannel) {
+  mFailedChannel = aFailedChannel;
+  mFailedURI = aFailedURI;
+  mFailedLoadType = mLoadType;
+
+  if (mLSHE) {
+    // Abandon mLSHE's BFCache entry and create a new one.  This way, if
+    // we go back or forward to another SHEntry with the same doc
+    // identifier, the error page won't persist.
+    mLSHE->AbandonBFCacheEntry();
+  }
+
+  RefPtr<nsDocShellLoadState> loadState = new nsDocShellLoadState(aErrorURI);
+  loadState->SetTriggeringPrincipal(nsContentUtils::GetSystemPrincipal());
+  if (mBrowsingContext) {
+    loadState->SetTriggeringSandboxFlags(mBrowsingContext->GetSandboxFlags());
+  }
+  loadState->SetLoadType(LOAD_ERROR_PAGE);
+  loadState->SetFirstParty(true);
+  loadState->SetSourceBrowsingContext(mBrowsingContext);
+  if (mozilla::SessionHistoryInParent() && mLoadingEntry) {
+    // We keep the loading entry for the load that failed here. If the user
+    // reloads we want to try to reload the original load, not the error page.
+    loadState->SetLoadingSessionHistoryInfo(
+        MakeUnique<LoadingSessionHistoryInfo>(*mLoadingEntry));
+  }
+  return InternalLoad(loadState);
+}
+
+NS_IMETHODIMP
+nsDocShell::Reload(uint32_t aReloadFlags) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;  // JS may not handle returning of an error code
+  }
+
+  NS_ASSERTION(((aReloadFlags & INTERNAL_LOAD_FLAGS_LOADURI_SETUP_FLAGS) == 0),
+               "Reload command not updated to use load flags!");
+  NS_ASSERTION((aReloadFlags & EXTRA_LOAD_FLAGS) == 0,
+               "Don't pass these flags to Reload");
+
+  uint32_t loadType = MAKE_LOAD_TYPE(LOAD_RELOAD_NORMAL, aReloadFlags);
+  NS_ENSURE_TRUE(IsValidLoadType(loadType), NS_ERROR_INVALID_ARG);
+
+  // Send notifications to the HistoryListener if any, about the impending
+  // reload
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (mozilla::SessionHistoryInParent()) {
+    MOZ_LOG(gSHLog, LogLevel::Debug, ("nsDocShell %p Reload", this));
+    bool forceReload = IsForceReloadType(loadType);
+    if (!XRE_IsParentProcess()) {
+      ++mPendingReloadCount;
+      RefPtr<nsDocShell> docShell(this);
+      nsCOMPtr<nsIContentViewer> cv(mContentViewer);
+      NS_ENSURE_STATE(cv);
+
+      bool okToUnload = true;
+      MOZ_TRY(cv->PermitUnload(&okToUnload));
+      if (!okToUnload) {
+        return NS_OK;
+      }
+
+      RefPtr<Document> doc(GetDocument());
+      RefPtr<BrowsingContext> browsingContext(mBrowsingContext);
+      nsCOMPtr<nsIURI> currentURI(mCurrentURI);
+      nsCOMPtr<nsIReferrerInfo> referrerInfo(mReferrerInfo);
+      RefPtr<StopDetector> stopDetector = new StopDetector();
+      nsCOMPtr<nsILoadGroup> loadGroup;
+      GetLoadGroup(getter_AddRefs(loadGroup));
+      if (loadGroup) {
+        // loadGroup may be null in theory. In that case stopDetector just
+        // doesn't do anything.
+        loadGroup->AddRequest(stopDetector, nullptr);
+      }
+
+      ContentChild::GetSingleton()->SendNotifyOnHistoryReload(
+          mBrowsingContext, forceReload,
+          [docShell, doc, loadType, browsingContext, currentURI, referrerInfo,
+           loadGroup, stopDetector](
+              std::tuple<bool, Maybe<NotNull<RefPtr<nsDocShellLoadState>>>,
+                         Maybe<bool>>&& aResult) {
+            auto scopeExit = MakeScopeExit([loadGroup, stopDetector]() {
+              if (loadGroup) {
+                loadGroup->RemoveRequest(stopDetector, nullptr, NS_OK);
+              }
+            });
+
+            // Decrease mPendingReloadCount before any other early returns!
+            if (--(docShell->mPendingReloadCount) > 0) {
+              return;
+            }
+
+            if (stopDetector->Canceled()) {
+              return;
+            }
+            bool canReload;
+            Maybe<NotNull<RefPtr<nsDocShellLoadState>>> loadState;
+            Maybe<bool> reloadingActiveEntry;
+
+            std::tie(canReload, loadState, reloadingActiveEntry) = aResult;
+
+            if (!canReload) {
+              return;
+            }
+
+            if (loadState.isSome()) {
+              MOZ_LOG(
+                  gSHLog, LogLevel::Debug,
+                  ("nsDocShell %p Reload - LoadHistoryEntry", docShell.get()));
+              loadState.ref()->SetNotifiedBeforeUnloadListeners(true);
+              docShell->LoadHistoryEntry(loadState.ref(), loadType,
+                                         reloadingActiveEntry.ref());
+            } else {
+              MOZ_LOG(gSHLog, LogLevel::Debug,
+                      ("nsDocShell %p ReloadDocument", docShell.get()));
+              ReloadDocument(docShell, doc, loadType, browsingContext,
+                             currentURI, referrerInfo,
+                             /* aNotifiedBeforeUnloadListeners */ true);
+            }
+          },
+          [](mozilla::ipc::ResponseRejectReason) {});
+    } else {
+      // Parent process
+      bool canReload = false;
+      Maybe<NotNull<RefPtr<nsDocShellLoadState>>> loadState;
+      Maybe<bool> reloadingActiveEntry;
+      if (!mBrowsingContext->IsDiscarded()) {
+        mBrowsingContext->Canonical()->NotifyOnHistoryReload(
+            forceReload, canReload, loadState, reloadingActiveEntry);
+      }
+      if (canReload) {
+        if (loadState.isSome()) {
+          MOZ_LOG(gSHLog, LogLevel::Debug,
+                  ("nsDocShell %p Reload - LoadHistoryEntry", this));
+          LoadHistoryEntry(loadState.ref(), loadType,
+                           reloadingActiveEntry.ref());
+        } else {
+          MOZ_LOG(gSHLog, LogLevel::Debug,
+                  ("nsDocShell %p ReloadDocument", this));
+          RefPtr<Document> doc = GetDocument();
+          RefPtr<BrowsingContext> bc = mBrowsingContext;
+          nsCOMPtr<nsIURI> currentURI = mCurrentURI;
+          nsCOMPtr<nsIReferrerInfo> referrerInfo = mReferrerInfo;
+          ReloadDocument(this, doc, loadType, bc, currentURI, referrerInfo);
+        }
+      }
+    }
+    return NS_OK;
+  }
+
+  bool canReload = true;
+  if (rootSH) {
+    rootSH->LegacySHistory()->NotifyOnHistoryReload(&canReload);
+  }
+
+  if (!canReload) {
+    return NS_OK;
+  }
+
+  /* If you change this part of code, make sure bug 45297 does not re-occur */
+  if (mOSHE) {
+    nsCOMPtr<nsISHEntry> oshe = mOSHE;
+    return LoadHistoryEntry(
+        oshe, loadType,
+        aReloadFlags & nsIWebNavigation::LOAD_FLAGS_USER_ACTIVATION);
+  }
+
+  if (mLSHE) {  // In case a reload happened before the current load is done
+    nsCOMPtr<nsISHEntry> lshe = mLSHE;
+    return LoadHistoryEntry(
+        lshe, loadType,
+        aReloadFlags & nsIWebNavigation::LOAD_FLAGS_USER_ACTIVATION);
+  }
+
+  RefPtr<Document> doc = GetDocument();
+  RefPtr<BrowsingContext> bc = mBrowsingContext;
+  nsCOMPtr<nsIURI> currentURI = mCurrentURI;
+  nsCOMPtr<nsIReferrerInfo> referrerInfo = mReferrerInfo;
+  return ReloadDocument(this, doc, loadType, bc, currentURI, referrerInfo);
+}
+
+/* static */
+nsresult nsDocShell::ReloadDocument(nsDocShell* aDocShell, Document* aDocument,
+                                    uint32_t aLoadType,
+                                    BrowsingContext* aBrowsingContext,
+                                    nsIURI* aCurrentURI,
+                                    nsIReferrerInfo* aReferrerInfo,
+                                    bool aNotifiedBeforeUnloadListeners) {
+  if (!aDocument) {
+    return NS_OK;
+  }
+
+  // Do not inherit owner from document
+  uint32_t flags = INTERNAL_LOAD_FLAGS_NONE;
+  nsAutoString srcdoc;
+  nsIURI* baseURI = nullptr;
+  nsCOMPtr<nsIURI> originalURI;
+  nsCOMPtr<nsIURI> resultPrincipalURI;
+  bool loadReplace = false;
+
+  nsIPrincipal* triggeringPrincipal = aDocument->NodePrincipal();
+  nsCOMPtr<nsIContentSecurityPolicy> csp = aDocument->GetCsp();
+  uint32_t triggeringSandboxFlags = aDocument->GetSandboxFlags();
+
+  nsAutoString contentTypeHint;
+  aDocument->GetContentType(contentTypeHint);
+
+  if (aDocument->IsSrcdocDocument()) {
+    aDocument->GetSrcdocData(srcdoc);
+    flags |= INTERNAL_LOAD_FLAGS_IS_SRCDOC;
+    baseURI = aDocument->GetBaseURI();
+  } else {
+    srcdoc = VoidString();
+  }
+  nsCOMPtr<nsIChannel> chan = aDocument->GetChannel();
+  if (chan) {
+    uint32_t loadFlags;
+    chan->GetLoadFlags(&loadFlags);
+    loadReplace = loadFlags & nsIChannel::LOAD_REPLACE;
+    nsCOMPtr<nsIHttpChannel> httpChan(do_QueryInterface(chan));
+    if (httpChan) {
+      httpChan->GetOriginalURI(getter_AddRefs(originalURI));
+    }
+
+    nsCOMPtr<nsILoadInfo> loadInfo = chan->LoadInfo();
+    loadInfo->GetResultPrincipalURI(getter_AddRefs(resultPrincipalURI));
+  }
+
+  if (!triggeringPrincipal) {
+    MOZ_ASSERT(false, "Reload needs a valid triggeringPrincipal");
+    return NS_ERROR_FAILURE;
+  }
+
+  // Stack variables to ensure changes to the member variables don't affect to
+  // the call.
+  nsCOMPtr<nsIURI> currentURI = aCurrentURI;
+
+  // Reload always rewrites result principal URI.
+  Maybe<nsCOMPtr<nsIURI>> emplacedResultPrincipalURI;
+  emplacedResultPrincipalURI.emplace(std::move(resultPrincipalURI));
+
+  RefPtr<WindowContext> context = aBrowsingContext->GetCurrentWindowContext();
+  RefPtr<nsDocShellLoadState> loadState = new nsDocShellLoadState(currentURI);
+  loadState->SetReferrerInfo(aReferrerInfo);
+  loadState->SetOriginalURI(originalURI);
+  loadState->SetMaybeResultPrincipalURI(emplacedResultPrincipalURI);
+  loadState->SetLoadReplace(loadReplace);
+  loadState->SetTriggeringPrincipal(triggeringPrincipal);
+  loadState->SetTriggeringSandboxFlags(triggeringSandboxFlags);
+  loadState->SetPrincipalToInherit(triggeringPrincipal);
+  loadState->SetCsp(csp);
+  loadState->SetInternalLoadFlags(flags);
+  loadState->SetTypeHint(NS_ConvertUTF16toUTF8(contentTypeHint));
+  loadState->SetLoadType(aLoadType);
+  loadState->SetFirstParty(true);
+  loadState->SetSrcdocData(srcdoc);
+  loadState->SetSourceBrowsingContext(aBrowsingContext);
+  loadState->SetBaseURI(baseURI);
+  loadState->SetHasValidUserGestureActivation(
+      context && context->HasValidTransientUserGestureActivation());
+  loadState->SetNotifiedBeforeUnloadListeners(aNotifiedBeforeUnloadListeners);
+  return aDocShell->InternalLoad(loadState);
+}
+
+NS_IMETHODIMP
+nsDocShell::Stop(uint32_t aStopFlags) {
+  // Revoke any pending event related to content viewer restoration
+  mRestorePresentationEvent.Revoke();
+
+  if (mLoadType == LOAD_ERROR_PAGE) {
+    if (mLSHE) {
+      // Since error page loads never unset mLSHE, do so now
+      SetHistoryEntryAndUpdateBC(Some(nullptr), Some<nsISHEntry*>(mLSHE));
+    }
+    mActiveEntryIsLoadingFromSessionHistory = false;
+
+    mFailedChannel = nullptr;
+    mFailedURI = nullptr;
+  }
+
+  if (nsIWebNavigation::STOP_CONTENT & aStopFlags) {
+    // Stop the document loading and animations
+    if (mContentViewer) {
+      nsCOMPtr<nsIContentViewer> cv = mContentViewer;
+      cv->Stop();
+    }
+  } else if (nsIWebNavigation::STOP_NETWORK & aStopFlags) {
+    // Stop the document loading only
+    if (mContentViewer) {
+      RefPtr<Document> doc = mContentViewer->GetDocument();
+      if (doc) {
+        doc->StopDocumentLoad();
+      }
+    }
+  }
+
+  if (nsIWebNavigation::STOP_NETWORK & aStopFlags) {
+    // Suspend any timers that were set for this loader.  We'll clear
+    // them out for good in CreateContentViewer.
+    if (mRefreshURIList) {
+      SuspendRefreshURIs();
+      mSavedRefreshURIList.swap(mRefreshURIList);
+      mRefreshURIList = nullptr;
+    }
+
+    // XXXbz We could also pass |this| to nsIURILoader::Stop.  That will
+    // just call Stop() on us as an nsIDocumentLoader... We need fewer
+    // redundant apis!
+    Stop();
+
+    // Clear out mChannelToDisconnectOnPageHide. This page won't go in the
+    // BFCache now, and the Stop above will have removed the DocumentChannel
+    // from the loadgroup.
+    mChannelToDisconnectOnPageHide = 0;
+  }
+
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIWebNavigation> shellAsNav(do_QueryObject(child));
+    if (shellAsNav) {
+      shellAsNav->Stop(aStopFlags);
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDocument(Document** aDocument) {
+  NS_ENSURE_ARG_POINTER(aDocument);
+  NS_ENSURE_SUCCESS(EnsureContentViewer(), NS_ERROR_FAILURE);
+
+  RefPtr<Document> doc = mContentViewer->GetDocument();
+  if (!doc) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  doc.forget(aDocument);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCurrentURI(nsIURI** aURI) {
+  NS_ENSURE_ARG_POINTER(aURI);
+
+  nsCOMPtr<nsIURI> uri = mCurrentURI;
+  uri.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetSessionHistoryXPCOM(nsISupports** aSessionHistory) {
+  NS_ENSURE_ARG_POINTER(aSessionHistory);
+  RefPtr<ChildSHistory> shistory = GetSessionHistory();
+  shistory.forget(aSessionHistory);
+  return NS_OK;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIWebPageDescriptor
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::LoadPageAsViewSource(nsIDocShell* aOtherDocShell,
+                                 const nsAString& aURI) {
+  if (!aOtherDocShell) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+  nsCOMPtr<nsIURI> newURI;
+  nsresult rv = NS_NewURI(getter_AddRefs(newURI), aURI);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  RefPtr<nsDocShellLoadState> loadState;
+  uint32_t cacheKey;
+  auto* otherDocShell = nsDocShell::Cast(aOtherDocShell);
+  if (mozilla::SessionHistoryInParent()) {
+    loadState = new nsDocShellLoadState(newURI);
+    if (!otherDocShell->FillLoadStateFromCurrentEntry(*loadState)) {
+      return NS_ERROR_INVALID_POINTER;
+    }
+    cacheKey = otherDocShell->GetCacheKeyFromCurrentEntry().valueOr(0);
+  } else {
+    nsCOMPtr<nsISHEntry> entry;
+    bool isOriginalSHE;
+    otherDocShell->GetCurrentSHEntry(getter_AddRefs(entry), &isOriginalSHE);
+    if (!entry) {
+      return NS_ERROR_INVALID_POINTER;
+    }
+    rv = entry->CreateLoadInfo(getter_AddRefs(loadState));
+    NS_ENSURE_SUCCESS(rv, rv);
+    entry->GetCacheKey(&cacheKey);
+    loadState->SetURI(newURI);
+    loadState->SetSHEntry(nullptr);
+  }
+
+  // We're doing a load of the page, via an API that
+  // is only exposed to system code.  The triggering principal for this load
+  // should be the system principal.
+  loadState->SetTriggeringPrincipal(nsContentUtils::GetSystemPrincipal());
+  loadState->SetOriginalURI(nullptr);
+  loadState->SetResultPrincipalURI(nullptr);
+
+  return InternalLoad(loadState, Some(cacheKey));
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCurrentDescriptor(nsISupports** aPageDescriptor) {
+  MOZ_ASSERT(aPageDescriptor, "Null out param?");
+
+  *aPageDescriptor = nullptr;
+
+  nsISHEntry* src = mOSHE ? mOSHE : mLSHE;
+  if (src) {
+    nsCOMPtr<nsISHEntry> dest;
+
+    nsresult rv = src->Clone(getter_AddRefs(dest));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // null out inappropriate cloned attributes...
+    dest->SetParent(nullptr);
+    dest->SetIsSubFrame(false);
+
+    return CallQueryInterface(dest, aPageDescriptor);
+  }
+
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+already_AddRefed<nsIInputStream> nsDocShell::GetPostDataFromCurrentEntry()
+    const {
+  nsCOMPtr<nsIInputStream> postData;
+  if (mozilla::SessionHistoryInParent()) {
+    if (mActiveEntry) {
+      postData = mActiveEntry->GetPostData();
+    } else if (mLoadingEntry) {
+      postData = mLoadingEntry->mInfo.GetPostData();
+    }
+  } else {
+    if (mOSHE) {
+      postData = mOSHE->GetPostData();
+    } else if (mLSHE) {
+      postData = mLSHE->GetPostData();
+    }
+  }
+
+  return postData.forget();
+}
+
+Maybe<uint32_t> nsDocShell::GetCacheKeyFromCurrentEntry() const {
+  if (mozilla::SessionHistoryInParent()) {
+    if (mActiveEntry) {
+      return Some(mActiveEntry->GetCacheKey());
+    }
+
+    if (mLoadingEntry) {
+      return Some(mLoadingEntry->mInfo.GetCacheKey());
+    }
+  } else {
+    if (mOSHE) {
+      return Some(mOSHE->GetCacheKey());
+    }
+
+    if (mLSHE) {
+      return Some(mLSHE->GetCacheKey());
+    }
+  }
+
+  return Nothing();
+}
+
+bool nsDocShell::FillLoadStateFromCurrentEntry(
+    nsDocShellLoadState& aLoadState) {
+  if (mLoadingEntry) {
+    mLoadingEntry->mInfo.FillLoadInfo(aLoadState);
+    return true;
+  }
+  if (mActiveEntry) {
+    mActiveEntry->FillLoadInfo(aLoadState);
+    return true;
+  }
+  return false;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIBaseWindow
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::InitWindow(nativeWindow aParentNativeWindow,
+                       nsIWidget* aParentWidget, int32_t aX, int32_t aY,
+                       int32_t aWidth, int32_t aHeight) {
+  SetParentWidget(aParentWidget);
+  SetPositionAndSize(aX, aY, aWidth, aHeight, 0);
+  NS_ENSURE_TRUE(Initialize(), NS_ERROR_FAILURE);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::Destroy() {
+  // XXX: We allow this function to be called just once.  If you are going to
+  // reset new variables in this function, please make sure the variables will
+  // never be re-initialized.  Adding assertions to check |mIsBeingDestroyed|
+  // in the setter functions for the variables would be enough.
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_DOCSHELL_DYING;
+  }
+
+  NS_ASSERTION(mItemType == typeContent || mItemType == typeChrome,
+               "Unexpected item type in docshell");
+
+  nsCOMPtr<nsIObserverService> serv = services::GetObserverService();
+  if (serv) {
+    const char* msg = mItemType == typeContent
+                          ? NS_WEBNAVIGATION_DESTROY
+                          : NS_CHROME_WEBNAVIGATION_DESTROY;
+    serv->NotifyObservers(GetAsSupports(this), msg, nullptr);
+  }
+
+  mIsBeingDestroyed = true;
+
+  // Brak the cycle with the initial client, if present.
+  mInitialClientSource.reset();
+
+  // Make sure we don't record profile timeline markers anymore
+  SetRecordProfileTimelineMarkers(false);
+
+  // Make sure to blow away our mLoadingURI just in case.  No loads
+  // from inside this pagehide.
+  mLoadingURI = nullptr;
+
+  // Fire unload event before we blow anything away.
+  (void)FirePageHideNotification(true);
+
+  // Clear pointers to any detached nsEditorData that's lying
+  // around in shistory entries. Breaks cycle. See bug 430921.
+  if (mOSHE) {
+    mOSHE->SetEditorData(nullptr);
+  }
+  if (mLSHE) {
+    mLSHE->SetEditorData(nullptr);
+  }
+
+  // Note: mContentListener can be null if Init() failed and we're being
+  // called from the destructor.
+  if (mContentListener) {
+    mContentListener->DropDocShellReference();
+    mContentListener->SetParentContentListener(nullptr);
+    // Note that we do NOT set mContentListener to null here; that
+    // way if someone tries to do a load in us after this point
+    // the nsDSURIContentListener will block it.  All of which
+    // means that we should do this before calling Stop(), of
+    // course.
+  }
+
+  // Stop any URLs that are currently being loaded...
+  Stop(nsIWebNavigation::STOP_ALL);
+
+  mEditorData = nullptr;
+
+  // Save the state of the current document, before destroying the window.
+  // This is needed to capture the state of a frameset when the new document
+  // causes the frameset to be destroyed...
+  PersistLayoutHistoryState();
+
+  // Remove this docshell from its parent's child list
+  nsCOMPtr<nsIDocShellTreeItem> docShellParentAsItem =
+      do_QueryInterface(GetAsSupports(mParent));
+  if (docShellParentAsItem) {
+    docShellParentAsItem->RemoveChild(this);
+  }
+
+  if (mContentViewer) {
+    mContentViewer->Close(nullptr);
+    mContentViewer->Destroy();
+    mContentViewer = nullptr;
+  }
+
+  nsDocLoader::Destroy();
+
+  mParentWidget = nullptr;
+  mCurrentURI = nullptr;
+
+  if (mScriptGlobal) {
+    mScriptGlobal->DetachFromDocShell(!mWillChangeProcess);
+    mScriptGlobal = nullptr;
+  }
+
+  if (GetSessionHistory()) {
+    // We want to destroy these content viewers now rather than
+    // letting their destruction wait for the session history
+    // entries to get garbage collected.  (Bug 488394)
+    GetSessionHistory()->EvictLocalContentViewers();
+  }
+
+  if (mWillChangeProcess && !mBrowsingContext->IsDiscarded()) {
+    mBrowsingContext->PrepareForProcessChange();
+  }
+
+  SetTreeOwner(nullptr);
+
+  mBrowserChild = nullptr;
+
+  mChromeEventHandler = nullptr;
+
+  // Cancel any timers that were set for this docshell; this is needed
+  // to break the cycle between us and the timers.
+  CancelRefreshURITimers();
+
+  return NS_OK;
+}
+
+double nsDocShell::GetWidgetCSSToDeviceScale() {
+  if (mParentWidget) {
+    return mParentWidget->GetDefaultScale().scale;
+  }
+  if (nsCOMPtr<nsIBaseWindow> ownerWindow = do_QueryInterface(mTreeOwner)) {
+    return ownerWindow->GetWidgetCSSToDeviceScale();
+  }
+  return 1.0;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDevicePixelsPerDesktopPixel(double* aScale) {
+  if (mParentWidget) {
+    *aScale = mParentWidget->GetDesktopToDeviceScale().scale;
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIBaseWindow> ownerWindow(do_QueryInterface(mTreeOwner));
+  if (ownerWindow) {
+    return ownerWindow->GetDevicePixelsPerDesktopPixel(aScale);
+  }
+
+  *aScale = 1.0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetPosition(int32_t aX, int32_t aY) {
+  mBounds.MoveTo(aX, aY);
+
+  if (mContentViewer) {
+    NS_ENSURE_SUCCESS(mContentViewer->Move(aX, aY), NS_ERROR_FAILURE);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetPositionDesktopPix(int32_t aX, int32_t aY) {
+  nsCOMPtr<nsIBaseWindow> ownerWindow(do_QueryInterface(mTreeOwner));
+  if (ownerWindow) {
+    return ownerWindow->SetPositionDesktopPix(aX, aY);
+  }
+
+  double scale = 1.0;
+  GetDevicePixelsPerDesktopPixel(&scale);
+  return SetPosition(NSToIntRound(aX * scale), NSToIntRound(aY * scale));
+}
+
+NS_IMETHODIMP
+nsDocShell::GetPosition(int32_t* aX, int32_t* aY) {
+  return GetPositionAndSize(aX, aY, nullptr, nullptr);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetSize(int32_t aWidth, int32_t aHeight, bool aRepaint) {
+  int32_t x = 0, y = 0;
+  GetPosition(&x, &y);
+  return SetPositionAndSize(x, y, aWidth, aHeight,
+                            aRepaint ? nsIBaseWindow::eRepaint : 0);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetSize(int32_t* aWidth, int32_t* aHeight) {
+  return GetPositionAndSize(nullptr, nullptr, aWidth, aHeight);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetPositionAndSize(int32_t aX, int32_t aY, int32_t aWidth,
+                               int32_t aHeight, uint32_t aFlags) {
+  mBounds.SetRect(aX, aY, aWidth, aHeight);
+
+  // Hold strong ref, since SetBounds can make us null out mContentViewer
+  nsCOMPtr<nsIContentViewer> viewer = mContentViewer;
+  if (viewer) {
+    uint32_t cvflags = (aFlags & nsIBaseWindow::eDelayResize)
+                           ? nsIContentViewer::eDelayResize
+                           : 0;
+    // XXX Border figured in here or is that handled elsewhere?
+    nsresult rv = viewer->SetBoundsWithFlags(mBounds, cvflags);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetPositionAndSize(int32_t* aX, int32_t* aY, int32_t* aWidth,
+                               int32_t* aHeight) {
+  if (mParentWidget) {
+    // ensure size is up-to-date if window has changed resolution
+    LayoutDeviceIntRect r = mParentWidget->GetClientBounds();
+    SetPositionAndSize(mBounds.X(), mBounds.Y(), r.Width(), r.Height(), 0);
+  }
+
+  // We should really consider just getting this information from
+  // our window instead of duplicating the storage and code...
+  if (aWidth || aHeight) {
+    // Caller wants to know our size; make sure to give them up to
+    // date information.
+    RefPtr<Document> doc(do_GetInterface(GetAsSupports(mParent)));
+    if (doc) {
+      doc->FlushPendingNotifications(FlushType::Layout);
+    }
+  }
+
+  DoGetPositionAndSize(aX, aY, aWidth, aHeight);
+  return NS_OK;
+}
+
+void nsDocShell::DoGetPositionAndSize(int32_t* aX, int32_t* aY, int32_t* aWidth,
+                                      int32_t* aHeight) {
+  if (aX) {
+    *aX = mBounds.X();
+  }
+  if (aY) {
+    *aY = mBounds.Y();
+  }
+  if (aWidth) {
+    *aWidth = mBounds.Width();
+  }
+  if (aHeight) {
+    *aHeight = mBounds.Height();
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::SetDimensions(DimensionRequest&& aRequest) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDimensions(DimensionKind aDimensionKind, int32_t* aX,
+                          int32_t* aY, int32_t* aCX, int32_t* aCY) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDocShell::Repaint(bool aForce) {
+  PresShell* presShell = GetPresShell();
+  NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
+
+  RefPtr<nsViewManager> viewManager = presShell->GetViewManager();
+  NS_ENSURE_TRUE(viewManager, NS_ERROR_FAILURE);
+
+  viewManager->InvalidateAllViews();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetParentWidget(nsIWidget** aParentWidget) {
+  NS_ENSURE_ARG_POINTER(aParentWidget);
+
+  *aParentWidget = mParentWidget;
+  NS_IF_ADDREF(*aParentWidget);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetParentWidget(nsIWidget* aParentWidget) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+  mParentWidget = aParentWidget;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetParentNativeWindow(nativeWindow* aParentNativeWindow) {
+  NS_ENSURE_ARG_POINTER(aParentNativeWindow);
+
+  if (mParentWidget) {
+    *aParentNativeWindow = mParentWidget->GetNativeData(NS_NATIVE_WIDGET);
+  } else {
+    *aParentNativeWindow = nullptr;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetParentNativeWindow(nativeWindow aParentNativeWindow) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetNativeHandle(nsAString& aNativeHandle) {
+  // the nativeHandle should be accessed from nsIAppWindow
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetVisibility(bool* aVisibility) {
+  NS_ENSURE_ARG_POINTER(aVisibility);
+
+  *aVisibility = false;
+
+  if (!mContentViewer) {
+    return NS_OK;
+  }
+
+  PresShell* presShell = GetPresShell();
+  if (!presShell) {
+    return NS_OK;
+  }
+
+  // get the view manager
+  nsViewManager* vm = presShell->GetViewManager();
+  NS_ENSURE_TRUE(vm, NS_ERROR_FAILURE);
+
+  // get the root view
+  nsView* view = vm->GetRootView();  // views are not ref counted
+  NS_ENSURE_TRUE(view, NS_ERROR_FAILURE);
+
+  // if our root view is hidden, we are not visible
+  if (view->GetVisibility() == ViewVisibility::Hide) {
+    return NS_OK;
+  }
+
+  // otherwise, we must walk up the document and view trees checking
+  // for a hidden view, unless we're an off screen browser, which
+  // would make this test meaningless.
+
+  RefPtr<nsDocShell> docShell = this;
+  RefPtr<nsDocShell> parentItem = docShell->GetInProcessParentDocshell();
+  while (parentItem) {
+    // Null-check for crash in bug 267804
+    if (!parentItem->GetPresShell()) {
+      MOZ_ASSERT_UNREACHABLE("parent docshell has null pres shell");
+      return NS_OK;
+    }
+
+    vm = docShell->GetPresShell()->GetViewManager();
+    if (vm) {
+      view = vm->GetRootView();
+    }
+
+    if (view) {
+      view = view->GetParent();  // anonymous inner view
+      if (view) {
+        view = view->GetParent();  // subdocumentframe's view
+      }
+    }
+
+    nsIFrame* frame = view ? view->GetFrame() : nullptr;
+    if (frame && !frame->IsVisibleConsideringAncestors(
+                     nsIFrame::VISIBILITY_CROSS_CHROME_CONTENT_BOUNDARY)) {
+      return NS_OK;
+    }
+
+    docShell = parentItem;
+    parentItem = docShell->GetInProcessParentDocshell();
+  }
+
+  nsCOMPtr<nsIBaseWindow> treeOwnerAsWin(do_QueryInterface(mTreeOwner));
+  if (!treeOwnerAsWin) {
+    *aVisibility = true;
+    return NS_OK;
+  }
+
+  // Check with the tree owner as well to give embedders a chance to
+  // expose visibility as well.
+  nsresult rv = treeOwnerAsWin->GetVisibility(aVisibility);
+  if (rv == NS_ERROR_NOT_IMPLEMENTED) {
+    // The tree owner had no opinion on our visibility.
+    *aVisibility = true;
+    return NS_OK;
+  }
+  return rv;
+}
+
+void nsDocShell::ActivenessMaybeChanged() {
+  const bool isActive = mBrowsingContext->IsActive();
+  if (RefPtr<PresShell> presShell = GetPresShell()) {
+    presShell->ActivenessMaybeChanged();
+  }
+
+  // Tell the window about it
+  if (mScriptGlobal) {
+    mScriptGlobal->SetIsBackground(!isActive);
+    if (RefPtr<Document> doc = mScriptGlobal->GetExtantDoc()) {
+      // Update orientation when the top-level browsing context becomes active.
+      if (isActive && mBrowsingContext->IsTop()) {
+        // We only care about the top-level browsing context.
+        auto orientation = mBrowsingContext->GetOrientationLock();
+        ScreenOrientation::UpdateActiveOrientationLock(orientation);
+      }
+
+      doc->PostVisibilityUpdateEvent();
+    }
+  }
+
+  // Tell the nsDOMNavigationTiming about it
+  RefPtr<nsDOMNavigationTiming> timing = mTiming;
+  if (!timing && mContentViewer) {
+    if (Document* doc = mContentViewer->GetDocument()) {
+      timing = doc->GetNavigationTiming();
+    }
+  }
+  if (timing) {
+    timing->NotifyDocShellStateChanged(
+        isActive ? nsDOMNavigationTiming::DocShellState::eActive
+                 : nsDOMNavigationTiming::DocShellState::eInactive);
+  }
+
+  // Restart or stop meta refresh timers if necessary
+  if (mDisableMetaRefreshWhenInactive) {
+    if (isActive) {
+      ResumeRefreshURIs();
+    } else {
+      SuspendRefreshURIs();
+    }
+  }
+
+  if (InputTaskManager::CanSuspendInputEvent()) {
+    mBrowsingContext->Group()->UpdateInputTaskManagerIfNeeded(isActive);
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::SetDefaultLoadFlags(uint32_t aDefaultLoadFlags) {
+  if (!mWillChangeProcess) {
+    // Intentionally ignoring handling discarded browsing contexts.
+    Unused << mBrowsingContext->SetDefaultLoadFlags(aDefaultLoadFlags);
+  } else {
+    // Bug 1623565: DevTools tries to clean up defaultLoadFlags on
+    // shutdown. Sorry DevTools, your DocShell is in another process.
+    NS_WARNING("nsDocShell::SetDefaultLoadFlags called on Zombie DocShell");
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDefaultLoadFlags(uint32_t* aDefaultLoadFlags) {
+  *aDefaultLoadFlags = mBrowsingContext->GetDefaultLoadFlags();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetFailedChannel(nsIChannel** aFailedChannel) {
+  NS_ENSURE_ARG_POINTER(aFailedChannel);
+  Document* doc = GetDocument();
+  if (!doc) {
+    *aFailedChannel = nullptr;
+    return NS_OK;
+  }
+  NS_IF_ADDREF(*aFailedChannel = doc->GetFailedChannel());
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetVisibility(bool aVisibility) {
+  // Show()/Hide() may change mContentViewer.
+  nsCOMPtr<nsIContentViewer> cv = mContentViewer;
+  if (!cv) {
+    return NS_OK;
+  }
+  if (aVisibility) {
+    cv->Show();
+  } else {
+    cv->Hide();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetEnabled(bool* aEnabled) {
+  NS_ENSURE_ARG_POINTER(aEnabled);
+  *aEnabled = true;
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetEnabled(bool aEnabled) { return NS_ERROR_NOT_IMPLEMENTED; }
+
+NS_IMETHODIMP
+nsDocShell::GetMainWidget(nsIWidget** aMainWidget) {
+  // We don't create our own widget, so simply return the parent one.
+  return GetParentWidget(aMainWidget);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetTitle(nsAString& aTitle) {
+  aTitle = mTitle;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetTitle(const nsAString& aTitle) {
+  // Avoid unnecessary updates of the title if the URI and the title haven't
+  // changed.
+  if (mTitleValidForCurrentURI && mTitle == aTitle) {
+    return NS_OK;
+  }
+
+  // Store local title
+  mTitle = aTitle;
+  mTitleValidForCurrentURI = true;
+
+  // When title is set on the top object it should then be passed to the
+  // tree owner.
+  if (mBrowsingContext->IsTop()) {
+    nsCOMPtr<nsIBaseWindow> treeOwnerAsWin(do_QueryInterface(mTreeOwner));
+    if (treeOwnerAsWin) {
+      treeOwnerAsWin->SetTitle(aTitle);
+    }
+  }
+
+  if (mCurrentURI && mLoadType != LOAD_ERROR_PAGE) {
+    UpdateGlobalHistoryTitle(mCurrentURI);
+  }
+
+  // Update SessionHistory with the document's title.
+  if (mLoadType != LOAD_BYPASS_HISTORY && mLoadType != LOAD_ERROR_PAGE) {
+    SetTitleOnHistoryEntry(true);
+  }
+
+  return NS_OK;
+}
+
+void nsDocShell::SetTitleOnHistoryEntry(bool aUpdateEntryInSessionHistory) {
+  if (mOSHE) {
+    mOSHE->SetTitle(mTitle);
+  }
+
+  if (mActiveEntry && mBrowsingContext) {
+    mActiveEntry->SetTitle(mTitle);
+    if (aUpdateEntryInSessionHistory) {
+      if (XRE_IsParentProcess()) {
+        SessionHistoryEntry* entry =
+            mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+        if (entry) {
+          entry->SetTitle(mTitle);
+        }
+      } else {
+        mozilla::Unused
+            << ContentChild::GetSingleton()->SendSessionHistoryEntryTitle(
+                   mBrowsingContext, mTitle);
+      }
+    }
+  }
+}
+
+nsPoint nsDocShell::GetCurScrollPos() {
+  nsPoint scrollPos;
+  if (nsIScrollableFrame* sf = GetRootScrollFrame()) {
+    scrollPos = sf->GetVisualViewportOffset();
+  }
+  return scrollPos;
+}
+
+nsresult nsDocShell::SetCurScrollPosEx(int32_t aCurHorizontalPos,
+                                       int32_t aCurVerticalPos) {
+  nsIScrollableFrame* sf = GetRootScrollFrame();
+  NS_ENSURE_TRUE(sf, NS_ERROR_FAILURE);
+
+  ScrollMode scrollMode =
+      sf->IsSmoothScroll() ? ScrollMode::SmoothMsd : ScrollMode::Instant;
+
+  nsPoint targetPos(aCurHorizontalPos, aCurVerticalPos);
+  sf->ScrollTo(targetPos, scrollMode);
+
+  // Set the visual viewport offset as well.
+
+  RefPtr<PresShell> presShell = GetPresShell();
+  NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
+
+  nsPresContext* presContext = presShell->GetPresContext();
+  NS_ENSURE_TRUE(presContext, NS_ERROR_FAILURE);
+
+  // Only the root content document can have a distinct visual viewport offset.
+  if (!presContext->IsRootContentDocumentCrossProcess()) {
+    return NS_OK;
+  }
+
+  // Not on a platform with a distinct visual viewport - don't bother setting
+  // the visual viewport offset.
+  if (!presShell->IsVisualViewportSizeSet()) {
+    return NS_OK;
+  }
+
+  presShell->ScrollToVisual(targetPos, layers::FrameMetrics::eMainThread,
+                            scrollMode);
+
+  return NS_OK;
+}
+
+void nsDocShell::SetScrollbarPreference(mozilla::ScrollbarPreference aPref) {
+  if (mScrollbarPref == aPref) {
+    return;
+  }
+  mScrollbarPref = aPref;
+  auto* ps = GetPresShell();
+  if (!ps) {
+    return;
+  }
+  nsIFrame* scrollFrame = ps->GetRootScrollFrame();
+  if (!scrollFrame) {
+    return;
+  }
+  ps->FrameNeedsReflow(scrollFrame,
+                       IntrinsicDirty::FrameAncestorsAndDescendants,
+                       NS_FRAME_IS_DIRTY);
+}
+
+//*****************************************************************************
+// nsDocShell::nsIRefreshURI
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::RefreshURI(nsIURI* aURI, nsIPrincipal* aPrincipal,
+                       uint32_t aDelay) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  NS_ENSURE_ARG(aURI);
+
+  /* Check if Meta refresh/redirects are permitted. Some
+   * embedded applications may not want to do this.
+   * Must do this before sending out NOTIFY_REFRESH events
+   * because listeners may have side effects (e.g. displaying a
+   * button to manually trigger the refresh later).
+   */
+  bool allowRedirects = true;
+  GetAllowMetaRedirects(&allowRedirects);
+  if (!allowRedirects) {
+    return NS_OK;
+  }
+
+  // If any web progress listeners are listening for NOTIFY_REFRESH events,
+  // give them a chance to block this refresh.
+  bool sameURI;
+  nsresult rv = aURI->Equals(mCurrentURI, &sameURI);
+  if (NS_FAILED(rv)) {
+    sameURI = false;
+  }
+  if (!RefreshAttempted(this, aURI, aDelay, sameURI)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsITimerCallback> refreshTimer =
+      new nsRefreshTimer(this, aURI, aPrincipal, aDelay);
+
+  BusyFlags busyFlags = GetBusyFlags();
+
+  if (!mRefreshURIList) {
+    mRefreshURIList = nsArray::Create();
+  }
+
+  if (busyFlags & BUSY_FLAGS_BUSY ||
+      (!mBrowsingContext->IsActive() && mDisableMetaRefreshWhenInactive)) {
+    // We don't  want to create the timer right now. Instead queue up the
+    // request and trigger the timer in EndPageLoad() or whenever we become
+    // active.
+    mRefreshURIList->AppendElement(refreshTimer);
+  } else {
+    // There is no page loading going on right now.  Create the
+    // timer and fire it right away.
+    nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+    NS_ENSURE_TRUE(win, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsITimer> timer;
+    MOZ_TRY_VAR(timer, NS_NewTimerWithCallback(refreshTimer, aDelay,
+                                               nsITimer::TYPE_ONE_SHOT));
+
+    mRefreshURIList->AppendElement(timer);  // owning timer ref
+  }
+  return NS_OK;
+}
+
+nsresult nsDocShell::ForceRefreshURIFromTimer(nsIURI* aURI,
+                                              nsIPrincipal* aPrincipal,
+                                              uint32_t aDelay,
+                                              nsITimer* aTimer) {
+  MOZ_ASSERT(aTimer, "Must have a timer here");
+
+  // Remove aTimer from mRefreshURIList if needed
+  if (mRefreshURIList) {
+    uint32_t n = 0;
+    mRefreshURIList->GetLength(&n);
+
+    for (uint32_t i = 0; i < n; ++i) {
+      nsCOMPtr<nsITimer> timer = do_QueryElementAt(mRefreshURIList, i);
+      if (timer == aTimer) {
+        mRefreshURIList->RemoveElementAt(i);
+        break;
+      }
+    }
+  }
+
+  return ForceRefreshURI(aURI, aPrincipal, aDelay);
+}
+
+NS_IMETHODIMP
+nsDocShell::ForceRefreshURI(nsIURI* aURI, nsIPrincipal* aPrincipal,
+                            uint32_t aDelay) {
+  NS_ENSURE_ARG(aURI);
+
+  RefPtr<nsDocShellLoadState> loadState = new nsDocShellLoadState(aURI);
+  loadState->SetOriginalURI(mCurrentURI);
+  loadState->SetResultPrincipalURI(aURI);
+  loadState->SetResultPrincipalURIIsSome(true);
+  loadState->SetKeepResultPrincipalURIIfSet(true);
+  loadState->SetIsMetaRefresh(true);
+
+  // Set the triggering pricipal to aPrincipal if available, or current
+  // document's principal otherwise.
+  nsCOMPtr<nsIPrincipal> principal = aPrincipal;
+  RefPtr<Document> doc = GetDocument();
+  if (!principal) {
+    if (!doc) {
+      return NS_ERROR_FAILURE;
+    }
+    principal = doc->NodePrincipal();
+  }
+  loadState->SetTriggeringPrincipal(principal);
+  if (doc) {
+    loadState->SetCsp(doc->GetCsp());
+    loadState->SetHasValidUserGestureActivation(
+        doc->HasValidTransientUserGestureActivation());
+    loadState->SetTriggeringSandboxFlags(doc->GetSandboxFlags());
+  }
+
+  loadState->SetPrincipalIsExplicit(true);
+
+  /* Check if this META refresh causes a redirection
+   * to another site.
+   */
+  bool equalUri = false;
+  nsresult rv = aURI->Equals(mCurrentURI, &equalUri);
+
+  nsCOMPtr<nsIReferrerInfo> referrerInfo;
+  if (NS_SUCCEEDED(rv) && !equalUri && aDelay <= REFRESH_REDIRECT_TIMER) {
+    /* It is a META refresh based redirection within the threshold time
+     * we have in mind (15000 ms as defined by REFRESH_REDIRECT_TIMER).
+     * Pass a REPLACE flag to LoadURI().
+     */
+    loadState->SetLoadType(LOAD_REFRESH_REPLACE);
+
+    /* For redirects we mimic HTTP, which passes the
+     * original referrer.
+     * We will pass in referrer but will not send to server
+     */
+    if (mReferrerInfo) {
+      referrerInfo = static_cast<ReferrerInfo*>(mReferrerInfo.get())
+                         ->CloneWithNewSendReferrer(false);
+    }
+  } else {
+    loadState->SetLoadType(LOAD_REFRESH);
+    /* We do need to pass in a referrer, but we don't want it to
+     * be sent to the server.
+     * For most refreshes the current URI is an appropriate
+     * internal referrer.
+     */
+    referrerInfo = new ReferrerInfo(mCurrentURI, ReferrerPolicy::_empty, false);
+  }
+
+  loadState->SetReferrerInfo(referrerInfo);
+  loadState->SetLoadFlags(
+      nsIWebNavigation::LOAD_FLAGS_DISALLOW_INHERIT_PRINCIPAL);
+  loadState->SetFirstParty(true);
+
+  /*
+   * LoadURI(...) will cancel all refresh timers... This causes the
+   * Timer and its refreshData instance to be released...
+   */
+  LoadURI(loadState, false);
+
+  return NS_OK;
+}
+
+static const char16_t* SkipASCIIWhitespace(const char16_t* aStart,
+                                           const char16_t* aEnd) {
+  const char16_t* iter = aStart;
+  while (iter != aEnd && mozilla::IsAsciiWhitespace(*iter)) {
+    ++iter;
+  }
+  return iter;
+}
+
+static std::tuple<const char16_t*, const char16_t*> ExtractURLString(
+    const char16_t* aPosition, const char16_t* aEnd) {
+  MOZ_ASSERT(aPosition != aEnd);
+
+  // 1. Let urlString be the substring of input from the code point at
+  //    position to the end of the string.
+  const char16_t* urlStart = aPosition;
+  const char16_t* urlEnd = aEnd;
+
+  // 2. If the code point in input pointed to by position is U+0055 (U) or
+  //    U+0075 (u), then advance position to the next code point.
+  //    Otherwise, jump to the step labeled skip quotes.
+  if (*aPosition == 'U' || *aPosition == 'u') {
+    ++aPosition;
+
+    // 3. If the code point in input pointed to by position is U+0052 (R) or
+    //    U+0072 (r), then advance position to the next code point.
+    //    Otherwise, jump to the step labeled parse.
+    if (aPosition == aEnd || (*aPosition != 'R' && *aPosition != 'r')) {
+      return std::make_tuple(urlStart, urlEnd);
+    }
+
+    ++aPosition;
+
+    // 4. If the code point in input pointed to by position is U+004C (L) or
+    //    U+006C (l), then advance position to the next code point.
+    //    Otherwise, jump to the step labeled parse.
+    if (aPosition == aEnd || (*aPosition != 'L' && *aPosition != 'l')) {
+      return std::make_tuple(urlStart, urlEnd);
+    }
+
+    ++aPosition;
+
+    // 5. Skip ASCII whitespace within input given position.
+    aPosition = SkipASCIIWhitespace(aPosition, aEnd);
+
+    // 6. If the code point in input pointed to by position is U+003D (=),
+    //    then advance position to the next code point. Otherwise, jump to
+    //    the step labeled parse.
+    if (aPosition == aEnd || *aPosition != '=') {
+      return std::make_tuple(urlStart, urlEnd);
+    }
+
+    ++aPosition;
+
+    // 7. Skip ASCII whitespace within input given position.
+    aPosition = SkipASCIIWhitespace(aPosition, aEnd);
+  }
+
+  // 8. Skip quotes: If the code point in input pointed to by position is
+  //    U+0027 (') or U+0022 ("), then let quote be that code point, and
+  //    advance position to the next code point. Otherwise, let quote be
+  //    the empty string.
+  Maybe<char> quote;
+  if (aPosition != aEnd && (*aPosition == '\'' || *aPosition == '"')) {
+    quote.emplace(*aPosition);
+    ++aPosition;
+  }
+
+  // 9. Set urlString to the substring of input from the code point at
+  //    position to the end of the string.
+  urlStart = aPosition;
+  urlEnd = aEnd;
+
+  // 10. If quote is not the empty string, and there is a code point in
+  //     urlString equal to quote, then truncate urlString at that code
+  //     point, so that it and all subsequent code points are removed.
+  const char16_t* quotePos;
+  if (quote.isSome() &&
+      (quotePos = nsCharTraits<char16_t>::find(
+           urlStart, std::distance(urlStart, aEnd), quote.value()))) {
+    urlEnd = quotePos;
+  }
+
+  return std::make_tuple(urlStart, urlEnd);
+}
+
+void nsDocShell::SetupRefreshURIFromHeader(Document* aDocument,
+                                           const nsAString& aHeader) {
+  if (mIsBeingDestroyed) {
+    return;
+  }
+
+  const char16_t* position = aHeader.BeginReading();
+  const char16_t* end = aHeader.EndReading();
+
+  // See
+  // https://html.spec.whatwg.org/#pragma-directives:shared-declarative-refresh-steps.
+
+  // 3. Skip ASCII whitespace
+  position = SkipASCIIWhitespace(position, end);
+
+  // 4. Let time be 0.
+  CheckedInt<uint32_t> milliSeconds;
+
+  // 5. Collect a sequence of code points that are ASCII digits
+  const char16_t* digitsStart = position;
+  while (position != end && mozilla::IsAsciiDigit(*position)) {
+    ++position;
+  }
+
+  if (position == digitsStart) {
+    // 6. If timeString is the empty string, then:
+    //    1. If the code point in input pointed to by position is not U+002E
+    //       (.), then return.
+    if (position == end || *position != '.') {
+      return;
+    }
+  } else {
+    // 7. Otherwise, set time to the result of parsing timeString using the
+    //    rules for parsing non-negative integers.
+    nsContentUtils::ParseHTMLIntegerResultFlags result;
+    uint32_t seconds =
+        nsContentUtils::ParseHTMLInteger(digitsStart, position, &result);
+    MOZ_ASSERT(!(result & nsContentUtils::eParseHTMLInteger_Negative));
+    if (result & nsContentUtils::eParseHTMLInteger_Error) {
+      // The spec assumes no errors here (since we only pass ASCII digits in),
+      // but we can still overflow, so this block should deal with that (and
+      // only that).
+      MOZ_ASSERT(!(result & nsContentUtils::eParseHTMLInteger_ErrorOverflow));
+      return;
+    }
+    MOZ_ASSERT(
+        !(result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput));
+
+    milliSeconds = seconds;
+    milliSeconds *= 1000;
+    if (!milliSeconds.isValid()) {
+      return;
+    }
+  }
+
+  // 8. Collect a sequence of code points that are ASCII digits and U+002E FULL
+  //    STOP characters (.) from input given position. Ignore any collected
+  //    characters.
+  while (position != end &&
+         (mozilla::IsAsciiDigit(*position) || *position == '.')) {
+    ++position;
+  }
+
+  // 9. Let urlRecord be document's URL.
+  nsCOMPtr<nsIURI> urlRecord(aDocument->GetDocumentURI());
+
+  // 10. If position is not past the end of input
+  if (position != end) {
+    // 1. If the code point in input pointed to by position is not U+003B (;),
+    //    U+002C (,), or ASCII whitespace, then return.
+    if (*position != ';' && *position != ',' &&
+        !mozilla::IsAsciiWhitespace(*position)) {
+      return;
+    }
+
+    // 2. Skip ASCII whitespace within input given position.
+    position = SkipASCIIWhitespace(position, end);
+
+    // 3. If the code point in input pointed to by position is U+003B (;) or
+    //    U+002C (,), then advance position to the next code point.
+    if (position != end && (*position == ';' || *position == ',')) {
+      ++position;
+
+      // 4. Skip ASCII whitespace within input given position.
+      position = SkipASCIIWhitespace(position, end);
+    }
+
+    // 11. If position is not past the end of input, then:
+    if (position != end) {
+      const char16_t* urlStart;
+      const char16_t* urlEnd;
+
+      // 1-10. See ExtractURLString.
+      std::tie(urlStart, urlEnd) = ExtractURLString(position, end);
+
+      // 11. Parse: Parse urlString relative to document. If that fails, return.
+      //     Otherwise, set urlRecord to the resulting URL record.
+      nsresult rv =
+          NS_NewURI(getter_AddRefs(urlRecord),
+                    Substring(urlStart, std::distance(urlStart, urlEnd)),
+                    /* charset = */ nullptr, aDocument->GetDocBaseURI());
+      NS_ENSURE_SUCCESS_VOID(rv);
+    }
+  }
+
+  nsIPrincipal* principal = aDocument->NodePrincipal();
+  nsCOMPtr<nsIScriptSecurityManager> securityManager =
+      nsContentUtils::GetSecurityManager();
+  nsresult rv = securityManager->CheckLoadURIWithPrincipal(
+      principal, urlRecord,
+      nsIScriptSecurityManager::LOAD_IS_AUTOMATIC_DOCUMENT_REPLACEMENT,
+      aDocument->InnerWindowID());
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  bool isjs = true;
+  rv = NS_URIChainHasFlags(
+      urlRecord, nsIProtocolHandler::URI_OPENING_EXECUTES_SCRIPT, &isjs);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  if (isjs) {
+    return;
+  }
+
+  RefreshURI(urlRecord, principal, milliSeconds.value());
+}
+
+static void DoCancelRefreshURITimers(nsIMutableArray* aTimerList) {
+  if (!aTimerList) {
+    return;
+  }
+
+  uint32_t n = 0;
+  aTimerList->GetLength(&n);
+
+  while (n) {
+    nsCOMPtr<nsITimer> timer(do_QueryElementAt(aTimerList, --n));
+
+    aTimerList->RemoveElementAt(n);  // bye bye owning timer ref
+
+    if (timer) {
+      timer->Cancel();
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::CancelRefreshURITimers() {
+  DoCancelRefreshURITimers(mRefreshURIList);
+  DoCancelRefreshURITimers(mSavedRefreshURIList);
+  DoCancelRefreshURITimers(mBFCachedRefreshURIList);
+  mRefreshURIList = nullptr;
+  mSavedRefreshURIList = nullptr;
+  mBFCachedRefreshURIList = nullptr;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetRefreshPending(bool* aResult) {
+  if (!mRefreshURIList) {
+    *aResult = false;
+    return NS_OK;
+  }
+
+  uint32_t count;
+  nsresult rv = mRefreshURIList->GetLength(&count);
+  if (NS_SUCCEEDED(rv)) {
+    *aResult = (count != 0);
+  }
+  return rv;
+}
+
+void nsDocShell::RefreshURIToQueue() {
+  if (mRefreshURIList) {
+    uint32_t n = 0;
+    mRefreshURIList->GetLength(&n);
+
+    for (uint32_t i = 0; i < n; ++i) {
+      nsCOMPtr<nsITimer> timer = do_QueryElementAt(mRefreshURIList, i);
+      if (!timer) {
+        continue;  // this must be a nsRefreshURI already
+      }
+
+      // Replace this timer object with a nsRefreshTimer object.
+      nsCOMPtr<nsITimerCallback> callback;
+      timer->GetCallback(getter_AddRefs(callback));
+
+      timer->Cancel();
+
+      mRefreshURIList->ReplaceElementAt(callback, i);
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::SuspendRefreshURIs() {
+  RefreshURIToQueue();
+
+  // Suspend refresh URIs for our child shells as well.
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> shell = do_QueryObject(child);
+    if (shell) {
+      shell->SuspendRefreshURIs();
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::ResumeRefreshURIs() {
+  RefreshURIFromQueue();
+
+  // Resume refresh URIs for our child shells as well.
+  for (auto* child : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> shell = do_QueryObject(child);
+    if (shell) {
+      shell->ResumeRefreshURIs();
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::RefreshURIFromQueue() {
+  if (!mRefreshURIList) {
+    return NS_OK;
+  }
+  uint32_t n = 0;
+  mRefreshURIList->GetLength(&n);
+
+  while (n) {
+    nsCOMPtr<nsITimerCallback> refreshInfo =
+        do_QueryElementAt(mRefreshURIList, --n);
+
+    if (refreshInfo) {
+      // This is the nsRefreshTimer object, waiting to be
+      // setup in a timer object and fired.
+      // Create the timer and  trigger it.
+      uint32_t delay = static_cast<nsRefreshTimer*>(
+                           static_cast<nsITimerCallback*>(refreshInfo))
+                           ->GetDelay();
+      nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+      if (win) {
+        nsCOMPtr<nsITimer> timer;
+        NS_NewTimerWithCallback(getter_AddRefs(timer), refreshInfo, delay,
+                                nsITimer::TYPE_ONE_SHOT);
+
+        if (timer) {
+          // Replace the nsRefreshTimer element in the queue with
+          // its corresponding timer object, so that in case another
+          // load comes through before the timer can go off, the timer will
+          // get cancelled in CancelRefreshURITimer()
+          mRefreshURIList->ReplaceElementAt(timer, n);
+        }
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+static bool IsFollowupPartOfMultipart(nsIRequest* aRequest) {
+  nsCOMPtr<nsIMultiPartChannel> multiPartChannel = do_QueryInterface(aRequest);
+  bool firstPart = false;
+  return multiPartChannel &&
+         NS_SUCCEEDED(multiPartChannel->GetIsFirstPart(&firstPart)) &&
+         !firstPart;
+}
+
+nsresult nsDocShell::Embed(nsIContentViewer* aContentViewer,
+                           WindowGlobalChild* aWindowActor,
+                           bool aIsTransientAboutBlank, bool aPersist,
+                           nsIRequest* aRequest, nsIURI* aPreviousURI) {
+  // Save the LayoutHistoryState of the previous document, before
+  // setting up new document
+  PersistLayoutHistoryState();
+
+  nsresult rv = SetupNewViewer(aContentViewer, aWindowActor);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // XXX What if SetupNewViewer fails?
+  if (mozilla::SessionHistoryInParent() ? !!mLoadingEntry : !!mLSHE) {
+    // Set history.state
+    SetDocCurrentStateObj(mLSHE,
+                          mLoadingEntry ? &mLoadingEntry->mInfo : nullptr);
+  }
+
+  if (mLSHE) {
+    // Restore the editing state, if it's stored in session history.
+    if (mLSHE->HasDetachedEditor()) {
+      ReattachEditorToWindow(mLSHE);
+    }
+
+    SetHistoryEntryAndUpdateBC(Nothing(), Some<nsISHEntry*>(mLSHE));
+  }
+
+  if (!aIsTransientAboutBlank && mozilla::SessionHistoryInParent() &&
+      !IsFollowupPartOfMultipart(aRequest)) {
+    bool expired = false;
+    uint32_t cacheKey = 0;
+    nsCOMPtr<nsICacheInfoChannel> cacheChannel = do_QueryInterface(aRequest);
+    if (cacheChannel) {
+      // Check if the page has expired from cache
+      uint32_t expTime = 0;
+      cacheChannel->GetCacheTokenExpirationTime(&expTime);
+      uint32_t now = PRTimeToSeconds(PR_Now());
+      if (expTime <= now) {
+        expired = true;
+      }
+
+      // The checks for updating cache key are similar to the old session
+      // history in OnNewURI. Try to update the cache key if
+      //  - we should update session history and aren't doing a session
+      //    history load.
+      //  - we're doing a forced reload.
+      if (((!mLoadingEntry || !mLoadingEntry->mLoadIsFromSessionHistory) &&
+           mBrowsingContext->ShouldUpdateSessionHistory(mLoadType)) ||
+          IsForceReloadType(mLoadType)) {
+        cacheChannel->GetCacheKey(&cacheKey);
+      }
+    }
+
+    MOZ_LOG(gSHLog, LogLevel::Debug, ("document %p Embed", this));
+    MoveLoadingToActiveEntry(aPersist, expired, cacheKey, aPreviousURI);
+  }
+
+  bool updateHistory = true;
+
+  // Determine if this type of load should update history
+  switch (mLoadType) {
+    case LOAD_NORMAL_REPLACE:
+    case LOAD_REFRESH_REPLACE:
+    case LOAD_STOP_CONTENT_AND_REPLACE:
+    case LOAD_RELOAD_BYPASS_CACHE:
+    case LOAD_RELOAD_BYPASS_PROXY:
+    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
+    case LOAD_REPLACE_BYPASS_CACHE:
+      updateHistory = false;
+      break;
+    default:
+      break;
+  }
+
+  if (!updateHistory) {
+    SetLayoutHistoryState(nullptr);
+  }
+
+  return NS_OK;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIWebProgressListener
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::OnProgressChange(nsIWebProgress* aProgress, nsIRequest* aRequest,
+                             int32_t aCurSelfProgress, int32_t aMaxSelfProgress,
+                             int32_t aCurTotalProgress,
+                             int32_t aMaxTotalProgress) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStateChange(nsIWebProgress* aProgress, nsIRequest* aRequest,
+                          uint32_t aStateFlags, nsresult aStatus) {
+  if ((~aStateFlags & (STATE_START | STATE_IS_NETWORK)) == 0) {
+    // Save timing statistics.
+    nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+    nsCOMPtr<nsIURI> uri;
+    channel->GetURI(getter_AddRefs(uri));
+    nsAutoCString aURI;
+    uri->GetAsciiSpec(aURI);
+
+    if (this == aProgress) {
+      mozilla::Unused << MaybeInitTiming();
+      mTiming->NotifyFetchStart(uri,
+                                ConvertLoadTypeToNavigationType(mLoadType));
+      // If we are starting a DocumentChannel, we need to pass the timing
+      // statistics so that should a process switch occur, the starting type can
+      // be passed to the new DocShell running in the other content process.
+      if (RefPtr<DocumentChannel> docChannel = do_QueryObject(aRequest)) {
+        docChannel->SetNavigationTiming(mTiming);
+      }
+    }
+
+    // Page has begun to load
+    mBusyFlags = (BusyFlags)(BUSY_FLAGS_BUSY | BUSY_FLAGS_BEFORE_PAGE_LOAD);
+
+    if ((aStateFlags & STATE_RESTORING) == 0) {
+      // Show the progress cursor if the pref is set
+      if (StaticPrefs::ui_use_activity_cursor()) {
+        nsCOMPtr<nsIWidget> mainWidget;
+        GetMainWidget(getter_AddRefs(mainWidget));
+        if (mainWidget) {
+          mainWidget->SetCursor(nsIWidget::Cursor{eCursor_spinning});
+        }
+      }
+
+      if (StaticPrefs::browser_sessionstore_platform_collection_AtStartup()) {
+        if (IsForceReloadType(mLoadType)) {
+          if (WindowContext* windowContext =
+                  mBrowsingContext->GetCurrentWindowContext()) {
+            SessionStoreChild::From(windowContext->GetWindowGlobalChild())
+                ->ResetSessionStore(mBrowsingContext,
+                                    mBrowsingContext->GetSessionStoreEpoch());
+          }
+        }
+      }
+    }
+  } else if ((~aStateFlags & (STATE_TRANSFERRING | STATE_IS_DOCUMENT)) == 0) {
+    // Page is loading
+    mBusyFlags = (BusyFlags)(BUSY_FLAGS_BUSY | BUSY_FLAGS_PAGE_LOADING);
+  } else if ((aStateFlags & STATE_STOP) && (aStateFlags & STATE_IS_NETWORK)) {
+    // Page has finished loading
+    mBusyFlags = BUSY_FLAGS_NONE;
+
+    // Hide the progress cursor if the pref is set
+    if (StaticPrefs::ui_use_activity_cursor()) {
+      nsCOMPtr<nsIWidget> mainWidget;
+      GetMainWidget(getter_AddRefs(mainWidget));
+      if (mainWidget) {
+        mainWidget->SetCursor(nsIWidget::Cursor{eCursor_standard});
+      }
+    }
+  }
+
+  if ((~aStateFlags & (STATE_IS_DOCUMENT | STATE_STOP)) == 0) {
+    nsCOMPtr<nsIWebProgress> webProgress =
+        do_QueryInterface(GetAsSupports(this));
+    // Is the document stop notification for this document?
+    if (aProgress == webProgress.get()) {
+      nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+      EndPageLoad(aProgress, channel, aStatus);
+    }
+  }
+  // note that redirect state changes will go through here as well, but it
+  // is better to handle those in OnRedirectStateChange where more
+  // information is available.
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::OnLocationChange(nsIWebProgress* aProgress, nsIRequest* aRequest,
+                             nsIURI* aURI, uint32_t aFlags) {
+  // Since we've now changed Documents, notify the BrowsingContext that we've
+  // changed. Ideally we'd just let the BrowsingContext do this when it
+  // changes the current window global, but that happens before this and we
+  // have a lot of tests that depend on the specific ordering of messages.
+  bool isTopLevel = false;
+  if (XRE_IsParentProcess() &&
+      !(aFlags & nsIWebProgressListener::LOCATION_CHANGE_SAME_DOCUMENT) &&
+      NS_SUCCEEDED(aProgress->GetIsTopLevel(&isTopLevel)) && isTopLevel) {
+    GetBrowsingContext()->Canonical()->UpdateSecurityState();
+  }
+  return NS_OK;
+}
+
+void nsDocShell::OnRedirectStateChange(nsIChannel* aOldChannel,
+                                       nsIChannel* aNewChannel,
+                                       uint32_t aRedirectFlags,
+                                       uint32_t aStateFlags) {
+  NS_ASSERTION(aStateFlags & STATE_REDIRECTING,
+               "Calling OnRedirectStateChange when there is no redirect");
+
+  if (!(aStateFlags & STATE_IS_DOCUMENT)) {
+    return;  // not a toplevel document
+  }
+
+  nsCOMPtr<nsIURI> oldURI, newURI;
+  aOldChannel->GetURI(getter_AddRefs(oldURI));
+  aNewChannel->GetURI(getter_AddRefs(newURI));
+  if (!oldURI || !newURI) {
+    return;
+  }
+
+  // DocumentChannel adds redirect chain to global history in the parent
+  // process. The redirect chain can't be queried from the content process, so
+  // there's no need to update global history here.
+  RefPtr<DocumentChannel> docChannel = do_QueryObject(aOldChannel);
+  if (!docChannel) {
+    // Below a URI visit is saved (see AddURIVisit method doc).
+    // The visit chain looks something like:
+    //   ...
+    //   Site N - 1
+    //                =>  Site N
+    //   (redirect to =>) Site N + 1 (we are here!)
+
+    // Get N - 1 and transition type
+    nsCOMPtr<nsIURI> previousURI;
+    uint32_t previousFlags = 0;
+    ExtractLastVisit(aOldChannel, getter_AddRefs(previousURI), &previousFlags);
+
+    if (aRedirectFlags & nsIChannelEventSink::REDIRECT_INTERNAL ||
+        net::ChannelIsPost(aOldChannel)) {
+      // 1. Internal redirects are ignored because they are specific to the
+      //    channel implementation.
+      // 2. POSTs are not saved by global history.
+      //
+      // Regardless, we need to propagate the previous visit to the new
+      // channel.
+      SaveLastVisit(aNewChannel, previousURI, previousFlags);
+    } else {
+      // Get the HTTP response code, if available.
+      uint32_t responseStatus = 0;
+      nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aOldChannel);
+      if (httpChannel) {
+        Unused << httpChannel->GetResponseStatus(&responseStatus);
+      }
+
+      // Add visit N -1 => N
+      AddURIVisit(oldURI, previousURI, previousFlags, responseStatus);
+
+      // Since N + 1 could be the final destination, we will not save N => N + 1
+      // here.  OnNewURI will do that, so we will cache it.
+      SaveLastVisit(aNewChannel, oldURI, aRedirectFlags);
+    }
+  }
+
+  if (!(aRedirectFlags & nsIChannelEventSink::REDIRECT_INTERNAL) &&
+      mLoadType & (LOAD_CMD_RELOAD | LOAD_CMD_HISTORY)) {
+    mLoadType = LOAD_NORMAL_REPLACE;
+    SetHistoryEntryAndUpdateBC(Some(nullptr), Nothing());
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStatusChange(nsIWebProgress* aWebProgress, nsIRequest* aRequest,
+                           nsresult aStatus, const char16_t* aMessage) {
+  MOZ_ASSERT_UNREACHABLE("notification excluded in AddProgressListener(...)");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::OnSecurityChange(nsIWebProgress* aWebProgress, nsIRequest* aRequest,
+                             uint32_t aState) {
+  MOZ_ASSERT_UNREACHABLE("notification excluded in AddProgressListener(...)");
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::OnContentBlockingEvent(nsIWebProgress* aWebProgress,
+                                   nsIRequest* aRequest, uint32_t aEvent) {
+  MOZ_ASSERT_UNREACHABLE("notification excluded in AddProgressListener(...)");
+  return NS_OK;
+}
+
+already_AddRefed<nsIURIFixupInfo> nsDocShell::KeywordToURI(
+    const nsACString& aKeyword, bool aIsPrivateContext) {
+  nsCOMPtr<nsIURIFixupInfo> info;
+  if (!XRE_IsContentProcess()) {
+    nsCOMPtr<nsIURIFixup> uriFixup = components::URIFixup::Service();
+    if (uriFixup) {
+      uriFixup->KeywordToURI(aKeyword, aIsPrivateContext, getter_AddRefs(info));
+    }
+  }
+  return info.forget();
+}
+
+/* static */
+already_AddRefed<nsIURI> nsDocShell::MaybeFixBadCertDomainErrorURI(
+    nsIChannel* aChannel, nsIURI* aUrl) {
+  if (!aChannel) {
+    return nullptr;
+  }
+
+  nsresult rv = NS_OK;
+  nsAutoCString host;
+  rv = aUrl->GetAsciiHost(host);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // No point in going further if "www." is included in the hostname
+  // already. That is the only hueristic we're applying in this function.
+  if (StringBeginsWith(host, "www."_ns)) {
+    return nullptr;
+  }
+
+  // Return if fixup enable pref is turned off.
+  if (!mozilla::StaticPrefs::security_bad_cert_domain_error_url_fix_enabled()) {
+    return nullptr;
+  }
+
+  // Return if scheme is not HTTPS.
+  if (!SchemeIsHTTPS(aUrl)) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsILoadInfo> info = aChannel->LoadInfo();
+  if (!info) {
+    return nullptr;
+  }
+
+  // Skip doing the fixup if our channel was redirected, because we
+  // shouldn't be guessing things about the post-redirect URI.
+  if (!info->RedirectChain().IsEmpty()) {
+    return nullptr;
+  }
+
+  int32_t port = 0;
+  rv = aUrl->GetPort(&port);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // Don't fix up hosts with ports.
+  if (port != -1) {
+    return nullptr;
+  }
+
+  // Don't fix up localhost url.
+  if (host == "localhost") {
+    return nullptr;
+  }
+
+  // Don't fix up hostnames with IP address.
+  if (net_IsValidIPv4Addr(host) || net_IsValidIPv6Addr(host)) {
+    return nullptr;
+  }
+
+  nsAutoCString userPass;
+  rv = aUrl->GetUserPass(userPass);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // Security - URLs with user / password info should NOT be modified.
+  if (!userPass.IsEmpty()) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsITransportSecurityInfo> tsi;
+  rv = aChannel->GetSecurityInfo(getter_AddRefs(tsi));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  if (NS_WARN_IF(!tsi)) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIX509Cert> cert;
+  rv = tsi->GetServerCert(getter_AddRefs(cert));
+  if (NS_WARN_IF(NS_FAILED(rv) || !cert)) {
+    return nullptr;
+  }
+
+  nsTArray<uint8_t> certBytes;
+  rv = cert->GetRawDER(certBytes);
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  mozilla::pkix::Input serverCertInput;
+  mozilla::pkix::Result rv1 =
+      serverCertInput.Init(certBytes.Elements(), certBytes.Length());
+  if (rv1 != mozilla::pkix::Success) {
+    return nullptr;
+  }
+
+  nsAutoCString newHost("www."_ns);
+  newHost.Append(host);
+
+  mozilla::pkix::Input newHostInput;
+  rv1 = newHostInput.Init(
+      BitwiseCast<const uint8_t*, const char*>(newHost.BeginReading()),
+      newHost.Length());
+  if (rv1 != mozilla::pkix::Success) {
+    return nullptr;
+  }
+
+  // Check if adding a "www." prefix to the request's hostname will
+  // cause the response's certificate to match.
+  rv1 = mozilla::pkix::CheckCertHostname(serverCertInput, newHostInput);
+  if (rv1 != mozilla::pkix::Success) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIURI> newURI;
+  Unused << NS_MutateURI(aUrl).SetHost(newHost).Finalize(
+      getter_AddRefs(newURI));
+
+  return newURI.forget();
+}
+
+/* static */
+already_AddRefed<nsIURI> nsDocShell::AttemptURIFixup(
+    nsIChannel* aChannel, nsresult aStatus,
+    const mozilla::Maybe<nsCString>& aOriginalURIString, uint32_t aLoadType,
+    bool aIsTopFrame, bool aAllowKeywordFixup, bool aUsePrivateBrowsing,
+    bool aNotifyKeywordSearchLoading, nsIInputStream** aNewPostData) {
+  if (aStatus != NS_ERROR_UNKNOWN_HOST && aStatus != NS_ERROR_NET_RESET &&
+      aStatus != NS_ERROR_CONNECTION_REFUSED &&
+      aStatus !=
+          mozilla::psm::GetXPCOMFromNSSError(SSL_ERROR_BAD_CERT_DOMAIN)) {
+    return nullptr;
+  }
+
+  if (!(aLoadType == LOAD_NORMAL && aIsTopFrame) && !aAllowKeywordFixup) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIURI> url;
+  nsresult rv = aChannel->GetURI(getter_AddRefs(url));
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  //
+  // Try and make an alternative URI from the old one
+  //
+  nsCOMPtr<nsIURI> newURI;
+  nsCOMPtr<nsIInputStream> newPostData;
+
+  nsAutoCString oldSpec;
+  url->GetSpec(oldSpec);
+
+  //
+  // First try keyword fixup
+  //
+  nsAutoString keywordProviderName, keywordAsSent;
+  if (aStatus == NS_ERROR_UNKNOWN_HOST && aAllowKeywordFixup) {
+    // we should only perform a keyword search under the following
+    // conditions:
+    // (0) Pref keyword.enabled is true
+    // (1) the url scheme is http (or https)
+    // (2) the url does not have a protocol scheme
+    // If we don't enforce such a policy, then we end up doing
+    // keyword searchs on urls we don't intend like imap, file,
+    // mailbox, etc. This could lead to a security problem where we
+    // send data to the keyword server that we shouldn't be.
+    // Someone needs to clean up keywords in general so we can
+    // determine on a per url basis if we want keywords
+    // enabled...this is just a bandaid...
+    nsAutoCString scheme;
+    Unused << url->GetScheme(scheme);
+    if (Preferences::GetBool("keyword.enabled", false) &&
+        StringBeginsWith(scheme, "http"_ns)) {
+      bool attemptFixup = false;
+      nsAutoCString host;
+      Unused << url->GetHost(host);
+      if (host.FindChar('.') == kNotFound) {
+        attemptFixup = true;
+      } else {
+        // For domains with dots, we check the public suffix validity.
+        nsCOMPtr<nsIEffectiveTLDService> tldService =
+            do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);
+        if (tldService) {
+          nsAutoCString suffix;
+          attemptFixup =
+              NS_SUCCEEDED(tldService->GetKnownPublicSuffix(url, suffix)) &&
+              suffix.IsEmpty();
+        }
+      }
+      if (attemptFixup) {
+        nsCOMPtr<nsIURIFixupInfo> info;
+        // only send non-qualified hosts to the keyword server
+        if (aOriginalURIString && !aOriginalURIString->IsEmpty()) {
+          info = KeywordToURI(*aOriginalURIString, aUsePrivateBrowsing);
+        } else {
+          //
+          // If this string was passed through nsStandardURL by
+          // chance, then it may have been converted from UTF-8 to
+          // ACE, which would result in a completely bogus keyword
+          // query.  Here we try to recover the original Unicode
+          // value, but this is not 100% correct since the value may
+          // have been normalized per the IDN normalization rules.
+          //
+          // Since we don't have access to the exact original string
+          // that was entered by the user, this will just have to do.
+          bool isACE;
+          nsAutoCString utf8Host;
+          nsCOMPtr<nsIIDNService> idnSrv =
+              do_GetService(NS_IDNSERVICE_CONTRACTID);
+          if (idnSrv && NS_SUCCEEDED(idnSrv->IsACE(host, &isACE)) && isACE &&
+              NS_SUCCEEDED(idnSrv->ConvertACEtoUTF8(host, utf8Host))) {
+            info = KeywordToURI(utf8Host, aUsePrivateBrowsing);
+
+          } else {
+            info = KeywordToURI(host, aUsePrivateBrowsing);
+          }
+        }
+        if (info) {
+          info->GetPreferredURI(getter_AddRefs(newURI));
+          if (newURI) {
+            info->GetKeywordAsSent(keywordAsSent);
+            info->GetKeywordProviderName(keywordProviderName);
+            info->GetPostData(getter_AddRefs(newPostData));
+          }
+        }
+      }
+    }
+  }
+
+  //
+  // Now try change the address, e.g. turn http://foo into
+  // http://www.foo.com, and if that doesn't work try https with
+  // https://foo and https://www.foo.com.
+  //
+  if (aStatus == NS_ERROR_UNKNOWN_HOST || aStatus == NS_ERROR_NET_RESET) {
+    // Skip fixup for anything except a normal document load
+    // operation on the topframe.
+    bool doCreateAlternate = aLoadType == LOAD_NORMAL && aIsTopFrame;
+
+    if (doCreateAlternate) {
+      nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+      nsIPrincipal* principal = loadInfo->TriggeringPrincipal();
+      // Only do this if our channel was loaded directly by the user from the
+      // URL bar or similar (system principal) and not redirected, because we
+      // shouldn't be guessing things about links from other sites, or a
+      // post-redirect URI.
+      doCreateAlternate = principal && principal->IsSystemPrincipal() &&
+                          loadInfo->RedirectChain().IsEmpty();
+    }
+    // Test if keyword lookup produced a new URI or not
+    if (doCreateAlternate && newURI) {
+      bool sameURI = false;
+      url->Equals(newURI, &sameURI);
+      if (!sameURI) {
+        // Keyword lookup made a new URI so no need to try
+        // an alternate one.
+        doCreateAlternate = false;
+      }
+    }
+    if (doCreateAlternate) {
+      newURI = nullptr;
+      newPostData = nullptr;
+      keywordProviderName.Truncate();
+      keywordAsSent.Truncate();
+      nsCOMPtr<nsIURIFixup> uriFixup = components::URIFixup::Service();
+      if (uriFixup) {
+        nsCOMPtr<nsIURIFixupInfo> fixupInfo;
+        uriFixup->GetFixupURIInfo(oldSpec,
+                                  nsIURIFixup::FIXUP_FLAGS_MAKE_ALTERNATE_URI,
+                                  getter_AddRefs(fixupInfo));
+        if (fixupInfo) {
+          fixupInfo->GetPreferredURI(getter_AddRefs(newURI));
+        }
+      }
+    }
+  } else if (aStatus == NS_ERROR_CONNECTION_REFUSED &&
+             Preferences::GetBool("browser.fixup.fallback-to-https", false)) {
+    // Try HTTPS, since http didn't work
+    if (SchemeIsHTTP(url)) {
+      int32_t port = 0;
+      url->GetPort(&port);
+
+      // Fall back to HTTPS only if port is default
+      if (port == -1) {
+        newURI = nullptr;
+        newPostData = nullptr;
+        Unused << NS_MutateURI(url)
+                      .SetScheme("https"_ns)
+                      .Finalize(getter_AddRefs(newURI));
+      }
+    }
+  }
+
+  // If we have a SSL_ERROR_BAD_CERT_DOMAIN error, try prefixing the domain name
+  // with www. to see if we can avoid showing the cert error page. For example,
+  // https://example.com -> https://www.example.com.
+  if (aStatus ==
+      mozilla::psm::GetXPCOMFromNSSError(SSL_ERROR_BAD_CERT_DOMAIN)) {
+    newPostData = nullptr;
+    newURI = MaybeFixBadCertDomainErrorURI(aChannel, url);
+  }
+
+  // Did we make a new URI that is different to the old one? If so
+  // load it.
+  //
+  if (newURI) {
+    // Make sure the new URI is different from the old one,
+    // otherwise there's little point trying to load it again.
+    bool sameURI = false;
+    url->Equals(newURI, &sameURI);
+    if (!sameURI) {
+      if (aNewPostData) {
+        newPostData.forget(aNewPostData);
+      }
+      if (aNotifyKeywordSearchLoading) {
+        // This notification is meant for Firefox Health Report so it
+        // can increment counts from the search engine
+        MaybeNotifyKeywordSearchLoading(keywordProviderName, keywordAsSent);
+      }
+      return newURI.forget();
+    }
+  }
+
+  return nullptr;
+}
+
+nsresult nsDocShell::FilterStatusForErrorPage(
+    nsresult aStatus, nsIChannel* aChannel, uint32_t aLoadType,
+    bool aIsTopFrame, bool aUseErrorPages, bool aIsInitialDocument,
+    bool* aSkippedUnknownProtocolNavigation) {
+  // Errors to be shown only on top-level frames
+  if ((aStatus == NS_ERROR_UNKNOWN_HOST ||
+       aStatus == NS_ERROR_CONNECTION_REFUSED ||
+       aStatus == NS_ERROR_UNKNOWN_PROXY_HOST ||
+       aStatus == NS_ERROR_PROXY_CONNECTION_REFUSED ||
+       aStatus == NS_ERROR_PROXY_FORBIDDEN ||
+       aStatus == NS_ERROR_PROXY_NOT_IMPLEMENTED ||
+       aStatus == NS_ERROR_PROXY_AUTHENTICATION_FAILED ||
+       aStatus == NS_ERROR_PROXY_TOO_MANY_REQUESTS ||
+       aStatus == NS_ERROR_MALFORMED_URI ||
+       aStatus == NS_ERROR_BLOCKED_BY_POLICY ||
+       aStatus == NS_ERROR_DOM_COOP_FAILED ||
+       aStatus == NS_ERROR_DOM_COEP_FAILED) &&
+      (aIsTopFrame || aUseErrorPages)) {
+    return aStatus;
+  }
+
+  if (aStatus == NS_ERROR_NET_TIMEOUT ||
+      aStatus == NS_ERROR_NET_TIMEOUT_EXTERNAL ||
+      aStatus == NS_ERROR_PROXY_GATEWAY_TIMEOUT ||
+      aStatus == NS_ERROR_REDIRECT_LOOP ||
+      aStatus == NS_ERROR_UNKNOWN_SOCKET_TYPE ||
+      aStatus == NS_ERROR_NET_INTERRUPT || aStatus == NS_ERROR_NET_RESET ||
+      aStatus == NS_ERROR_PROXY_BAD_GATEWAY || aStatus == NS_ERROR_OFFLINE ||
+      aStatus == NS_ERROR_MALWARE_URI || aStatus == NS_ERROR_PHISHING_URI ||
+      aStatus == NS_ERROR_UNWANTED_URI || aStatus == NS_ERROR_HARMFUL_URI ||
+      aStatus == NS_ERROR_UNSAFE_CONTENT_TYPE ||
+      aStatus == NS_ERROR_INTERCEPTION_FAILED ||
+      aStatus == NS_ERROR_NET_INADEQUATE_SECURITY ||
+      aStatus == NS_ERROR_NET_HTTP2_SENT_GOAWAY ||
+      aStatus == NS_ERROR_NET_HTTP3_PROTOCOL_ERROR ||
+      aStatus == NS_ERROR_DOM_BAD_URI || aStatus == NS_ERROR_FILE_NOT_FOUND ||
+      aStatus == NS_ERROR_FILE_ACCESS_DENIED ||
+      aStatus == NS_ERROR_CORRUPTED_CONTENT ||
+      aStatus == NS_ERROR_INVALID_CONTENT_ENCODING ||
+      NS_ERROR_GET_MODULE(aStatus) == NS_ERROR_MODULE_SECURITY) {
+    // Errors to be shown for any frame
+    return aStatus;
+  }
+
+  if (aStatus == NS_ERROR_UNKNOWN_PROTOCOL) {
+    // For unknown protocols we only display an error if the load is triggered
+    // by the browser itself, or we're replacing the initial document (and
+    // nothing else). Showing the error for page-triggered navigations causes
+    // annoying behavior for users, see bug 1528305.
+    //
+    // We could, maybe, try to detect if this is in response to some user
+    // interaction (like clicking a link, or something else) and maybe show
+    // the error page in that case. But this allows for ctrl+clicking and such
+    // to see the error page.
+    nsCOMPtr<nsILoadInfo> info = aChannel->LoadInfo();
+    if (!info->TriggeringPrincipal()->IsSystemPrincipal() &&
+        StaticPrefs::dom_no_unknown_protocol_error_enabled() &&
+        !aIsInitialDocument) {
+      if (aSkippedUnknownProtocolNavigation) {
+        *aSkippedUnknownProtocolNavigation = true;
+      }
+      return NS_OK;
+    }
+    return aStatus;
+  }
+
+  if (aStatus == NS_ERROR_DOCUMENT_NOT_CACHED) {
+    // Non-caching channels will simply return NS_ERROR_OFFLINE.
+    // Caching channels would have to look at their flags to work
+    // out which error to return. Or we can fix up the error here.
+    if (!(aLoadType & LOAD_CMD_HISTORY)) {
+      return NS_ERROR_OFFLINE;
+    }
+    return aStatus;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::EndPageLoad(nsIWebProgress* aProgress,
+                                 nsIChannel* aChannel, nsresult aStatus) {
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug,
+          ("DOCSHELL %p EndPageLoad status: %" PRIx32 "\n", this,
+           static_cast<uint32_t>(aStatus)));
+  if (!aChannel) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  // Make sure to discard the initial client if we never created the initial
+  // about:blank document.  Do this before possibly returning from the method
+  // due to an error.
+  mInitialClientSource.reset();
+
+  nsCOMPtr<nsIConsoleReportCollector> reporter = do_QueryInterface(aChannel);
+  if (reporter) {
+    nsCOMPtr<nsILoadGroup> loadGroup;
+    aChannel->GetLoadGroup(getter_AddRefs(loadGroup));
+    if (loadGroup) {
+      reporter->FlushConsoleReports(loadGroup);
+    } else {
+      reporter->FlushConsoleReports(GetDocument());
+    }
+  }
+
+  nsCOMPtr<nsIURI> url;
+  nsresult rv = aChannel->GetURI(getter_AddRefs(url));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsITimedChannel> timingChannel = do_QueryInterface(aChannel);
+  if (timingChannel) {
+    TimeStamp channelCreationTime;
+    rv = timingChannel->GetChannelCreation(&channelCreationTime);
+    if (NS_SUCCEEDED(rv) && !channelCreationTime.IsNull()) {
+      Telemetry::AccumulateTimeDelta(Telemetry::TOTAL_CONTENT_PAGE_LOAD_TIME,
+                                     channelCreationTime);
+    }
+  }
+
+  // Timing is picked up by the window, we don't need it anymore
+  mTiming = nullptr;
+
+  // clean up reload state for meta charset
+  if (eCharsetReloadRequested == mCharsetReloadState) {
+    mCharsetReloadState = eCharsetReloadStopOrigional;
+  } else {
+    mCharsetReloadState = eCharsetReloadInit;
+  }
+
+  // Save a pointer to the currently-loading history entry.
+  // nsDocShell::EndPageLoad will clear mLSHE, but we may need this history
+  // entry further down in this method.
+  nsCOMPtr<nsISHEntry> loadingSHE = mLSHE;
+  mozilla::Unused << loadingSHE;  // XXX: Not sure if we need this anymore
+
+  //
+  // one of many safeguards that prevent death and destruction if
+  // someone is so very very rude as to bring this window down
+  // during this load handler.
+  //
+  nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
+
+  // Notify the ContentViewer that the Document has finished loading.  This
+  // will cause any OnLoad(...) and PopState(...) handlers to fire.
+  if (!mEODForCurrentDocument && mContentViewer) {
+    mIsExecutingOnLoadHandler = true;
+    nsCOMPtr<nsIContentViewer> contentViewer = mContentViewer;
+    contentViewer->LoadComplete(aStatus);
+    mIsExecutingOnLoadHandler = false;
+
+    mEODForCurrentDocument = true;
+  }
+  /* Check if the httpChannel has any cache-control related response headers,
+   * like no-store, no-cache. If so, update SHEntry so that
+   * when a user goes back/forward to this page, we appropriately do
+   * form value restoration or load from server.
+   */
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aChannel));
+  if (!httpChannel) {
+    // HttpChannel could be hiding underneath a Multipart channel.
+    GetHttpChannel(aChannel, getter_AddRefs(httpChannel));
+  }
+
+  if (httpChannel) {
+    // figure out if SH should be saving layout state.
+    bool discardLayoutState = ShouldDiscardLayoutState(httpChannel);
+    if (mLSHE && discardLayoutState && (mLoadType & LOAD_CMD_NORMAL) &&
+        (mLoadType != LOAD_BYPASS_HISTORY) && (mLoadType != LOAD_ERROR_PAGE)) {
+      mLSHE->SetSaveLayoutStateFlag(false);
+    }
+  }
+
+  // Clear mLSHE after calling the onLoadHandlers. This way, if the
+  // onLoadHandler tries to load something different in
+  // itself or one of its children, we can deal with it appropriately.
+  if (mLSHE) {
+    mLSHE->SetLoadType(LOAD_HISTORY);
+
+    // Clear the mLSHE reference to indicate document loading is done one
+    // way or another.
+    SetHistoryEntryAndUpdateBC(Some(nullptr), Nothing());
+  }
+  mActiveEntryIsLoadingFromSessionHistory = false;
+
+  // if there's a refresh header in the channel, this method
+  // will set it up for us.
+  if (mBrowsingContext->IsActive() || !mDisableMetaRefreshWhenInactive)
+    RefreshURIFromQueue();
+
+  // Test whether this is the top frame or a subframe
+  bool isTopFrame = mBrowsingContext->IsTop();
+
+  bool hadErrorStatus = false;
+  // If status code indicates an error it means that DocumentChannel already
+  // tried to fixup the uri and failed. Throw an error dialog box here.
+  if (NS_FAILED(aStatus)) {
+    // If we got CONTENT_BLOCKED from EndPageLoad, then we need to fire
+    // the error event to our embedder, since tests are relying on this.
+    // The error event is usually fired by the caller of InternalLoad, but
+    // this particular error can happen asynchronously.
+    // Bug 1629201 is filed for having much clearer decision making around
+    // which cases need error events.
+    bool fireFrameErrorEvent = (aStatus == NS_ERROR_CONTENT_BLOCKED_SHOW_ALT ||
+                                aStatus == NS_ERROR_CONTENT_BLOCKED);
+    UnblockEmbedderLoadEventForFailure(fireFrameErrorEvent);
+
+    bool isInitialDocument =
+        !GetExtantDocument() || GetExtantDocument()->IsInitialDocument();
+    bool skippedUnknownProtocolNavigation = false;
+    aStatus = FilterStatusForErrorPage(aStatus, aChannel, mLoadType, isTopFrame,
+                                       mBrowsingContext->GetUseErrorPages(),
+                                       isInitialDocument,
+                                       &skippedUnknownProtocolNavigation);
+    hadErrorStatus = true;
+    if (NS_FAILED(aStatus)) {
+      if (!mIsBeingDestroyed) {
+        DisplayLoadError(aStatus, url, nullptr, aChannel);
+      }
+    } else if (skippedUnknownProtocolNavigation) {
+      nsTArray<nsString> params;
+      if (NS_FAILED(
+              NS_GetSanitizedURIStringFromURI(url, *params.AppendElement()))) {
+        params.LastElement().AssignLiteral(u"(unknown uri)");
+      }
+      nsContentUtils::ReportToConsole(
+          nsIScriptError::warningFlag, "DOM"_ns, GetExtantDocument(),
+          nsContentUtils::eDOM_PROPERTIES, "UnknownProtocolNavigationPrevented",
+          params);
+    }
+  } else {
+    // If we have a host
+    nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+    PredictorLearnRedirect(url, aChannel, loadInfo->GetOriginAttributes());
+  }
+
+  if (hadErrorStatus) {
+    // Don't send session store updates if the reason EndPageLoad was called is
+    // because we are process switching. Sometimes the update takes too long and
+    // incorrectly overrides session store data from the following load.
+    return NS_OK;
+  }
+  if (StaticPrefs::browser_sessionstore_platform_collection_AtStartup()) {
+    if (WindowContext* windowContext =
+            mBrowsingContext->GetCurrentWindowContext()) {
+      using Change = SessionStoreChangeListener::Change;
+
+      // We've finished loading the page and now we want to collect all the
+      // session store state that the page is initialized with.
+      SessionStoreChangeListener::CollectSessionStoreData(
+          windowContext,
+          EnumSet<Change>(Change::Input, Change::Scroll, Change::SessionHistory,
+                          Change::WireFrame));
+    }
+  }
+
+  return NS_OK;
+}
+
+//*****************************************************************************
+// nsDocShell: Content Viewer Management
+//*****************************************************************************
+
+nsresult nsDocShell::EnsureContentViewer() {
+  if (mContentViewer) {
+    return NS_OK;
+  }
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIContentSecurityPolicy> cspToInheritForAboutBlank;
+  nsCOMPtr<nsIURI> baseURI;
+  nsIPrincipal* principal = GetInheritedPrincipal(false);
+  nsIPrincipal* partitionedPrincipal = GetInheritedPrincipal(false, true);
+
+  nsCOMPtr<nsIDocShellTreeItem> parentItem;
+  GetInProcessSameTypeParent(getter_AddRefs(parentItem));
+  if (parentItem) {
+    if (nsCOMPtr<nsPIDOMWindowOuter> domWin = GetWindow()) {
+      nsCOMPtr<Element> parentElement = domWin->GetFrameElementInternal();
+      if (parentElement) {
+        baseURI = parentElement->GetBaseURI();
+        cspToInheritForAboutBlank = parentElement->GetCsp();
+      }
+    }
+  }
+
+  nsresult rv = CreateAboutBlankContentViewer(
+      principal, partitionedPrincipal, cspToInheritForAboutBlank, baseURI,
+      /* aIsInitialDocument */ true);
+
+  NS_ENSURE_STATE(mContentViewer);
+
+  if (NS_SUCCEEDED(rv)) {
+    RefPtr<Document> doc(GetDocument());
+    MOZ_ASSERT(doc,
+               "Should have doc if CreateAboutBlankContentViewer "
+               "succeeded!");
+    MOZ_ASSERT(doc->IsInitialDocument(), "Document should be initial document");
+
+    // Documents created using EnsureContentViewer may be transient
+    // placeholders created by framescripts before content has a
+    // chance to load. In some cases, window.open(..., "noopener")
+    // will create such a document and then synchronously tear it
+    // down, firing a "pagehide" event. Doing so violates our
+    // assertions about DocGroups. It's easier to silence the
+    // assertion here than to avoid creating the extra document.
+    doc->IgnoreDocGroupMismatches();
+  }
+
+  return rv;
+}
+
+nsresult nsDocShell::CreateAboutBlankContentViewer(
+    nsIPrincipal* aPrincipal, nsIPrincipal* aPartitionedPrincipal,
+    nsIContentSecurityPolicy* aCSP, nsIURI* aBaseURI, bool aIsInitialDocument,
+    const Maybe<nsILoadInfo::CrossOriginEmbedderPolicy>& aCOEP,
+    bool aTryToSaveOldPresentation, bool aCheckPermitUnload,
+    WindowGlobalChild* aActor) {
+  RefPtr<Document> blankDoc;
+  nsCOMPtr<nsIContentViewer> viewer;
+  nsresult rv = NS_ERROR_FAILURE;
+
+  MOZ_ASSERT_IF(aActor, aActor->DocumentPrincipal() == aPrincipal);
+
+  /* mCreatingDocument should never be true at this point. However, it's
+     a theoretical possibility. We want to know about it and make it stop,
+     and this sounds like a job for an assertion. */
+  NS_ASSERTION(!mCreatingDocument,
+               "infinite(?) loop creating document averted");
+  if (mCreatingDocument) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (!mBrowsingContext->AncestorsAreCurrent() ||
+      mBrowsingContext->IsInBFCache()) {
+    mBrowsingContext->RemoveRootFromBFCacheSync();
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // mContentViewer->PermitUnload may release |this| docshell.
+  nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
+
+  AutoRestore<bool> creatingDocument(mCreatingDocument);
+  mCreatingDocument = true;
+
+  if (aPrincipal && !aPrincipal->IsSystemPrincipal() &&
+      mItemType != typeChrome) {
+    MOZ_ASSERT(aPrincipal->OriginAttributesRef() ==
+               mBrowsingContext->OriginAttributesRef());
+  }
+
+  // Make sure timing is created.  But first record whether we had it
+  // already, so we don't clobber the timing for an in-progress load.
+  bool hadTiming = mTiming;
+  bool toBeReset = MaybeInitTiming();
+  if (mContentViewer) {
+    if (aCheckPermitUnload) {
+      // We've got a content viewer already. Make sure the user
+      // permits us to discard the current document and replace it
+      // with about:blank. And also ensure we fire the unload events
+      // in the current document.
+
+      // Unload gets fired first for
+      // document loaded from the session history.
+      mTiming->NotifyBeforeUnload();
+
+      bool okToUnload;
+      rv = mContentViewer->PermitUnload(&okToUnload);
+
+      if (NS_SUCCEEDED(rv) && !okToUnload) {
+        // The user chose not to unload the page, interrupt the load.
+        MaybeResetInitTiming(toBeReset);
+        return NS_ERROR_FAILURE;
+      }
+      if (mTiming) {
+        mTiming->NotifyUnloadAccepted(mCurrentURI);
+      }
+    }
+
+    mSavingOldViewer =
+        aTryToSaveOldPresentation &&
+        CanSavePresentation(LOAD_NORMAL, nullptr, nullptr,
+                            /* aReportBFCacheComboTelemetry */ true);
+
+    // Make sure to blow away our mLoadingURI just in case.  No loads
+    // from inside this pagehide.
+    mLoadingURI = nullptr;
+
+    // Stop any in-progress loading, so that we don't accidentally trigger any
+    // PageShow notifications from Embed() interrupting our loading below.
+    Stop();
+
+    // Notify the current document that it is about to be unloaded!!
+    //
+    // It is important to fire the unload() notification *before* any state
+    // is changed within the DocShell - otherwise, javascript will get the
+    // wrong information :-(
+    //
+    (void)FirePageHideNotification(!mSavingOldViewer);
+    // pagehide notification might destroy this docshell.
+    if (mIsBeingDestroyed) {
+      return NS_ERROR_DOCSHELL_DYING;
+    }
+  }
+
+  // Now make sure we don't think we're in the middle of firing unload after
+  // this point.  This will make us fire unload when the about:blank document
+  // unloads... but that's ok, more or less.  Would be nice if it fired load
+  // too, of course.
+  mFiredUnloadEvent = false;
+
+  nsCOMPtr<nsIDocumentLoaderFactory> docFactory =
+      nsContentUtils::FindInternalContentViewer("text/html"_ns);
+
+  if (docFactory) {
+    nsCOMPtr<nsIPrincipal> principal, partitionedPrincipal;
+    const uint32_t sandboxFlags =
+        mBrowsingContext->GetHasLoadedNonInitialDocument()
+            ? mBrowsingContext->GetSandboxFlags()
+            : mBrowsingContext->GetInitialSandboxFlags();
+    // If we're sandboxed, then create a new null principal. We skip
+    // this if we're being created from WindowGlobalChild, since in
+    // that case we already have a null principal if required.
+    // We can't compare againt the BrowsingContext sandbox flag, since
+    // the value was taken when the load initiated and may have since
+    // changed.
+    if ((sandboxFlags & SANDBOXED_ORIGIN) && !aActor) {
+      if (aPrincipal) {
+        principal = NullPrincipal::CreateWithInheritedAttributes(aPrincipal);
+      } else {
+        principal = NullPrincipal::Create(GetOriginAttributes());
+      }
+      partitionedPrincipal = principal;
+    } else {
+      principal = aPrincipal;
+      partitionedPrincipal = aPartitionedPrincipal;
+    }
+
+    // We cannot get the foreign partitioned prinicpal for the initial
+    // about:blank page. So, we change to check if we need to use the
+    // partitioned principal for the service worker here.
+    MaybeCreateInitialClientSource(
+        StoragePrincipalHelper::ShouldUsePartitionPrincipalForServiceWorker(
+            this)
+            ? partitionedPrincipal
+            : principal);
+
+    // generate (about:blank) document to load
+    blankDoc = nsContentDLF::CreateBlankDocument(mLoadGroup, principal,
+                                                 partitionedPrincipal, this);
+    if (blankDoc) {
+      // Hack: manually set the CSP for the new document
+      // Please create an actual copy of the CSP (do not share the same
+      // reference) otherwise appending a new policy within the new
+      // document will be incorrectly propagated to the opening doc.
+      if (aCSP) {
+        RefPtr<nsCSPContext> cspToInherit = new nsCSPContext();
+        cspToInherit->InitFromOther(static_cast<nsCSPContext*>(aCSP));
+        blankDoc->SetCsp(cspToInherit);
+      }
+
+      blankDoc->SetIsInitialDocument(aIsInitialDocument);
+
+      blankDoc->SetEmbedderPolicy(aCOEP);
+
+      // Hack: set the base URI manually, since this document never
+      // got Reset() with a channel.
+      blankDoc->SetBaseURI(aBaseURI);
+
+      // Copy our sandbox flags to the document. These are immutable
+      // after being set here.
+      blankDoc->SetSandboxFlags(sandboxFlags);
+
+      blankDoc->InitFeaturePolicy();
+
+      // create a content viewer for us and the new document
+      docFactory->CreateInstanceForDocument(
+          NS_ISUPPORTS_CAST(nsIDocShell*, this), blankDoc, "view",
+          getter_AddRefs(viewer));
+
+      // hook 'em up
+      if (viewer) {
+        viewer->SetContainer(this);
+        rv = Embed(viewer, aActor, true, false, nullptr, mCurrentURI);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        SetCurrentURI(blankDoc->GetDocumentURI(), nullptr,
+                      /* aFireLocationChange */ true,
+                      /* aIsInitialAboutBlank */ true,
+                      /* aLocationFlags */ 0);
+        rv = mIsBeingDestroyed ? NS_ERROR_NOT_AVAILABLE : NS_OK;
+      }
+    }
+  }
+
+  // The transient about:blank viewer doesn't have a session history entry.
+  SetHistoryEntryAndUpdateBC(Nothing(), Some(nullptr));
+
+  // Clear out our mTiming like we would in EndPageLoad, if we didn't
+  // have one before entering this function.
+  if (!hadTiming) {
+    mTiming = nullptr;
+    mBlankTiming = true;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocShell::CreateAboutBlankContentViewer(nsIPrincipal* aPrincipal,
+                                          nsIPrincipal* aPartitionedPrincipal,
+                                          nsIContentSecurityPolicy* aCSP) {
+  return CreateAboutBlankContentViewer(aPrincipal, aPartitionedPrincipal, aCSP,
+                                       nullptr, /* aIsInitialDocument */ false);
+}
+
+nsresult nsDocShell::CreateContentViewerForActor(
+    WindowGlobalChild* aWindowActor) {
+  MOZ_ASSERT(aWindowActor);
+
+  // FIXME: WindowGlobalChild should provide the PartitionedPrincipal.
+  // FIXME: We may want to support non-initial documents here.
+  nsresult rv = CreateAboutBlankContentViewer(
+      aWindowActor->DocumentPrincipal(), aWindowActor->DocumentPrincipal(),
+      /* aCsp */ nullptr,
+      /* aBaseURI */ nullptr,
+      /* aIsInitialDocument */ true,
+      /* aCOEP */ Nothing(),
+      /* aTryToSaveOldPresentation */ true,
+      /* aCheckPermitUnload */ true, aWindowActor);
+#ifdef DEBUG
+  if (NS_SUCCEEDED(rv)) {
+    RefPtr<Document> doc(GetDocument());
+    MOZ_ASSERT(
+        doc,
+        "Should have a document if CreateAboutBlankContentViewer succeeded");
+    MOZ_ASSERT(doc->GetOwnerGlobal() == aWindowActor->GetWindowGlobal(),
+               "New document should be in the same global as our actor");
+    MOZ_ASSERT(doc->IsInitialDocument(),
+               "New document should be an initial document");
+  }
+#endif
+
+  return rv;
+}
+
+bool nsDocShell::CanSavePresentation(uint32_t aLoadType,
+                                     nsIRequest* aNewRequest,
+                                     Document* aNewDocument,
+                                     bool aReportBFCacheComboTelemetry) {
+  if (!mOSHE) {
+    return false;  // no entry to save into
+  }
+
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent(),
+             "mOSHE cannot be non-null with SHIP");
+  nsCOMPtr<nsIContentViewer> viewer = mOSHE->GetContentViewer();
+  if (viewer) {
+    NS_WARNING("mOSHE already has a content viewer!");
+    return false;
+  }
+
+  // Only save presentation for "normal" loads and link loads.  Anything else
+  // probably wants to refetch the page, so caching the old presentation
+  // would be incorrect.
+  if (aLoadType != LOAD_NORMAL && aLoadType != LOAD_HISTORY &&
+      aLoadType != LOAD_LINK && aLoadType != LOAD_STOP_CONTENT &&
+      aLoadType != LOAD_STOP_CONTENT_AND_REPLACE &&
+      aLoadType != LOAD_ERROR_PAGE) {
+    return false;
+  }
+
+  // If the session history entry has the saveLayoutState flag set to false,
+  // then we should not cache the presentation.
+  if (!mOSHE->GetSaveLayoutStateFlag()) {
+    return false;
+  }
+
+  // If the document is not done loading, don't cache it.
+  if (!mScriptGlobal || mScriptGlobal->IsLoading()) {
+    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
+            ("Blocked due to document still loading"));
+    return false;
+  }
+
+  if (mScriptGlobal->WouldReuseInnerWindow(aNewDocument)) {
+    return false;
+  }
+
+  // Avoid doing the work of saving the presentation state in the case where
+  // the content viewer cache is disabled.
+  if (nsSHistory::GetMaxTotalViewers() == 0) {
+    return false;
+  }
+
+  // Don't cache the content viewer if we're in a subframe.
+  if (mBrowsingContext->GetParent()) {
+    return false;  // this is a subframe load
+  }
+
+  // If the document does not want its presentation cached, then don't.
+  RefPtr<Document> doc = mScriptGlobal->GetExtantDoc();
+
+  uint32_t bfCacheCombo = 0;
+  bool canSavePresentation =
+      doc->CanSavePresentation(aNewRequest, bfCacheCombo, true);
+  MOZ_ASSERT_IF(canSavePresentation, bfCacheCombo == 0);
+  if (canSavePresentation && doc->IsTopLevelContentDocument()) {
+    auto* browsingContextGroup = mBrowsingContext->Group();
+    nsTArray<RefPtr<BrowsingContext>>& topLevelContext =
+        browsingContextGroup->Toplevels();
+
+    for (const auto& browsingContext : topLevelContext) {
+      if (browsingContext != mBrowsingContext) {
+        if (StaticPrefs::docshell_shistory_bfcache_require_no_opener()) {
+          canSavePresentation = false;
+        }
+        bfCacheCombo |= BFCacheStatus::NOT_ONLY_TOPLEVEL_IN_BCG;
+        break;
+      }
+    }
+  }
+
+  if (aReportBFCacheComboTelemetry) {
+    ReportBFCacheComboTelemetry(bfCacheCombo);
+  }
+  return doc && canSavePresentation;
+}
+
+/* static */
+void nsDocShell::ReportBFCacheComboTelemetry(uint32_t aCombo) {
+  // There are 11 possible reasons to make a request fails to use BFCache
+  // (see BFCacheStatus in dom/base/Document.h), and we'd like to record
+  // the common combinations for reasons which make requests fail to use
+  // BFCache. These combinations are generated based on some local browsings,
+  // we need to adjust them when necessary.
+  enum BFCacheStatusCombo : uint32_t {
+    BFCACHE_SUCCESS,
+    NOT_ONLY_TOPLEVEL = mozilla::dom::BFCacheStatus::NOT_ONLY_TOPLEVEL_IN_BCG,
+    // If both unload and beforeunload listeners are presented, it'll be
+    // recorded as unload
+    UNLOAD = mozilla::dom::BFCacheStatus::UNLOAD_LISTENER,
+    UNLOAD_REQUEST = mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
+                     mozilla::dom::BFCacheStatus::REQUEST,
+    REQUEST = mozilla::dom::BFCacheStatus::REQUEST,
+    UNLOAD_REQUEST_PEER = mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
+                          mozilla::dom::BFCacheStatus::REQUEST |
+                          mozilla::dom::BFCacheStatus::ACTIVE_PEER_CONNECTION,
+    UNLOAD_REQUEST_PEER_MSE =
+        mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
+        mozilla::dom::BFCacheStatus::REQUEST |
+        mozilla::dom::BFCacheStatus::ACTIVE_PEER_CONNECTION |
+        mozilla::dom::BFCacheStatus::CONTAINS_MSE_CONTENT,
+    UNLOAD_REQUEST_MSE = mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
+                         mozilla::dom::BFCacheStatus::REQUEST |
+                         mozilla::dom::BFCacheStatus::CONTAINS_MSE_CONTENT,
+    SUSPENDED_UNLOAD_REQUEST_PEER =
+        mozilla::dom::BFCacheStatus::SUSPENDED |
+        mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
+        mozilla::dom::BFCacheStatus::REQUEST |
+        mozilla::dom::BFCacheStatus::ACTIVE_PEER_CONNECTION,
+    REMOTE_SUBFRAMES = mozilla::dom::BFCacheStatus::CONTAINS_REMOTE_SUBFRAMES,
+    BEFOREUNLOAD = mozilla::dom::BFCacheStatus::BEFOREUNLOAD_LISTENER,
+  };
+
+  // Beforeunload is recorded as a blocker only if it is the only one to block
+  // bfcache.
+  if (aCombo != mozilla::dom::BFCacheStatus::BEFOREUNLOAD_LISTENER) {
+    aCombo &= ~mozilla::dom::BFCacheStatus::BEFOREUNLOAD_LISTENER;
+  }
+  switch (aCombo) {
+    case BFCACHE_SUCCESS:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::BFCache_Success);
+      break;
+    case NOT_ONLY_TOPLEVEL:
+      if (StaticPrefs::docshell_shistory_bfcache_require_no_opener()) {
+        Telemetry::AccumulateCategorical(
+            Telemetry::LABELS_BFCACHE_COMBO::Other);
+        break;
+      }
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::BFCache_Success);
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Success_Not_Toplevel);
+      break;
+    case UNLOAD:
+      Telemetry::AccumulateCategorical(Telemetry::LABELS_BFCACHE_COMBO::Unload);
+      break;
+    case BEFOREUNLOAD:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Beforeunload);
+      break;
+    case UNLOAD_REQUEST:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Unload_Req);
+      break;
+    case REQUEST:
+      Telemetry::AccumulateCategorical(Telemetry::LABELS_BFCACHE_COMBO::Req);
+      break;
+    case UNLOAD_REQUEST_PEER:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Unload_Req_Peer);
+      break;
+    case UNLOAD_REQUEST_PEER_MSE:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Unload_Req_Peer_MSE);
+      break;
+    case UNLOAD_REQUEST_MSE:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Unload_Req_MSE);
+      break;
+    case SUSPENDED_UNLOAD_REQUEST_PEER:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::SPD_Unload_Req_Peer);
+      break;
+    case REMOTE_SUBFRAMES:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Remote_Subframes);
+      break;
+    default:
+      Telemetry::AccumulateCategorical(Telemetry::LABELS_BFCACHE_COMBO::Other);
+      break;
+  }
+};
+
+void nsDocShell::ReattachEditorToWindow(nsISHEntry* aSHEntry) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  NS_ASSERTION(!mEditorData,
+               "Why reattach an editor when we already have one?");
+  NS_ASSERTION(aSHEntry && aSHEntry->HasDetachedEditor(),
+               "Reattaching when there's not a detached editor.");
+
+  if (mEditorData || !aSHEntry) {
+    return;
+  }
+
+  mEditorData = WrapUnique(aSHEntry->ForgetEditorData());
+  if (mEditorData) {
+#ifdef DEBUG
+    nsresult rv =
+#endif
+        mEditorData->ReattachToWindow(this);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "Failed to reattach editing session");
+  }
+}
+
+void nsDocShell::DetachEditorFromWindow() {
+  if (!mEditorData || mEditorData->WaitingForLoad()) {
+    // If there's nothing to detach, or if the editor data is actually set
+    // up for the _new_ page that's coming in, don't detach.
+    return;
+  }
+
+  NS_ASSERTION(!mOSHE || !mOSHE->HasDetachedEditor(),
+               "Detaching editor when it's already detached.");
+
+  nsresult res = mEditorData->DetachFromWindow();
+  NS_ASSERTION(NS_SUCCEEDED(res), "Failed to detach editor");
+
+  if (NS_SUCCEEDED(res)) {
+    // Make mOSHE hold the owning ref to the editor data.
+    if (mOSHE) {
+      MOZ_ASSERT(!mIsBeingDestroyed || !mOSHE->HasDetachedEditor(),
+                 "We should not set the editor data again once after we "
+                 "detached the editor data during destroying this docshell");
+      mOSHE->SetEditorData(mEditorData.release());
+    } else {
+      mEditorData = nullptr;
+    }
+  }
+
+#ifdef DEBUG
+  {
+    bool isEditable;
+    GetEditable(&isEditable);
+    NS_ASSERTION(!isEditable,
+                 "Window is still editable after detaching editor.");
+  }
+#endif  // DEBUG
+}
+
+nsresult nsDocShell::CaptureState() {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+
+  if (!mOSHE || mOSHE == mLSHE) {
+    // No entry to save into, or we're replacing the existing entry.
+    return NS_ERROR_FAILURE;
+  }
+
+  if (!mScriptGlobal) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsISupports> windowState = mScriptGlobal->SaveWindowState();
+  NS_ENSURE_TRUE(windowState, NS_ERROR_FAILURE);
+
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gPageCacheLog, LogLevel::Debug))) {
+    nsAutoCString spec;
+    nsCOMPtr<nsIURI> uri = mOSHE->GetURI();
+    if (uri) {
+      uri->GetSpec(spec);
+    }
+    MOZ_LOG(gPageCacheLog, LogLevel::Debug,
+            ("Saving presentation into session history, URI: %s", spec.get()));
+  }
+
+  mOSHE->SetWindowState(windowState);
+
+  // Suspend refresh URIs and save off the timer queue
+  mOSHE->SetRefreshURIList(mSavedRefreshURIList);
+
+  // Capture the current content viewer bounds.
+  if (mContentViewer) {
+    nsIntRect bounds;
+    mContentViewer->GetBounds(bounds);
+    mOSHE->SetViewerBounds(bounds);
+  }
+
+  // Capture the docshell hierarchy.
+  mOSHE->ClearChildShells();
+
+  uint32_t childCount = mChildList.Length();
+  for (uint32_t i = 0; i < childCount; ++i) {
+    nsCOMPtr<nsIDocShellTreeItem> childShell = do_QueryInterface(ChildAt(i));
+    NS_ASSERTION(childShell, "null child shell");
+
+    mOSHE->AddChildShell(childShell);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::RestorePresentationEvent::Run() {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+
+  if (mDocShell && NS_FAILED(mDocShell->RestoreFromHistory())) {
+    NS_WARNING("RestoreFromHistory failed");
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::BeginRestore(nsIContentViewer* aContentViewer, bool aTop) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+
+  nsresult rv;
+  if (!aContentViewer) {
+    rv = EnsureContentViewer();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aContentViewer = mContentViewer;
+  }
+
+  // Dispatch events for restoring the presentation.  We try to simulate
+  // the progress notifications loading the document would cause, so we add
+  // the document's channel to the loadgroup to initiate stateChange
+  // notifications.
+
+  RefPtr<Document> doc = aContentViewer->GetDocument();
+  if (doc) {
+    nsIChannel* channel = doc->GetChannel();
+    if (channel) {
+      mEODForCurrentDocument = false;
+      mIsRestoringDocument = true;
+      mLoadGroup->AddRequest(channel, nullptr);
+      mIsRestoringDocument = false;
+    }
+  }
+
+  if (!aTop) {
+    // This point corresponds to us having gotten OnStartRequest or
+    // STATE_START, so do the same thing that CreateContentViewer does at
+    // this point to ensure that unload/pagehide events for this document
+    // will fire when it's unloaded again.
+    mFiredUnloadEvent = false;
+
+    // For non-top frames, there is no notion of making sure that the
+    // previous document is in the domwindow when STATE_START notifications
+    // happen.  We can just call BeginRestore for all of the child shells
+    // now.
+    rv = BeginRestoreChildren();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::BeginRestoreChildren() {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+
+  for (auto* childDocLoader : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> child = do_QueryObject(childDocLoader);
+    if (child) {
+      nsresult rv = child->BeginRestore(nullptr, false);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::FinishRestore() {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+
+  // First we call finishRestore() on our children.  In the simulated load,
+  // all of the child frames finish loading before the main document.
+
+  for (auto* childDocLoader : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> child = do_QueryObject(childDocLoader);
+    if (child) {
+      child->FinishRestore();
+    }
+  }
+
+  if (mOSHE && mOSHE->HasDetachedEditor()) {
+    ReattachEditorToWindow(mOSHE);
+  }
+
+  RefPtr<Document> doc = GetDocument();
+  if (doc) {
+    // Finally, we remove the request from the loadgroup.  This will
+    // cause onStateChange(STATE_STOP) to fire, which will fire the
+    // pageshow event to the chrome.
+
+    nsIChannel* channel = doc->GetChannel();
+    if (channel) {
+      mIsRestoringDocument = true;
+      mLoadGroup->RemoveRequest(channel, nullptr, NS_OK);
+      mIsRestoringDocument = false;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetRestoringDocument(bool* aRestoring) {
+  *aRestoring = mIsRestoringDocument;
+  return NS_OK;
+}
+
+nsresult nsDocShell::RestorePresentation(nsISHEntry* aSHEntry,
+                                         bool* aRestoring) {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  NS_ASSERTION(mLoadType & LOAD_CMD_HISTORY,
+               "RestorePresentation should only be called for history loads");
+
+  nsCOMPtr<nsIContentViewer> viewer = aSHEntry->GetContentViewer();
+
+  nsAutoCString spec;
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gPageCacheLog, LogLevel::Debug))) {
+    nsCOMPtr<nsIURI> uri = aSHEntry->GetURI();
+    if (uri) {
+      uri->GetSpec(spec);
+    }
+  }
+
+  *aRestoring = false;
+
+  if (!viewer) {
+    MOZ_LOG(gPageCacheLog, LogLevel::Debug,
+            ("no saved presentation for uri: %s", spec.get()));
+    return NS_OK;
+  }
+
+  // We need to make sure the content viewer's container is this docshell.
+  // In subframe navigation, it's possible for the docshell that the
+  // content viewer was originally loaded into to be replaced with a
+  // different one.  We don't currently support restoring the presentation
+  // in that case.
+
+  nsCOMPtr<nsIDocShell> container;
+  viewer->GetContainer(getter_AddRefs(container));
+  if (!::SameCOMIdentity(container, GetAsSupports(this))) {
+    MOZ_LOG(gPageCacheLog, LogLevel::Debug,
+            ("No valid container, clearing presentation"));
+    aSHEntry->SetContentViewer(nullptr);
+    return NS_ERROR_FAILURE;
+  }
+
+  NS_ASSERTION(mContentViewer != viewer, "Restoring existing presentation");
+
+  MOZ_LOG(gPageCacheLog, LogLevel::Debug,
+          ("restoring presentation from session history: %s", spec.get()));
+
+  SetHistoryEntryAndUpdateBC(Some(aSHEntry), Nothing());
+
+  // Post an event that will remove the request after we've returned
+  // to the event loop.  This mimics the way it is called by nsIChannel
+  // implementations.
+
+  // Revoke any pending restore (just in case).
+  NS_ASSERTION(!mRestorePresentationEvent.IsPending(),
+               "should only have one RestorePresentationEvent");
+  mRestorePresentationEvent.Revoke();
+
+  RefPtr<RestorePresentationEvent> evt = new RestorePresentationEvent(this);
+  nsresult rv = Dispatch(TaskCategory::Other, do_AddRef(evt));
+  if (NS_SUCCEEDED(rv)) {
+    mRestorePresentationEvent = evt.get();
+    // The rest of the restore processing will happen on our event
+    // callback.
+    *aRestoring = true;
+  }
+
+  return rv;
+}
+
+namespace {
+class MOZ_STACK_CLASS PresentationEventForgetter {
+ public:
+  explicit PresentationEventForgetter(
+      nsRevocableEventPtr<nsDocShell::RestorePresentationEvent>&
+          aRestorePresentationEvent)
+      : mRestorePresentationEvent(aRestorePresentationEvent),
+        mEvent(aRestorePresentationEvent.get()) {}
+
+  ~PresentationEventForgetter() { Forget(); }
+
+  void Forget() {
+    if (mRestorePresentationEvent.get() == mEvent) {
+      mRestorePresentationEvent.Forget();
+      mEvent = nullptr;
+    }
+  }
+
+ private:
+  nsRevocableEventPtr<nsDocShell::RestorePresentationEvent>&
+      mRestorePresentationEvent;
+  RefPtr<nsDocShell::RestorePresentationEvent> mEvent;
+};
+
+}  // namespace
+
+bool nsDocShell::SandboxFlagsImplyCookies(const uint32_t& aSandboxFlags) {
+  return (aSandboxFlags & (SANDBOXED_ORIGIN | SANDBOXED_SCRIPTS)) == 0;
+}
+
+nsresult nsDocShell::RestoreFromHistory() {
+  MOZ_ASSERT(!mozilla::SessionHistoryInParent());
+  MOZ_ASSERT(mRestorePresentationEvent.IsPending());
+  PresentationEventForgetter forgetter(mRestorePresentationEvent);
+
+  // This section of code follows the same ordering as CreateContentViewer.
+  if (!mLSHE) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIContentViewer> viewer = mLSHE->GetContentViewer();
+  if (!viewer) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mSavingOldViewer) {
+    // We determined that it was safe to cache the document presentation
+    // at the time we initiated the new load.  We need to check whether
+    // it's still safe to do so, since there may have been DOM mutations
+    // or new requests initiated.
+    RefPtr<Document> doc = viewer->GetDocument();
+    nsIRequest* request = nullptr;
+    if (doc) {
+      request = doc->GetChannel();
+    }
+    mSavingOldViewer = CanSavePresentation(
+        mLoadType, request, doc, /* aReportBFCacheComboTelemetry */ false);
+  }
+
+  // Protect against mLSHE going away via a load triggered from
+  // pagehide or unload.
+  nsCOMPtr<nsISHEntry> origLSHE = mLSHE;
+
+  // Make sure to blow away our mLoadingURI just in case.  No loads
+  // from inside this pagehide.
+  mLoadingURI = nullptr;
+
+  // Notify the old content viewer that it's being hidden.
+  FirePageHideNotification(!mSavingOldViewer);
+  // pagehide notification might destroy this docshell.
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_DOCSHELL_DYING;
+  }
+
+  // If mLSHE was changed as a result of the pagehide event, then
+  // something else was loaded.  Don't finish restoring.
+  if (mLSHE != origLSHE) {
+    return NS_OK;
+  }
+
+  // Add the request to our load group.  We do this before swapping out
+  // the content viewers so that consumers of STATE_START can access
+  // the old document.  We only deal with the toplevel load at this time --
+  // to be consistent with normal document loading, subframes cannot start
+  // loading until after data arrives, which is after STATE_START completes.
+
+  RefPtr<RestorePresentationEvent> currentPresentationRestoration =
+      mRestorePresentationEvent.get();
+  Stop();
+  // Make sure we're still restoring the same presentation.
+  // If we aren't, docshell is in process doing another load already.
+  NS_ENSURE_STATE(currentPresentationRestoration ==
+                  mRestorePresentationEvent.get());
+  BeginRestore(viewer, true);
+  NS_ENSURE_STATE(currentPresentationRestoration ==
+                  mRestorePresentationEvent.get());
+  forgetter.Forget();
+
+  // Set mFiredUnloadEvent = false so that the unload handler for the
+  // *new* document will fire.
+  mFiredUnloadEvent = false;
+
+  mURIResultedInDocument = true;
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (rootSH) {
+    mPreviousEntryIndex = rootSH->Index();
+    rootSH->LegacySHistory()->UpdateIndex();
+    mLoadedEntryIndex = rootSH->Index();
+    MOZ_LOG(gPageCacheLog, LogLevel::Verbose,
+            ("Previous index: %d, Loaded index: %d", mPreviousEntryIndex,
+             mLoadedEntryIndex));
+  }
+
+  // Rather than call Embed(), we will retrieve the viewer from the session
+  // history entry and swap it in.
+  // XXX can we refactor this so that we can just call Embed()?
+  PersistLayoutHistoryState();
+  nsresult rv;
+  if (mContentViewer) {
+    if (mSavingOldViewer && NS_FAILED(CaptureState())) {
+      if (mOSHE) {
+        mOSHE->SyncPresentationState();
+      }
+      mSavingOldViewer = false;
+    }
+  }
+
+  mSavedRefreshURIList = nullptr;
+
+  // In cases where we use a transient about:blank viewer between loads,
+  // we never show the transient viewer, so _its_ previous viewer is never
+  // unhooked from the view hierarchy.  Destroy any such previous viewer now,
+  // before we grab the root view sibling, so that we don't grab a view
+  // that's about to go away.
+
+  if (mContentViewer) {
+    // Make sure to hold a strong ref to previousViewer here while we
+    // drop the reference to it from mContentViewer.
+    nsCOMPtr<nsIContentViewer> previousViewer =
+        mContentViewer->GetPreviousViewer();
+    if (previousViewer) {
+      mContentViewer->SetPreviousViewer(nullptr);
+      previousViewer->Destroy();
+    }
+  }
+
+  // Save off the root view's parent and sibling so that we can insert the
+  // new content viewer's root view at the same position.  Also save the
+  // bounds of the root view's widget.
+
+  nsView* rootViewSibling = nullptr;
+  nsView* rootViewParent = nullptr;
+  nsIntRect newBounds(0, 0, 0, 0);
+
+  PresShell* oldPresShell = GetPresShell();
+  if (oldPresShell) {
+    nsViewManager* vm = oldPresShell->GetViewManager();
+    if (vm) {
+      nsView* oldRootView = vm->GetRootView();
+
+      if (oldRootView) {
+        rootViewSibling = oldRootView->GetNextSibling();
+        rootViewParent = oldRootView->GetParent();
+
+        mContentViewer->GetBounds(newBounds);
+      }
+    }
+  }
+
+  nsCOMPtr<nsIContent> container;
+  RefPtr<Document> sibling;
+  if (rootViewParent && rootViewParent->GetParent()) {
+    nsIFrame* frame = rootViewParent->GetParent()->GetFrame();
+    container = frame ? frame->GetContent() : nullptr;
+  }
+  if (rootViewSibling) {
+    nsIFrame* frame = rootViewSibling->GetFrame();
+    sibling = frame ? frame->PresShell()->GetDocument() : nullptr;
+  }
+
+  // Transfer ownership to mContentViewer.  By ensuring that either the
+  // docshell or the session history, but not both, have references to the
+  // content viewer, we prevent the viewer from being torn down after
+  // Destroy() is called.
+
+  if (mContentViewer) {
+    mContentViewer->Close(mSavingOldViewer ? mOSHE.get() : nullptr);
+    viewer->SetPreviousViewer(mContentViewer);
+  }
+  if (mOSHE && (!mContentViewer || !mSavingOldViewer)) {
+    // We don't plan to save a viewer in mOSHE; tell it to drop
+    // any other state it's holding.
+    mOSHE->SyncPresentationState();
+  }
+
+  // Order the mContentViewer setup just like Embed does.
+  mContentViewer = nullptr;
+
+  // Now that we're about to switch documents, forget all of our children.
+  // Note that we cached them as needed up in CaptureState above.
+  DestroyChildren();
+
+  mContentViewer.swap(viewer);
+
+  // Grab all of the related presentation from the SHEntry now.
+  // Clearing the viewer from the SHEntry will clear all of this state.
+  nsCOMPtr<nsISupports> windowState = mLSHE->GetWindowState();
+  mLSHE->SetWindowState(nullptr);
+
+  bool sticky = mLSHE->GetSticky();
+
+  RefPtr<Document> document = mContentViewer->GetDocument();
+
+  nsCOMArray<nsIDocShellTreeItem> childShells;
+  int32_t i = 0;
+  nsCOMPtr<nsIDocShellTreeItem> child;
+  while (NS_SUCCEEDED(mLSHE->ChildShellAt(i++, getter_AddRefs(child))) &&
+         child) {
+    childShells.AppendObject(child);
+  }
+
+  // get the previous content viewer size
+  nsIntRect oldBounds(0, 0, 0, 0);
+  mLSHE->GetViewerBounds(oldBounds);
+
+  // Restore the refresh URI list.  The refresh timers will be restarted
+  // when EndPageLoad() is called.
+  nsCOMPtr<nsIMutableArray> refreshURIList = mLSHE->GetRefreshURIList();
+
+  // Reattach to the window object.
+  mIsRestoringDocument = true;  // for MediaDocument::BecomeInteractive
+  rv = mContentViewer->Open(windowState, mLSHE);
+  mIsRestoringDocument = false;
+
+  // Hack to keep nsDocShellEditorData alive across the
+  // SetContentViewer(nullptr) call below.
+  UniquePtr<nsDocShellEditorData> data(mLSHE->ForgetEditorData());
+
+  // Now remove it from the cached presentation.
+  mLSHE->SetContentViewer(nullptr);
+  mEODForCurrentDocument = false;
+
+  mLSHE->SetEditorData(data.release());
+
+#ifdef DEBUG
+  {
+    nsCOMPtr<nsIMutableArray> refreshURIs = mLSHE->GetRefreshURIList();
+    nsCOMPtr<nsIDocShellTreeItem> childShell;
+    mLSHE->ChildShellAt(0, getter_AddRefs(childShell));
+    NS_ASSERTION(!refreshURIs && !childShell,
+                 "SHEntry should have cleared presentation state");
+  }
+#endif
+
+  // Restore the sticky state of the viewer.  The viewer has set this state
+  // on the history entry in Destroy() just before marking itself non-sticky,
+  // to avoid teardown of the presentation.
+  mContentViewer->SetSticky(sticky);
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // mLSHE is now our currently-loaded document.
+  SetHistoryEntryAndUpdateBC(Nothing(), Some<nsISHEntry*>(mLSHE));
+
+  // We aren't going to restore any items from the LayoutHistoryState,
+  // but we don't want them to stay around in case the page is reloaded.
+  SetLayoutHistoryState(nullptr);
+
+  // This is the end of our Embed() replacement
+
+  mSavingOldViewer = false;
+  mEODForCurrentDocument = false;
+
+  if (document) {
+    RefPtr<nsDocShell> parent = GetInProcessParentDocshell();
+    if (parent) {
+      RefPtr<Document> d = parent->GetDocument();
+      if (d) {
+        if (d->EventHandlingSuppressed()) {
+          document->SuppressEventHandling(d->EventHandlingSuppressed());
+        }
+      }
+    }
+
+    // Use the uri from the mLSHE we had when we entered this function
+    // (which need not match the document's URI if anchors are involved),
+    // since that's the history entry we're loading.  Note that if we use
+    // origLSHE we don't have to worry about whether the entry in question
+    // is still mLSHE or whether it's now mOSHE.
+    nsCOMPtr<nsIURI> uri = origLSHE->GetURI();
+    SetCurrentURI(uri, document->GetChannel(), /* aFireLocationChange */ true,
+                  /* aIsInitialAboutBlank */ false,
+                  /* aLocationFlags */ 0);
+  }
+
+  // This is the end of our CreateContentViewer() replacement.
+  // Now we simulate a load.  First, we restore the state of the javascript
+  // window object.
+  nsCOMPtr<nsPIDOMWindowOuter> privWin = GetWindow();
+  NS_ASSERTION(privWin, "could not get nsPIDOMWindow interface");
+
+  // Now, dispatch a title change event which would happen as the
+  // <head> is parsed.
+  document->NotifyPossibleTitleChange(false);
+
+  // Now we simulate appending child docshells for subframes.
+  for (i = 0; i < childShells.Count(); ++i) {
+    nsIDocShellTreeItem* childItem = childShells.ObjectAt(i);
+    nsCOMPtr<nsIDocShell> childShell = do_QueryInterface(childItem);
+
+    // Make sure to not clobber the state of the child.  Since AddChild
+    // always clobbers it, save it off first.
+    bool allowRedirects;
+    childShell->GetAllowMetaRedirects(&allowRedirects);
+
+    bool allowSubframes;
+    childShell->GetAllowSubframes(&allowSubframes);
+
+    bool allowImages;
+    childShell->GetAllowImages(&allowImages);
+
+    bool allowMedia = childShell->GetAllowMedia();
+
+    bool allowDNSPrefetch;
+    childShell->GetAllowDNSPrefetch(&allowDNSPrefetch);
+
+    bool allowContentRetargeting = childShell->GetAllowContentRetargeting();
+    bool allowContentRetargetingOnChildren =
+        childShell->GetAllowContentRetargetingOnChildren();
+
+    // this.AddChild(child) calls child.SetDocLoaderParent(this), meaning that
+    // the child inherits our state. Among other things, this means that the
+    // child inherits our mPrivateBrowsingId, which is what we want.
+    AddChild(childItem);
+
+    childShell->SetAllowMetaRedirects(allowRedirects);
+    childShell->SetAllowSubframes(allowSubframes);
+    childShell->SetAllowImages(allowImages);
+    childShell->SetAllowMedia(allowMedia);
+    childShell->SetAllowDNSPrefetch(allowDNSPrefetch);
+    childShell->SetAllowContentRetargeting(allowContentRetargeting);
+    childShell->SetAllowContentRetargetingOnChildren(
+        allowContentRetargetingOnChildren);
+
+    rv = childShell->BeginRestore(nullptr, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // Make sure to restore the window state after adding the child shells back
+  // to the tree.  This is necessary for Thaw() and Resume() to propagate
+  // properly.
+  rv = privWin->RestoreWindowState(windowState);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<PresShell> presShell = GetPresShell();
+
+  // We may be displayed on a different monitor (or in a different
+  // HiDPI mode) than when we got into the history list.  So we need
+  // to check if this has happened. See bug 838239.
+
+  // Because the prescontext normally handles resolution changes via
+  // a runnable (see nsPresContext::UIResolutionChanged), its device
+  // context won't be -immediately- updated as a result of calling
+  // presShell->BackingScaleFactorChanged().
+
+  // But we depend on that device context when adjusting the view size
+  // via mContentViewer->SetBounds(newBounds) below. So we need to
+  // explicitly tell it to check for changed resolution here.
+  if (presShell) {
+    RefPtr<nsPresContext> pc = presShell->GetPresContext();
+    if (pc->DeviceContext()->CheckDPIChange()) {
+      presShell->BackingScaleFactorChanged();
+    }
+    // Recompute zoom and text-zoom and such.
+    pc->RecomputeBrowsingContextDependentData();
+  }
+
+  nsViewManager* newVM = presShell ? presShell->GetViewManager() : nullptr;
+  nsView* newRootView = newVM ? newVM->GetRootView() : nullptr;
+
+  // Insert the new root view at the correct location in the view tree.
+  if (container) {
+    nsSubDocumentFrame* subDocFrame =
+        do_QueryFrame(container->GetPrimaryFrame());
+    rootViewParent = subDocFrame ? subDocFrame->EnsureInnerView() : nullptr;
+  } else {
+    rootViewParent = nullptr;
+  }
+  if (sibling && sibling->GetPresShell() &&
+      sibling->GetPresShell()->GetViewManager()) {
+    rootViewSibling = sibling->GetPresShell()->GetViewManager()->GetRootView();
+  } else {
+    rootViewSibling = nullptr;
+  }
+  if (rootViewParent && newRootView &&
+      newRootView->GetParent() != rootViewParent) {
+    nsViewManager* parentVM = rootViewParent->GetViewManager();
+    if (parentVM) {
+      // InsertChild(parent, child, sib, true) inserts the child after
+      // sib in content order, which is before sib in view order. BUT
+      // when sib is null it inserts at the end of the the document
+      // order, i.e., first in view order.  But when oldRootSibling is
+      // null, the old root as at the end of the view list --- last in
+      // content order --- and we want to call InsertChild(parent, child,
+      // nullptr, false) in that case.
+      parentVM->InsertChild(rootViewParent, newRootView, rootViewSibling,
+                            rootViewSibling ? true : false);
+
+      NS_ASSERTION(newRootView->GetNextSibling() == rootViewSibling,
+                   "error in InsertChild");
+    }
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> privWinInner = privWin->GetCurrentInnerWindow();
+
+  // If parent is suspended, increase suspension count.
+  // This can't be done as early as event suppression since this
+  // depends on docshell tree.
+  privWinInner->SyncStateFromParentWindow();
+
+  // Now that all of the child docshells have been put into place, we can
+  // restart the timers for the window and all of the child frames.
+  privWinInner->Resume();
+
+  // Now that we have found the inner window of the page restored
+  // from the history, we have to  make sure that
+  // performance.navigation.type is 2.
+  Performance* performance = privWinInner->GetPerformance();
+  if (performance) {
+    performance->GetDOMTiming()->NotifyRestoreStart();
+  }
+
+  // Restore the refresh URI list.  The refresh timers will be restarted
+  // when EndPageLoad() is called.
+  mRefreshURIList = refreshURIList;
+
+  // Meta-refresh timers have been restarted for this shell, but not
+  // for our children.  Walk the child shells and restart their timers.
+  for (auto* childDocLoader : mChildList.ForwardRange()) {
+    nsCOMPtr<nsIDocShell> child = do_QueryObject(childDocLoader);
+    if (child) {
+      child->ResumeRefreshURIs();
+    }
+  }
+
+  // Make sure this presentation is the same size as the previous
+  // presentation.  If this is not the same size we showed it at last time,
+  // then we need to resize the widget.
+
+  // XXXbryner   This interacts poorly with Firefox's infobar.  If the old
+  // presentation had the infobar visible, then we will resize the new
+  // presentation to that smaller size.  However, firing the locationchanged
+  // event will hide the infobar, which will immediately resize the window
+  // back to the larger size.  A future optimization might be to restore
+  // the presentation at the "wrong" size, then fire the locationchanged
+  // event and check whether the docshell's new size is the same as the
+  // cached viewer size (skipping the resize if they are equal).
+
+  if (newRootView) {
+    if (!newBounds.IsEmpty() && !newBounds.IsEqualEdges(oldBounds)) {
+      MOZ_LOG(gPageCacheLog, LogLevel::Debug,
+              ("resize widget(%d, %d, %d, %d)", newBounds.x, newBounds.y,
+               newBounds.width, newBounds.height));
+      mContentViewer->SetBounds(newBounds);
+    } else {
+      nsIScrollableFrame* rootScrollFrame =
+          presShell->GetRootScrollFrameAsScrollable();
+      if (rootScrollFrame) {
+        rootScrollFrame->PostScrolledAreaEventForCurrentArea();
+      }
+    }
+  }
+
+  // The FinishRestore call below can kill these, null them out so we don't
+  // have invalid pointer lying around.
+  newRootView = rootViewSibling = rootViewParent = nullptr;
+  newVM = nullptr;
+
+  // If the IsUnderHiddenEmbedderElement() state has been changed, we need to
+  // update it.
+  if (oldPresShell && presShell &&
+      presShell->IsUnderHiddenEmbedderElement() !=
+          oldPresShell->IsUnderHiddenEmbedderElement()) {
+    presShell->SetIsUnderHiddenEmbedderElement(
+        oldPresShell->IsUnderHiddenEmbedderElement());
+  }
+
+  // Simulate the completion of the load.
+  nsDocShell::FinishRestore();
+
+  // Restart plugins, and paint the content.
+  if (presShell) {
+    presShell->Thaw();
+  }
+
+  return privWin->FireDelayedDOMEvents(true);
+}
+
+nsresult nsDocShell::CreateContentViewer(const nsACString& aContentType,
+                                         nsIRequest* aRequest,
+                                         nsIStreamListener** aContentHandler) {
+  if (DocGroup::TryToLoadIframesInBackground()) {
+    ResetToFirstLoad();
+  }
+
+  *aContentHandler = nullptr;
+
+  if (!mTreeOwner || mIsBeingDestroyed) {
+    // If we don't have a tree owner, then we're in the process of being
+    // destroyed. Rather than continue trying to load something, just give up.
+    return NS_ERROR_DOCSHELL_DYING;
+  }
+
+  if (!mBrowsingContext->AncestorsAreCurrent() ||
+      mBrowsingContext->IsInBFCache()) {
+    mBrowsingContext->RemoveRootFromBFCacheSync();
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Can we check the content type of the current content viewer
+  // and reuse it without destroying it and re-creating it?
+
+  NS_ASSERTION(mLoadGroup, "Someone ignored return from Init()?");
+
+  // Instantiate the content viewer object
+  nsCOMPtr<nsIContentViewer> viewer;
+  nsresult rv = NewContentViewerObj(aContentType, aRequest, mLoadGroup,
+                                    aContentHandler, getter_AddRefs(viewer));
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Notify the current document that it is about to be unloaded!!
+  //
+  // It is important to fire the unload() notification *before* any state
+  // is changed within the DocShell - otherwise, javascript will get the
+  // wrong information :-(
+  //
+
+  if (mSavingOldViewer) {
+    // We determined that it was safe to cache the document presentation
+    // at the time we initiated the new load.  We need to check whether
+    // it's still safe to do so, since there may have been DOM mutations
+    // or new requests initiated.
+    RefPtr<Document> doc = viewer->GetDocument();
+    mSavingOldViewer = CanSavePresentation(
+        mLoadType, aRequest, doc, /* aReportBFCacheComboTelemetry */ false);
+  }
+
+  NS_ASSERTION(!mLoadingURI, "Re-entering unload?");
+
+  nsCOMPtr<nsIChannel> aOpenedChannel = do_QueryInterface(aRequest);
+  if (aOpenedChannel) {
+    aOpenedChannel->GetURI(getter_AddRefs(mLoadingURI));
+  }
+
+  // Grab the current URI, we need to pass it to Embed, and OnNewURI will reset
+  // it before we do call Embed.
+  nsCOMPtr<nsIURI> previousURI = mCurrentURI;
+
+  FirePageHideNotification(!mSavingOldViewer);
+  if (mIsBeingDestroyed) {
+    // Force to stop the newly created orphaned viewer.
+    viewer->Stop();
+    return NS_ERROR_DOCSHELL_DYING;
+  }
+  mLoadingURI = nullptr;
+
+  // Set mFiredUnloadEvent = false so that the unload handler for the
+  // *new* document will fire.
+  mFiredUnloadEvent = false;
+
+  // we've created a new document so go ahead and call
+  // OnNewURI(), but don't fire OnLocationChange()
+  // notifications before we've called Embed(). See bug 284993.
+  mURIResultedInDocument = true;
+  bool errorOnLocationChangeNeeded = false;
+  nsCOMPtr<nsIChannel> failedChannel = mFailedChannel;
+  nsCOMPtr<nsIURI> failedURI;
+
+  if (mLoadType == LOAD_ERROR_PAGE) {
+    // We need to set the SH entry and our current URI here and not
+    // at the moment we load the page. We want the same behavior
+    // of Stop() as for a normal page load. See bug 514232 for details.
+
+    // Revert mLoadType to load type to state the page load failed,
+    // following function calls need it.
+    mLoadType = mFailedLoadType;
+
+    Document* doc = viewer->GetDocument();
+    if (doc) {
+      doc->SetFailedChannel(failedChannel);
+    }
+
+    nsCOMPtr<nsIPrincipal> triggeringPrincipal;
+    if (failedChannel) {
+      // Make sure we have a URI to set currentURI.
+      NS_GetFinalChannelURI(failedChannel, getter_AddRefs(failedURI));
+    } else {
+      // if there is no failed channel we have to explicitly provide
+      // a triggeringPrincipal for the history entry.
+      triggeringPrincipal = nsContentUtils::GetSystemPrincipal();
+    }
+
+    if (!failedURI) {
+      failedURI = mFailedURI;
+    }
+    if (!failedURI) {
+      // We need a URI object to store a session history entry, so make up a URI
+      NS_NewURI(getter_AddRefs(failedURI), "about:blank");
+    }
+
+    // When we don't have failedURI, something wrong will happen. See
+    // bug 291876.
+    MOZ_ASSERT(failedURI, "We don't have a URI for history APIs.");
+
+    mFailedChannel = nullptr;
+    mFailedURI = nullptr;
+
+    // Create an shistory entry for the old load.
+    if (failedURI) {
+      errorOnLocationChangeNeeded =
+          OnNewURI(failedURI, failedChannel, triggeringPrincipal, nullptr,
+                   nullptr, nullptr, false, false, false);
+    }
+
+    // Be sure to have a correct mLSHE, it may have been cleared by
+    // EndPageLoad. See bug 302115.
+    ChildSHistory* shistory = GetSessionHistory();
+    if (!mozilla::SessionHistoryInParent() && shistory && !mLSHE) {
+      int32_t idx = shistory->LegacySHistory()->GetRequestedIndex();
+      if (idx == -1) {
+        idx = shistory->Index();
+      }
+      shistory->LegacySHistory()->GetEntryAtIndex(idx, getter_AddRefs(mLSHE));
+    }
+
+    mLoadType = LOAD_ERROR_PAGE;
+  }
+
+  nsCOMPtr<nsIURI> finalURI;
+  // If this a redirect, use the final url (uri)
+  // else use the original url
+  //
+  // Note that this should match what documents do (see Document::Reset).
+  NS_GetFinalChannelURI(aOpenedChannel, getter_AddRefs(finalURI));
+
+  bool onLocationChangeNeeded = false;
+  if (finalURI) {
+    // Pass false for aCloneSHChildren, since we're loading a new page here.
+    onLocationChangeNeeded =
+        OnNewURI(finalURI, aOpenedChannel, nullptr, nullptr, nullptr, nullptr,
+                 false, true, false);
+  }
+
+  // let's try resetting the load group if we need to...
+  nsCOMPtr<nsILoadGroup> currentLoadGroup;
+  NS_ENSURE_SUCCESS(
+      aOpenedChannel->GetLoadGroup(getter_AddRefs(currentLoadGroup)),
+      NS_ERROR_FAILURE);
+
+  if (currentLoadGroup != mLoadGroup) {
+    nsLoadFlags loadFlags = 0;
+
+    // Cancel any URIs that are currently loading...
+    // XXX: Need to do this eventually      Stop();
+    //
+    // Retarget the document to this loadgroup...
+    //
+    /* First attach the channel to the right loadgroup
+     * and then remove from the old loadgroup. This
+     * puts the notifications in the right order and
+     * we don't null-out mLSHE in OnStateChange() for
+     * all redirected urls
+     */
+    aOpenedChannel->SetLoadGroup(mLoadGroup);
+
+    // Mark the channel as being a document URI...
+    aOpenedChannel->GetLoadFlags(&loadFlags);
+    loadFlags |= nsIChannel::LOAD_DOCUMENT_URI;
+    nsCOMPtr<nsILoadInfo> loadInfo = aOpenedChannel->LoadInfo();
+    if (SandboxFlagsImplyCookies(loadInfo->GetSandboxFlags())) {
+      loadFlags |= nsIRequest::LOAD_DOCUMENT_NEEDS_COOKIE;
+    }
+
+    aOpenedChannel->SetLoadFlags(loadFlags);
+
+    mLoadGroup->AddRequest(aRequest, nullptr);
+    if (currentLoadGroup) {
+      currentLoadGroup->RemoveRequest(aRequest, nullptr, NS_BINDING_RETARGETED);
+    }
+
+    // Update the notification callbacks, so that progress and
+    // status information are sent to the right docshell...
+    aOpenedChannel->SetNotificationCallbacks(this);
+  }
+
+  if (DocGroup::TryToLoadIframesInBackground()) {
+    if ((!mContentViewer || GetDocument()->IsInitialDocument()) &&
+        IsSubframe()) {
+      // At this point, we know we just created a new iframe document based on
+      // the response from the server, and we check if it's a cross-domain
+      // iframe
+
+      RefPtr<Document> newDoc = viewer->GetDocument();
+
+      RefPtr<nsDocShell> parent = GetInProcessParentDocshell();
+      nsCOMPtr<nsIPrincipal> parentPrincipal =
+          parent->GetDocument()->NodePrincipal();
+      nsCOMPtr<nsIPrincipal> thisPrincipal = newDoc->NodePrincipal();
+
+      SiteIdentifier parentSite;
+      SiteIdentifier thisSite;
+
+      nsresult rv =
+          BasePrincipal::Cast(parentPrincipal)->GetSiteIdentifier(parentSite);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      rv = BasePrincipal::Cast(thisPrincipal)->GetSiteIdentifier(thisSite);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (!parentSite.Equals(thisSite)) {
+        if (profiler_thread_is_being_profiled_for_markers()) {
+          nsCOMPtr<nsIURI> prinURI;
+          BasePrincipal::Cast(thisPrincipal)->GetURI(getter_AddRefs(prinURI));
+          nsPrintfCString marker(
+              "Iframe loaded in background: %s",
+              nsContentUtils::TruncatedURLForDisplay(prinURI).get());
+          PROFILER_MARKER_TEXT("Background Iframe", DOM, {}, marker);
+        }
+        SetBackgroundLoadIframe();
+      }
+    }
+  }
+
+  NS_ENSURE_SUCCESS(Embed(viewer, nullptr, false,
+                          ShouldAddToSessionHistory(finalURI, aOpenedChannel),
+                          aOpenedChannel, previousURI),
+                    NS_ERROR_FAILURE);
+
+  if (!mBrowsingContext->GetHasLoadedNonInitialDocument()) {
+    MOZ_ALWAYS_SUCCEEDS(mBrowsingContext->SetHasLoadedNonInitialDocument(true));
+  }
+
+  if (TreatAsBackgroundLoad()) {
+    nsCOMPtr<nsIRunnable> triggerParentCheckDocShell =
+        NewRunnableMethod("nsDocShell::TriggerParentCheckDocShellIsEmpty", this,
+                          &nsDocShell::TriggerParentCheckDocShellIsEmpty);
+    nsresult rv = NS_DispatchToCurrentThread(triggerParentCheckDocShell);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  mSavedRefreshURIList = nullptr;
+  mSavingOldViewer = false;
+  mEODForCurrentDocument = false;
+
+  // if this document is part of a multipart document,
+  // the ID can be used to distinguish it from the other parts.
+  nsCOMPtr<nsIMultiPartChannel> multiPartChannel(do_QueryInterface(aRequest));
+  if (multiPartChannel) {
+    if (PresShell* presShell = GetPresShell()) {
+      if (Document* doc = presShell->GetDocument()) {
+        uint32_t partID;
+        multiPartChannel->GetPartID(&partID);
+        doc->SetPartID(partID);
+      }
+    }
+  }
+
+  if (errorOnLocationChangeNeeded) {
+    FireOnLocationChange(this, failedChannel, failedURI,
+                         LOCATION_CHANGE_ERROR_PAGE);
+  } else if (onLocationChangeNeeded) {
+    uint32_t locationFlags =
+        (mLoadType & LOAD_CMD_RELOAD) ? uint32_t(LOCATION_CHANGE_RELOAD) : 0;
+    FireOnLocationChange(this, aRequest, mCurrentURI, locationFlags);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::NewContentViewerObj(const nsACString& aContentType,
+                                         nsIRequest* aRequest,
+                                         nsILoadGroup* aLoadGroup,
+                                         nsIStreamListener** aContentHandler,
+                                         nsIContentViewer** aViewer) {
+  nsCOMPtr<nsIChannel> aOpenedChannel = do_QueryInterface(aRequest);
+
+  nsCOMPtr<nsIDocumentLoaderFactory> docLoaderFactory =
+      nsContentUtils::FindInternalContentViewer(aContentType);
+  if (!docLoaderFactory) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Now create an instance of the content viewer nsLayoutDLF makes the
+  // determination if it should be a "view-source" instead of "view"
+  nsresult rv = docLoaderFactory->CreateInstance(
+      "view", aOpenedChannel, aLoadGroup, aContentType, this, nullptr,
+      aContentHandler, aViewer);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  (*aViewer)->SetContainer(this);
+  return NS_OK;
+}
+
+nsresult nsDocShell::SetupNewViewer(nsIContentViewer* aNewViewer,
+                                    WindowGlobalChild* aWindowActor) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  //
+  // Copy content viewer state from previous or parent content viewer.
+  //
+  // The following logic is mirrored in nsHTMLDocument::StartDocumentLoad!
+  //
+  // Do NOT to maintain a reference to the old content viewer outside
+  // of this "copying" block, or it will not be destroyed until the end of
+  // this routine and all <SCRIPT>s and event handlers fail! (bug 20315)
+  //
+  // In this block of code, if we get an error result, we return it
+  // but if we get a null pointer, that's perfectly legal for parent
+  // and parentContentViewer.
+  //
+
+  int32_t x = 0;
+  int32_t y = 0;
+  int32_t cx = 0;
+  int32_t cy = 0;
+
+  // This will get the size from the current content viewer or from the
+  // Init settings
+  DoGetPositionAndSize(&x, &y, &cx, &cy);
+
+  nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
+  NS_ENSURE_SUCCESS(GetInProcessSameTypeParent(getter_AddRefs(parentAsItem)),
+                    NS_ERROR_FAILURE);
+  nsCOMPtr<nsIDocShell> parent(do_QueryInterface(parentAsItem));
+
+  const Encoding* reloadEncoding = nullptr;
+  int32_t reloadEncodingSource = kCharsetUninitialized;
+  // |newMUDV| also serves as a flag to set the data from the above vars
+  nsCOMPtr<nsIContentViewer> newCv;
+
+  if (mContentViewer || parent) {
+    nsCOMPtr<nsIContentViewer> oldCv;
+    if (mContentViewer) {
+      // Get any interesting state from old content viewer
+      // XXX: it would be far better to just reuse the document viewer ,
+      //      since we know we're just displaying the same document as before
+      oldCv = mContentViewer;
+
+      // Tell the old content viewer to hibernate in session history when
+      // it is destroyed.
+
+      if (mSavingOldViewer && NS_FAILED(CaptureState())) {
+        if (mOSHE) {
+          mOSHE->SyncPresentationState();
+        }
+        mSavingOldViewer = false;
+      }
+    } else {
+      // No old content viewer, so get state from parent's content viewer
+      parent->GetContentViewer(getter_AddRefs(oldCv));
+    }
+
+    if (oldCv) {
+      newCv = aNewViewer;
+      if (newCv) {
+        reloadEncoding =
+            oldCv->GetReloadEncodingAndSource(&reloadEncodingSource);
+      }
+    }
+  }
+
+  nscolor bgcolor = NS_RGBA(0, 0, 0, 0);
+  bool isUnderHiddenEmbedderElement = false;
+  // Ensure that the content viewer is destroyed *after* the GC - bug 71515
+  nsCOMPtr<nsIContentViewer> contentViewer = mContentViewer;
+  if (contentViewer) {
+    // Stop any activity that may be happening in the old document before
+    // releasing it...
+    contentViewer->Stop();
+
+    // Try to extract the canvas background color from the old
+    // presentation shell, so we can use it for the next document.
+    if (PresShell* presShell = contentViewer->GetPresShell()) {
+      bgcolor = presShell->GetCanvasBackground();
+      isUnderHiddenEmbedderElement = presShell->IsUnderHiddenEmbedderElement();
+    }
+
+    contentViewer->Close(mSavingOldViewer ? mOSHE.get() : nullptr);
+    aNewViewer->SetPreviousViewer(contentViewer);
+  }
+  if (mOSHE && (!mContentViewer || !mSavingOldViewer)) {
+    // We don't plan to save a viewer in mOSHE; tell it to drop
+    // any other state it's holding.
+    mOSHE->SyncPresentationState();
+  }
+
+  mContentViewer = nullptr;
+
+  // Now that we're about to switch documents, forget all of our children.
+  // Note that we cached them as needed up in CaptureState above.
+  DestroyChildren();
+
+  mContentViewer = aNewViewer;
+
+  nsCOMPtr<nsIWidget> widget;
+  NS_ENSURE_SUCCESS(GetMainWidget(getter_AddRefs(widget)), NS_ERROR_FAILURE);
+
+  nsIntRect bounds(x, y, cx, cy);
+
+  mContentViewer->SetNavigationTiming(mTiming);
+
+  if (NS_FAILED(mContentViewer->Init(widget, bounds, aWindowActor))) {
+    nsCOMPtr<nsIContentViewer> viewer = mContentViewer;
+    viewer->Close(nullptr);
+    viewer->Destroy();
+    mContentViewer = nullptr;
+    mCurrentURI = nullptr;
+    NS_WARNING("ContentViewer Initialization failed");
+    return NS_ERROR_FAILURE;
+  }
+
+  // If we have old state to copy, set the old state onto the new content
+  // viewer
+  if (newCv) {
+    newCv->SetReloadEncodingAndSource(reloadEncoding, reloadEncodingSource);
+  }
+
+  NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
+
+  // Stuff the bgcolor from the old pres shell into the new
+  // pres shell. This improves page load continuity.
+  if (RefPtr<PresShell> presShell = mContentViewer->GetPresShell()) {
+    presShell->SetCanvasBackground(bgcolor);
+    presShell->ActivenessMaybeChanged();
+    if (isUnderHiddenEmbedderElement) {
+      presShell->SetIsUnderHiddenEmbedderElement(isUnderHiddenEmbedderElement);
+    }
+  }
+
+  // XXX: It looks like the LayoutState gets restored again in Embed()
+  //      right after the call to SetupNewViewer(...)
+
+  // We don't show the mContentViewer yet, since we want to draw the old page
+  // until we have enough of the new page to show.  Just return with the new
+  // viewer still set to hidden.
+
+  return NS_OK;
+}
+
+void nsDocShell::SetDocCurrentStateObj(nsISHEntry* aShEntry,
+                                       SessionHistoryInfo* aInfo) {
+  NS_ENSURE_TRUE_VOID(mContentViewer);
+
+  RefPtr<Document> document = GetDocument();
+  NS_ENSURE_TRUE_VOID(document);
+
+  nsCOMPtr<nsIStructuredCloneContainer> scContainer;
+  if (mozilla::SessionHistoryInParent()) {
+    // If aInfo is null, just set the document's state object to null.
+    if (aInfo) {
+      scContainer = aInfo->GetStateData();
+    }
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("nsDocShell %p SetCurrentDocState %p", this, scContainer.get()));
+  } else {
+    if (aShEntry) {
+      scContainer = aShEntry->GetStateData();
+
+      // If aShEntry is null, just set the document's state object to null.
+    }
+  }
+
+  // It's OK for scContainer too be null here; that just means there's no
+  // state data associated with this history entry.
+  document->SetStateObject(scContainer);
+}
+
+nsresult nsDocShell::CheckLoadingPermissions() {
+  // This method checks whether the caller may load content into
+  // this docshell. Even though we've done our best to hide windows
+  // from code that doesn't have the right to access them, it's
+  // still possible for an evil site to open a window and access
+  // frames in the new window through window.frames[] (which is
+  // allAccess for historic reasons), so we still need to do this
+  // check on load.
+  nsresult rv = NS_OK;
+
+  if (!IsSubframe()) {
+    // We're not a frame. Permit all loads.
+    return rv;
+  }
+
+  // Note - The check for a current JSContext here isn't necessarily sensical.
+  // It's just designed to preserve the old semantics during a mass-conversion
+  // patch.
+  if (!nsContentUtils::GetCurrentJSContext()) {
+    return NS_OK;
+  }
+
+  // Check if the caller is from the same origin as this docshell,
+  // or any of its ancestors.
+  for (RefPtr<BrowsingContext> bc = mBrowsingContext; bc;
+       bc = bc->GetParent()) {
+    // If the BrowsingContext is not in process, then it
+    // is true by construction that its principal will not
+    // subsume the current docshell principal.
+    if (!bc->IsInProcess()) {
+      continue;
+    }
+
+    nsCOMPtr<nsIScriptGlobalObject> sgo =
+        bc->GetDocShell()->GetScriptGlobalObject();
+    nsCOMPtr<nsIScriptObjectPrincipal> sop(do_QueryInterface(sgo));
+
+    nsIPrincipal* p;
+    if (!sop || !(p = sop->GetPrincipal())) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    if (nsContentUtils::SubjectPrincipal()->Subsumes(p)) {
+      // Same origin, permit load
+      return NS_OK;
+    }
+  }
+
+  return NS_ERROR_DOM_PROP_ACCESS_DENIED;
+}
+
+//*****************************************************************************
+// nsDocShell: Site Loading
+//*****************************************************************************
+
+void nsDocShell::CopyFavicon(nsIURI* aOldURI, nsIURI* aNewURI,
+                             bool aInPrivateBrowsing) {
+  if (XRE_IsContentProcess()) {
+    dom::ContentChild* contentChild = dom::ContentChild::GetSingleton();
+    if (contentChild) {
+      contentChild->SendCopyFavicon(aOldURI, aNewURI, aInPrivateBrowsing);
+    }
+    return;
+  }
+
+#ifdef MOZ_PLACES
+  nsCOMPtr<nsIFaviconService> favSvc =
+      do_GetService("@mozilla.org/browser/favicon-service;1");
+  if (favSvc) {
+    favSvc->CopyFavicons(aOldURI, aNewURI,
+                         aInPrivateBrowsing
+                             ? nsIFaviconService::FAVICON_LOAD_PRIVATE
+                             : nsIFaviconService::FAVICON_LOAD_NON_PRIVATE,
+                         nullptr);
+  }
+#endif
+}
+
+class InternalLoadEvent : public Runnable {
+ public:
+  InternalLoadEvent(nsDocShell* aDocShell, nsDocShellLoadState* aLoadState)
+      : mozilla::Runnable("InternalLoadEvent"),
+        mDocShell(aDocShell),
+        mLoadState(aLoadState) {
+    // For events, both target and filename should be the version of "null" they
+    // expect. By the time the event is fired, both window targeting and file
+    // downloading have been handled, so we should never have an internal load
+    // event that retargets or had a download.
+    mLoadState->SetTarget(u""_ns);
+    mLoadState->SetFileName(VoidString());
+  }
+
+  NS_IMETHOD
+  Run() override {
+#ifndef ANDROID
+    MOZ_ASSERT(mLoadState->TriggeringPrincipal(),
+               "InternalLoadEvent: Should always have a principal here");
+#endif
+    return mDocShell->InternalLoad(mLoadState);
+  }
+
+ private:
+  RefPtr<nsDocShell> mDocShell;
+  RefPtr<nsDocShellLoadState> mLoadState;
+};
+
+/**
+ * Returns true if we started an asynchronous load (i.e., from the network), but
+ * the document we're loading there hasn't yet become this docshell's active
+ * document.
+ *
+ * When JustStartedNetworkLoad is true, you should be careful about modifying
+ * mLoadType and mLSHE.  These are both set when the asynchronous load first
+ * starts, and the load expects that, when it eventually runs InternalLoad,
+ * mLoadType and mLSHE will have their original values.
+ */
+bool nsDocShell::JustStartedNetworkLoad() {
+  return mDocumentRequest && mDocumentRequest != GetCurrentDocChannel();
+}
+
+// The contentType will be INTERNAL_(I)FRAME if this docshell is for a
+// non-toplevel browsing context in spec terms. (frame, iframe, <object>,
+// <embed>, etc)
+//
+// This return value will be used when we call NS_CheckContentLoadPolicy, and
+// later when we call DoURILoad.
+nsContentPolicyType nsDocShell::DetermineContentType() {
+  if (!IsSubframe()) {
+    return nsIContentPolicy::TYPE_DOCUMENT;
+  }
+
+  const auto& maybeEmbedderElementType =
+      GetBrowsingContext()->GetEmbedderElementType();
+  if (!maybeEmbedderElementType) {
+    // If the EmbedderElementType hasn't been set yet, just assume we're
+    // an iframe since that's more common.
+    return nsIContentPolicy::TYPE_INTERNAL_IFRAME;
+  }
+
+  return maybeEmbedderElementType->EqualsLiteral("iframe")
+             ? nsIContentPolicy::TYPE_INTERNAL_IFRAME
+             : nsIContentPolicy::TYPE_INTERNAL_FRAME;
+}
+
+bool nsDocShell::NoopenerForceEnabled() {
+  // If current's top-level browsing context's active document's
+  // cross-origin-opener-policy is "same-origin" or "same-origin + COEP" then
+  // if currentDoc's origin is not same origin with currentDoc's top-level
+  // origin, noopener is force enabled, and name is cleared to "_blank".
+  auto topPolicy = mBrowsingContext->Top()->GetOpenerPolicy();
+  return (topPolicy == nsILoadInfo::OPENER_POLICY_SAME_ORIGIN ||
+          topPolicy ==
+              nsILoadInfo::
+                  OPENER_POLICY_SAME_ORIGIN_EMBEDDER_POLICY_REQUIRE_CORP) &&
+         !mBrowsingContext->SameOriginWithTop();
+}
+
+nsresult nsDocShell::PerformRetargeting(nsDocShellLoadState* aLoadState) {
+  MOZ_ASSERT(aLoadState, "need a load state!");
+  MOZ_ASSERT(!aLoadState->Target().IsEmpty(), "should have a target here!");
+  MOZ_ASSERT(aLoadState->TargetBrowsingContext().IsNull(),
+             "should not have picked target yet");
+
+  nsresult rv = NS_OK;
+  RefPtr<BrowsingContext> targetContext;
+
+  // Only _self, _parent, and _top are supported in noopener case.  But we
+  // have to be careful to not apply that to the noreferrer case.  See bug
+  // 1358469.
+  bool allowNamedTarget =
+      !aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_NO_OPENER) ||
+      aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_DONT_SEND_REFERRER);
+  if (allowNamedTarget ||
+      aLoadState->Target().LowerCaseEqualsLiteral("_self") ||
+      aLoadState->Target().LowerCaseEqualsLiteral("_parent") ||
+      aLoadState->Target().LowerCaseEqualsLiteral("_top")) {
+    Document* document = GetDocument();
+    NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);
+    WindowGlobalChild* wgc = document->GetWindowGlobalChild();
+    NS_ENSURE_TRUE(wgc, NS_ERROR_FAILURE);
+    targetContext = wgc->FindBrowsingContextWithName(
+        aLoadState->Target(), /* aUseEntryGlobalForAccessCheck */ false);
+  }
+
+  if (!targetContext) {
+    // If the targetContext doesn't exist, then this is a new docShell and we
+    // should consider this a TYPE_DOCUMENT load
+    //
+    // For example, when target="_blank"
+
+    // If there's no targetContext, that means we are about to create a new
+    // window. Perform a content policy check before creating the window. Please
+    // note for all other docshell loads content policy checks are performed
+    // within the contentSecurityManager when the channel is about to be
+    // openend.
+    nsISupports* requestingContext = nullptr;
+    if (XRE_IsContentProcess()) {
+      // In e10s the child process doesn't have access to the element that
+      // contains the browsing context (because that element is in the chrome
+      // process). So we just pass mScriptGlobal.
+      requestingContext = ToSupports(mScriptGlobal);
+    } else {
+      // This is for loading non-e10s tabs and toplevel windows of various
+      // sorts.
+      // For the toplevel window cases, requestingElement will be null.
+      nsCOMPtr<Element> requestingElement =
+          mScriptGlobal->GetFrameElementInternal();
+      requestingContext = requestingElement;
+    }
+
+    // Ideally we should use the same loadinfo as within DoURILoad which
+    // should match this one when both are applicable.
+    nsCOMPtr<nsILoadInfo> secCheckLoadInfo =
+        new LoadInfo(mScriptGlobal, aLoadState->URI(),
+                     aLoadState->TriggeringPrincipal(), requestingContext,
+                     nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK, 0);
+
+    // Since Content Policy checks are performed within docShell as well as
+    // the ContentSecurityManager we need a reliable way to let certain
+    // nsIContentPolicy consumers ignore duplicate calls.
+    secCheckLoadInfo->SetSkipContentPolicyCheckForWebRequest(true);
+
+    int16_t shouldLoad = nsIContentPolicy::ACCEPT;
+    rv = NS_CheckContentLoadPolicy(aLoadState->URI(), secCheckLoadInfo,
+                                   ""_ns,  // mime guess
+                                   &shouldLoad);
+
+    if (NS_FAILED(rv) || NS_CP_REJECTED(shouldLoad)) {
+      if (NS_SUCCEEDED(rv)) {
+        if (shouldLoad == nsIContentPolicy::REJECT_TYPE) {
+          return NS_ERROR_CONTENT_BLOCKED_SHOW_ALT;
+        }
+        if (shouldLoad == nsIContentPolicy::REJECT_POLICY) {
+          return NS_ERROR_BLOCKED_BY_POLICY;
+        }
+      }
+
+      return NS_ERROR_CONTENT_BLOCKED;
+    }
+  }
+
+  //
+  // Resolve the window target before going any further...
+  // If the load has been targeted to another DocShell, then transfer the
+  // load to it...
+  //
+
+  // We've already done our owner-inheriting.  Mask out that bit, so we
+  // don't try inheriting an owner from the target window if we came up
+  // with a null owner above.
+  aLoadState->UnsetInternalLoadFlag(INTERNAL_LOAD_FLAGS_INHERIT_PRINCIPAL);
+
+  if (!targetContext) {
+    // If the docshell's document is sandboxed, only open a new window
+    // if the document's SANDBOXED_AUXILLARY_NAVIGATION flag is not set.
+    // (i.e. if allow-popups is specified)
+    NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
+    Document* doc = mContentViewer->GetDocument();
+
+    const bool isDocumentAuxSandboxed =
+        doc && (doc->GetSandboxFlags() & SANDBOXED_AUXILIARY_NAVIGATION);
+
+    if (isDocumentAuxSandboxed) {
+      return NS_ERROR_DOM_INVALID_ACCESS_ERR;
+    }
+
+    nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+    NS_ENSURE_TRUE(win, NS_ERROR_NOT_AVAILABLE);
+
+    RefPtr<BrowsingContext> newBC;
+    nsAutoCString spec;
+    aLoadState->URI()->GetSpec(spec);
+
+    // If we are a noopener load, we just hand the whole thing over to our
+    // window.
+    if (aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_NO_OPENER) ||
+        NoopenerForceEnabled()) {
+      // Various asserts that we know to hold because NO_OPENER loads can only
+      // happen for links.
+      MOZ_ASSERT(!aLoadState->LoadReplace());
+      MOZ_ASSERT(aLoadState->PrincipalToInherit() ==
+                 aLoadState->TriggeringPrincipal());
+      MOZ_ASSERT(!(aLoadState->InternalLoadFlags() &
+                   ~(INTERNAL_LOAD_FLAGS_NO_OPENER |
+                     INTERNAL_LOAD_FLAGS_DONT_SEND_REFERRER)),
+                 "Only INTERNAL_LOAD_FLAGS_NO_OPENER and "
+                 "INTERNAL_LOAD_FLAGS_DONT_SEND_REFERRER can be set");
+      MOZ_ASSERT_IF(aLoadState->PostDataStream(),
+                    aLoadState->IsFormSubmission());
+      MOZ_ASSERT(!aLoadState->HeadersStream());
+      // If OnLinkClickSync was invoked inside the onload handler, the load
+      // type would be set to LOAD_NORMAL_REPLACE; otherwise it should be
+      // LOAD_LINK.
+      MOZ_ASSERT(aLoadState->LoadType() == LOAD_LINK ||
+                 aLoadState->LoadType() == LOAD_NORMAL_REPLACE);
+      MOZ_ASSERT(!aLoadState->LoadIsFromSessionHistory());
+      MOZ_ASSERT(aLoadState->FirstParty());  // Windowwatcher will assume this.
+
+      RefPtr<nsDocShellLoadState> loadState =
+          new nsDocShellLoadState(aLoadState->URI());
+
+      // Set up our loadinfo so it will do the load as much like we would have
+      // as possible.
+      loadState->SetReferrerInfo(aLoadState->GetReferrerInfo());
+      loadState->SetOriginalURI(aLoadState->OriginalURI());
+
+      Maybe<nsCOMPtr<nsIURI>> resultPrincipalURI;
+      aLoadState->GetMaybeResultPrincipalURI(resultPrincipalURI);
+
+      loadState->SetMaybeResultPrincipalURI(resultPrincipalURI);
+      loadState->SetKeepResultPrincipalURIIfSet(
+          aLoadState->KeepResultPrincipalURIIfSet());
+      // LoadReplace will always be false due to asserts above, skip setting
+      // it.
+      loadState->SetTriggeringPrincipal(aLoadState->TriggeringPrincipal());
+      loadState->SetTriggeringSandboxFlags(
+          aLoadState->TriggeringSandboxFlags());
+      loadState->SetCsp(aLoadState->Csp());
+      loadState->SetInheritPrincipal(aLoadState->HasInternalLoadFlags(
+          INTERNAL_LOAD_FLAGS_INHERIT_PRINCIPAL));
+      // Explicit principal because we do not want any guesses as to what the
+      // principal to inherit is: it should be aTriggeringPrincipal.
+      loadState->SetPrincipalIsExplicit(true);
+      loadState->SetLoadType(LOAD_LINK);
+      loadState->SetForceAllowDataURI(aLoadState->HasInternalLoadFlags(
+          INTERNAL_LOAD_FLAGS_FORCE_ALLOW_DATA_URI));
+
+      loadState->SetHasValidUserGestureActivation(
+          aLoadState->HasValidUserGestureActivation());
+
+      // Propagate POST data to the new load.
+      loadState->SetPostDataStream(aLoadState->PostDataStream());
+      loadState->SetIsFormSubmission(aLoadState->IsFormSubmission());
+
+      rv = win->Open(NS_ConvertUTF8toUTF16(spec),
+                     aLoadState->Target(),  // window name
+                     u""_ns,                // Features
+                     loadState,
+                     true,  // aForceNoOpener
+                     getter_AddRefs(newBC));
+      MOZ_ASSERT(!newBC);
+      return rv;
+    }
+
+    rv = win->OpenNoNavigate(NS_ConvertUTF8toUTF16(spec),
+                             aLoadState->Target(),  // window name
+                             u""_ns,                // Features
+                             getter_AddRefs(newBC));
+
+    // In some cases the Open call doesn't actually result in a new
+    // window being opened.  We can detect these cases by examining the
+    // document in |newBC|, if any.
+    nsCOMPtr<nsPIDOMWindowOuter> piNewWin =
+        newBC ? newBC->GetDOMWindow() : nullptr;
+    if (piNewWin) {
+      RefPtr<Document> newDoc = piNewWin->GetExtantDoc();
+      if (!newDoc || newDoc->IsInitialDocument()) {
+        aLoadState->SetInternalLoadFlag(INTERNAL_LOAD_FLAGS_FIRST_LOAD);
+      }
+    }
+
+    if (newBC) {
+      targetContext = newBC;
+    }
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_TRUE(targetContext, rv);
+
+  // If our target BrowsingContext is still pending initialization, ignore the
+  // navigation request targeting it.
+  if (NS_WARN_IF(targetContext->GetPendingInitialization())) {
+    return NS_OK;
+  }
+
+  aLoadState->SetTargetBrowsingContext(targetContext);
+  //
+  // Transfer the load to the target BrowsingContext... Clear the window target
+  // name to the empty string to prevent recursive retargeting!
+  //
+  // No window target
+  aLoadState->SetTarget(u""_ns);
+  // No forced download
+  aLoadState->SetFileName(VoidString());
+  return targetContext->InternalLoad(aLoadState);
+}
+
+static nsAutoCString RefMaybeNull(nsIURI* aURI) {
+  nsAutoCString result;
+  if (NS_FAILED(aURI->GetRef(result))) {
+    result.SetIsVoid(true);
+  }
+  return result;
+}
+
+uint32_t nsDocShell::GetSameDocumentNavigationFlags(nsIURI* aNewURI) {
+  uint32_t flags = LOCATION_CHANGE_SAME_DOCUMENT;
+
+  bool equal = false;
+  if (mCurrentURI &&
+      NS_SUCCEEDED(mCurrentURI->EqualsExceptRef(aNewURI, &equal)) && equal &&
+      RefMaybeNull(mCurrentURI) != RefMaybeNull(aNewURI)) {
+    flags |= LOCATION_CHANGE_HASHCHANGE;
+  }
+
+  return flags;
+}
+
+bool nsDocShell::IsSameDocumentNavigation(nsDocShellLoadState* aLoadState,
+                                          SameDocumentNavigationState& aState) {
+  MOZ_ASSERT(aLoadState);
+  if (!(aLoadState->LoadType() == LOAD_NORMAL ||
+        aLoadState->LoadType() == LOAD_STOP_CONTENT ||
+        LOAD_TYPE_HAS_FLAGS(aLoadState->LoadType(),
+                            LOAD_FLAGS_REPLACE_HISTORY) ||
+        aLoadState->LoadType() == LOAD_HISTORY ||
+        aLoadState->LoadType() == LOAD_LINK)) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> currentURI = mCurrentURI;
+
+  nsresult rvURINew = aLoadState->URI()->GetRef(aState.mNewHash);
+  if (NS_SUCCEEDED(rvURINew)) {
+    rvURINew = aLoadState->URI()->GetHasRef(&aState.mNewURIHasRef);
+  }
+
+  if (currentURI && NS_SUCCEEDED(rvURINew)) {
+    nsresult rvURIOld = currentURI->GetRef(aState.mCurrentHash);
+    if (NS_SUCCEEDED(rvURIOld)) {
+      rvURIOld = currentURI->GetHasRef(&aState.mCurrentURIHasRef);
+    }
+    if (NS_SUCCEEDED(rvURIOld)) {
+      if (NS_FAILED(currentURI->EqualsExceptRef(aLoadState->URI(),
+                                                &aState.mSameExceptHashes))) {
+        aState.mSameExceptHashes = false;
+      }
+    }
+  }
+
+  if (!aState.mSameExceptHashes && currentURI && NS_SUCCEEDED(rvURINew)) {
+    // Maybe aLoadState->URI() came from the exposable form of currentURI?
+    nsCOMPtr<nsIURI> currentExposableURI =
+        nsIOService::CreateExposableURI(currentURI);
+    nsresult rvURIOld = currentExposableURI->GetRef(aState.mCurrentHash);
+    if (NS_SUCCEEDED(rvURIOld)) {
+      rvURIOld = currentExposableURI->GetHasRef(&aState.mCurrentURIHasRef);
+    }
+    if (NS_SUCCEEDED(rvURIOld)) {
+      if (NS_FAILED(currentExposableURI->EqualsExceptRef(
+              aLoadState->URI(), &aState.mSameExceptHashes))) {
+        aState.mSameExceptHashes = false;
+      }
+      // HTTPS-Only Mode upgrades schemes from http to https in Necko, hence we
+      // have to perform a special check here to avoid an actual navigation. If
+      // HTTPS-Only Mode is enabled and the two URIs are same-origin (modulo the
+      // fact that the new URI is currently http), then set mSameExceptHashes to
+      // true and only perform a fragment navigation.
+      if (!aState.mSameExceptHashes) {
+        if (nsCOMPtr<nsIChannel> docChannel = GetCurrentDocChannel()) {
+          nsCOMPtr<nsILoadInfo> docLoadInfo = docChannel->LoadInfo();
+          if (!docLoadInfo->GetLoadErrorPage() &&
+              nsHTTPSOnlyUtils::IsEqualURIExceptSchemeAndRef(
+                  currentExposableURI, aLoadState->URI(), docLoadInfo)) {
+            uint32_t status = docLoadInfo->GetHttpsOnlyStatus();
+            if (status & (nsILoadInfo::HTTPS_ONLY_UPGRADED_LISTENER_REGISTERED |
+                          nsILoadInfo::HTTPS_ONLY_UPGRADED_HTTPS_FIRST)) {
+              // At this point the requested URI is for sure a fragment
+              // navigation via HTTP and HTTPS-Only mode or HTTPS-First is
+              // enabled. Also it is not interfering the upgrade order of
+              // https://searchfox.org/mozilla-central/source/netwerk/base/nsNetUtil.cpp#2948-2953.
+              // Since we are on an HTTPS site the fragment
+              // navigation should also be an HTTPS.
+              // For that reason we should upgrade the URI to HTTPS.
+              aState.mSecureUpgradeURI = true;
+              aState.mSameExceptHashes = true;
+            }
+          }
+        }
+      }
+    }
+  }
+
+  if (mozilla::SessionHistoryInParent()) {
+    if (mActiveEntry && aLoadState->LoadIsFromSessionHistory()) {
+      aState.mHistoryNavBetweenSameDoc = mActiveEntry->SharesDocumentWith(
+          aLoadState->GetLoadingSessionHistoryInfo()->mInfo);
+    }
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("nsDocShell::IsSameDocumentNavigation %p NavBetweenSameDoc=%d",
+             this, aState.mHistoryNavBetweenSameDoc));
+  } else {
+    if (mOSHE && aLoadState->LoadIsFromSessionHistory()) {
+      // We're doing a history load.
+
+      mOSHE->SharesDocumentWith(aLoadState->SHEntry(),
+                                &aState.mHistoryNavBetweenSameDoc);
+    }
+  }
+
+  // A same document navigation happens when we navigate between two SHEntries
+  // for the same document. We do a same document navigation under two
+  // circumstances. Either
+  //
+  //  a) we're navigating between two different SHEntries which share a
+  //     document, or
+  //
+  //  b) we're navigating to a new shentry whose URI differs from the
+  //     current URI only in its hash, the new hash is non-empty, and
+  //     we're not doing a POST.
+  //
+  // The restriction that the SHEntries in (a) must be different ensures
+  // that history.go(0) and the like trigger full refreshes, rather than
+  // same document navigations.
+  if (!mozilla::SessionHistoryInParent()) {
+    bool doSameDocumentNavigation =
+        (aState.mHistoryNavBetweenSameDoc && mOSHE != aLoadState->SHEntry()) ||
+        (!aLoadState->SHEntry() && !aLoadState->PostDataStream() &&
+         aState.mSameExceptHashes && aState.mNewURIHasRef);
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("nsDocShell %p NavBetweenSameDoc=%d is same doc = %d", this,
+             aState.mHistoryNavBetweenSameDoc, doSameDocumentNavigation));
+    return doSameDocumentNavigation;
+  }
+
+  if (aState.mHistoryNavBetweenSameDoc &&
+      !aLoadState->GetLoadingSessionHistoryInfo()->mLoadingCurrentEntry) {
+    return true;
+  }
+
+  MOZ_LOG(
+      gSHLog, LogLevel::Debug,
+      ("nsDocShell::IsSameDocumentNavigation %p !LoadIsFromSessionHistory=%s "
+       "!PostDataStream: %s mSameExceptHashes: %s mNewURIHasRef: %s",
+       this, !aLoadState->LoadIsFromSessionHistory() ? "true" : "false",
+       !aLoadState->PostDataStream() ? "true" : "false",
+       aState.mSameExceptHashes ? "true" : "false",
+       aState.mNewURIHasRef ? "true" : "false"));
+  return !aLoadState->LoadIsFromSessionHistory() &&
+         !aLoadState->PostDataStream() && aState.mSameExceptHashes &&
+         aState.mNewURIHasRef;
+}
+
+nsresult nsDocShell::HandleSameDocumentNavigation(
+    nsDocShellLoadState* aLoadState, SameDocumentNavigationState& aState) {
+#ifdef DEBUG
+  SameDocumentNavigationState state;
+  MOZ_ASSERT(IsSameDocumentNavigation(aLoadState, state));
+#endif
+
+  MOZ_LOG(gSHLog, LogLevel::Debug,
+          ("nsDocShell::HandleSameDocumentNavigation %p %s -> %s", this,
+           mCurrentURI->GetSpecOrDefault().get(),
+           aLoadState->URI()->GetSpecOrDefault().get()));
+
+  RefPtr<Document> doc = GetDocument();
+  NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
+  doc->DoNotifyPossibleTitleChange();
+
+  nsCOMPtr<nsIURI> currentURI = mCurrentURI;
+
+  // We need to upgrade the new URI from http: to https:
+  nsCOMPtr<nsIURI> newURI = aLoadState->URI();
+  if (aState.mSecureUpgradeURI) {
+    MOZ_TRY(NS_GetSecureUpgradedURI(aLoadState->URI(), getter_AddRefs(newURI)));
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("Upgraded URI to %s", newURI->GetSpecOrDefault().get()));
+  }
+
+#ifdef DEBUG
+  if (aState.mSameExceptHashes) {
+    bool sameExceptHashes = false;
+    currentURI->EqualsExceptRef(newURI, &sameExceptHashes);
+    MOZ_ASSERT(sameExceptHashes);
+  }
+#endif
+
+  // Save the position of the scrollers.
+  nsPoint scrollPos = GetCurScrollPos();
+
+  // Reset mLoadType to its original value once we exit this block, because this
+  // same document navigation might have started after a normal, network load,
+  // and we don't want to clobber its load type. See bug 737307.
+  AutoRestore<uint32_t> loadTypeResetter(mLoadType);
+
+  // If a non-same-document-navigation (i.e., a network load) is pending, make
+  // this a replacement load, so that we don't add a SHEntry here and the
+  // network load goes into the SHEntry it expects to.
+  if (JustStartedNetworkLoad() && (aLoadState->LoadType() & LOAD_CMD_NORMAL)) {
+    mLoadType = LOAD_NORMAL_REPLACE;
+  } else {
+    mLoadType = aLoadState->LoadType();
+  }
+
+  mURIResultedInDocument = true;
+
+  nsCOMPtr<nsISHEntry> oldLSHE = mLSHE;
+
+  // we need to assign aLoadState->SHEntry() to mLSHE right here, so that on
+  // History loads, SetCurrentURI() called from OnNewURI() will send proper
+  // onLocationChange() notifications to the browser to update back/forward
+  // buttons.
+  SetHistoryEntryAndUpdateBC(Some<nsISHEntry*>(aLoadState->SHEntry()),
+                             Nothing());
+  UniquePtr<mozilla::dom::LoadingSessionHistoryInfo> oldLoadingEntry;
+  mLoadingEntry.swap(oldLoadingEntry);
+  if (aLoadState->GetLoadingSessionHistoryInfo()) {
+    mLoadingEntry = MakeUnique<LoadingSessionHistoryInfo>(
+        *aLoadState->GetLoadingSessionHistoryInfo());
+    mNeedToReportActiveAfterLoadingBecomesActive = false;
+  }
+
+  // Set the doc's URI according to the new history entry's URI.
+  doc->SetDocumentURI(newURI);
+
+  /* This is a anchor traversal within the same page.
+   * call OnNewURI() so that, this traversal will be
+   * recorded in session and global history.
+   */
+  nsCOMPtr<nsIPrincipal> newURITriggeringPrincipal, newURIPrincipalToInherit,
+      newURIPartitionedPrincipalToInherit;
+  nsCOMPtr<nsIContentSecurityPolicy> newCsp;
+  if (mozilla::SessionHistoryInParent() ? !!mActiveEntry : !!mOSHE) {
+    if (mozilla::SessionHistoryInParent()) {
+      newURITriggeringPrincipal = mActiveEntry->GetTriggeringPrincipal();
+      newURIPrincipalToInherit = mActiveEntry->GetPrincipalToInherit();
+      newURIPartitionedPrincipalToInherit =
+          mActiveEntry->GetPartitionedPrincipalToInherit();
+      newCsp = mActiveEntry->GetCsp();
+    } else {
+      newURITriggeringPrincipal = mOSHE->GetTriggeringPrincipal();
+      newURIPrincipalToInherit = mOSHE->GetPrincipalToInherit();
+      newURIPartitionedPrincipalToInherit =
+          mOSHE->GetPartitionedPrincipalToInherit();
+      newCsp = mOSHE->GetCsp();
+    }
+  } else {
+    newURITriggeringPrincipal = aLoadState->TriggeringPrincipal();
+    newURIPrincipalToInherit = doc->NodePrincipal();
+    newURIPartitionedPrincipalToInherit = doc->PartitionedPrincipal();
+    newCsp = doc->GetCsp();
+  }
+
+  uint32_t locationChangeFlags = GetSameDocumentNavigationFlags(newURI);
+
+  // Pass true for aCloneSHChildren, since we're not
+  // changing documents here, so all of our subframes are
+  // still relevant to the new session history entry.
+  //
+  // It also makes OnNewURI(...) set LOCATION_CHANGE_SAME_DOCUMENT
+  // flag on firing onLocationChange(...).
+  // Anyway, aCloneSHChildren param is simply reflecting
+  // doSameDocumentNavigation in this scope.
+  //
+  // Note: we'll actually fire onLocationChange later, in order to preserve
+  // ordering of HistoryCommit() in the parent vs onLocationChange (bug
+  // 1668126)
+  bool locationChangeNeeded = OnNewURI(
+      newURI, nullptr, newURITriggeringPrincipal, newURIPrincipalToInherit,
+      newURIPartitionedPrincipalToInherit, newCsp, false, true, true);
+
+  nsCOMPtr<nsIInputStream> postData;
+  uint32_t cacheKey = 0;
+
+  bool scrollRestorationIsManual = false;
+  if (!mozilla::SessionHistoryInParent()) {
+    if (mOSHE) {
+      /* save current position of scroller(s) (bug 59774) */
+      mOSHE->SetScrollPosition(scrollPos.x, scrollPos.y);
+      scrollRestorationIsManual = mOSHE->GetScrollRestorationIsManual();
+      // Get the postdata and page ident from the current page, if
+      // the new load is being done via normal means.  Note that
+      // "normal means" can be checked for just by checking for
+      // LOAD_CMD_NORMAL, given the loadType and allowScroll check
+      // above -- it filters out some LOAD_CMD_NORMAL cases that we
+      // wouldn't want here.
+      if (aLoadState->LoadType() & LOAD_CMD_NORMAL) {
+        postData = mOSHE->GetPostData();
+        cacheKey = mOSHE->GetCacheKey();
+      }
+
+      // Link our new SHEntry to the old SHEntry's back/forward
+      // cache data, since the two SHEntries correspond to the
+      // same document.
+      if (mLSHE) {
+        if (!aLoadState->LoadIsFromSessionHistory()) {
+          // If we're not doing a history load, scroll restoration
+          // should be inherited from the previous session history entry.
+          SetScrollRestorationIsManualOnHistoryEntry(mLSHE,
+                                                     scrollRestorationIsManual);
+        }
+        mLSHE->AdoptBFCacheEntry(mOSHE);
+      }
+    }
+  } else {
+    if (mActiveEntry) {
+      mActiveEntry->SetScrollPosition(scrollPos.x, scrollPos.y);
+      if (mBrowsingContext) {
+        CollectWireframe();
+        if (XRE_IsParentProcess()) {
+          SessionHistoryEntry* entry =
+              mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+          if (entry) {
+            entry->SetScrollPosition(scrollPos.x, scrollPos.y);
+          }
+        } else {
+          mozilla::Unused << ContentChild::GetSingleton()
+                                 ->SendSessionHistoryEntryScrollPosition(
+                                     mBrowsingContext, scrollPos.x,
+                                     scrollPos.y);
+        }
+      }
+    }
+    if (mLoadingEntry) {
+      if (!mLoadingEntry->mLoadIsFromSessionHistory) {
+        // If we're not doing a history load, scroll restoration
+        // should be inherited from the previous session history entry.
+        // XXX This needs most probably tweaks once fragment navigation is
+        // fixed to work with session-history-in-parent.
+        SetScrollRestorationIsManualOnHistoryEntry(nullptr,
+                                                   scrollRestorationIsManual);
+      }
+    }
+  }
+
+  // If we're doing a history load, use its scroll restoration state.
+  if (aLoadState->LoadIsFromSessionHistory()) {
+    if (mozilla::SessionHistoryInParent()) {
+      scrollRestorationIsManual = aLoadState->GetLoadingSessionHistoryInfo()
+                                      ->mInfo.GetScrollRestorationIsManual();
+    } else {
+      scrollRestorationIsManual =
+          aLoadState->SHEntry()->GetScrollRestorationIsManual();
+    }
+  }
+
+  /* Assign mLSHE to mOSHE. This will either be a new entry created
+   * by OnNewURI() for normal loads or aLoadState->SHEntry() for history
+   * loads.
+   */
+  if (!mozilla::SessionHistoryInParent()) {
+    if (mLSHE) {
+      SetHistoryEntryAndUpdateBC(Nothing(), Some<nsISHEntry*>(mLSHE));
+      // Save the postData obtained from the previous page
+      // in to the session history entry created for the
+      // anchor page, so that any history load of the anchor
+      // page will restore the appropriate postData.
+      if (postData) {
+        mOSHE->SetPostData(postData);
+      }
+
+      // Make sure we won't just repost without hitting the
+      // cache first
+      if (cacheKey != 0) {
+        mOSHE->SetCacheKey(cacheKey);
+      }
+    }
+
+    /* Set the title for the SH entry for this target url so that
+     * SH menus in go/back/forward buttons won't be empty for this.
+     * Note, this happens on mOSHE (and mActiveEntry in the future) because of
+     * the code above.
+     * Note, when session history lives in the parent process, this does not
+     * update the title there.
+     */
+    SetTitleOnHistoryEntry(false);
+  } else {
+    if (aLoadState->LoadIsFromSessionHistory()) {
+      MOZ_LOG(
+          gSHLog, LogLevel::Debug,
+          ("Moving the loading entry to the active entry on nsDocShell %p to "
+           "%s",
+           this, mLoadingEntry->mInfo.GetURI()->GetSpecOrDefault().get()));
+
+      nsCOMPtr<nsILayoutHistoryState> currentLayoutHistoryState;
+      if (mActiveEntry) {
+        currentLayoutHistoryState = mActiveEntry->GetLayoutHistoryState();
+      }
+
+      UniquePtr<SessionHistoryInfo> previousActiveEntry(mActiveEntry.release());
+      mActiveEntry = MakeUnique<SessionHistoryInfo>(mLoadingEntry->mInfo);
+      if (currentLayoutHistoryState) {
+        // Restore the existing nsILayoutHistoryState object, since it is
+        // possibly being used by the layout. When doing a new load, the
+        // shared state is copied from the existing active entry, so this
+        // special case is needed only with the history loads.
+        mActiveEntry->SetLayoutHistoryState(currentLayoutHistoryState);
+      }
+
+      if (cacheKey != 0) {
+        mActiveEntry->SetCacheKey(cacheKey);
+      }
+      // We're passing in mCurrentURI, which could be null. SessionHistoryCommit
+      // does require a non-null uri if this is for a refresh load of the same
+      // URI, but in that case mCurrentURI won't be null here.
+      mBrowsingContext->SessionHistoryCommit(
+          *mLoadingEntry, mLoadType, mCurrentURI, previousActiveEntry.get(),
+          true, true,
+          /* No expiration update on the same document loads*/
+          false, cacheKey);
+      // FIXME Need to set postdata.
+
+      // Set the title for the SH entry for this target url so that
+      // SH menus in go/back/forward buttons won't be empty for this.
+      // Note, when session history lives in the parent process, this does not
+      // update the title there.
+      SetTitleOnHistoryEntry(false);
+    } else {
+      Maybe<bool> scrollRestorationIsManual;
+      if (mActiveEntry) {
+        scrollRestorationIsManual.emplace(
+            mActiveEntry->GetScrollRestorationIsManual());
+
+        // Get the postdata and page ident from the current page, if the new
+        // load is being done via normal means.  Note that "normal means" can be
+        // checked for just by checking for LOAD_CMD_NORMAL, given the loadType
+        // and allowScroll check above -- it filters out some LOAD_CMD_NORMAL
+        // cases that we wouldn't want here.
+        if (aLoadState->LoadType() & LOAD_CMD_NORMAL) {
+          postData = mActiveEntry->GetPostData();
+          cacheKey = mActiveEntry->GetCacheKey();
+        }
+      }
+
+      MOZ_LOG(gSHLog, LogLevel::Debug,
+              ("Creating an active entry on nsDocShell %p to %s", this,
+               newURI->GetSpecOrDefault().get()));
+      if (mActiveEntry) {
+        mActiveEntry = MakeUnique<SessionHistoryInfo>(*mActiveEntry, newURI);
+      } else {
+        mActiveEntry = MakeUnique<SessionHistoryInfo>(
+            newURI, newURITriggeringPrincipal, newURIPrincipalToInherit,
+            newURIPartitionedPrincipalToInherit, newCsp, mContentTypeHint);
+      }
+
+      // Save the postData obtained from the previous page in to the session
+      // history entry created for the anchor page, so that any history load of
+      // the anchor page will restore the appropriate postData.
+      if (postData) {
+        mActiveEntry->SetPostData(postData);
+      }
+
+      // Make sure we won't just repost without hitting the
+      // cache first
+      if (cacheKey != 0) {
+        mActiveEntry->SetCacheKey(cacheKey);
+      }
+
+      // Set the title for the SH entry for this target url so that
+      // SH menus in go/back/forward buttons won't be empty for this.
+      mActiveEntry->SetTitle(mTitle);
+
+      if (scrollRestorationIsManual.isSome()) {
+        mActiveEntry->SetScrollRestorationIsManual(
+            scrollRestorationIsManual.value());
+      }
+
+      if (LOAD_TYPE_HAS_FLAGS(mLoadType, LOAD_FLAGS_REPLACE_HISTORY)) {
+        mBrowsingContext->ReplaceActiveSessionHistoryEntry(mActiveEntry.get());
+      } else {
+        mBrowsingContext->IncrementHistoryEntryCountForBrowsingContext();
+        // FIXME We should probably just compute mChildOffset in the parent
+        //       instead of passing it over IPC here.
+        mBrowsingContext->SetActiveSessionHistoryEntry(
+            Some(scrollPos), mActiveEntry.get(), mLoadType, cacheKey);
+        // FIXME Do we need to update mPreviousEntryIndex and mLoadedEntryIndex?
+      }
+    }
+  }
+
+  if (locationChangeNeeded) {
+    FireOnLocationChange(this, nullptr, newURI, locationChangeFlags);
+  }
+
+  /* Restore the original LSHE if we were loading something
+   * while same document navigation was initiated.
+   */
+  SetHistoryEntryAndUpdateBC(Some<nsISHEntry*>(oldLSHE), Nothing());
+  mLoadingEntry.swap(oldLoadingEntry);
+
+  /* Set the title for the Global History entry for this anchor url.
+   */
+  UpdateGlobalHistoryTitle(newURI);
+
+  SetDocCurrentStateObj(mOSHE, mActiveEntry.get());
+
+  // Inform the favicon service that the favicon for oldURI also
+  // applies to newURI.
+  CopyFavicon(currentURI, newURI, UsePrivateBrowsing());
+
+  RefPtr<nsGlobalWindowOuter> scriptGlobal = mScriptGlobal;
+  RefPtr<nsGlobalWindowInner> win =
+      scriptGlobal ? scriptGlobal->GetCurrentInnerWindowInternal() : nullptr;
+
+  // ScrollToAnchor doesn't necessarily cause us to scroll the window;
+  // the function decides whether a scroll is appropriate based on the
+  // arguments it receives.  But even if we don't end up scrolling,
+  // ScrollToAnchor performs other important tasks, such as informing
+  // the presShell that we have a new hash.  See bug 680257.
+  nsresult rv = ScrollToAnchor(aState.mCurrentURIHasRef, aState.mNewURIHasRef,
+                               aState.mNewHash, aLoadState->LoadType());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  /* restore previous position of scroller(s), if we're moving
+   * back in history (bug 59774)
+   */
+  nscoord bx = 0;
+  nscoord by = 0;
+  bool needsScrollPosUpdate = false;
+  if ((mozilla::SessionHistoryInParent() ? !!mActiveEntry : !!mOSHE) &&
+      (aLoadState->LoadType() == LOAD_HISTORY ||
+       aLoadState->LoadType() == LOAD_RELOAD_NORMAL) &&
+      !scrollRestorationIsManual) {
+    needsScrollPosUpdate = true;
+    if (mozilla::SessionHistoryInParent()) {
+      mActiveEntry->GetScrollPosition(&bx, &by);
+    } else {
+      mOSHE->GetScrollPosition(&bx, &by);
+    }
+  }
+
+  // Dispatch the popstate and hashchange events, as appropriate.
+  //
+  // The event dispatch below can cause us to re-enter script and
+  // destroy the docshell, nulling out mScriptGlobal. Hold a stack
+  // reference to avoid null derefs. See bug 914521.
+  if (win) {
+    // Fire a hashchange event URIs differ, and only in their hashes.
+    bool doHashchange = aState.mSameExceptHashes &&
+                        (aState.mCurrentURIHasRef != aState.mNewURIHasRef ||
+                         !aState.mCurrentHash.Equals(aState.mNewHash));
+
+    if (aState.mHistoryNavBetweenSameDoc || doHashchange) {
+      win->DispatchSyncPopState();
+    }
+
+    if (needsScrollPosUpdate && win->HasActiveDocument()) {
+      SetCurScrollPosEx(bx, by);
+    }
+
+    if (doHashchange) {
+      // Note that currentURI hasn't changed because it's on the
+      // stack, so we can just use it directly as the old URI.
+      win->DispatchAsyncHashchange(currentURI, newURI);
+    }
+  }
+
+  return NS_OK;
+}
+
+static bool NavigationShouldTakeFocus(nsDocShell* aDocShell,
+                                      nsDocShellLoadState* aLoadState) {
+  if (!aLoadState->AllowFocusMove()) {
+    return false;
+  }
+  if (!aLoadState->HasValidUserGestureActivation()) {
+    return false;
+  }
+  const auto& sourceBC = aLoadState->SourceBrowsingContext();
+  if (!sourceBC || !sourceBC->IsActive()) {
+    // If the navigation didn't come from a foreground tab, then we don't steal
+    // focus.
+    return false;
+  }
+  auto* bc = aDocShell->GetBrowsingContext();
+  if (sourceBC.get() == bc) {
+    // If it comes from the same tab / frame, don't steal focus either.
+    return false;
+  }
+  auto* fm = nsFocusManager::GetFocusManager();
+  if (fm && bc->IsActive() && fm->IsInActiveWindow(bc)) {
+    // If we're already on the foreground tab of the foreground window, then we
+    // don't need to do this. This helps to e.g. not steal focus from the
+    // browser chrome unnecessarily.
+    return false;
+  }
+  if (auto* doc = aDocShell->GetExtantDocument()) {
+    if (doc->IsInitialDocument()) {
+      // If we're the initial load for the browsing context, the browser
+      // chrome determines what to focus. This is important because the
+      // browser chrome may want to e.g focus the url-bar
+      return false;
+    }
+  }
+  // Take loadDivertedInBackground into account so the behavior would be the
+  // same as how the tab first opened.
+  return !Preferences::GetBool("browser.tabs.loadDivertedInBackground", false);
+}
+
+nsresult nsDocShell::InternalLoad(nsDocShellLoadState* aLoadState,
+                                  Maybe<uint32_t> aCacheKey) {
+  MOZ_ASSERT(aLoadState, "need a load state!");
+  MOZ_ASSERT(aLoadState->TriggeringPrincipal(),
+             "need a valid TriggeringPrincipal");
+
+  if (!aLoadState->TriggeringPrincipal()) {
+    MOZ_ASSERT(false, "InternalLoad needs a valid triggeringPrincipal");
+    return NS_ERROR_FAILURE;
+  }
+  if (NS_WARN_IF(mBrowsingContext->GetPendingInitialization())) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  const bool shouldTakeFocus = NavigationShouldTakeFocus(this, aLoadState);
+
+  mOriginalUriString.Truncate();
+
+  MOZ_LOG(gDocShellLeakLog, LogLevel::Debug,
+          ("DOCSHELL %p InternalLoad %s\n", this,
+           aLoadState->URI()->GetSpecOrDefault().get()));
+
+  NS_ENSURE_TRUE(IsValidLoadType(aLoadState->LoadType()), NS_ERROR_INVALID_ARG);
+
+  // Cancel loads coming from Docshells that are being destroyed.
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsresult rv = EnsureScriptEnvironment();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // If we have a target to move to, do that now.
+  if (!aLoadState->Target().IsEmpty()) {
+    return PerformRetargeting(aLoadState);
+  }
+
+  if (aLoadState->TargetBrowsingContext().IsNull()) {
+    aLoadState->SetTargetBrowsingContext(GetBrowsingContext());
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(
+      aLoadState->TargetBrowsingContext() == GetBrowsingContext(),
+      "Load must be targeting this BrowsingContext");
+
+  MOZ_TRY(CheckDisallowedJavascriptLoad(aLoadState));
+
+  // If we don't have a target, we're loading into ourselves, and our load
+  // delegate may want to intercept that load.
+  SameDocumentNavigationState sameDocumentNavigationState;
+  bool sameDocument =
+      IsSameDocumentNavigation(aLoadState, sameDocumentNavigationState) &&
+      !aLoadState->GetPendingRedirectedChannel();
+
+  // Note: We do this check both here and in BrowsingContext::
+  // LoadURI/InternalLoad, since document-specific sandbox flags are only
+  // available in the process triggering the load, and we don't want the target
+  // process to have to trust the triggering process to do the appropriate
+  // checks for the BrowsingContext's sandbox flags.
+  MOZ_TRY(mBrowsingContext->CheckSandboxFlags(aLoadState));
+
+  NS_ENSURE_STATE(!HasUnloadedParent());
+
+  rv = CheckLoadingPermissions();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (mFiredUnloadEvent) {
+    if (IsOKToLoadURI(aLoadState->URI())) {
+      MOZ_ASSERT(aLoadState->Target().IsEmpty(),
+                 "Shouldn't have a window target here!");
+
+      // If this is a replace load, make whatever load triggered
+      // the unload event also a replace load, so we don't
+      // create extra history entries.
+      if (LOAD_TYPE_HAS_FLAGS(aLoadState->LoadType(),
+                              LOAD_FLAGS_REPLACE_HISTORY)) {
+        mLoadType = LOAD_NORMAL_REPLACE;
+      }
+
+      // Do this asynchronously
+      nsCOMPtr<nsIRunnable> ev = new InternalLoadEvent(this, aLoadState);
+      return Dispatch(TaskCategory::Other, ev.forget());
+    }
+
+    // Just ignore this load attempt
+    return NS_OK;
+  }
+
+  // If we are loading a URI that should inherit a security context (basically
+  // javascript: at this point), and the caller has said that principal
+  // inheritance is allowed, there are a few possible cases:
+  //
+  // 1) We are provided with the principal to inherit. In that case, we just use
+  //    it.
+  //
+  // 2) The load is coming from some other application. In this case we don't
+  //    want to inherit from whatever document we have loaded now, since the
+  //    load is unrelated to it.
+  //
+  // 3) It's a load from our application, but does not provide an explicit
+  //    principal to inherit. In that case, we want to inherit the principal of
+  //    our current document, or of our parent document (if any) if we don't
+  //    have a current document.
+  {
+    bool inherits;
+
+    if (!aLoadState->HasLoadFlags(LOAD_FLAGS_FROM_EXTERNAL) &&
+        !aLoadState->PrincipalToInherit() &&
+        (aLoadState->HasInternalLoadFlags(
+            INTERNAL_LOAD_FLAGS_INHERIT_PRINCIPAL)) &&
+        NS_SUCCEEDED(nsContentUtils::URIInheritsSecurityContext(
+            aLoadState->URI(), &inherits)) &&
+        inherits) {
+      aLoadState->SetPrincipalToInherit(GetInheritedPrincipal(true));
+    }
+    // If principalToInherit is still null (e.g. if some of the conditions of
+    // were not satisfied), then no inheritance of any sort will happen: the
+    // load will just get a principal based on the URI being loaded.
+  }
+
+  // If this docshell is owned by a frameloader, make sure to cancel
+  // possible frameloader initialization before loading a new page.
+  nsCOMPtr<nsIDocShellTreeItem> parent = GetInProcessParentDocshell();
+  if (parent) {
+    RefPtr<Document> doc = parent->GetDocument();
+    if (doc) {
+      doc->TryCancelFrameLoaderInitialization(this);
+    }
+  }
+
+  // Before going any further vet loads initiated by external programs.
+  if (aLoadState->HasLoadFlags(LOAD_FLAGS_FROM_EXTERNAL)) {
+    MOZ_DIAGNOSTIC_ASSERT(aLoadState->LoadType() == LOAD_NORMAL);
+
+    // Disallow external chrome: loads targetted at content windows
+    if (SchemeIsChrome(aLoadState->URI())) {
+      NS_WARNING("blocked external chrome: url -- use '--chrome' option");
+      return NS_ERROR_FAILURE;
+    }
+
+    // clear the decks to prevent context bleed-through (bug 298255)
+    rv = CreateAboutBlankContentViewer(nullptr, nullptr, nullptr, nullptr,
+                                       /* aIsInitialDocument */ false);
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  mAllowKeywordFixup = aLoadState->HasInternalLoadFlags(
+      INTERNAL_LOAD_FLAGS_ALLOW_THIRD_PARTY_FIXUP);
+  mURIResultedInDocument = false;  // reset the clock...
+
+  // See if this is actually a load between two history entries for the same
+  // document. If the process fails, or if we successfully navigate within the
+  // same document, return.
+  if (sameDocument) {
+    nsresult rv =
+        HandleSameDocumentNavigation(aLoadState, sameDocumentNavigationState);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (shouldTakeFocus) {
+      mBrowsingContext->Focus(CallerType::System, IgnoreErrors());
+    }
+    return rv;
+  }
+
+  // mContentViewer->PermitUnload can destroy |this| docShell, which
+  // causes the next call of CanSavePresentation to crash.
+  // Hold onto |this| until we return, to prevent a crash from happening.
+  // (bug#331040)
+  nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
+
+  // Don't init timing for javascript:, since it generally doesn't
+  // actually start a load or anything.  If it does, we'll init
+  // timing then, from OnStateChange.
+
+  // XXXbz mTiming should know what channel it's for, so we don't
+  // need this hackery.
+  bool toBeReset = false;
+  bool isJavaScript = SchemeIsJavascript(aLoadState->URI());
+
+  if (!isJavaScript) {
+    toBeReset = MaybeInitTiming();
+  }
+  bool isNotDownload = aLoadState->FileName().IsVoid();
+  if (mTiming && isNotDownload) {
+    mTiming->NotifyBeforeUnload();
+  }
+  // Check if the page doesn't want to be unloaded. The javascript:
+  // protocol handler deals with this for javascript: URLs.
+  if (!isJavaScript && isNotDownload &&
+      !aLoadState->NotifiedBeforeUnloadListeners() && mContentViewer) {
+    bool okToUnload;
+
+    // Check if request is exempted from HTTPSOnlyMode and if https-first is
+    // enabled, if so it means:
+    //    * https-first failed to upgrade request to https
+    //    * we already asked for permission to unload and the user accepted
+    //      otherwise we wouldn't be here.
+    bool isPrivateWin = GetOriginAttributes().mPrivateBrowsingId > 0;
+    bool isHistoryOrReload = false;
+    uint32_t loadType = aLoadState->LoadType();
+
+    // Check if request is a reload.
+    if (loadType == LOAD_RELOAD_NORMAL ||
+        loadType == LOAD_RELOAD_BYPASS_CACHE ||
+        loadType == LOAD_RELOAD_BYPASS_PROXY ||
+        loadType == LOAD_RELOAD_BYPASS_PROXY_AND_CACHE ||
+        loadType == LOAD_HISTORY) {
+      isHistoryOrReload = true;
+    }
+
+    // If it isn't a reload, the request already failed to be upgraded and
+    // https-first is enabled then don't ask the user again for permission to
+    // unload and just unload.
+    if (!isHistoryOrReload && aLoadState->IsExemptFromHTTPSOnlyMode() &&
+        nsHTTPSOnlyUtils::IsHttpsFirstModeEnabled(isPrivateWin)) {
+      rv = mContentViewer->PermitUnload(
+          nsIContentViewer::PermitUnloadAction::eDontPromptAndUnload,
+          &okToUnload);
+    } else {
+      rv = mContentViewer->PermitUnload(&okToUnload);
+    }
+
+    if (NS_SUCCEEDED(rv) && !okToUnload) {
+      // The user chose not to unload the page, interrupt the
+      // load.
+      MaybeResetInitTiming(toBeReset);
+      return NS_OK;
+    }
+  }
+
+  if (mTiming && isNotDownload) {
+    mTiming->NotifyUnloadAccepted(mCurrentURI);
+  }
+
+  // In e10s, in the parent process, we refuse to load anything other than
+  // "safe" resources that we ship or trust enough to give "special" URLs.
+  // Similar check will be performed by the ParentProcessDocumentChannel if in
+  // use.
+  if (XRE_IsE10sParentProcess() &&
+      !DocumentChannel::CanUseDocumentChannel(aLoadState->URI()) &&
+      !CanLoadInParentProcess(aLoadState->URI())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Whenever a top-level browsing context is navigated, the user agent MUST
+  // lock the orientation of the document to the document's default
+  // orientation. We don't explicitly check for a top-level browsing context
+  // here because orientation is only set on top-level browsing contexts.
+  if (mBrowsingContext->GetOrientationLock() != hal::ScreenOrientation::None) {
+    MOZ_ASSERT(mBrowsingContext->IsTop());
+    MOZ_ALWAYS_SUCCEEDS(
+        mBrowsingContext->SetOrientationLock(hal::ScreenOrientation::None));
+    if (mBrowsingContext->IsActive()) {
+      ScreenOrientation::UpdateActiveOrientationLock(
+          hal::ScreenOrientation::None);
+    }
+  }
+
+  // Check for saving the presentation here, before calling Stop().
+  // This is necessary so that we can catch any pending requests.
+  // Since the new request has not been created yet, we pass null for the
+  // new request parameter.
+  // Also pass nullptr for the document, since it doesn't affect the return
+  // value for our purposes here.
+  bool savePresentation =
+      CanSavePresentation(aLoadState->LoadType(), nullptr, nullptr,
+                          /* aReportBFCacheComboTelemetry */ true);
+
+  // nsDocShell::CanSavePresentation is for non-SHIP version only. Do a
+  // separate check for SHIP so that we know if there are ongoing requests
+  // before calling Stop() below.
+  if (mozilla::SessionHistoryInParent()) {
+    Document* document = GetDocument();
+    uint32_t flags = 0;
+    if (document && !document->CanSavePresentation(nullptr, flags, true)) {
+      // This forces some flags into the WindowGlobalParent's mBFCacheStatus,
+      // which we'll then use in CanonicalBrowsingContext::AllowedInBFCache,
+      // and in particular we'll store BFCacheStatus::REQUEST if needed.
+      // Also, we want to report all the flags to the parent process here (and
+      // not just BFCacheStatus::NOT_ALLOWED), so that it can update the
+      // telemetry data correctly.
+      document->DisallowBFCaching(flags);
+    }
+  }
+
+  // Don't stop current network activity for javascript: URL's since
+  // they might not result in any data, and thus nothing should be
+  // stopped in those cases. In the case where they do result in
+  // data, the javascript: URL channel takes care of stopping
+  // current network activity.
+  if (!isJavaScript && isNotDownload) {
+    // Stop any current network activity.
+    // Also stop content if this is a zombie doc. otherwise
+    // the onload will be delayed by other loads initiated in the
+    // background by the first document that
+    // didn't fully load before the next load was initiated.
+    // If not a zombie, don't stop content until data
+    // starts arriving from the new URI...
+
+    if ((mContentViewer && mContentViewer->GetPreviousViewer()) ||
+        LOAD_TYPE_HAS_FLAGS(aLoadState->LoadType(), LOAD_FLAGS_STOP_CONTENT)) {
+      rv = Stop(nsIWebNavigation::STOP_ALL);
+    } else {
+      rv = Stop(nsIWebNavigation::STOP_NETWORK);
+    }
+
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  mLoadType = aLoadState->LoadType();
+
+  // aLoadState->SHEntry() should be assigned to mLSHE, only after Stop() has
+  // been called. But when loading an error page, do not clear the
+  // mLSHE for the real page.
+  if (mLoadType != LOAD_ERROR_PAGE) {
+    SetHistoryEntryAndUpdateBC(Some<nsISHEntry*>(aLoadState->SHEntry()),
+                               Nothing());
+    if (aLoadState->LoadIsFromSessionHistory() &&
+        !mozilla::SessionHistoryInParent()) {
+      // We're making history navigation or a reload. Make sure our history ID
+      // points to the same ID as SHEntry's docshell ID.
+      nsID historyID = {};
+      aLoadState->SHEntry()->GetDocshellID(historyID);
+
+      Unused << mBrowsingContext->SetHistoryID(historyID);
+    }
+  }
+
+  mSavingOldViewer = savePresentation;
+
+  // If we have a saved content viewer in history, restore and show it now.
+  if (aLoadState->LoadIsFromSessionHistory() &&
+      (mLoadType & LOAD_CMD_HISTORY)) {
+    // https://html.spec.whatwg.org/#history-traversal:
+    // To traverse the history
+    // "If entry has a different Document object than the current entry, then
+    // run the following substeps: Remove any tasks queued by the history
+    // traversal task source..."
+    // Same document object case was handled already above with
+    // HandleSameDocumentNavigation call.
+    RefPtr<ChildSHistory> shistory = GetRootSessionHistory();
+    if (shistory) {
+      shistory->RemovePendingHistoryNavigations();
+    }
+    if (!mozilla::SessionHistoryInParent()) {
+      // It's possible that the previous viewer of mContentViewer is the
+      // viewer that will end up in aLoadState->SHEntry() when it gets closed.
+      // If that's the case, we need to go ahead and force it into its shentry
+      // so we can restore it.
+      if (mContentViewer) {
+        nsCOMPtr<nsIContentViewer> prevViewer =
+            mContentViewer->GetPreviousViewer();
+        if (prevViewer) {
+#ifdef DEBUG
+          nsCOMPtr<nsIContentViewer> prevPrevViewer =
+              prevViewer->GetPreviousViewer();
+          NS_ASSERTION(!prevPrevViewer, "Should never have viewer chain here");
+#endif
+          nsCOMPtr<nsISHEntry> viewerEntry;
+          prevViewer->GetHistoryEntry(getter_AddRefs(viewerEntry));
+          if (viewerEntry == aLoadState->SHEntry()) {
+            // Make sure this viewer ends up in the right place
+            mContentViewer->SetPreviousViewer(nullptr);
+            prevViewer->Destroy();
+          }
+        }
+      }
+      nsCOMPtr<nsISHEntry> oldEntry = mOSHE;
+      bool restoring;
+      rv = RestorePresentation(aLoadState->SHEntry(), &restoring);
+      if (restoring) {
+        Telemetry::Accumulate(Telemetry::BFCACHE_PAGE_RESTORED, true);
+        return rv;
+      }
+      Telemetry::Accumulate(Telemetry::BFCACHE_PAGE_RESTORED, false);
+
+      // We failed to restore the presentation, so clean up.
+      // Both the old and new history entries could potentially be in
+      // an inconsistent state.
+      if (NS_FAILED(rv)) {
+        if (oldEntry) {
+          oldEntry->SyncPresentationState();
+        }
+
+        aLoadState->SHEntry()->SyncPresentationState();
+      }
+    }
+  }
+
+  bool isTopLevelDoc = mBrowsingContext->IsTopContent();
+
+  OriginAttributes attrs = GetOriginAttributes();
+  attrs.SetFirstPartyDomain(isTopLevelDoc, aLoadState->URI());
+
+  PredictorLearn(aLoadState->URI(), nullptr,
+                 nsINetworkPredictor::LEARN_LOAD_TOPLEVEL, attrs);
+  PredictorPredict(aLoadState->URI(), nullptr,
+                   nsINetworkPredictor::PREDICT_LOAD, attrs, nullptr);
+
+  nsCOMPtr<nsIRequest> req;
+  rv = DoURILoad(aLoadState, aCacheKey, getter_AddRefs(req));
+
+  if (NS_SUCCEEDED(rv)) {
+    if (shouldTakeFocus) {
+      mBrowsingContext->Focus(CallerType::System, IgnoreErrors());
+    }
+  }
+
+  if (NS_FAILED(rv)) {
+    nsCOMPtr<nsIChannel> chan(do_QueryInterface(req));
+    UnblockEmbedderLoadEventForFailure();
+    nsCOMPtr<nsIURI> uri = aLoadState->URI();
+    if (DisplayLoadError(rv, uri, nullptr, chan) &&
+        // FIXME: At this point code was using internal load flags, but checking
+        // non-internal load flags?
+        aLoadState->HasLoadFlags(LOAD_FLAGS_ERROR_LOAD_CHANGES_RV)) {
+      return NS_ERROR_LOAD_SHOWED_ERRORPAGE;
+    }
+
+    // We won't report any error if this is an unknown protocol error. The
+    // reason behind this is that it will allow enumeration of external
+    // protocols if we report an error for each unknown protocol.
+    if (NS_ERROR_UNKNOWN_PROTOCOL == rv) {
+      return NS_OK;
+    }
+  }
+
+  return rv;
+}
+
+/* static */
+bool nsDocShell::CanLoadInParentProcess(nsIURI* aURI) {
+  nsCOMPtr<nsIURI> uri = aURI;
+  // In e10s, in the parent process, we refuse to load anything other than
+  // "safe" resources that we ship or trust enough to give "special" URLs.
+  bool canLoadInParent = false;
+  if (NS_SUCCEEDED(NS_URIChainHasFlags(
+          uri, nsIProtocolHandler::URI_IS_UI_RESOURCE, &canLoadInParent)) &&
+      canLoadInParent) {
+    // We allow UI resources.
+    return true;
+  }
+  // For about: and extension-based URIs, which don't get
+  // URI_IS_UI_RESOURCE, first remove layers of view-source:, if present.
+  while (uri && uri->SchemeIs("view-source")) {
+    nsCOMPtr<nsINestedURI> nested = do_QueryInterface(uri);
+    if (nested) {
+      nested->GetInnerURI(getter_AddRefs(uri));
+    } else {
+      break;
+    }
+  }
+  // Allow about: URIs, and allow moz-extension ones if we're running
+  // extension content in the parent process.
+  if (!uri || uri->SchemeIs("about") ||
+      (!StaticPrefs::extensions_webextensions_remote() &&
+       uri->SchemeIs("moz-extension"))) {
+    return true;
+  }
+#ifdef MOZ_THUNDERBIRD
+  if (uri->SchemeIs("imap") || uri->SchemeIs("mailbox") ||
+      uri->SchemeIs("news") || uri->SchemeIs("nntp") ||
+      uri->SchemeIs("snews")) {
+    return true;
+  }
+#endif
+  nsAutoCString scheme;
+  uri->GetScheme(scheme);
+  // Allow ext+foo URIs (extension-registered custom protocols). See
+  // https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/protocol_handlers
+  if (StringBeginsWith(scheme, "ext+"_ns) &&
+      !StaticPrefs::extensions_webextensions_remote()) {
+    return true;
+  }
+  // Final exception for some legacy automated tests:
+  if (xpc::IsInAutomation() &&
+      StaticPrefs::security_allow_unsafe_parent_loads()) {
+    return true;
+  }
+  return false;
+}
+
+nsIPrincipal* nsDocShell::GetInheritedPrincipal(
+    bool aConsiderCurrentDocument, bool aConsiderPartitionedPrincipal) {
+  RefPtr<Document> document;
+  bool inheritedFromCurrent = false;
+
+  if (aConsiderCurrentDocument && mContentViewer) {
+    document = mContentViewer->GetDocument();
+    inheritedFromCurrent = true;
+  }
+
+  if (!document) {
+    nsCOMPtr<nsIDocShellTreeItem> parentItem;
+    GetInProcessSameTypeParent(getter_AddRefs(parentItem));
+    if (parentItem) {
+      document = parentItem->GetDocument();
+    }
+  }
+
+  if (!document) {
+    if (!aConsiderCurrentDocument) {
+      return nullptr;
+    }
+
+    // Make sure we end up with _something_ as the principal no matter
+    // what.If this fails, we'll just get a null docViewer and bail.
+    EnsureContentViewer();
+    if (!mContentViewer) {
+      return nullptr;
+    }
+    document = mContentViewer->GetDocument();
+  }
+
+  //-- Get the document's principal
+  if (document) {
+    nsIPrincipal* docPrincipal = aConsiderPartitionedPrincipal
+                                     ? document->PartitionedPrincipal()
+                                     : document->NodePrincipal();
+
+    // Don't allow loads in typeContent docShells to inherit the system
+    // principal from existing documents.
+    if (inheritedFromCurrent && mItemType == typeContent &&
+        docPrincipal->IsSystemPrincipal()) {
+      return nullptr;
+    }
+
+    return docPrincipal;
+  }
+
+  return nullptr;
+}
+
+/* static */ nsresult nsDocShell::CreateRealChannelForDocument(
+    nsIChannel** aChannel, nsIURI* aURI, nsILoadInfo* aLoadInfo,
+    nsIInterfaceRequestor* aCallbacks, nsLoadFlags aLoadFlags,
+    const nsAString& aSrcdoc, nsIURI* aBaseURI) {
+  nsCOMPtr<nsIChannel> channel;
+  if (aSrcdoc.IsVoid()) {
+    MOZ_TRY(NS_NewChannelInternal(getter_AddRefs(channel), aURI, aLoadInfo,
+                                  nullptr,  // PerformanceStorage
+                                  nullptr,  // loadGroup
+                                  aCallbacks, aLoadFlags));
+
+    if (aBaseURI) {
+      nsCOMPtr<nsIViewSourceChannel> vsc = do_QueryInterface(channel);
+      if (vsc) {
+        MOZ_ALWAYS_SUCCEEDS(vsc->SetBaseURI(aBaseURI));
+      }
+    }
+  } else if (SchemeIsViewSource(aURI)) {
+    // Instantiate view source handler protocol, if it doesn't exist already.
+    nsCOMPtr<nsIIOService> io(do_GetIOService());
+    MOZ_ASSERT(io);
+    nsCOMPtr<nsIProtocolHandler> handler;
+    nsresult rv =
+        io->GetProtocolHandler("view-source", getter_AddRefs(handler));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    nsViewSourceHandler* vsh = nsViewSourceHandler::GetInstance();
+    if (!vsh) {
+      return NS_ERROR_FAILURE;
+    }
+
+    MOZ_TRY(vsh->NewSrcdocChannel(aURI, aBaseURI, aSrcdoc, aLoadInfo,
+                                  getter_AddRefs(channel)));
+  } else {
+    MOZ_TRY(NS_NewInputStreamChannelInternal(getter_AddRefs(channel), aURI,
+                                             aSrcdoc, "text/html"_ns, aLoadInfo,
+                                             true));
+    nsCOMPtr<nsIInputStreamChannel> isc = do_QueryInterface(channel);
+    MOZ_ASSERT(isc);
+    isc->SetBaseURI(aBaseURI);
+  }
+
+  if (aLoadFlags != nsIRequest::LOAD_NORMAL) {
+    nsresult rv = channel->SetLoadFlags(aLoadFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  channel.forget(aChannel);
+  return NS_OK;
+}
+
+/* static */ bool nsDocShell::CreateAndConfigureRealChannelForLoadState(
+    BrowsingContext* aBrowsingContext, nsDocShellLoadState* aLoadState,
+    LoadInfo* aLoadInfo, nsIInterfaceRequestor* aCallbacks,
+    nsDocShell* aDocShell, const OriginAttributes& aOriginAttributes,
+    nsLoadFlags aLoadFlags, uint32_t aCacheKey, nsresult& aRv,
+    nsIChannel** aChannel) {
+  MOZ_ASSERT(aLoadInfo);
+
+  nsString srcdoc = VoidString();
+  bool isSrcdoc =
+      aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_IS_SRCDOC);
+  if (isSrcdoc) {
+    srcdoc = aLoadState->SrcdocData();
+  }
+
+  aLoadInfo->SetTriggeringRemoteType(
+      aLoadState->GetEffectiveTriggeringRemoteType());
+
+  if (aLoadState->PrincipalToInherit()) {
+    aLoadInfo->SetPrincipalToInherit(aLoadState->PrincipalToInherit());
+  }
+  aLoadInfo->SetLoadTriggeredFromExternal(
+      aLoadState->HasLoadFlags(LOAD_FLAGS_FROM_EXTERNAL));
+  aLoadInfo->SetForceAllowDataURI(aLoadState->HasInternalLoadFlags(
+      INTERNAL_LOAD_FLAGS_FORCE_ALLOW_DATA_URI));
+  aLoadInfo->SetOriginalFrameSrcLoad(
+      aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_ORIGINAL_FRAME_SRC));
+
+  bool inheritAttrs = false;
+  if (aLoadState->PrincipalToInherit()) {
+    inheritAttrs = nsContentUtils::ChannelShouldInheritPrincipal(
+        aLoadState->PrincipalToInherit(), aLoadState->URI(),
+        true,  // aInheritForAboutBlank
+        isSrcdoc);
+  }
+
+  // Strip the target query parameters before creating the channel.
+  aLoadState->MaybeStripTrackerQueryStrings(aBrowsingContext);
+
+  OriginAttributes attrs;
+
+  // Inherit origin attributes from PrincipalToInherit if inheritAttrs is
+  // true. Otherwise we just use the origin attributes from docshell.
+  if (inheritAttrs) {
+    MOZ_ASSERT(aLoadState->PrincipalToInherit(),
+               "We should have PrincipalToInherit here.");
+    attrs = aLoadState->PrincipalToInherit()->OriginAttributesRef();
+    // If firstPartyIsolation is not enabled, then PrincipalToInherit should
+    // have the same origin attributes with docshell.
+    MOZ_ASSERT_IF(!OriginAttributes::IsFirstPartyEnabled(),
+                  attrs == aOriginAttributes);
+  } else {
+    attrs = aOriginAttributes;
+    attrs.SetFirstPartyDomain(IsTopLevelDoc(aBrowsingContext, aLoadInfo),
+                              aLoadState->URI());
+  }
+
+  aRv = aLoadInfo->SetOriginAttributes(attrs);
+  if (NS_WARN_IF(NS_FAILED(aRv))) {
+    return false;
+  }
+
+  if (aLoadState->GetIsFromProcessingFrameAttributes()) {
+    aLoadInfo->SetIsFromProcessingFrameAttributes();
+  }
+
+  // Propagate the IsFormSubmission flag to the loadInfo.
+  if (aLoadState->IsFormSubmission()) {
+    aLoadInfo->SetIsFormSubmission(true);
+  }
+
+  aLoadInfo->SetUnstrippedURI(aLoadState->GetUnstrippedURI());
+
+  nsCOMPtr<nsIChannel> channel;
+  aRv = CreateRealChannelForDocument(getter_AddRefs(channel), aLoadState->URI(),
+                                     aLoadInfo, aCallbacks, aLoadFlags, srcdoc,
+                                     aLoadState->BaseURI());
+  NS_ENSURE_SUCCESS(aRv, false);
+
+  if (!channel) {
+    return false;
+  }
+
+  // If the HTTPS-Only mode is enabled, every insecure request gets upgraded to
+  // HTTPS by default. This behavior can be disabled through the loadinfo flag
+  // HTTPS_ONLY_EXEMPT.
+  nsHTTPSOnlyUtils::TestSitePermissionAndPotentiallyAddExemption(channel);
+
+  // hack
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(channel));
+  nsCOMPtr<nsIHttpChannelInternal> httpChannelInternal(
+      do_QueryInterface(channel));
+  nsCOMPtr<nsIURI> referrer;
+  nsIReferrerInfo* referrerInfo = aLoadState->GetReferrerInfo();
+  if (referrerInfo) {
+    referrerInfo->GetOriginalReferrer(getter_AddRefs(referrer));
+  }
+  if (httpChannelInternal) {
+    if (aLoadState->HasInternalLoadFlags(
+            INTERNAL_LOAD_FLAGS_FORCE_ALLOW_COOKIES)) {
+      aRv = httpChannelInternal->SetThirdPartyFlags(
+          nsIHttpChannelInternal::THIRD_PARTY_FORCE_ALLOW);
+      MOZ_ASSERT(NS_SUCCEEDED(aRv));
+    }
+    if (aLoadState->FirstParty()) {
+      aRv = httpChannelInternal->SetDocumentURI(aLoadState->URI());
+      MOZ_ASSERT(NS_SUCCEEDED(aRv));
+    } else {
+      aRv = httpChannelInternal->SetDocumentURI(referrer);
+      MOZ_ASSERT(NS_SUCCEEDED(aRv));
+    }
+    aRv = httpChannelInternal->SetRedirectMode(
+        nsIHttpChannelInternal::REDIRECT_MODE_MANUAL);
+    MOZ_ASSERT(NS_SUCCEEDED(aRv));
+  }
+
+  if (httpChannel) {
+    if (aLoadState->HeadersStream()) {
+      aRv = AddHeadersToChannel(aLoadState->HeadersStream(), httpChannel);
+    }
+    // Set the referrer explicitly
+    // Referrer is currenly only set for link clicks here.
+    if (referrerInfo) {
+      aRv = httpChannel->SetReferrerInfo(referrerInfo);
+      MOZ_ASSERT(NS_SUCCEEDED(aRv));
+    }
+
+    // Mark the http channel as UrgentStart for top level document loading in
+    // active tab.
+    if (IsUrgentStart(aBrowsingContext, aLoadInfo, aLoadState->LoadType())) {
+      nsCOMPtr<nsIClassOfService> cos(do_QueryInterface(channel));
+      if (cos) {
+        cos->AddClassFlags(nsIClassOfService::UrgentStart);
+      }
+    }
+  }
+
+  channel->SetOriginalURI(aLoadState->OriginalURI() ? aLoadState->OriginalURI()
+                                                    : aLoadState->URI());
+
+  const nsACString& typeHint = aLoadState->TypeHint();
+  if (!typeHint.IsVoid()) {
+    channel->SetContentType(typeHint);
+  }
+
+  const nsAString& fileName = aLoadState->FileName();
+  if (!fileName.IsVoid()) {
+    aRv = channel->SetContentDisposition(nsIChannel::DISPOSITION_ATTACHMENT);
+    NS_ENSURE_SUCCESS(aRv, false);
+    if (!fileName.IsEmpty()) {
+      aRv = channel->SetContentDispositionFilename(fileName);
+      NS_ENSURE_SUCCESS(aRv, false);
+    }
+  }
+
+  if (nsCOMPtr<nsIWritablePropertyBag2> props = do_QueryInterface(channel)) {
+    nsCOMPtr<nsIURI> referrer;
+    nsIReferrerInfo* referrerInfo = aLoadState->GetReferrerInfo();
+    if (referrerInfo) {
+      referrerInfo->GetOriginalReferrer(getter_AddRefs(referrer));
+    }
+    // save true referrer for those who need it (e.g. xpinstall whitelisting)
+    // Currently only http and ftp channels support this.
+    props->SetPropertyAsInterface(u"docshell.internalReferrer"_ns, referrer);
+
+    if (aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_FIRST_LOAD)) {
+      props->SetPropertyAsBool(u"docshell.newWindowTarget"_ns, true);
+    }
+  }
+
+  nsCOMPtr<nsICacheInfoChannel> cacheChannel(do_QueryInterface(channel));
+  auto loadType = aLoadState->LoadType();
+
+  if (loadType == LOAD_RELOAD_NORMAL &&
+      StaticPrefs::
+          browser_soft_reload_only_force_validate_top_level_document()) {
+    nsCOMPtr<nsICacheInfoChannel> cachingChannel = do_QueryInterface(channel);
+    if (cachingChannel) {
+      cachingChannel->SetForceValidateCacheContent(true);
+    }
+  }
+
+  // figure out if we need to set the post data stream on the channel...
+  if (aLoadState->PostDataStream()) {
+    if (nsCOMPtr<nsIFormPOSTActionChannel> postChannel =
+            do_QueryInterface(channel)) {
+      // XXX it's a bit of a hack to rewind the postdata stream here but
+      // it has to be done in case the post data is being reused multiple
+      // times.
+      nsCOMPtr<nsISeekableStream> postDataSeekable =
+          do_QueryInterface(aLoadState->PostDataStream());
+      if (postDataSeekable) {
+        aRv = postDataSeekable->Seek(nsISeekableStream::NS_SEEK_SET, 0);
+        NS_ENSURE_SUCCESS(aRv, false);
+      }
+
+      // we really need to have a content type associated with this stream!!
+      postChannel->SetUploadStream(aLoadState->PostDataStream(), ""_ns, -1);
+
+      // Ownership of the stream has transferred to the channel, clear our
+      // reference.
+      aLoadState->SetPostDataStream(nullptr);
+    }
+
+    /* If there is a valid postdata *and* it is a History Load,
+     * set up the cache key on the channel, to retrieve the
+     * data *only* from the cache. If it is a normal reload, the
+     * cache is free to go to the server for updated postdata.
+     */
+    if (cacheChannel && aCacheKey != 0) {
+      if (loadType == LOAD_HISTORY || loadType == LOAD_RELOAD_CHARSET_CHANGE) {
+        cacheChannel->SetCacheKey(aCacheKey);
+        uint32_t loadFlags;
+        if (NS_SUCCEEDED(channel->GetLoadFlags(&loadFlags))) {
+          channel->SetLoadFlags(loadFlags |
+                                nsICachingChannel::LOAD_ONLY_FROM_CACHE);
+        }
+      } else if (loadType == LOAD_RELOAD_NORMAL) {
+        cacheChannel->SetCacheKey(aCacheKey);
+      }
+    }
+  } else {
+    /* If there is no postdata, set the cache key on the channel, and
+     * do not set the LOAD_ONLY_FROM_CACHE flag, so that the channel
+     * will be free to get it from net if it is not found in cache.
+     * New cache may use it creatively on CGI pages with GET
+     * method and even on those that say "no-cache"
+     */
+    if (loadType == LOAD_HISTORY || loadType == LOAD_RELOAD_NORMAL ||
+        loadType == LOAD_RELOAD_CHARSET_CHANGE ||
+        loadType == LOAD_RELOAD_CHARSET_CHANGE_BYPASS_CACHE ||
+        loadType == LOAD_RELOAD_CHARSET_CHANGE_BYPASS_PROXY_AND_CACHE) {
+      if (cacheChannel && aCacheKey != 0) {
+        cacheChannel->SetCacheKey(aCacheKey);
+      }
+    }
+  }
+
+  if (nsCOMPtr<nsIScriptChannel> scriptChannel = do_QueryInterface(channel)) {
+    // Allow execution against our context if the principals match
+    scriptChannel->SetExecutionPolicy(nsIScriptChannel::EXECUTE_NORMAL);
+  }
+
+  if (nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(channel)) {
+    timedChannel->SetTimingEnabled(true);
+
+    nsString initiatorType;
+    switch (aLoadInfo->InternalContentPolicyType()) {
+      case nsIContentPolicy::TYPE_INTERNAL_EMBED:
+        initiatorType = u"embed"_ns;
+        break;
+      case nsIContentPolicy::TYPE_INTERNAL_OBJECT:
+        initiatorType = u"object"_ns;
+        break;
+      default: {
+        const auto& embedderElementType =
+            aBrowsingContext->GetEmbedderElementType();
+        if (embedderElementType) {
+          initiatorType = *embedderElementType;
+        }
+        break;
+      }
+    }
+
+    if (!initiatorType.IsEmpty()) {
+      timedChannel->SetInitiatorType(initiatorType);
+    }
+  }
+
+  nsCOMPtr<nsIURI> rpURI;
+  aLoadInfo->GetResultPrincipalURI(getter_AddRefs(rpURI));
+  Maybe<nsCOMPtr<nsIURI>> originalResultPrincipalURI;
+  aLoadState->GetMaybeResultPrincipalURI(originalResultPrincipalURI);
+  if (originalResultPrincipalURI &&
+      (!aLoadState->KeepResultPrincipalURIIfSet() || !rpURI)) {
+    // Unconditionally override, we want the replay to be equal to what has
+    // been captured.
+    aLoadInfo->SetResultPrincipalURI(originalResultPrincipalURI.ref());
+  }
+
+  if (aLoadState->OriginalURI() && aLoadState->LoadReplace()) {
+    // The LOAD_REPLACE flag and its handling here will be removed as part
+    // of bug 1319110.  For now preserve its restoration here to not break
+    // any code expecting it being set specially on redirected channels.
+    // If the flag has originally been set to change result of
+    // NS_GetFinalChannelURI it won't have any effect and also won't cause
+    // any harm.
+    uint32_t loadFlags;
+    aRv = channel->GetLoadFlags(&loadFlags);
+    NS_ENSURE_SUCCESS(aRv, false);
+    channel->SetLoadFlags(loadFlags | nsIChannel::LOAD_REPLACE);
+  }
+
+  nsCOMPtr<nsIContentSecurityPolicy> csp = aLoadState->Csp();
+  if (csp) {
+    // Navigational requests that are same origin need to be upgraded in case
+    // upgrade-insecure-requests is present. Please note that for document
+    // navigations that bit is re-computed in case we encounter a server
+    // side redirect so the navigation is not same-origin anymore.
+    bool upgradeInsecureRequests = false;
+    csp->GetUpgradeInsecureRequests(&upgradeInsecureRequests);
+    if (upgradeInsecureRequests) {
+      // only upgrade if the navigation is same origin
+      nsCOMPtr<nsIPrincipal> resultPrincipal;
+      aRv = nsContentUtils::GetSecurityManager()->GetChannelResultPrincipal(
+          channel, getter_AddRefs(resultPrincipal));
+      NS_ENSURE_SUCCESS(aRv, false);
+      if (nsContentSecurityUtils::IsConsideredSameOriginForUIR(
+              aLoadState->TriggeringPrincipal(), resultPrincipal)) {
+        aLoadInfo->SetUpgradeInsecureRequests(true);
+      }
+    }
+
+    // For document loads we store the CSP that potentially needs to
+    // be inherited by the new document, e.g. in case we are loading
+    // an opaque origin like a data: URI. The actual inheritance
+    // check happens within Document::InitCSP().
+    // Please create an actual copy of the CSP (do not share the same
+    // reference) otherwise a Meta CSP of an opaque origin will
+    // incorrectly be propagated to the embedding document.
+    RefPtr<nsCSPContext> cspToInherit = new nsCSPContext();
+    cspToInherit->InitFromOther(static_cast<nsCSPContext*>(csp.get()));
+    aLoadInfo->SetCSPToInherit(cspToInherit);
+  }
+
+  channel.forget(aChannel);
+  return true;
+}
+
+bool nsDocShell::IsAboutBlankLoadOntoInitialAboutBlank(
+    nsIURI* aURI, bool aInheritPrincipal, nsIPrincipal* aPrincipalToInherit) {
+  return NS_IsAboutBlank(aURI) && aInheritPrincipal &&
+         (aPrincipalToInherit == GetInheritedPrincipal(false)) &&
+         (!mContentViewer || !mContentViewer->GetDocument() ||
+          mContentViewer->GetDocument()->IsInitialDocument());
+}
+
+nsresult nsDocShell::DoURILoad(nsDocShellLoadState* aLoadState,
+                               Maybe<uint32_t> aCacheKey,
+                               nsIRequest** aRequest) {
+  // Double-check that we're still around to load this URI.
+  if (mIsBeingDestroyed) {
+    // Return NS_OK despite not doing anything to avoid throwing exceptions
+    // from nsLocation::SetHref if the unload handler of the existing page
+    // tears us down.
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURILoader> uriLoader = components::URILoader::Service();
+  if (NS_WARN_IF(!uriLoader)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Persist and sync layout history state before we load a new uri, as this
+  // might be our last chance to do so, in the content process.
+  PersistLayoutHistoryState();
+  SynchronizeLayoutHistoryState();
+
+  nsresult rv;
+  nsContentPolicyType contentPolicyType = DetermineContentType();
+
+  if (IsSubframe()) {
+    MOZ_ASSERT(contentPolicyType == nsIContentPolicy::TYPE_INTERNAL_IFRAME ||
+                   contentPolicyType == nsIContentPolicy::TYPE_INTERNAL_FRAME,
+               "DoURILoad thinks this is a frame and InternalLoad does not");
+
+    if (StaticPrefs::dom_block_external_protocol_in_iframes()) {
+      // Only allow URLs able to return data in iframes.
+      if (nsContentUtils::IsExternalProtocol(aLoadState->URI())) {
+        // The context to check user-interaction with for the purposes of
+        // popup-blocking.
+        //
+        // We generally want to check the context that initiated the navigation.
+        WindowContext* sourceWindowContext = [&] {
+          const MaybeDiscardedBrowsingContext& sourceBC =
+              aLoadState->SourceBrowsingContext();
+          if (!sourceBC.IsNullOrDiscarded()) {
+            if (WindowContext* wc = sourceBC.get()->GetCurrentWindowContext()) {
+              return wc;
+            }
+          }
+          return mBrowsingContext->GetParentWindowContext();
+        }();
+
+        MOZ_ASSERT(sourceWindowContext);
+        // FIXME: We can't check user-interaction against an OOP window. This is
+        // the next best thing we can really do. The load state keeps whether
+        // the navigation had a user interaction in process
+        // (aLoadState->HasValidUserGestureActivation()), but we can't really
+        // consume it, which we want to prevent popup-spamming from the same
+        // click event.
+        WindowContext* context =
+            sourceWindowContext->IsInProcess()
+                ? sourceWindowContext
+                : mBrowsingContext->GetCurrentWindowContext();
+        const bool popupBlocked = [&] {
+          const bool active = mBrowsingContext->IsActive();
+
+          // For same-origin-with-top windows, we grant a single free popup
+          // without user activation, see bug 1680721.
+          //
+          // We consume the flag now even if there's no user activation.
+          const bool hasFreePass = [&] {
+            if (!active ||
+                !(context->IsInProcess() && context->SameOriginWithTop())) {
+              return false;
+            }
+            nsGlobalWindowInner* win =
+                context->TopWindowContext()->GetInnerWindow();
+            return win && win->TryOpenExternalProtocolIframe();
+          }();
+
+          if (context->IsInProcess() &&
+              context->ConsumeTransientUserGestureActivation()) {
+            // If the user has interacted with the page, consume it.
+            return false;
+          }
+
+          // TODO(emilio): Can we remove this check? It seems like what prompted
+          // this code (bug 1514547) should be covered by transient user
+          // activation, see bug 1514547.
+          if (active &&
+              PopupBlocker::ConsumeTimerTokenForExternalProtocolIframe()) {
+            return false;
+          }
+
+          if (sourceWindowContext->CanShowPopup()) {
+            return false;
+          }
+
+          if (hasFreePass) {
+            return false;
+          }
+
+          return true;
+        }();
+
+        // No error must be returned when iframes are blocked.
+        if (popupBlocked) {
+          nsAutoString message;
+          nsresult rv = nsContentUtils::GetLocalizedString(
+              nsContentUtils::eDOM_PROPERTIES,
+              "ExternalProtocolFrameBlockedNoUserActivation", message);
+          if (NS_SUCCEEDED(rv)) {
+            nsContentUtils::ReportToConsoleByWindowID(
+                message, nsIScriptError::warningFlag, "DOM"_ns,
+                context->InnerWindowId());
+          }
+          return NS_OK;
+        }
+      }
+    }
+
+    // Only allow view-source scheme in top-level docshells. view-source is
+    // the only scheme to which this applies at the moment due to potential
+    // timing attacks to read data from cross-origin iframes. If this widens
+    // we should add a protocol flag for whether the scheme is allowed in
+    // frames and use something like nsNetUtil::NS_URIChainHasFlags.
+    nsCOMPtr<nsIURI> tempURI = aLoadState->URI();
+    nsCOMPtr<nsINestedURI> nestedURI = do_QueryInterface(tempURI);
+    while (nestedURI) {
+      // view-source should always be an nsINestedURI, loop and check the
+      // scheme on this and all inner URIs that are also nested URIs.
+      if (SchemeIsViewSource(tempURI)) {
+        return NS_ERROR_UNKNOWN_PROTOCOL;
+      }
+      nestedURI->GetInnerURI(getter_AddRefs(tempURI));
+      nestedURI = do_QueryInterface(tempURI);
+    }
+  } else {
+    MOZ_ASSERT(contentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+               "DoURILoad thinks this is a document and InternalLoad does not");
+  }
+
+  // We want to inherit aLoadState->PrincipalToInherit() when:
+  // 1. ChannelShouldInheritPrincipal returns true.
+  // 2. aLoadState->URI() is not data: URI, or data: URI is not
+  //    configured as unique opaque origin.
+  bool inheritPrincipal = false;
+
+  if (aLoadState->PrincipalToInherit()) {
+    bool isSrcdoc =
+        aLoadState->HasInternalLoadFlags(INTERNAL_LOAD_FLAGS_IS_SRCDOC);
+    bool inheritAttrs = nsContentUtils::ChannelShouldInheritPrincipal(
+        aLoadState->PrincipalToInherit(), aLoadState->URI(),
+        true,  // aInheritForAboutBlank
+        isSrcdoc);
+
+    inheritPrincipal = inheritAttrs && !SchemeIsData(aLoadState->URI());
+  }
+
+  // See https://bugzilla.mozilla.org/show_bug.cgi?id=1736570
+  const bool isAboutBlankLoadOntoInitialAboutBlank =
+      IsAboutBlankLoadOntoInitialAboutBlank(aLoadState->URI(), inheritPrincipal,
+                                            aLoadState->PrincipalToInherit());
+
+  // FIXME We still have a ton of codepaths that don't pass through
+  //       DocumentLoadListener, so probably need to create session history info
+  //       in more places.
+  if (aLoadState->GetLoadingSessionHistoryInfo()) {
+    SetLoadingSessionHistoryInfo(*aLoadState->GetLoadingSessionHistoryInfo());
+  } else if (isAboutBlankLoadOntoInitialAboutBlank &&
+             mozilla::SessionHistoryInParent()) {
+    // Materialize LoadingSessionHistoryInfo here, because DocumentChannel
+    // loads have it, and later history behavior depends on it existing.
+    UniquePtr<SessionHistoryInfo> entry = MakeUnique<SessionHistoryInfo>(
+        aLoadState->URI(), aLoadState->TriggeringPrincipal(),
+        aLoadState->PrincipalToInherit(),
+        aLoadState->PartitionedPrincipalToInherit(), aLoadState->Csp(),
+        mContentTypeHint);
+    mozilla::dom::LoadingSessionHistoryInfo info(*entry);
+    SetLoadingSessionHistoryInfo(info, true);
+  }
+
+  // open a channel for the url
+
+  // If we have a pending channel, use the channel we've already created here.
+  // We don't need to set up load flags for our channel, as it has already been
+  // created.
+
+  if (nsCOMPtr<nsIChannel> channel =
+          aLoadState->GetPendingRedirectedChannel()) {
+    // If we have a request outparameter, shove our channel into it.
+    if (aRequest) {
+      nsCOMPtr<nsIRequest> outRequest = channel;
+      outRequest.forget(aRequest);
+    }
+
+    return OpenRedirectedChannel(aLoadState);
+  }
+
+  // There are two cases we care about:
+  // * Top-level load: In this case, loadingNode is null, but loadingWindow
+  //   is our mScriptGlobal. We pass null for loadingPrincipal in this case.
+  // * Subframe load: loadingWindow is null, but loadingNode is the frame
+  //   element for the load. loadingPrincipal is the NodePrincipal of the
+  //   frame element.
+  nsCOMPtr<nsINode> loadingNode;
+  nsCOMPtr<nsPIDOMWindowOuter> loadingWindow;
+  nsCOMPtr<nsIPrincipal> loadingPrincipal;
+  nsCOMPtr<nsISupports> topLevelLoadingContext;
+
+  if (contentPolicyType == nsIContentPolicy::TYPE_DOCUMENT) {
+    loadingNode = nullptr;
+    loadingPrincipal = nullptr;
+    loadingWindow = mScriptGlobal;
+    if (XRE_IsContentProcess()) {
+      // In e10s the child process doesn't have access to the element that
+      // contains the browsing context (because that element is in the chrome
+      // process).
+      nsCOMPtr<nsIBrowserChild> browserChild = GetBrowserChild();
+      topLevelLoadingContext = ToSupports(browserChild);
+    } else {
+      // This is for loading non-e10s tabs and toplevel windows of various
+      // sorts.
+      // For the toplevel window cases, requestingElement will be null.
+      nsCOMPtr<Element> requestingElement =
+          loadingWindow->GetFrameElementInternal();
+      topLevelLoadingContext = requestingElement;
+    }
+  } else {
+    loadingWindow = nullptr;
+    loadingNode = mScriptGlobal->GetFrameElementInternal();
+    if (loadingNode) {
+      // If we have a loading node, then use that as our loadingPrincipal.
+      loadingPrincipal = loadingNode->NodePrincipal();
+#ifdef DEBUG
+      // Get the docshell type for requestingElement.
+      RefPtr<Document> requestingDoc = loadingNode->OwnerDoc();
+      nsCOMPtr<nsIDocShell> elementDocShell = requestingDoc->GetDocShell();
+      // requestingElement docshell type = current docshell type.
+      MOZ_ASSERT(
+          mItemType == elementDocShell->ItemType(),
+          "subframes should have the same docshell type as their parent");
+#endif
+    } else {
+      if (mIsBeingDestroyed) {
+        // If this isn't a top-level load and mScriptGlobal's frame element is
+        // null, then the element got removed from the DOM while we were trying
+        // to load this resource. This docshell is scheduled for destruction
+        // already, so bail out here.
+        return NS_OK;
+      }
+      // If we are not being destroyed and we do not have access to the loading
+      // node, then we are a remote subframe. Set the loading principal
+      // to be a null principal and then set it correctly in the parent.
+      loadingPrincipal = NullPrincipal::Create(GetOriginAttributes(), nullptr);
+    }
+  }
+
+  if (!aLoadState->TriggeringPrincipal()) {
+    MOZ_ASSERT(false, "DoURILoad needs a valid triggeringPrincipal");
+    return NS_ERROR_FAILURE;
+  }
+
+  uint32_t sandboxFlags = mBrowsingContext->GetSandboxFlags();
+  nsSecurityFlags securityFlags =
+      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL;
+
+  if (mLoadType == LOAD_ERROR_PAGE) {
+    securityFlags |= nsILoadInfo::SEC_LOAD_ERROR_PAGE;
+  }
+
+  if (inheritPrincipal) {
+    securityFlags |= nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL;
+  }
+
+  // Must never have a parent for TYPE_DOCUMENT loads
+  MOZ_ASSERT_IF(contentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+                !mBrowsingContext->GetParent());
+  // Subdocuments must have a parent
+  MOZ_ASSERT_IF(contentPolicyType == nsIContentPolicy::TYPE_SUBDOCUMENT,
+                mBrowsingContext->GetParent());
+  mBrowsingContext->SetTriggeringAndInheritPrincipals(
+      aLoadState->TriggeringPrincipal(), aLoadState->PrincipalToInherit(),
+      aLoadState->GetLoadIdentifier());
+  RefPtr<LoadInfo> loadInfo =
+      (contentPolicyType == nsIContentPolicy::TYPE_DOCUMENT)
+          ? new LoadInfo(loadingWindow, aLoadState->URI(),
+                         aLoadState->TriggeringPrincipal(),
+                         topLevelLoadingContext, securityFlags, sandboxFlags)
+          : new LoadInfo(loadingPrincipal, aLoadState->TriggeringPrincipal(),
+                         loadingNode, securityFlags, contentPolicyType,
+                         Maybe<mozilla::dom::ClientInfo>(),
+                         Maybe<mozilla::dom::ServiceWorkerDescriptor>(),
+                         sandboxFlags);
+  RefPtr<WindowContext> context = mBrowsingContext->GetCurrentWindowContext();
+
+  if (isAboutBlankLoadOntoInitialAboutBlank) {
+    // Match the DocumentChannel case where the default for third-partiness
+    // differs from the default in LoadInfo construction here.
+    // toolkit/components/antitracking/test/browser/browser_aboutblank.js
+    // fails without this.
+    BrowsingContext* top = mBrowsingContext->Top();
+    if (top == mBrowsingContext) {
+      // If we're at the top, this must be a window.open()ed
+      // window, and we can't be third-party relative to ourselves.
+      loadInfo->SetIsThirdPartyContextToTopWindow(false);
+    } else {
+      if (Document* topDoc = top->GetDocument()) {
+        bool thirdParty = false;
+        mozilla::Unused << topDoc->GetPrincipal()->IsThirdPartyPrincipal(
+            aLoadState->PrincipalToInherit(), &thirdParty);
+        loadInfo->SetIsThirdPartyContextToTopWindow(thirdParty);
+      } else {
+        // If top is in a different process, we have to be third-party relative
+        // to it.
+        loadInfo->SetIsThirdPartyContextToTopWindow(true);
+      }
+    }
+  }
+
+  if (mLoadType != LOAD_ERROR_PAGE && context && context->IsInProcess() &&
+      context->HasValidTransientUserGestureActivation()) {
+    aLoadState->SetHasValidUserGestureActivation(true);
+  }
+
+  // in case this docshell load was triggered by a valid transient user gesture,
+  // or also the load originates from external, then we pass that information on
+  // to the loadinfo, which allows e.g. setting Sec-Fetch-User request headers.
+  if (aLoadState->HasValidUserGestureActivation() ||
+      aLoadState->HasLoadFlags(LOAD_FLAGS_FROM_EXTERNAL)) {
+    loadInfo->SetHasValidUserGestureActivation(true);
+  }
+  loadInfo->SetTriggeringSandboxFlags(aLoadState->TriggeringSandboxFlags());
+  loadInfo->SetIsMetaRefresh(aLoadState->IsMetaRefresh());
+
+  uint32_t cacheKey = 0;
+  if (aCacheKey) {
+    cacheKey = *aCacheKey;
+  } else if (mozilla::SessionHistoryInParent()) {
+    if (mLoadingEntry) {
+      cacheKey = mLoadingEntry->mInfo.GetCacheKey();
+    } else if (mActiveEntry) {  // for reload cases
+      cacheKey = mActiveEntry->GetCacheKey();
+    }
+  } else {
+    if (mLSHE) {
+      cacheKey = mLSHE->GetCacheKey();
+    } else if (mOSHE) {  // for reload cases
+      cacheKey = mOSHE->GetCacheKey();
+    }
+  }
+
+  bool uriModified;
+  if (mLSHE || mLoadingEntry) {
+    if (mLoadingEntry) {
+      uriModified = mLoadingEntry->mInfo.GetURIWasModified();
+    } else {
+      uriModified = mLSHE->GetURIWasModified();
+    }
+  } else {
+    uriModified = false;
+  }
+
+  bool isXFOError = false;
+  if (mFailedChannel) {
+    nsresult status;
+    mFailedChannel->GetStatus(&status);
+    isXFOError = status == NS_ERROR_XFO_VIOLATION;
+  }
+
+  nsLoadFlags loadFlags = aLoadState->CalculateChannelLoadFlags(
+      mBrowsingContext, Some(uriModified), Some(isXFOError));
+
+  nsCOMPtr<nsIChannel> channel;
+  if (DocumentChannel::CanUseDocumentChannel(aLoadState->URI()) &&
+      !isAboutBlankLoadOntoInitialAboutBlank) {
+    channel = DocumentChannel::CreateForDocument(aLoadState, loadInfo,
+                                                 loadFlags, this, cacheKey,
+                                                 uriModified, isXFOError);
+    MOZ_ASSERT(channel);
+
+    // Disable keyword fixup when using DocumentChannel, since
+    // DocumentLoadListener will handle this for us (in the parent process).
+    mAllowKeywordFixup = false;
+  } else if (!CreateAndConfigureRealChannelForLoadState(
+                 mBrowsingContext, aLoadState, loadInfo, this, this,
+                 GetOriginAttributes(), loadFlags, cacheKey, rv,
+                 getter_AddRefs(channel))) {
+    return rv;
+  }
+
+  // Make sure to give the caller a channel if we managed to create one
+  // This is important for correct error page/session history interaction
+  if (aRequest) {
+    NS_ADDREF(*aRequest = channel);
+  }
+
+  nsCOMPtr<nsIContentSecurityPolicy> csp = aLoadState->Csp();
+  if (csp) {
+    // Check CSP navigate-to
+    bool allowsNavigateTo = false;
+    rv = csp->GetAllowsNavigateTo(aLoadState->URI(),
+                                  aLoadState->IsFormSubmission(),
+                                  false, /* aWasRedirected */
+                                  false, /* aEnforceWhitelist */
+                                  &allowsNavigateTo);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!allowsNavigateTo) {
+      return NS_ERROR_CSP_NAVIGATE_TO_VIOLATION;
+    }
+  }
+
+  const nsACString& typeHint = aLoadState->TypeHint();
+  if (!typeHint.IsVoid()) {
+    mContentTypeHint = typeHint;
+  } else {
+    mContentTypeHint.Truncate();
+  }
+
+  // Load attributes depend on load type...
+  if (mLoadType == LOAD_RELOAD_CHARSET_CHANGE) {
+    // Use SetAllowStaleCacheContent (not LOAD_FROM_CACHE flag) since we
+    // only want to force cache load for this channel, not the whole
+    // loadGroup.
+    nsCOMPtr<nsICacheInfoChannel> cachingChannel = do_QueryInterface(channel);
+    if (cachingChannel) {
+      cachingChannel->SetAllowStaleCacheContent(true);
+    }
+  }
+
+  uint32_t openFlags =
+      nsDocShell::ComputeURILoaderFlags(mBrowsingContext, mLoadType);
+  return OpenInitializedChannel(channel, uriLoader, openFlags);
+}
+
+static nsresult AppendSegmentToString(nsIInputStream* aIn, void* aClosure,
+                                      const char* aFromRawSegment,
+                                      uint32_t aToOffset, uint32_t aCount,
+                                      uint32_t* aWriteCount) {
+  // aFromSegment now contains aCount bytes of data.
+
+  nsAutoCString* buf = static_cast<nsAutoCString*>(aClosure);
+  buf->Append(aFromRawSegment, aCount);
+
+  // Indicate that we have consumed all of aFromSegment
+  *aWriteCount = aCount;
+  return NS_OK;
+}
+
+/* static */ nsresult nsDocShell::AddHeadersToChannel(
+    nsIInputStream* aHeadersData, nsIChannel* aGenericChannel) {
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aGenericChannel);
+  NS_ENSURE_STATE(httpChannel);
+
+  uint32_t numRead;
+  nsAutoCString headersString;
+  nsresult rv = aHeadersData->ReadSegments(
+      AppendSegmentToString, &headersString, UINT32_MAX, &numRead);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // used during the manipulation of the String from the InputStream
+  nsAutoCString headerName;
+  nsAutoCString headerValue;
+  int32_t crlf;
+  int32_t colon;
+
+  //
+  // Iterate over the headersString: for each "\r\n" delimited chunk,
+  // add the value as a header to the nsIHttpChannel
+  //
+
+  static const char kWhitespace[] = "\b\t\r\n ";
+  while (true) {
+    crlf = headersString.Find("\r\n");
+    if (crlf == kNotFound) {
+      return NS_OK;
+    }
+
+    const nsACString& oneHeader = StringHead(headersString, crlf);
+
+    colon = oneHeader.FindChar(':');
+    if (colon == kNotFound) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    headerName = StringHead(oneHeader, colon);
+    headerValue = Substring(oneHeader, colon + 1);
+
+    headerName.Trim(kWhitespace);
+    headerValue.Trim(kWhitespace);
+
+    headersString.Cut(0, crlf + 2);
+
+    //
+    // FINALLY: we can set the header!
+    //
+
+    rv = httpChannel->SetRequestHeader(headerName, headerValue, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  MOZ_ASSERT_UNREACHABLE("oops");
+  return NS_ERROR_UNEXPECTED;
+}
+
+/* static */ uint32_t nsDocShell::ComputeURILoaderFlags(
+    BrowsingContext* aBrowsingContext, uint32_t aLoadType) {
+  MOZ_ASSERT(aBrowsingContext);
+
+  uint32_t openFlags = 0;
+  if (aLoadType == LOAD_LINK) {
+    openFlags |= nsIURILoader::IS_CONTENT_PREFERRED;
+  }
+  if (!aBrowsingContext->GetAllowContentRetargeting()) {
+    openFlags |= nsIURILoader::DONT_RETARGET;
+  }
+
+  return openFlags;
+}
+
+nsresult nsDocShell::OpenInitializedChannel(nsIChannel* aChannel,
+                                            nsIURILoader* aURILoader,
+                                            uint32_t aOpenFlags) {
+  nsresult rv = NS_OK;
+
+  // If anything fails here, make sure to clear our initial ClientSource.
+  auto cleanupInitialClient =
+      MakeScopeExit([&] { mInitialClientSource.reset(); });
+
+  nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+  NS_ENSURE_TRUE(win, NS_ERROR_FAILURE);
+
+  MaybeCreateInitialClientSource();
+
+  // Let the client channel helper know if we are using DocumentChannel,
+  // since redirects get handled in the parent process in that case.
+  RefPtr<net::DocumentChannel> docChannel = do_QueryObject(aChannel);
+  if (docChannel && XRE_IsContentProcess()) {
+    // Tell the content process nsDocumentOpenInfo to not try to do
+    // any sort of targeting.
+    aOpenFlags |= nsIURILoader::DONT_RETARGET;
+  }
+
+  // Since we are loading a document we need to make sure the proper reserved
+  // and initial client data is stored on the nsILoadInfo.  The
+  // ClientChannelHelper does this and ensures that it is propagated properly
+  // on redirects.  We pass no reserved client here so that the helper will
+  // create the reserved ClientSource if necessary.
+  Maybe<ClientInfo> noReservedClient;
+  if (docChannel) {
+    // When using DocumentChannel, all redirect handling is done in the parent,
+    // so we just need the child variant to watch for the internal redirect
+    // to the final channel.
+    rv = AddClientChannelHelperInChild(
+        aChannel, win->EventTargetFor(TaskCategory::Other));
+    docChannel->SetInitialClientInfo(GetInitialClientInfo());
+  } else {
+    rv = AddClientChannelHelper(aChannel, std::move(noReservedClient),
+                                GetInitialClientInfo(),
+                                win->EventTargetFor(TaskCategory::Other));
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aURILoader->OpenURI(aChannel, aOpenFlags, this);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // We're about to load a new page and it may take time before necko
+  // gives back any data, so main thread might have a chance to process a
+  // collector slice
+  nsJSContext::MaybeRunNextCollectorSlice(this, JS::GCReason::DOCSHELL);
+
+  // Success.  Keep the initial ClientSource if it exists.
+  cleanupInitialClient.release();
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::OpenRedirectedChannel(nsDocShellLoadState* aLoadState) {
+  nsCOMPtr<nsIChannel> channel = aLoadState->GetPendingRedirectedChannel();
+  MOZ_ASSERT(channel);
+
+  // If anything fails here, make sure to clear our initial ClientSource.
+  auto cleanupInitialClient =
+      MakeScopeExit([&] { mInitialClientSource.reset(); });
+
+  nsCOMPtr<nsPIDOMWindowOuter> win = GetWindow();
+  NS_ENSURE_TRUE(win, NS_ERROR_FAILURE);
+
+  MaybeCreateInitialClientSource();
+
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+
+  LoadInfo* li = static_cast<LoadInfo*>(loadInfo.get());
+  if (loadInfo->GetExternalContentPolicyType() ==
+      ExtContentPolicy::TYPE_DOCUMENT) {
+    li->UpdateBrowsingContextID(mBrowsingContext->Id());
+  } else if (loadInfo->GetExternalContentPolicyType() ==
+             ExtContentPolicy::TYPE_SUBDOCUMENT) {
+    li->UpdateFrameBrowsingContextID(mBrowsingContext->Id());
+  }
+  // TODO: more attributes need to be updated on the LoadInfo (bug 1561706)
+
+  // If we did a process switch, then we should have an existing allocated
+  // ClientInfo, so we just need to allocate a corresponding ClientSource.
+  CreateReservedSourceIfNeeded(channel,
+                               win->EventTargetFor(TaskCategory::Other));
+
+  RefPtr<nsDocumentOpenInfo> loader =
+      new nsDocumentOpenInfo(this, nsIURILoader::DONT_RETARGET, nullptr);
+  channel->SetLoadGroup(mLoadGroup);
+
+  MOZ_ALWAYS_SUCCEEDS(loader->Prepare());
+
+  nsresult rv = NS_OK;
+  if (XRE_IsParentProcess()) {
+    // If we're in the parent, the we don't have an nsIChildChannel, just
+    // the original channel, which is already open in this process.
+
+    // DocumentLoadListener expects to get an nsIParentChannel, so
+    // we create a wrapper around the channel and nsIStreamListener
+    // that forwards functionality as needed, and then we register
+    // it under the provided identifier.
+    RefPtr<ParentChannelWrapper> wrapper =
+        new ParentChannelWrapper(channel, loader);
+    wrapper->Register(aLoadState->GetPendingRedirectChannelRegistrarId());
+
+    mLoadGroup->AddRequest(channel, nullptr);
+  } else if (nsCOMPtr<nsIChildChannel> childChannel =
+                 do_QueryInterface(channel)) {
+    // Our channel was redirected from another process, so doesn't need to
+    // be opened again. However, it does need its listener hooked up
+    // correctly.
+    rv = childChannel->CompleteRedirectSetup(loader);
+  } else {
+    // It's possible for the redirected channel to not implement
+    // nsIChildChannel and be entirely local (like srcdoc). In that case we
+    // can just open the local instance and it will work.
+    rv = channel->AsyncOpen(loader);
+  }
+  if (rv == NS_ERROR_NO_CONTENT) {
+    return NS_OK;
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Success.  Keep the initial ClientSource if it exists.
+  cleanupInitialClient.release();
+  return NS_OK;
+}
+
+nsresult nsDocShell::ScrollToAnchor(bool aCurHasRef, bool aNewHasRef,
+                                    nsACString& aNewHash, uint32_t aLoadType) {
+  if (!mCurrentURI) {
+    return NS_OK;
+  }
+
+  RefPtr<PresShell> presShell = GetPresShell();
+  if (!presShell) {
+    // If we failed to get the shell, or if there is no shell,
+    // nothing left to do here.
+    return NS_OK;
+  }
+
+  nsIScrollableFrame* rootScroll = presShell->GetRootScrollFrameAsScrollable();
+  if (rootScroll) {
+    rootScroll->ClearDidHistoryRestore();
+  }
+
+  // If we have no new anchor, we do not want to scroll, unless there is a
+  // current anchor and we are doing a history load.  So return if we have no
+  // new anchor, and there is no current anchor or the load is not a history
+  // load.
+  if ((!aCurHasRef || aLoadType != LOAD_HISTORY) && !aNewHasRef) {
+    return NS_OK;
+  }
+
+  // Both the new and current URIs refer to the same page. We can now
+  // browse to the hash stored in the new URI.
+
+  if (!aNewHash.IsEmpty()) {
+    // anchor is there, but if it's a load from history,
+    // we don't have any anchor jumping to do
+    bool scroll = aLoadType != LOAD_HISTORY && aLoadType != LOAD_RELOAD_NORMAL;
+
+    // We assume that the bytes are in UTF-8, as it says in the
+    // spec:
+    // http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.1
+
+    // We try the UTF-8 string first, and then try the document's
+    // charset (see below).  If the string is not UTF-8,
+    // conversion will fail and give us an empty Unicode string.
+    // In that case, we should just fall through to using the
+    // page's charset.
+    nsresult rv = NS_ERROR_FAILURE;
+    NS_ConvertUTF8toUTF16 uStr(aNewHash);
+    if (!uStr.IsEmpty()) {
+      rv = presShell->GoToAnchor(uStr, scroll, ScrollFlags::ScrollSmoothAuto);
+    }
+
+    if (NS_FAILED(rv)) {
+      char* str = ToNewCString(aNewHash, mozilla::fallible);
+      if (!str) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+      nsUnescape(str);
+      NS_ConvertUTF8toUTF16 utf16Str(str);
+      if (!utf16Str.IsEmpty()) {
+        rv = presShell->GoToAnchor(utf16Str, scroll,
+                                   ScrollFlags::ScrollSmoothAuto);
+      }
+      free(str);
+    }
+
+    // Above will fail if the anchor name is not UTF-8.  Need to
+    // convert from document charset to unicode.
+    if (NS_FAILED(rv)) {
+      // Get a document charset
+      NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
+      Document* doc = mContentViewer->GetDocument();
+      NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
+      nsAutoCString charset;
+      doc->GetDocumentCharacterSet()->Name(charset);
+
+      nsCOMPtr<nsITextToSubURI> textToSubURI =
+          do_GetService(NS_ITEXTTOSUBURI_CONTRACTID, &rv);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Unescape and convert to unicode
+      nsAutoString uStr;
+
+      rv = textToSubURI->UnEscapeAndConvert(charset, aNewHash, uStr);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Ignore return value of GoToAnchor, since it will return an error
+      // if there is no such anchor in the document, which is actually a
+      // success condition for us (we want to update the session history
+      // with the new URI no matter whether we actually scrolled
+      // somewhere).
+      //
+      // When aNewHash contains "%00", unescaped string may be empty.
+      // And GoToAnchor asserts if we ask it to scroll to an empty ref.
+      presShell->GoToAnchor(uStr, scroll && !uStr.IsEmpty(),
+                            ScrollFlags::ScrollSmoothAuto);
+    }
+  } else {
+    // Tell the shell it's at an anchor, without scrolling.
+    presShell->GoToAnchor(u""_ns, false);
+
+    // An empty anchor was found, but if it's a load from history,
+    // we don't have to jump to the top of the page. Scrollbar
+    // position will be restored by the caller, based on positions
+    // stored in session history.
+    if (aLoadType == LOAD_HISTORY || aLoadType == LOAD_RELOAD_NORMAL) {
+      return NS_OK;
+    }
+    // An empty anchor. Scroll to the top of the page.  Ignore the
+    // return value; failure to scroll here (e.g. if there is no
+    // root scrollframe) is not grounds for canceling the load!
+    SetCurScrollPosEx(0, 0);
+  }
+
+  return NS_OK;
+}
+
+bool nsDocShell::OnNewURI(nsIURI* aURI, nsIChannel* aChannel,
+                          nsIPrincipal* aTriggeringPrincipal,
+                          nsIPrincipal* aPrincipalToInherit,
+                          nsIPrincipal* aPartitionedPrincipalToInherit,
+                          nsIContentSecurityPolicy* aCsp,
+                          bool aFireOnLocationChange, bool aAddToGlobalHistory,
+                          bool aCloneSHChildren) {
+  MOZ_ASSERT(aURI, "uri is null");
+  MOZ_ASSERT(!aChannel || !aTriggeringPrincipal, "Shouldn't have both set");
+
+  MOZ_ASSERT(!aPrincipalToInherit ||
+             (aPrincipalToInherit && aTriggeringPrincipal));
+
+#if defined(DEBUG)
+  if (MOZ_LOG_TEST(gDocShellLog, LogLevel::Debug)) {
+    nsAutoCString chanName;
+    if (aChannel) {
+      aChannel->GetName(chanName);
+    } else {
+      chanName.AssignLiteral("<no channel>");
+    }
+
+    MOZ_LOG(gDocShellLog, LogLevel::Debug,
+            ("nsDocShell[%p]::OnNewURI(\"%s\", [%s], 0x%x)\n", this,
+             aURI->GetSpecOrDefault().get(), chanName.get(), mLoadType));
+  }
+#endif
+
+  bool equalUri = false;
+
+  // Get the post data and the HTTP response code from the channel.
+  uint32_t responseStatus = 0;
+  nsCOMPtr<nsIInputStream> inputStream;
+  if (aChannel) {
+    nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aChannel));
+
+    // Check if the HTTPChannel is hiding under a multiPartChannel
+    if (!httpChannel) {
+      GetHttpChannel(aChannel, getter_AddRefs(httpChannel));
+    }
+
+    if (httpChannel) {
+      nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(httpChannel));
+      if (uploadChannel) {
+        uploadChannel->GetUploadStream(getter_AddRefs(inputStream));
+      }
+
+      // If the response status indicates an error, unlink this session
+      // history entry from any entries sharing its document.
+      nsresult rv = httpChannel->GetResponseStatus(&responseStatus);
+      if (mLSHE && NS_SUCCEEDED(rv) && responseStatus >= 400) {
+        mLSHE->AbandonBFCacheEntry();
+        // FIXME Do the same for mLoadingEntry
+      }
+    }
+  }
+
+  // Determine if this type of load should update history.
+  bool updateGHistory = ShouldUpdateGlobalHistory(mLoadType);
+
+  // We don't update session history on reload unless we're loading
+  // an iframe in shift-reload case.
+  bool updateSHistory = mBrowsingContext->ShouldUpdateSessionHistory(mLoadType);
+
+  // Create SH Entry (mLSHE) only if there is a SessionHistory object in the
+  // root browsing context.
+  // FIXME If session history in the parent is enabled then we only do this if
+  //       the session history object is in process, otherwise we can't really
+  //       use the mLSHE anyway. Once session history is only stored in the
+  //       parent then this code will probably be removed anyway.
+  RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+  if (!rootSH) {
+    updateSHistory = false;
+    updateGHistory = false;  // XXX Why global history too?
+  }
+
+  // Check if the url to be loaded is the same as the one already loaded.
+  if (mCurrentURI) {
+    aURI->Equals(mCurrentURI, &equalUri);
+  }
+
+#ifdef DEBUG
+  bool shAvailable = (rootSH != nullptr);
+
+  // XXX This log message is almost useless because |updateSHistory|
+  //     and |updateGHistory| are not correct at this point.
+
+  MOZ_LOG(gDocShellLog, LogLevel::Debug,
+          ("  shAvailable=%i updateSHistory=%i updateGHistory=%i"
+           " equalURI=%i\n",
+           shAvailable, updateSHistory, updateGHistory, equalUri));
+#endif
+
+  /* If the url to be loaded is the same as the one already there,
+   * and the original loadType is LOAD_NORMAL, LOAD_LINK, or
+   * LOAD_STOP_CONTENT, set loadType to LOAD_NORMAL_REPLACE so that
+   * AddToSessionHistory() won't mess with the current SHEntry and
+   * if this page has any frame children, it also will be handled
+   * properly. see bug 83684
+   *
+   * NB: If mOSHE is null but we have a current URI, then it probably
+   * means that we must be at the transient about:blank content viewer;
+   * we should let the normal load continue, since there's nothing to
+   * replace. Sometimes this happens after a session restore (eg process
+   * switch) and mCurrentURI is not about:blank; we assume we can let the load
+   * continue (Bug 1301399).
+   *
+   * XXX Hopefully changing the loadType at this time will not hurt
+   *  anywhere. The other way to take care of sequentially repeating
+   *  frameset pages is to add new methods to nsIDocShellTreeItem.
+   * Hopefully I don't have to do that.
+   */
+  if (equalUri &&
+      (mozilla::SessionHistoryInParent() ? !!mActiveEntry : !!mOSHE) &&
+      (mLoadType == LOAD_NORMAL || mLoadType == LOAD_LINK ||
+       mLoadType == LOAD_STOP_CONTENT) &&
+      !inputStream) {
+    mLoadType = LOAD_NORMAL_REPLACE;
+  }
+
+  // If this is a refresh to the currently loaded url, we don't
+  // have to update session or global history.
+  if (mLoadType == LOAD_REFRESH && !inputStream && equalUri) {
+    SetHistoryEntryAndUpdateBC(Some<nsISHEntry*>(mOSHE), Nothing());
+  }
+
+  /* If the user pressed shift-reload, cache will create a new cache key
+   * for the page. Save the new cacheKey in Session History.
+   * see bug 90098
+   */
+  if (aChannel && IsForceReloadType(mLoadType)) {
+    MOZ_ASSERT(!updateSHistory || IsSubframe(),
+               "We shouldn't be updating session history for forced"
+               " reloads unless we're in a newly created iframe!");
+
+    nsCOMPtr<nsICacheInfoChannel> cacheChannel(do_QueryInterface(aChannel));
+    uint32_t cacheKey = 0;
+    // Get the Cache Key and store it in SH.
+    if (cacheChannel) {
+      cacheChannel->GetCacheKey(&cacheKey);
+    }
+    // If we already have a loading history entry, store the new cache key
+    // in it.  Otherwise, since we're doing a reload and won't be updating
+    // our history entry, store the cache key in our current history entry.
+    SetCacheKeyOnHistoryEntry(mLSHE ? mLSHE : mOSHE, cacheKey);
+
+    if (!mozilla::SessionHistoryInParent()) {
+      // Since we're force-reloading, clear all the sub frame history.
+      ClearFrameHistory(mLSHE);
+      ClearFrameHistory(mOSHE);
+    }
+  }
+
+  if (!mozilla::SessionHistoryInParent()) {
+    // Clear subframe history on refresh.
+    // XXX: history.go(0) won't go this path as mLoadType is LOAD_HISTORY in
+    // this case. One should re-validate after bug 1331865 fixed.
+    if (mLoadType == LOAD_REFRESH) {
+      ClearFrameHistory(mLSHE);
+      ClearFrameHistory(mOSHE);
+    }
+
+    if (updateSHistory) {
+      // Update session history if necessary...
+      if (!mLSHE && (mItemType == typeContent) && mURIResultedInDocument) {
+        /* This is  a fresh page getting loaded for the first time
+         *.Create a Entry for it and add it to SH, if this is the
+         * rootDocShell
+         */
+        (void)AddToSessionHistory(aURI, aChannel, aTriggeringPrincipal,
+                                  aPrincipalToInherit,
+                                  aPartitionedPrincipalToInherit, aCsp,
+                                  aCloneSHChildren, getter_AddRefs(mLSHE));
+      }
+    } else if (GetSessionHistory() && mLSHE && mURIResultedInDocument) {
+      // Even if we don't add anything to SHistory, ensure the current index
+      // points to the same SHEntry as our mLSHE.
+
+      GetSessionHistory()->LegacySHistory()->EnsureCorrectEntryAtCurrIndex(
+          mLSHE);
+    }
+  }
+
+  // If this is a POST request, we do not want to include this in global
+  // history.
+  if (ShouldAddURIVisit(aChannel) && updateGHistory && aAddToGlobalHistory &&
+      !net::ChannelIsPost(aChannel)) {
+    nsCOMPtr<nsIURI> previousURI;
+    uint32_t previousFlags = 0;
+
+    if (mLoadType & LOAD_CMD_RELOAD) {
+      // On a reload request, we don't set redirecting flags.
+      previousURI = aURI;
+    } else {
+      ExtractLastVisit(aChannel, getter_AddRefs(previousURI), &previousFlags);
+    }
+
+    AddURIVisit(aURI, previousURI, previousFlags, responseStatus);
+  }
+
+  // If this was a history load or a refresh, or it was a history load but
+  // later changed to LOAD_NORMAL_REPLACE due to redirection, update the index
+  // in session history.
+  if (!mozilla::SessionHistoryInParent() && rootSH &&
+      ((mLoadType & (LOAD_CMD_HISTORY | LOAD_CMD_RELOAD)) ||
+       mLoadType == LOAD_NORMAL_REPLACE || mLoadType == LOAD_REFRESH_REPLACE)) {
+    mPreviousEntryIndex = rootSH->Index();
+    if (!mozilla::SessionHistoryInParent()) {
+      rootSH->LegacySHistory()->UpdateIndex();
+    }
+    mLoadedEntryIndex = rootSH->Index();
+    MOZ_LOG(gPageCacheLog, LogLevel::Verbose,
+            ("Previous index: %d, Loaded index: %d", mPreviousEntryIndex,
+             mLoadedEntryIndex));
+  }
+
+  // aCloneSHChildren exactly means "we are not loading a new document".
+  uint32_t locationFlags =
+      aCloneSHChildren ? uint32_t(LOCATION_CHANGE_SAME_DOCUMENT) : 0;
+
+  bool onLocationChangeNeeded =
+      SetCurrentURI(aURI, aChannel, aFireOnLocationChange,
+                    /* aIsInitialAboutBlank */ false, locationFlags);
+  // Make sure to store the referrer from the channel, if any
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aChannel));
+  if (httpChannel) {
+    mReferrerInfo = httpChannel->GetReferrerInfo();
+  }
+  return onLocationChangeNeeded;
+}
+
+Maybe<Wireframe> nsDocShell::GetWireframe() {
+  const bool collectWireFrame =
+      mozilla::SessionHistoryInParent() &&
+      StaticPrefs::browser_history_collectWireframes() &&
+      mBrowsingContext->IsTopContent() && mActiveEntry;
+
+  if (!collectWireFrame) {
+    return Nothing();
+  }
+
+  RefPtr<Document> doc = mContentViewer->GetDocument();
+  Nullable<Wireframe> wireframe;
+  doc->GetWireframeWithoutFlushing(false, wireframe);
+  if (wireframe.IsNull()) {
+    return Nothing();
+  }
+  return Some(wireframe.Value());
+}
+
+bool nsDocShell::CollectWireframe() {
+  Maybe<Wireframe> wireframe = GetWireframe();
+  if (wireframe.isNothing()) {
+    return false;
+  }
+
+  if (XRE_IsParentProcess()) {
+    SessionHistoryEntry* entry =
+        mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+    if (entry) {
+      entry->SetWireframe(wireframe);
+    }
+  } else {
+    mozilla::Unused
+        << ContentChild::GetSingleton()->SendSessionHistoryEntryWireframe(
+               mBrowsingContext, wireframe.ref());
+  }
+
+  return true;
+}
+
+//*****************************************************************************
+// nsDocShell: Session History
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::AddState(JS::Handle<JS::Value> aData, const nsAString& aTitle,
+                     const nsAString& aURL, bool aReplace, JSContext* aCx) {
+  MOZ_LOG(gSHLog, LogLevel::Debug,
+          ("nsDocShell[%p]: AddState(..., %s, %s, %d)", this,
+           NS_ConvertUTF16toUTF8(aTitle).get(),
+           NS_ConvertUTF16toUTF8(aURL).get(), aReplace));
+  // Implements History.pushState and History.replaceState
+
+  // Here's what we do, roughly in the order specified by HTML5.  The specific
+  // steps we are executing are at
+  // <https://html.spec.whatwg.org/multipage/history.html#dom-history-pushstate>
+  // and
+  // <https://html.spec.whatwg.org/multipage/history.html#url-and-history-update-steps>.
+  // This function basically implements #dom-history-pushstate and
+  // UpdateURLAndHistory implements #url-and-history-update-steps.
+  //
+  // A. Serialize aData using structured clone.  This is #dom-history-pushstate
+  //    step 5.
+  // B. If the third argument is present, #dom-history-pushstate step 7.
+  //     7.1. Resolve the url, relative to our document.
+  //     7.2. If (a) fails, raise a SECURITY_ERR
+  //     7.4. Compare the resulting absolute URL to the document's address.  If
+  //          any part of the URLs difer other than the <path>, <query>, and
+  //          <fragment> components, raise a SECURITY_ERR and abort.
+  // C. If !aReplace, #url-and-history-update-steps steps 2.1-2.3:
+  //     Remove from the session history all entries after the current entry,
+  //     as we would after a regular navigation, and save the current
+  //     entry's scroll position (bug 590573).
+  // D. #url-and-history-update-steps step 2.4 or step 3.  As apropriate,
+  //    either add a state object entry to the session history after the
+  //    current entry with the following properties, or modify the current
+  //    session history entry to set
+  //      a. cloned data as the state object,
+  //      b. if the third argument was present, the absolute URL found in
+  //         step 2
+  //    Also clear the new history entry's POST data (see bug 580069).
+  // E. If aReplace is false (i.e. we're doing a pushState instead of a
+  //    replaceState), notify bfcache that we've navigated to a new page.
+  // F. If the third argument is present, set the document's current address
+  //    to the absolute URL found in step B.  This is
+  //    #url-and-history-update-steps step 4.
+  //
+  // It's important that this function not run arbitrary scripts after step A
+  // and before completing step E.  For example, if a script called
+  // history.back() before we completed step E, bfcache might destroy an
+  // active content viewer.  Since EvictOutOfRangeContentViewers at the end of
+  // step E might run script, we can't just put a script blocker around the
+  // critical section.
+  //
+  // Note that we completely ignore the aTitle parameter.
+
+  nsresult rv;
+
+  // Don't clobber the load type of an existing network load.
+  AutoRestore<uint32_t> loadTypeResetter(mLoadType);
+
+  // pushState effectively becomes replaceState when we've started a network
+  // load but haven't adopted its document yet.  This mirrors what we do with
+  // changes to the hash at this stage of the game.
+  if (JustStartedNetworkLoad()) {
+    aReplace = true;
+  }
+
+  RefPtr<Document> document = GetDocument();
+  NS_ENSURE_TRUE(document, NS_ERROR_FAILURE);
+
+  // Step A: Serialize aData using structured clone.
+  // https://html.spec.whatwg.org/multipage/history.html#dom-history-pushstate
+  // step 5.
+  nsCOMPtr<nsIStructuredCloneContainer> scContainer;
+
+  // scContainer->Init might cause arbitrary JS to run, and this code might
+  // navigate the page we're on, potentially to a different origin! (bug
+  // 634834)  To protect against this, we abort if our principal changes due
+  // to the InitFromJSVal() call.
+  {
+    RefPtr<Document> origDocument = GetDocument();
+    if (!origDocument) {
+      return NS_ERROR_DOM_SECURITY_ERR;
+    }
+    nsCOMPtr<nsIPrincipal> origPrincipal = origDocument->NodePrincipal();
+
+    scContainer = new nsStructuredCloneContainer();
+    rv = scContainer->InitFromJSVal(aData, aCx);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    RefPtr<Document> newDocument = GetDocument();
+    if (!newDocument) {
+      return NS_ERROR_DOM_SECURITY_ERR;
+    }
+    nsCOMPtr<nsIPrincipal> newPrincipal = newDocument->NodePrincipal();
+
+    bool principalsEqual = false;
+    origPrincipal->Equals(newPrincipal, &principalsEqual);
+    NS_ENSURE_TRUE(principalsEqual, NS_ERROR_DOM_SECURITY_ERR);
+  }
+
+  // Check that the state object isn't too long.
+  int32_t maxStateObjSize = StaticPrefs::browser_history_maxStateObjectSize();
+  if (maxStateObjSize < 0) {
+    maxStateObjSize = 0;
+  }
+
+  uint64_t scSize;
+  rv = scContainer->GetSerializedNBytes(&scSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_TRUE(scSize <= (uint32_t)maxStateObjSize, NS_ERROR_ILLEGAL_VALUE);
+
+  // Step B: Resolve aURL.
+  // https://html.spec.whatwg.org/multipage/history.html#dom-history-pushstate
+  // step 7.
+  bool equalURIs = true;
+  nsCOMPtr<nsIURI> currentURI;
+  if (mCurrentURI) {
+    currentURI = nsIOService::CreateExposableURI(mCurrentURI);
+  } else {
+    currentURI = mCurrentURI;
+  }
+  nsCOMPtr<nsIURI> newURI;
+  if (aURL.Length() == 0) {
+    newURI = currentURI;
+  } else {
+    // 7.1: Resolve aURL relative to mURI
+
+    nsIURI* docBaseURI = document->GetDocBaseURI();
+    if (!docBaseURI) {
+      return NS_ERROR_FAILURE;
+    }
+
+    nsAutoCString spec;
+    docBaseURI->GetSpec(spec);
+
+    rv = NS_NewURI(getter_AddRefs(newURI), aURL,
+                   document->GetDocumentCharacterSet(), docBaseURI);
+
+    // 7.2: If 2a fails, raise a SECURITY_ERR
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_DOM_SECURITY_ERR;
+    }
+
+    // 7.4 and 7.5: Same-origin check.
+    if (!nsContentUtils::URIIsLocalFile(newURI)) {
+      // In addition to checking that the security manager says that
+      // the new URI has the same origin as our current URI, we also
+      // check that the two URIs have the same userpass. (The
+      // security manager says that |http://foo.com| and
+      // |http://me@foo.com| have the same origin.)  currentURI
+      // won't contain the password part of the userpass, so this
+      // means that it's never valid to specify a password in a
+      // pushState or replaceState URI.
+
+      nsCOMPtr<nsIScriptSecurityManager> secMan =
+          do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID);
+      NS_ENSURE_TRUE(secMan, NS_ERROR_FAILURE);
+
+      // It's very important that we check that newURI is of the same
+      // origin as currentURI, not docBaseURI, because a page can
+      // set docBaseURI arbitrarily to any domain.
+      nsAutoCString currentUserPass, newUserPass;
+      NS_ENSURE_SUCCESS(currentURI->GetUserPass(currentUserPass),
+                        NS_ERROR_FAILURE);
+      NS_ENSURE_SUCCESS(newURI->GetUserPass(newUserPass), NS_ERROR_FAILURE);
+      bool isPrivateWin =
+          document->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId >
+          0;
+      if (NS_FAILED(secMan->CheckSameOriginURI(currentURI, newURI, true,
+                                               isPrivateWin)) ||
+          !currentUserPass.Equals(newUserPass)) {
+        return NS_ERROR_DOM_SECURITY_ERR;
+      }
+    } else {
+      // It's a file:// URI
+      nsCOMPtr<nsIPrincipal> principal = document->GetPrincipal();
+
+      if (!principal || NS_FAILED(principal->CheckMayLoadWithReporting(
+                            newURI, false, document->InnerWindowID()))) {
+        return NS_ERROR_DOM_SECURITY_ERR;
+      }
+    }
+
+    if (currentURI) {
+      currentURI->Equals(newURI, &equalURIs);
+    } else {
+      equalURIs = false;
+    }
+
+  }  // end of same-origin check
+
+  // Step 8: call "URL and history update steps"
+  rv = UpdateURLAndHistory(document, newURI, scContainer, aTitle, aReplace,
+                           currentURI, equalURIs);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult nsDocShell::UpdateURLAndHistory(Document* aDocument, nsIURI* aNewURI,
+                                         nsIStructuredCloneContainer* aData,
+                                         const nsAString& aTitle, bool aReplace,
+                                         nsIURI* aCurrentURI, bool aEqualURIs) {
+  // Implements
+  // https://html.spec.whatwg.org/multipage/history.html#url-and-history-update-steps
+
+  // If we have a pending title change, handle it before creating a new entry.
+  aDocument->DoNotifyPossibleTitleChange();
+
+  // Step 2, if aReplace is false: Create a new entry in the session
+  // history. This will erase all SHEntries after the new entry and make this
+  // entry the current one.  This operation may modify mOSHE, which we need
+  // later, so we keep a reference here.
+  NS_ENSURE_TRUE(mOSHE || mActiveEntry || aReplace, NS_ERROR_FAILURE);
+  nsCOMPtr<nsISHEntry> oldOSHE = mOSHE;
+
+  // If this push/replaceState changed the document's current URI and the new
+  // URI differs from the old URI in more than the hash, or if the old
+  // SHEntry's URI was modified in this way by a push/replaceState call
+  // set URIWasModified to true for the current SHEntry (bug 669671).
+  bool sameExceptHashes = true;
+  aNewURI->EqualsExceptRef(aCurrentURI, &sameExceptHashes);
+  bool uriWasModified;
+  if (sameExceptHashes) {
+    if (mozilla::SessionHistoryInParent()) {
+      uriWasModified = mActiveEntry && mActiveEntry->GetURIWasModified();
+    } else {
+      uriWasModified = oldOSHE && oldOSHE->GetURIWasModified();
+    }
+  } else {
+    uriWasModified = true;
+  }
+
+  mLoadType = LOAD_PUSHSTATE;
+
+  nsCOMPtr<nsISHEntry> newSHEntry;
+  if (!aReplace) {
+    // Step 2.
+
+    // Step 2.2, "Remove any tasks queued by the history traversal task
+    // source that are associated with any Document objects in the
+    // top-level browsing context's document family."  This is very hard in
+    // SessionHistoryInParent since we can't synchronously access the
+    // pending navigations that are already sent to the parent. We can
+    // abort any AsyncGo navigations that are waiting to be sent.  If we
+    // send a message to the parent, it would be processed after any
+    // navigations previously sent.  So long as we consider the "history
+    // traversal task source" to be the list in this process we match the
+    // spec.  If we move the entire list to the parent, we can handle the
+    // aborting of loads there, but we don't have a way to synchronously
+    // remove entries as we do here for non-SHIP.
+    RefPtr<ChildSHistory> shistory = GetRootSessionHistory();
+    if (shistory) {
+      shistory->RemovePendingHistoryNavigations();
+    }
+
+    nsPoint scrollPos = GetCurScrollPos();
+
+    bool scrollRestorationIsManual;
+    if (mozilla::SessionHistoryInParent()) {
+      // FIXME Need to save the current scroll position on mActiveEntry.
+      scrollRestorationIsManual = mActiveEntry->GetScrollRestorationIsManual();
+    } else {
+      // Save the current scroll position (bug 590573).  Step 2.3.
+      mOSHE->SetScrollPosition(scrollPos.x, scrollPos.y);
+
+      scrollRestorationIsManual = mOSHE->GetScrollRestorationIsManual();
+    }
+
+    nsCOMPtr<nsIContentSecurityPolicy> csp = aDocument->GetCsp();
+
+    if (mozilla::SessionHistoryInParent()) {
+      MOZ_LOG(gSHLog, LogLevel::Debug,
+              ("nsDocShell %p UpdateActiveEntry (not replacing)", this));
+      nsString title(mActiveEntry->GetTitle());
+      UpdateActiveEntry(false,
+                        /* aPreviousScrollPos = */ Some(scrollPos), aNewURI,
+                        /* aOriginalURI = */ nullptr,
+                        /* aReferrerInfo = */ nullptr,
+                        /* aTriggeringPrincipal = */ aDocument->NodePrincipal(),
+                        csp, title, scrollRestorationIsManual, aData,
+                        uriWasModified);
+    } else {
+      // Since we're not changing which page we have loaded, pass
+      // true for aCloneChildren.
+      nsresult rv = AddToSessionHistory(
+          aNewURI, nullptr,
+          aDocument->NodePrincipal(),  // triggeringPrincipal
+          nullptr, nullptr, csp, true, getter_AddRefs(newSHEntry));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      NS_ENSURE_TRUE(newSHEntry, NS_ERROR_FAILURE);
+
+      // Session history entries created by pushState inherit scroll restoration
+      // mode from the current entry.
+      newSHEntry->SetScrollRestorationIsManual(scrollRestorationIsManual);
+
+      nsString title;
+      mOSHE->GetTitle(title);
+
+      // Set the new SHEntry's title (bug 655273).
+      newSHEntry->SetTitle(title);
+
+      // Link the new SHEntry to the old SHEntry's BFCache entry, since the
+      // two entries correspond to the same document.
+      NS_ENSURE_SUCCESS(newSHEntry->AdoptBFCacheEntry(oldOSHE),
+                        NS_ERROR_FAILURE);
+
+      // AddToSessionHistory may not modify mOSHE.  In case it doesn't,
+      // we'll just set mOSHE here.
+      mOSHE = newSHEntry;
+    }
+  } else if (mozilla::SessionHistoryInParent()) {
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("nsDocShell %p UpdateActiveEntry (replacing) mActiveEntry %p",
+             this, mActiveEntry.get()));
+    // Setting the resultPrincipalURI to nullptr is fine here: it will cause
+    // NS_GetFinalChannelURI to use the originalURI as the URI, which is aNewURI
+    // in our case.  We could also set it to aNewURI, with the same result.
+    // We don't use aTitle here, see bug 544535.
+    nsString title;
+    nsCOMPtr<nsIReferrerInfo> referrerInfo;
+    if (mActiveEntry) {
+      title = mActiveEntry->GetTitle();
+      referrerInfo = mActiveEntry->GetReferrerInfo();
+    } else {
+      referrerInfo = nullptr;
+    }
+    UpdateActiveEntry(
+        true, /* aPreviousScrollPos = */ Nothing(), aNewURI, aNewURI,
+        /* aReferrerInfo = */ referrerInfo, aDocument->NodePrincipal(),
+        aDocument->GetCsp(), title,
+        mActiveEntry && mActiveEntry->GetScrollRestorationIsManual(), aData,
+        uriWasModified);
+  } else {
+    // Step 3.
+    newSHEntry = mOSHE;
+
+    MOZ_LOG(gSHLog, LogLevel::Debug, ("nsDocShell %p step 3", this));
+    // Since we're not changing which page we have loaded, pass
+    // true for aCloneChildren.
+    if (!newSHEntry) {
+      nsresult rv = AddToSessionHistory(
+          aNewURI, nullptr,
+          aDocument->NodePrincipal(),  // triggeringPrincipal
+          nullptr, nullptr, aDocument->GetCsp(), true,
+          getter_AddRefs(newSHEntry));
+      NS_ENSURE_SUCCESS(rv, rv);
+      mOSHE = newSHEntry;
+    }
+
+    newSHEntry->SetURI(aNewURI);
+    newSHEntry->SetOriginalURI(aNewURI);
+    // We replaced the URI of the entry, clear the unstripped URI as it
+    // shouldn't be used for reloads anymore.
+    newSHEntry->SetUnstrippedURI(nullptr);
+    // Setting the resultPrincipalURI to nullptr is fine here: it will cause
+    // NS_GetFinalChannelURI to use the originalURI as the URI, which is aNewURI
+    // in our case.  We could also set it to aNewURI, with the same result.
+    newSHEntry->SetResultPrincipalURI(nullptr);
+    newSHEntry->SetLoadReplace(false);
+  }
+
+  if (!mozilla::SessionHistoryInParent()) {
+    // Step 2.4 and 3: Modify new/original session history entry and clear its
+    // POST data, if there is any.
+    newSHEntry->SetStateData(aData);
+    newSHEntry->SetPostData(nullptr);
+
+    newSHEntry->SetURIWasModified(uriWasModified);
+
+    // Step E as described at the top of AddState: If aReplace is false,
+    // indicating that we're doing a pushState rather than a replaceState,
+    // notify bfcache that we've added a page to the history so it can evict
+    // content viewers if appropriate. Otherwise call ReplaceEntry so that we
+    // notify nsIHistoryListeners that an entry was replaced.  We may not have a
+    // root session history if this call is coming from a document.open() in a
+    // docshell subtree that disables session history.
+    RefPtr<ChildSHistory> rootSH = GetRootSessionHistory();
+    if (rootSH) {
+      rootSH->LegacySHistory()->EvictContentViewersOrReplaceEntry(newSHEntry,
+                                                                  aReplace);
+    }
+  }
+
+  // Step 4: If the document's URI changed, update document's URI and update
+  // global history.
+  //
+  // We need to call FireOnLocationChange so that the browser's address bar
+  // gets updated and the back button is enabled, but we only need to
+  // explicitly call FireOnLocationChange if we're not calling SetCurrentURI,
+  // since SetCurrentURI will call FireOnLocationChange for us.
+  //
+  // Both SetCurrentURI(...) and FireDummyOnLocationChange() pass
+  // nullptr for aRequest param to FireOnLocationChange(...). Such an update
+  // notification is allowed only when we know docshell is not loading a new
+  // document and it requires LOCATION_CHANGE_SAME_DOCUMENT flag. Otherwise,
+  // FireOnLocationChange(...) breaks security UI.
+  //
+  // If the docshell is shutting down, don't update the document URI, as we
+  // can't load into a docshell that is being destroyed.
+  if (!aEqualURIs && !mIsBeingDestroyed) {
+    aDocument->SetDocumentURI(aNewURI);
+    SetCurrentURI(aNewURI, nullptr, /* aFireLocationChange */ true,
+                  /* aIsInitialAboutBlank */ false,
+                  GetSameDocumentNavigationFlags(aNewURI));
+
+    AddURIVisit(aNewURI, aCurrentURI, 0);
+
+    // AddURIVisit doesn't set the title for the new URI in global history,
+    // so do that here.
+    UpdateGlobalHistoryTitle(aNewURI);
+
+    // Inform the favicon service that our old favicon applies to this new
+    // URI.
+    CopyFavicon(aCurrentURI, aNewURI, UsePrivateBrowsing());
+  } else {
+    FireDummyOnLocationChange();
+  }
+  aDocument->SetStateObject(aData);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetCurrentScrollRestorationIsManual(bool* aIsManual) {
+  if (mozilla::SessionHistoryInParent()) {
+    *aIsManual = mActiveEntry && mActiveEntry->GetScrollRestorationIsManual();
+    return NS_OK;
+  }
+
+  *aIsManual = false;
+  if (mOSHE) {
+    return mOSHE->GetScrollRestorationIsManual(aIsManual);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetCurrentScrollRestorationIsManual(bool aIsManual) {
+  SetScrollRestorationIsManualOnHistoryEntry(mOSHE, aIsManual);
+
+  return NS_OK;
+}
+
+void nsDocShell::SetScrollRestorationIsManualOnHistoryEntry(
+    nsISHEntry* aSHEntry, bool aIsManual) {
+  if (aSHEntry) {
+    aSHEntry->SetScrollRestorationIsManual(aIsManual);
+  }
+
+  if (mActiveEntry && mBrowsingContext) {
+    mActiveEntry->SetScrollRestorationIsManual(aIsManual);
+    if (XRE_IsParentProcess()) {
+      SessionHistoryEntry* entry =
+          mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+      if (entry) {
+        entry->SetScrollRestorationIsManual(aIsManual);
+      }
+    } else {
+      mozilla::Unused << ContentChild::GetSingleton()
+                             ->SendSessionHistoryEntryScrollRestorationIsManual(
+                                 mBrowsingContext, aIsManual);
+    }
+  }
+}
+
+void nsDocShell::SetCacheKeyOnHistoryEntry(nsISHEntry* aSHEntry,
+                                           uint32_t aCacheKey) {
+  if (aSHEntry) {
+    aSHEntry->SetCacheKey(aCacheKey);
+  }
+
+  if (mActiveEntry && mBrowsingContext) {
+    mActiveEntry->SetCacheKey(aCacheKey);
+    if (XRE_IsParentProcess()) {
+      SessionHistoryEntry* entry =
+          mBrowsingContext->Canonical()->GetActiveSessionHistoryEntry();
+      if (entry) {
+        entry->SetCacheKey(aCacheKey);
+      }
+    } else {
+      mozilla::Unused
+          << ContentChild::GetSingleton()->SendSessionHistoryEntryCacheKey(
+                 mBrowsingContext, aCacheKey);
+    }
+  }
+}
+
+/* static */
+bool nsDocShell::ShouldAddToSessionHistory(nsIURI* aURI, nsIChannel* aChannel) {
+  // I believe none of the about: urls should go in the history. But then
+  // that could just be me... If the intent is only deny about:blank then we
+  // should just do a spec compare, rather than two gets of the scheme and
+  // then the path.  -Gagan
+  nsresult rv;
+  nsAutoCString buf;
+
+  rv = aURI->GetScheme(buf);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  if (buf.EqualsLiteral("about")) {
+    rv = aURI->GetPathQueryRef(buf);
+    if (NS_FAILED(rv)) {
+      return false;
+    }
+
+    if (buf.EqualsLiteral("blank")) {
+      return false;
+    }
+    // We only want to add about:newtab if it's not privileged, and
+    // if it is not configured to show the blank page.
+    if (buf.EqualsLiteral("newtab")) {
+      if (!StaticPrefs::browser_newtabpage_enabled()) {
+        return false;
+      }
+
+      NS_ENSURE_TRUE(aChannel, false);
+      nsCOMPtr<nsIPrincipal> resultPrincipal;
+      rv = nsContentUtils::GetSecurityManager()->GetChannelResultPrincipal(
+          aChannel, getter_AddRefs(resultPrincipal));
+      NS_ENSURE_SUCCESS(rv, false);
+      return !resultPrincipal->IsSystemPrincipal();
+    }
+  }
+
+  return true;
+}
+
+nsresult nsDocShell::AddToSessionHistory(
+    nsIURI* aURI, nsIChannel* aChannel, nsIPrincipal* aTriggeringPrincipal,
+    nsIPrincipal* aPrincipalToInherit,
+    nsIPrincipal* aPartitionedPrincipalToInherit,
+    nsIContentSecurityPolicy* aCsp, bool aCloneChildren,
+    nsISHEntry** aNewEntry) {
+  MOZ_ASSERT(aURI, "uri is null");
+  MOZ_ASSERT(!aChannel || !aTriggeringPrincipal, "Shouldn't have both set");
+  MOZ_DIAGNOSTIC_ASSERT(!mozilla::SessionHistoryInParent());
+
+#if defined(DEBUG)
+  if (MOZ_LOG_TEST(gDocShellLog, LogLevel::Debug)) {
+    nsAutoCString chanName;
+    if (aChannel) {
+      aChannel->GetName(chanName);
+    } else {
+      chanName.AssignLiteral("<no channel>");
+    }
+
+    MOZ_LOG(gDocShellLog, LogLevel::Debug,
+            ("nsDocShell[%p]::AddToSessionHistory(\"%s\", [%s])\n", this,
+             aURI->GetSpecOrDefault().get(), chanName.get()));
+  }
+#endif
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsISHEntry> entry;
+
+  /*
+   * If this is a LOAD_FLAGS_REPLACE_HISTORY in a subframe, we use
+   * the existing SH entry in the page and replace the url and
+   * other vitalities.
+   */
+  if (LOAD_TYPE_HAS_FLAGS(mLoadType, LOAD_FLAGS_REPLACE_HISTORY) &&
+      !mBrowsingContext->IsTop()) {
+    // This is a subframe
+    entry = mOSHE;
+    if (entry) {
+      entry->ClearEntry();
+    }
+  }
+
+  // Create a new entry if necessary.
+  if (!entry) {
+    entry = new nsSHEntry();
+  }
+
+  // Get the post data & referrer
+  nsCOMPtr<nsIInputStream> inputStream;
+  nsCOMPtr<nsIURI> originalURI;
+  nsCOMPtr<nsIURI> resultPrincipalURI;
+  nsCOMPtr<nsIURI> unstrippedURI;
+  bool loadReplace = false;
+  nsCOMPtr<nsIReferrerInfo> referrerInfo;
+  uint32_t cacheKey = 0;
+  nsCOMPtr<nsIPrincipal> triggeringPrincipal = aTriggeringPrincipal;
+  nsCOMPtr<nsIPrincipal> principalToInherit = aPrincipalToInherit;
+  nsCOMPtr<nsIPrincipal> partitionedPrincipalToInherit =
+      aPartitionedPrincipalToInherit;
+  nsCOMPtr<nsIContentSecurityPolicy> csp = aCsp;
+  bool expired = false;  // by default the page is not expired
+  bool discardLayoutState = false;
+  nsCOMPtr<nsICacheInfoChannel> cacheChannel;
+  bool userActivation = false;
+
+  if (aChannel) {
+    cacheChannel = do_QueryInterface(aChannel);
+
+    /* If there is a caching channel, get the Cache Key and store it
+     * in SH.
+     */
+    if (cacheChannel) {
+      cacheChannel->GetCacheKey(&cacheKey);
+    }
+    nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aChannel));
+
+    // Check if the httpChannel is hiding under a multipartChannel
+    if (!httpChannel) {
+      GetHttpChannel(aChannel, getter_AddRefs(httpChannel));
+    }
+    if (httpChannel) {
+      nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(httpChannel));
+      if (uploadChannel) {
+        uploadChannel->GetUploadStream(getter_AddRefs(inputStream));
+      }
+      httpChannel->GetOriginalURI(getter_AddRefs(originalURI));
+      uint32_t loadFlags;
+      aChannel->GetLoadFlags(&loadFlags);
+      loadReplace = loadFlags & nsIChannel::LOAD_REPLACE;
+      rv = httpChannel->GetReferrerInfo(getter_AddRefs(referrerInfo));
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+      discardLayoutState = ShouldDiscardLayoutState(httpChannel);
+    }
+
+    nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
+    if (!triggeringPrincipal) {
+      triggeringPrincipal = loadInfo->TriggeringPrincipal();
+    }
+    if (!csp) {
+      csp = loadInfo->GetCspToInherit();
+    }
+
+    loadInfo->GetResultPrincipalURI(getter_AddRefs(resultPrincipalURI));
+
+    loadInfo->GetUnstrippedURI(getter_AddRefs(unstrippedURI));
+
+    userActivation = loadInfo->GetHasValidUserGestureActivation();
+
+    // For now keep storing just the principal in the SHEntry.
+    if (!principalToInherit) {
+      if (loadInfo->GetLoadingSandboxed()) {
+        if (loadInfo->GetLoadingPrincipal()) {
+          principalToInherit = NullPrincipal::CreateWithInheritedAttributes(
+              loadInfo->GetLoadingPrincipal());
+        } else {
+          // get the OriginAttributes
+          OriginAttributes attrs;
+          loadInfo->GetOriginAttributes(&attrs);
+          principalToInherit = NullPrincipal::Create(attrs);
+        }
+      } else {
+        principalToInherit = loadInfo->PrincipalToInherit();
+      }
+    }
+
+    if (!partitionedPrincipalToInherit) {
+      // XXXehsan is it correct to fall back to the principal to inherit in all
+      // cases?  For example, what about the cases where we are using the load
+      // info's principal to inherit?  Do we need to add a similar concept to
+      // load info for partitioned principal?
+      partitionedPrincipalToInherit = principalToInherit;
+    }
+  }
+
+  nsAutoString srcdoc;
+  bool srcdocEntry = false;
+  nsCOMPtr<nsIURI> baseURI;
+
+  nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(aChannel);
+  if (inStrmChan) {
+    bool isSrcdocChannel;
+    inStrmChan->GetIsSrcdocChannel(&isSrcdocChannel);
+    if (isSrcdocChannel) {
+      inStrmChan->GetSrcdocData(srcdoc);
+      srcdocEntry = true;
+      inStrmChan->GetBaseURI(getter_AddRefs(baseURI));
+    } else {
+      srcdoc.SetIsVoid(true);
+    }
+  }
+  /* If cache got a 'no-store', ask SH not to store
+   * HistoryLayoutState. By default, SH will set this
+   * flag to true and save HistoryLayoutState.
+   */
+  bool saveLayoutState = !discardLayoutState;
+
+  if (cacheChannel) {
+    // Check if the page has expired from cache
+    uint32_t expTime = 0;
+    cacheChannel->GetCacheTokenExpirationTime(&expTime);
+    uint32_t now = PRTimeToSeconds(PR_Now());
+    if (expTime <= now) {
+      expired = true;
+    }
+  }
+
+  // Title is set in nsDocShell::SetTitle()
+  entry->Create(aURI,                 // uri
+                u""_ns,               // Title
+                inputStream,          // Post data stream
+                cacheKey,             // CacheKey
+                mContentTypeHint,     // Content-type
+                triggeringPrincipal,  // Channel or provided principal
+                principalToInherit, partitionedPrincipalToInherit, csp,
+                HistoryID(), GetCreatedDynamically(), originalURI,
+                resultPrincipalURI, unstrippedURI, loadReplace, referrerInfo,
+                srcdoc, srcdocEntry, baseURI, saveLayoutState, expired,
+                userActivation);
+
+  if (mBrowsingContext->IsTop() && GetSessionHistory()) {
+    bool shouldPersist = ShouldAddToSessionHistory(aURI, aChannel);
+    Maybe<int32_t> previousEntryIndex;
+    Maybe<int32_t> loadedEntryIndex;
+    rv = GetSessionHistory()->LegacySHistory()->AddToRootSessionHistory(
+        aCloneChildren, mOSHE, mBrowsingContext, entry, mLoadType,
+        shouldPersist, &previousEntryIndex, &loadedEntryIndex);
+
+    MOZ_ASSERT(NS_SUCCEEDED(rv), "Could not add entry to root session history");
+    if (previousEntryIndex.isSome()) {
+      mPreviousEntryIndex = previousEntryIndex.value();
+    }
+    if (loadedEntryIndex.isSome()) {
+      mLoadedEntryIndex = loadedEntryIndex.value();
+    }
+
+    // aCloneChildren implies that we are retaining the same document, thus we
+    // need to signal to the top WC that the new SHEntry may receive a fresh
+    // user interaction flag.
+    if (aCloneChildren) {
+      WindowContext* topWc = mBrowsingContext->GetTopWindowContext();
+      if (topWc && !topWc->IsDiscarded()) {
+        MOZ_ALWAYS_SUCCEEDS(topWc->SetSHEntryHasUserInteraction(false));
+      }
+    }
+  } else {
+    // This is a subframe, make sure that this new SHEntry will be
+    // marked with user interaction.
+    WindowContext* topWc = mBrowsingContext->GetTopWindowContext();
+    if (topWc && !topWc->IsDiscarded()) {
+      MOZ_ALWAYS_SUCCEEDS(topWc->SetSHEntryHasUserInteraction(false));
+    }
+    if (!mOSHE || !LOAD_TYPE_HAS_FLAGS(mLoadType, LOAD_FLAGS_REPLACE_HISTORY)) {
+      rv = AddChildSHEntryToParent(entry, mBrowsingContext->ChildOffset(),
+                                   aCloneChildren);
+    }
+  }
+
+  // Return the new SH entry...
+  if (aNewEntry) {
+    *aNewEntry = nullptr;
+    if (NS_SUCCEEDED(rv)) {
+      entry.forget(aNewEntry);
+    }
+  }
+
+  return rv;
+}
+
+void nsDocShell::UpdateActiveEntry(
+    bool aReplace, const Maybe<nsPoint>& aPreviousScrollPos, nsIURI* aURI,
+    nsIURI* aOriginalURI, nsIReferrerInfo* aReferrerInfo,
+    nsIPrincipal* aTriggeringPrincipal, nsIContentSecurityPolicy* aCsp,
+    const nsAString& aTitle, bool aScrollRestorationIsManual,
+    nsIStructuredCloneContainer* aData, bool aURIWasModified) {
+  MOZ_ASSERT(mozilla::SessionHistoryInParent());
+  MOZ_ASSERT(aURI, "uri is null");
+  MOZ_ASSERT(mLoadType == LOAD_PUSHSTATE,
+             "This code only deals with pushState");
+  MOZ_ASSERT_IF(aPreviousScrollPos.isSome(), !aReplace);
+
+  MOZ_LOG(gSHLog, LogLevel::Debug,
+          ("Creating an active entry on nsDocShell %p to %s", this,
+           aURI->GetSpecOrDefault().get()));
+
+  // Even if we're replacing an existing entry we create new a
+  // SessionHistoryInfo. In the parent process we'll keep the existing
+  // SessionHistoryEntry, but just replace its SessionHistoryInfo, that way the
+  // entry keeps identity but its data is replaced.
+  bool replace = aReplace && mActiveEntry;
+
+  if (!replace) {
+    CollectWireframe();
+  }
+
+  if (mActiveEntry) {
+    // Link this entry to the previous active entry.
+    mActiveEntry = MakeUnique<SessionHistoryInfo>(*mActiveEntry, aURI);
+  } else {
+    mActiveEntry = MakeUnique<SessionHistoryInfo>(
+        aURI, aTriggeringPrincipal, nullptr, nullptr, aCsp, mContentTypeHint);
+  }
+  mActiveEntry->SetOriginalURI(aOriginalURI);
+  mActiveEntry->SetUnstrippedURI(nullptr);
+  mActiveEntry->SetReferrerInfo(aReferrerInfo);
+  mActiveEntry->SetTitle(aTitle);
+  mActiveEntry->SetStateData(static_cast<nsStructuredCloneContainer*>(aData));
+  mActiveEntry->SetURIWasModified(aURIWasModified);
+  mActiveEntry->SetScrollRestorationIsManual(aScrollRestorationIsManual);
+
+  if (replace) {
+    mBrowsingContext->ReplaceActiveSessionHistoryEntry(mActiveEntry.get());
+  } else {
+    mBrowsingContext->IncrementHistoryEntryCountForBrowsingContext();
+    // FIXME We should probably just compute mChildOffset in the parent
+    //       instead of passing it over IPC here.
+    mBrowsingContext->SetActiveSessionHistoryEntry(
+        aPreviousScrollPos, mActiveEntry.get(), mLoadType,
+        /* aCacheKey = */ 0);
+    // FIXME Do we need to update mPreviousEntryIndex and mLoadedEntryIndex?
+  }
+}
+
+nsresult nsDocShell::LoadHistoryEntry(nsISHEntry* aEntry, uint32_t aLoadType,
+                                      bool aUserActivation) {
+  NS_ENSURE_TRUE(aEntry, NS_ERROR_FAILURE);
+
+  nsresult rv;
+  RefPtr<nsDocShellLoadState> loadState;
+  rv = aEntry->CreateLoadInfo(getter_AddRefs(loadState));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Calling CreateAboutBlankContentViewer can set mOSHE to null, and if
+  // that's the only thing holding a ref to aEntry that will cause aEntry to
+  // die while we're loading it.  So hold a strong ref to aEntry here, just
+  // in case.
+  nsCOMPtr<nsISHEntry> kungFuDeathGrip(aEntry);
+
+  loadState->SetHasValidUserGestureActivation(
+      loadState->HasValidUserGestureActivation() || aUserActivation);
+
+  return LoadHistoryEntry(loadState, aLoadType, aEntry == mOSHE);
+}
+
+nsresult nsDocShell::LoadHistoryEntry(const LoadingSessionHistoryInfo& aEntry,
+                                      uint32_t aLoadType,
+                                      bool aUserActivation) {
+  RefPtr<nsDocShellLoadState> loadState = aEntry.CreateLoadInfo();
+  loadState->SetHasValidUserGestureActivation(
+      loadState->HasValidUserGestureActivation() || aUserActivation);
+
+  return LoadHistoryEntry(loadState, aLoadType, aEntry.mLoadingCurrentEntry);
+}
+
+nsresult nsDocShell::LoadHistoryEntry(nsDocShellLoadState* aLoadState,
+                                      uint32_t aLoadType,
+                                      bool aLoadingCurrentEntry) {
+  if (!IsNavigationAllowed()) {
+    return NS_OK;
+  }
+
+  // We are setting load type afterwards so we don't have to
+  // send it in an IPC message
+  aLoadState->SetLoadType(aLoadType);
+
+  nsresult rv;
+  if (SchemeIsJavascript(aLoadState->URI())) {
+    // We're loading a URL that will execute script from inside asyncOpen.
+    // Replace the current document with about:blank now to prevent
+    // anything from the current document from leaking into any JavaScript
+    // code in the URL.
+    // Don't cache the presentation if we're going to just reload the
+    // current entry. Caching would lead to trying to save the different
+    // content viewers in the same nsISHEntry object.
+    rv = CreateAboutBlankContentViewer(
+        aLoadState->PrincipalToInherit(),
+        aLoadState->PartitionedPrincipalToInherit(), nullptr, nullptr,
+        /* aIsInitialDocument */ false, Nothing(), !aLoadingCurrentEntry);
+
+    if (NS_FAILED(rv)) {
+      // The creation of the intermittent about:blank content
+      // viewer failed for some reason (potentially because the
+      // user prevented it). Interrupt the history load.
+      return NS_OK;
+    }
+
+    if (!aLoadState->TriggeringPrincipal()) {
+      // Ensure that we have a triggeringPrincipal.  Otherwise javascript:
+      // URIs will pick it up from the about:blank page we just loaded,
+      // and we don't really want even that in this case.
+      nsCOMPtr<nsIPrincipal> principal =
+          NullPrincipal::Create(GetOriginAttributes());
+      aLoadState->SetTriggeringPrincipal(principal);
+    }
+  }
+
+  /* If there is a valid postdata *and* the user pressed
+   * reload or shift-reload, take user's permission before we
+   * repost the data to the server.
+   */
+  if ((aLoadType & LOAD_CMD_RELOAD) && aLoadState->PostDataStream()) {
+    bool repost;
+    rv = ConfirmRepost(&repost);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // If the user pressed cancel in the dialog, return.  We're done here.
+    if (!repost) {
+      return NS_BINDING_ABORTED;
+    }
+  }
+
+  // If there is no valid triggeringPrincipal, we deny the load
+  MOZ_ASSERT(aLoadState->TriggeringPrincipal(),
+             "need a valid triggeringPrincipal to load from history");
+  if (!aLoadState->TriggeringPrincipal()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return InternalLoad(aLoadState);  // No nsIRequest
+}
+
+NS_IMETHODIMP
+nsDocShell::PersistLayoutHistoryState() {
+  nsresult rv = NS_OK;
+
+  if (mozilla::SessionHistoryInParent() ? !!mActiveEntry : !!mOSHE) {
+    bool scrollRestorationIsManual;
+    if (mozilla::SessionHistoryInParent()) {
+      scrollRestorationIsManual = mActiveEntry->GetScrollRestorationIsManual();
+    } else {
+      scrollRestorationIsManual = mOSHE->GetScrollRestorationIsManual();
+    }
+    nsCOMPtr<nsILayoutHistoryState> layoutState;
+    if (RefPtr<PresShell> presShell = GetPresShell()) {
+      rv = presShell->CaptureHistoryState(getter_AddRefs(layoutState));
+    } else if (scrollRestorationIsManual) {
+      // Even if we don't have layout anymore, we may want to reset the
+      // current scroll state in layout history.
+      GetLayoutHistoryState(getter_AddRefs(layoutState));
+    }
+
+    if (scrollRestorationIsManual && layoutState) {
+      layoutState->ResetScrollState();
+    }
+  }
+
+  return rv;
+}
+
+void nsDocShell::SwapHistoryEntries(nsISHEntry* aOldEntry,
+                                    nsISHEntry* aNewEntry) {
+  if (aOldEntry == mOSHE) {
+    mOSHE = aNewEntry;
+  }
+
+  if (aOldEntry == mLSHE) {
+    mLSHE = aNewEntry;
+  }
+}
+
+void nsDocShell::SetHistoryEntryAndUpdateBC(const Maybe<nsISHEntry*>& aLSHE,
+                                            const Maybe<nsISHEntry*>& aOSHE) {
+  // We want to hold on to the reference in mLSHE before we update it.
+  // Otherwise, SetHistoryEntry could release the last reference to
+  // the entry while aOSHE is pointing to it.
+  nsCOMPtr<nsISHEntry> deathGripOldLSHE;
+  if (aLSHE.isSome()) {
+    deathGripOldLSHE = SetHistoryEntry(&mLSHE, aLSHE.value());
+    MOZ_ASSERT(mLSHE.get() == aLSHE.value());
+  }
+  nsCOMPtr<nsISHEntry> deathGripOldOSHE;
+  if (aOSHE.isSome()) {
+    deathGripOldOSHE = SetHistoryEntry(&mOSHE, aOSHE.value());
+    MOZ_ASSERT(mOSHE.get() == aOSHE.value());
+  }
+}
+
+already_AddRefed<nsISHEntry> nsDocShell::SetHistoryEntry(
+    nsCOMPtr<nsISHEntry>* aPtr, nsISHEntry* aEntry) {
+  // We need to sync up the docshell and session history trees for
+  // subframe navigation.  If the load was in a subframe, we forward up to
+  // the root docshell, which will then recursively sync up all docshells
+  // to their corresponding entries in the new session history tree.
+  // If we don't do this, then we can cache a content viewer on the wrong
+  // cloned entry, and subsequently restore it at the wrong time.
+  RefPtr<BrowsingContext> topBC = mBrowsingContext->Top();
+  if (topBC->IsDiscarded()) {
+    topBC = nullptr;
+  }
+  RefPtr<BrowsingContext> currBC =
+      mBrowsingContext->IsDiscarded() ? nullptr : mBrowsingContext;
+  if (topBC && *aPtr) {
+    (*aPtr)->SyncTreesForSubframeNavigation(aEntry, topBC, currBC);
+  }
+  nsCOMPtr<nsISHEntry> entry(aEntry);
+  entry.swap(*aPtr);
+  return entry.forget();
+}
+
+already_AddRefed<ChildSHistory> nsDocShell::GetRootSessionHistory() {
+  RefPtr<ChildSHistory> childSHistory =
+      mBrowsingContext->Top()->GetChildSessionHistory();
+  return childSHistory.forget();
+}
+
+nsresult nsDocShell::GetHttpChannel(nsIChannel* aChannel,
+                                    nsIHttpChannel** aReturn) {
+  NS_ENSURE_ARG_POINTER(aReturn);
+  if (!aChannel) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIMultiPartChannel> multiPartChannel(do_QueryInterface(aChannel));
+  if (multiPartChannel) {
+    nsCOMPtr<nsIChannel> baseChannel;
+    multiPartChannel->GetBaseChannel(getter_AddRefs(baseChannel));
+    nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(baseChannel));
+    *aReturn = httpChannel;
+    NS_IF_ADDREF(*aReturn);
+  }
+  return NS_OK;
+}
+
+bool nsDocShell::ShouldDiscardLayoutState(nsIHttpChannel* aChannel) {
+  // By default layout State will be saved.
+  if (!aChannel) {
+    return false;
+  }
+
+  // figure out if SH should be saving layout state
+  bool noStore = false;
+  Unused << aChannel->IsNoStoreResponse(&noStore);
+  return noStore;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetEditor(nsIEditor** aEditor) {
+  NS_ENSURE_ARG_POINTER(aEditor);
+  RefPtr<HTMLEditor> htmlEditor = GetHTMLEditorInternal();
+  htmlEditor.forget(aEditor);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetEditor(nsIEditor* aEditor) {
+  HTMLEditor* htmlEditor = aEditor ? aEditor->GetAsHTMLEditor() : nullptr;
+  // If TextEditor comes, throw an error.
+  if (aEditor && !htmlEditor) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  return SetHTMLEditorInternal(htmlEditor);
+}
+
+HTMLEditor* nsDocShell::GetHTMLEditorInternal() {
+  return mEditorData ? mEditorData->GetHTMLEditor() : nullptr;
+}
+
+nsresult nsDocShell::SetHTMLEditorInternal(HTMLEditor* aHTMLEditor) {
+  if (!aHTMLEditor && !mEditorData) {
+    return NS_OK;
+  }
+
+  nsresult rv = EnsureEditorData();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return mEditorData->SetHTMLEditor(aHTMLEditor);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetEditable(bool* aEditable) {
+  NS_ENSURE_ARG_POINTER(aEditable);
+  *aEditable = mEditorData && mEditorData->GetEditable();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetHasEditingSession(bool* aHasEditingSession) {
+  NS_ENSURE_ARG_POINTER(aHasEditingSession);
+
+  if (mEditorData) {
+    *aHasEditingSession = !!mEditorData->GetEditingSession();
+  } else {
+    *aHasEditingSession = false;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::MakeEditable(bool aInWaitForUriLoad) {
+  nsresult rv = EnsureEditorData();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return mEditorData->MakeEditable(aInWaitForUriLoad);
+}
+
+/* static */ bool nsDocShell::ShouldAddURIVisit(nsIChannel* aChannel) {
+  bool needToAddURIVisit = true;
+  nsCOMPtr<nsIPropertyBag2> props(do_QueryInterface(aChannel));
+  if (props) {
+    mozilla::Unused << props->GetPropertyAsBool(
+        u"docshell.needToAddURIVisit"_ns, &needToAddURIVisit);
+  }
+
+  return needToAddURIVisit;
+}
+
+/* static */ void nsDocShell::ExtractLastVisit(
+    nsIChannel* aChannel, nsIURI** aURI, uint32_t* aChannelRedirectFlags) {
+  nsCOMPtr<nsIPropertyBag2> props(do_QueryInterface(aChannel));
+  if (!props) {
+    return;
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIURI> uri(do_GetProperty(props, u"docshell.previousURI"_ns, &rv));
+  if (NS_SUCCEEDED(rv)) {
+    uri.forget(aURI);
+
+    rv = props->GetPropertyAsUint32(u"docshell.previousFlags"_ns,
+                                    aChannelRedirectFlags);
+
+    NS_WARNING_ASSERTION(
+        NS_SUCCEEDED(rv),
+        "Could not fetch previous flags, URI will be treated like referrer");
+
+  } else {
+    // There is no last visit for this channel, so this must be the first
+    // link.  Link the visit to the referrer of this request, if any.
+    // Treat referrer as null if there is an error getting it.
+    NS_GetReferrerFromChannel(aChannel, aURI);
+  }
+}
+
+void nsDocShell::SaveLastVisit(nsIChannel* aChannel, nsIURI* aURI,
+                               uint32_t aChannelRedirectFlags) {
+  nsCOMPtr<nsIWritablePropertyBag2> props(do_QueryInterface(aChannel));
+  if (!props || !aURI) {
+    return;
+  }
+
+  props->SetPropertyAsInterface(u"docshell.previousURI"_ns, aURI);
+  props->SetPropertyAsUint32(u"docshell.previousFlags"_ns,
+                             aChannelRedirectFlags);
+}
+
+/* static */ void nsDocShell::InternalAddURIVisit(
+    nsIURI* aURI, nsIURI* aPreviousURI, uint32_t aChannelRedirectFlags,
+    uint32_t aResponseStatus, BrowsingContext* aBrowsingContext,
+    nsIWidget* aWidget, uint32_t aLoadType) {
+  MOZ_ASSERT(aURI, "Visited URI is null!");
+  MOZ_ASSERT(aLoadType != LOAD_ERROR_PAGE && aLoadType != LOAD_BYPASS_HISTORY,
+             "Do not add error or bypass pages to global history");
+
+  bool usePrivateBrowsing = false;
+  aBrowsingContext->GetUsePrivateBrowsing(&usePrivateBrowsing);
+
+  // Only content-type docshells save URI visits.  Also don't do
+  // anything here if we're not supposed to use global history.
+  if (!aBrowsingContext->IsContent() ||
+      !aBrowsingContext->GetUseGlobalHistory() || usePrivateBrowsing) {
+    return;
+  }
+
+  nsCOMPtr<IHistory> history = components::History::Service();
+
+  if (history) {
+    uint32_t visitURIFlags = 0;
+
+    if (aBrowsingContext->IsTop()) {
+      visitURIFlags |= IHistory::TOP_LEVEL;
+    }
+
+    if (aChannelRedirectFlags & nsIChannelEventSink::REDIRECT_TEMPORARY) {
+      visitURIFlags |= IHistory::REDIRECT_TEMPORARY;
+    } else if (aChannelRedirectFlags &
+               nsIChannelEventSink::REDIRECT_PERMANENT) {
+      visitURIFlags |= IHistory::REDIRECT_PERMANENT;
+    } else {
+      MOZ_ASSERT(!aChannelRedirectFlags,
+                 "One of REDIRECT_TEMPORARY or REDIRECT_PERMANENT must be set "
+                 "if any flags in aChannelRedirectFlags is set.");
+    }
+
+    if (aResponseStatus >= 300 && aResponseStatus < 400) {
+      visitURIFlags |= IHistory::REDIRECT_SOURCE;
+      if (aResponseStatus == 301 || aResponseStatus == 308) {
+        visitURIFlags |= IHistory::REDIRECT_SOURCE_PERMANENT;
+      }
+    }
+    // Errors 400-501 and 505 are considered unrecoverable, in the sense a
+    // simple retry attempt by the user is unlikely to solve them.
+    // 408 is special cased, since may actually indicate a temporary
+    // connection problem.
+    else if (aResponseStatus != 408 &&
+             ((aResponseStatus >= 400 && aResponseStatus <= 501) ||
+              aResponseStatus == 505)) {
+      visitURIFlags |= IHistory::UNRECOVERABLE_ERROR;
+    }
+
+    mozilla::Unused << history->VisitURI(aWidget, aURI, aPreviousURI,
+                                         visitURIFlags,
+                                         aBrowsingContext->BrowserId());
+  }
+}
+
+void nsDocShell::AddURIVisit(nsIURI* aURI, nsIURI* aPreviousURI,
+                             uint32_t aChannelRedirectFlags,
+                             uint32_t aResponseStatus) {
+  nsPIDOMWindowOuter* outer = GetWindow();
+  nsCOMPtr<nsIWidget> widget = widget::WidgetUtils::DOMWindowToWidget(outer);
+
+  InternalAddURIVisit(aURI, aPreviousURI, aChannelRedirectFlags,
+                      aResponseStatus, mBrowsingContext, widget, mLoadType);
+}
+
+//*****************************************************************************
+// nsDocShell: Helper Routines
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::SetLoadType(uint32_t aLoadType) {
+  mLoadType = aLoadType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetLoadType(uint32_t* aLoadType) {
+  *aLoadType = mLoadType;
+  return NS_OK;
+}
+
+nsresult nsDocShell::ConfirmRepost(bool* aRepost) {
+  if (StaticPrefs::dom_confirm_repost_testing_always_accept()) {
+    *aRepost = true;
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIPromptCollection> prompter =
+      do_GetService("@mozilla.org/embedcomp/prompt-collection;1");
+  if (!prompter) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  return prompter->ConfirmRepost(mBrowsingContext, aRepost);
+}
+
+nsresult nsDocShell::GetPromptAndStringBundle(nsIPrompt** aPrompt,
+                                              nsIStringBundle** aStringBundle) {
+  NS_ENSURE_SUCCESS(GetInterface(NS_GET_IID(nsIPrompt), (void**)aPrompt),
+                    NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIStringBundleService> stringBundleService =
+      mozilla::components::StringBundle::Service();
+  NS_ENSURE_TRUE(stringBundleService, NS_ERROR_FAILURE);
+
+  NS_ENSURE_SUCCESS(
+      stringBundleService->CreateBundle(kAppstringsBundleURL, aStringBundle),
+      NS_ERROR_FAILURE);
+
+  return NS_OK;
+}
+
+nsIScrollableFrame* nsDocShell::GetRootScrollFrame() {
+  PresShell* presShell = GetPresShell();
+  NS_ENSURE_TRUE(presShell, nullptr);
+
+  return presShell->GetRootScrollFrameAsScrollable();
+}
+
+nsresult nsDocShell::EnsureScriptEnvironment() {
+  if (mScriptGlobal) {
+    return NS_OK;
+  }
+
+  if (mIsBeingDestroyed) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+#ifdef DEBUG
+  NS_ASSERTION(!mInEnsureScriptEnv,
+               "Infinite loop! Calling EnsureScriptEnvironment() from "
+               "within EnsureScriptEnvironment()!");
+
+  // Yeah, this isn't re-entrant safe, but that's ok since if we
+  // re-enter this method, we'll infinitely loop...
+  AutoRestore<bool> boolSetter(mInEnsureScriptEnv);
+  mInEnsureScriptEnv = true;
+#endif
+
+  nsCOMPtr<nsIWebBrowserChrome> browserChrome(do_GetInterface(mTreeOwner));
+  NS_ENSURE_TRUE(browserChrome, NS_ERROR_NOT_AVAILABLE);
+
+  uint32_t chromeFlags;
+  browserChrome->GetChromeFlags(&chromeFlags);
+
+  // If our window is modal and we're not opened as chrome, make
+  // this window a modal content window.
+  mScriptGlobal = nsGlobalWindowOuter::Create(this, mItemType == typeChrome);
+  MOZ_ASSERT(mScriptGlobal);
+
+  // Ensure the script object is set up to run script.
+  return mScriptGlobal->EnsureScriptEnvironment();
+}
+
+nsresult nsDocShell::EnsureEditorData() {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+
+  bool openDocHasDetachedEditor = mOSHE && mOSHE->HasDetachedEditor();
+  if (!mEditorData && !mIsBeingDestroyed && !openDocHasDetachedEditor) {
+    // We shouldn't recreate the editor data if it already exists, or
+    // we're shutting down, or we already have a detached editor data
+    // stored in the session history. We should only have one editordata
+    // per docshell.
+    mEditorData = MakeUnique<nsDocShellEditorData>(this);
+  }
+
+  return mEditorData ? NS_OK : NS_ERROR_NOT_AVAILABLE;
+}
+
+nsresult nsDocShell::EnsureFind() {
+  if (!mFind) {
+    mFind = new nsWebBrowserFind();
+  }
+
+  // we promise that the nsIWebBrowserFind that we return has been set
+  // up to point to the focused, or content window, so we have to
+  // set that up each time.
+
+  nsIScriptGlobalObject* scriptGO = GetScriptGlobalObject();
+  NS_ENSURE_TRUE(scriptGO, NS_ERROR_UNEXPECTED);
+
+  // default to our window
+  nsCOMPtr<nsPIDOMWindowOuter> ourWindow = do_QueryInterface(scriptGO);
+  nsCOMPtr<nsPIDOMWindowOuter> windowToSearch;
+  nsFocusManager::GetFocusedDescendant(ourWindow,
+                                       nsFocusManager::eIncludeAllDescendants,
+                                       getter_AddRefs(windowToSearch));
+
+  nsCOMPtr<nsIWebBrowserFindInFrames> findInFrames = do_QueryInterface(mFind);
+  if (!findInFrames) {
+    return NS_ERROR_NO_INTERFACE;
+  }
+
+  nsresult rv = findInFrames->SetRootSearchFrame(ourWindow);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  rv = findInFrames->SetCurrentSearchFrame(windowToSearch);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::IsBeingDestroyed(bool* aDoomed) {
+  NS_ENSURE_ARG(aDoomed);
+  *aDoomed = mIsBeingDestroyed;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetIsExecutingOnLoadHandler(bool* aResult) {
+  NS_ENSURE_ARG(aResult);
+  *aResult = mIsExecutingOnLoadHandler;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetLayoutHistoryState(nsILayoutHistoryState** aLayoutHistoryState) {
+  nsCOMPtr<nsILayoutHistoryState> state;
+  if (mozilla::SessionHistoryInParent()) {
+    if (mActiveEntry) {
+      state = mActiveEntry->GetLayoutHistoryState();
+    }
+  } else {
+    if (mOSHE) {
+      state = mOSHE->GetLayoutHistoryState();
+    }
+  }
+  state.forget(aLayoutHistoryState);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetLayoutHistoryState(nsILayoutHistoryState* aLayoutHistoryState) {
+  if (mOSHE) {
+    mOSHE->SetLayoutHistoryState(aLayoutHistoryState);
+  }
+  if (mActiveEntry) {
+    mActiveEntry->SetLayoutHistoryState(aLayoutHistoryState);
+  }
+  return NS_OK;
+}
+
+nsDocShell::InterfaceRequestorProxy::InterfaceRequestorProxy(
+    nsIInterfaceRequestor* aRequestor) {
+  if (aRequestor) {
+    mWeakPtr = do_GetWeakReference(aRequestor);
+  }
+}
+
+nsDocShell::InterfaceRequestorProxy::~InterfaceRequestorProxy() {
+  mWeakPtr = nullptr;
+}
+
+NS_IMPL_ISUPPORTS(nsDocShell::InterfaceRequestorProxy, nsIInterfaceRequestor)
+
+NS_IMETHODIMP
+nsDocShell::InterfaceRequestorProxy::GetInterface(const nsIID& aIID,
+                                                  void** aSink) {
+  NS_ENSURE_ARG_POINTER(aSink);
+  nsCOMPtr<nsIInterfaceRequestor> ifReq = do_QueryReferent(mWeakPtr);
+  if (ifReq) {
+    return ifReq->GetInterface(aIID, aSink);
+  }
+  *aSink = nullptr;
+  return NS_NOINTERFACE;
+}
+
+//*****************************************************************************
+// nsDocShell::nsIAuthPromptProvider
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::GetAuthPrompt(uint32_t aPromptReason, const nsIID& aIID,
+                          void** aResult) {
+  // a priority prompt request will override a false mAllowAuth setting
+  bool priorityPrompt = (aPromptReason == PROMPT_PROXY);
+
+  if (!mAllowAuth && !priorityPrompt) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // we're either allowing auth, or it's a proxy request
+  nsresult rv;
+  nsCOMPtr<nsIPromptFactory> wwatch =
+      do_GetService(NS_WINDOWWATCHER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = EnsureScriptEnvironment();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Get the an auth prompter for our window so that the parenting
+  // of the dialogs works as it should when using tabs.
+
+  return wwatch->GetPrompt(mScriptGlobal, aIID,
+                           reinterpret_cast<void**>(aResult));
+}
+
+//*****************************************************************************
+// nsDocShell::nsILoadContext
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsDocShell::GetAssociatedWindow(mozIDOMWindowProxy** aWindow) {
+  CallGetInterface(this, aWindow);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetTopWindow(mozIDOMWindowProxy** aWindow) {
+  return mBrowsingContext->GetTopWindow(aWindow);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetTopFrameElement(Element** aElement) {
+  return mBrowsingContext->GetTopFrameElement(aElement);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetUseTrackingProtection(bool* aUseTrackingProtection) {
+  return mBrowsingContext->GetUseTrackingProtection(aUseTrackingProtection);
+}
+
+NS_IMETHODIMP
+nsDocShell::SetUseTrackingProtection(bool aUseTrackingProtection) {
+  return mBrowsingContext->SetUseTrackingProtection(aUseTrackingProtection);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetIsContent(bool* aIsContent) {
+  *aIsContent = (mItemType == typeContent);
+  return NS_OK;
+}
+
+bool nsDocShell::IsOKToLoadURI(nsIURI* aURI) {
+  MOZ_ASSERT(aURI, "Must have a URI!");
+
+  if (!mFiredUnloadEvent) {
+    return true;
+  }
+
+  if (!mLoadingURI) {
+    return false;
+  }
+
+  bool isPrivateWin = false;
+  Document* doc = GetDocument();
+  if (doc) {
+    isPrivateWin =
+        doc->NodePrincipal()->OriginAttributesRef().mPrivateBrowsingId > 0;
+  }
+
+  nsCOMPtr<nsIScriptSecurityManager> secMan =
+      do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID);
+  return secMan && NS_SUCCEEDED(secMan->CheckSameOriginURI(
+                       aURI, mLoadingURI, false, isPrivateWin));
+}
+
+//
+// Routines for selection and clipboard
+//
+nsresult nsDocShell::GetControllerForCommand(const char* aCommand,
+                                             nsIController** aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = nullptr;
+
+  NS_ENSURE_TRUE(mScriptGlobal, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsPIWindowRoot> root = mScriptGlobal->GetTopWindowRoot();
+  NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
+
+  return root->GetControllerForCommand(aCommand, false /* for any window */,
+                                       aResult);
+}
+
+NS_IMETHODIMP
+nsDocShell::IsCommandEnabled(const char* aCommand, bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = false;
+
+  nsresult rv = NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIController> controller;
+  rv = GetControllerForCommand(aCommand, getter_AddRefs(controller));
+  if (controller) {
+    rv = controller->IsCommandEnabled(aCommand, aResult);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocShell::DoCommand(const char* aCommand) {
+  nsresult rv = NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIController> controller;
+  rv = GetControllerForCommand(aCommand, getter_AddRefs(controller));
+  if (controller) {
+    rv = controller->DoCommand(aCommand);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocShell::DoCommandWithParams(const char* aCommand,
+                                nsICommandParams* aParams) {
+  nsCOMPtr<nsIController> controller;
+  nsresult rv = GetControllerForCommand(aCommand, getter_AddRefs(controller));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsICommandController> commandController =
+      do_QueryInterface(controller, &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return commandController->DoCommandWithParams(aCommand, aParams);
+}
+
+nsresult nsDocShell::EnsureCommandHandler() {
+  if (!mCommandManager) {
+    if (nsCOMPtr<nsPIDOMWindowOuter> domWindow = GetWindow()) {
+      mCommandManager = new nsCommandManager(domWindow);
+    }
+  }
+  return mCommandManager ? NS_OK : NS_ERROR_FAILURE;
+}
+
+// link handling
+
+class OnLinkClickEvent : public Runnable {
+ public:
+  OnLinkClickEvent(nsDocShell* aHandler, nsIContent* aContent,
+                   nsDocShellLoadState* aLoadState, bool aNoOpenerImplied,
+                   bool aIsTrusted, nsIPrincipal* aTriggeringPrincipal);
+
+  NS_IMETHOD Run() override {
+    AutoPopupStatePusher popupStatePusher(mPopupState);
+
+    // We need to set up an AutoJSAPI here for the following reason: When we
+    // do OnLinkClickSync we'll eventually end up in
+    // nsGlobalWindow::OpenInternal which only does popup blocking if
+    // !LegacyIsCallerChromeOrNativeCode(). So we need to fake things so that
+    // we don't look like native code as far as LegacyIsCallerNativeCode() is
+    // concerned.
+    AutoJSAPI jsapi;
+    if (mIsTrusted || jsapi.Init(mContent->OwnerDoc()->GetScopeObject())) {
+      mHandler->OnLinkClickSync(mContent, mLoadState, mNoOpenerImplied,
+                                mTriggeringPrincipal);
+    }
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsDocShell> mHandler;
+  nsCOMPtr<nsIContent> mContent;
+  RefPtr<nsDocShellLoadState> mLoadState;
+  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+  PopupBlocker::PopupControlState mPopupState;
+  bool mNoOpenerImplied;
+  bool mIsTrusted;
+};
+
+OnLinkClickEvent::OnLinkClickEvent(nsDocShell* aHandler, nsIContent* aContent,
+                                   nsDocShellLoadState* aLoadState,
+                                   bool aNoOpenerImplied, bool aIsTrusted,
+                                   nsIPrincipal* aTriggeringPrincipal)
+    : mozilla::Runnable("OnLinkClickEvent"),
+      mHandler(aHandler),
+      mContent(aContent),
+      mLoadState(aLoadState),
+      mTriggeringPrincipal(aTriggeringPrincipal),
+      mPopupState(PopupBlocker::GetPopupControlState()),
+      mNoOpenerImplied(aNoOpenerImplied),
+      mIsTrusted(aIsTrusted) {}
+
+nsresult nsDocShell::OnLinkClick(
+    nsIContent* aContent, nsIURI* aURI, const nsAString& aTargetSpec,
+    const nsAString& aFileName, nsIInputStream* aPostDataStream,
+    nsIInputStream* aHeadersDataStream, bool aIsUserTriggered, bool aIsTrusted,
+    nsIPrincipal* aTriggeringPrincipal, nsIContentSecurityPolicy* aCsp) {
+#ifndef ANDROID
+  MOZ_ASSERT(aTriggeringPrincipal, "Need a valid triggeringPrincipal");
+#endif
+  NS_ASSERTION(NS_IsMainThread(), "wrong thread");
+
+  if (!IsNavigationAllowed() || !IsOKToLoadURI(aURI)) {
+    return NS_OK;
+  }
+
+  // On history navigation through Back/Forward buttons, don't execute
+  // automatic JavaScript redirection such as |anchorElement.click()| or
+  // |formElement.submit()|.
+  //
+  // XXX |formElement.submit()| bypasses this checkpoint because it calls
+  //     nsDocShell::OnLinkClickSync(...) instead.
+  if (ShouldBlockLoadingForBackButton()) {
+    return NS_OK;
+  }
+
+  if (aContent->IsEditable()) {
+    return NS_OK;
+  }
+
+  Document* ownerDoc = aContent->OwnerDoc();
+  if (nsContentUtils::IsExternalProtocol(aURI)) {
+    ownerDoc->EnsureNotEnteringAndExitFullscreen();
+  }
+
+  bool noOpenerImplied = false;
+  nsAutoString target(aTargetSpec);
+  if (aFileName.IsVoid() &&
+      ShouldOpenInBlankTarget(aTargetSpec, aURI, aContent, aIsUserTriggered)) {
+    target = u"_blank";
+    if (!aTargetSpec.Equals(target)) {
+      noOpenerImplied = true;
+    }
+  }
+
+  RefPtr<nsDocShellLoadState> loadState = new nsDocShellLoadState(aURI);
+  loadState->SetTarget(target);
+  loadState->SetFileName(aFileName);
+  loadState->SetPostDataStream(aPostDataStream);
+  loadState->SetHeadersStream(aHeadersDataStream);
+  loadState->SetFirstParty(true);
+  loadState->SetTriggeringPrincipal(
+      aTriggeringPrincipal ? aTriggeringPrincipal : aContent->NodePrincipal());
+  loadState->SetPrincipalToInherit(aContent->NodePrincipal());
+  loadState->SetCsp(aCsp ? aCsp : aContent->GetCsp());
+  loadState->SetAllowFocusMove(UserActivation::IsHandlingUserInput());
+
+  nsCOMPtr<nsIRunnable> ev =
+      new OnLinkClickEvent(this, aContent, loadState, noOpenerImplied,
+                           aIsTrusted, aTriggeringPrincipal);
+  return Dispatch(TaskCategory::UI, ev.forget());
+}
+
+bool nsDocShell::ShouldOpenInBlankTarget(const nsAString& aOriginalTarget,
+                                         nsIURI* aLinkURI, nsIContent* aContent,
+                                         bool aIsUserTriggered) {
+  if (net::SchemeIsJavascript(aLinkURI)) {
+    return false;
+  }
+
+  // External links from within app tabs should always open in new tabs
+  // instead of replacing the app tab's page (Bug 575561)
+  // nsIURI.host can throw for non-nsStandardURL nsIURIs. If we fail to
+  // get either host, just return false to use the original target.
+  nsAutoCString linkHost;
+  if (NS_FAILED(aLinkURI->GetHost(linkHost))) {
+    return false;
+  }
+
+  // The targetTopLevelLinkClicksToBlank property on BrowsingContext allows
+  // privileged code to change the default targeting behaviour. In particular,
+  // if a user-initiated link click for the (or targetting the) top-level frame
+  // is detected, we default the target to "_blank" to give it a new
+  // top-level BrowsingContext.
+  if (mBrowsingContext->TargetTopLevelLinkClicksToBlank() && aIsUserTriggered &&
+      ((aOriginalTarget.IsEmpty() && mBrowsingContext->IsTop()) ||
+       aOriginalTarget == u"_top"_ns)) {
+    return true;
+  }
+
+  // Don't modify non-default targets.
+  if (!aOriginalTarget.IsEmpty()) {
+    return false;
+  }
+
+  // Only check targets that are in extension panels or app tabs.
+  // (isAppTab will be false for app tab subframes).
+  nsString mmGroup = mBrowsingContext->Top()->GetMessageManagerGroup();
+  if (!mmGroup.EqualsLiteral("webext-browsers") &&
+      !mBrowsingContext->IsAppTab()) {
+    return false;
+  }
+
+  nsCOMPtr<nsIURI> docURI = aContent->OwnerDoc()->GetDocumentURIObject();
+  if (!docURI) {
+    return false;
+  }
+
+  nsAutoCString docHost;
+  if (NS_FAILED(docURI->GetHost(docHost))) {
+    return false;
+  }
+
+  if (linkHost.Equals(docHost)) {
+    return false;
+  }
+
+  // Special case: ignore "www" prefix if it is part of host string
+  return linkHost.Length() < docHost.Length()
+             ? !docHost.Equals("www."_ns + linkHost)
+             : !linkHost.Equals("www."_ns + docHost);
+}
+
+static bool ElementCanHaveNoopener(nsIContent* aContent) {
+  // Make sure we are dealing with either an <A>, <AREA>, or <FORM> element in
+  // the HTML, XHTML, or SVG namespace.
+  return aContent->IsAnyOfHTMLElements(nsGkAtoms::a, nsGkAtoms::area,
+                                       nsGkAtoms::form) ||
+         aContent->IsSVGElement(nsGkAtoms::a);
+}
+
+nsresult nsDocShell::OnLinkClickSync(nsIContent* aContent,
+                                     nsDocShellLoadState* aLoadState,
+                                     bool aNoOpenerImplied,
+                                     nsIPrincipal* aTriggeringPrincipal) {
+  if (!IsNavigationAllowed() || !IsOKToLoadURI(aLoadState->URI())) {
+    return NS_OK;
+  }
+
+  // XXX When the linking node was HTMLFormElement, it is synchronous event.
+  //     That is, the caller of this method is not |OnLinkClickEvent::Run()|
+  //     but |HTMLFormElement::SubmitSubmission(...)|.
+  if (aContent->IsHTMLElement(nsGkAtoms::form) &&
+      ShouldBlockLoadingForBackButton()) {
+    return NS_OK;
+  }
+
+  if (aContent->IsEditable()) {
+    return NS_OK;
+  }
+
+  // if the triggeringPrincipal is not passed explicitly, then we
+  // fall back to using doc->NodePrincipal() as the triggeringPrincipal.
+  nsCOMPtr<nsIPrincipal> triggeringPrincipal =
+      aTriggeringPrincipal ? aTriggeringPrincipal : aContent->NodePrincipal();
+
+  {
+    // defer to an external protocol handler if necessary...
+    nsCOMPtr<nsIExternalProtocolService> extProtService =
+        do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID);
+    if (extProtService) {
+      nsAutoCString scheme;
+      aLoadState->URI()->GetScheme(scheme);
+      if (!scheme.IsEmpty()) {
+        // if the URL scheme does not correspond to an exposed protocol, then
+        // we need to hand this link click over to the external protocol
+        // handler.
+        bool isExposed;
+        nsresult rv =
+            extProtService->IsExposedProtocol(scheme.get(), &isExposed);
+        if (NS_SUCCEEDED(rv) && !isExposed) {
+          return extProtService->LoadURI(
+              aLoadState->URI(), triggeringPrincipal, nullptr, mBrowsingContext,
+              /* aTriggeredExternally */
+              false,
+              /* aHasValidUserGestureActivation */
+              aContent->OwnerDoc()->HasValidTransientUserGestureActivation());
+        }
+      }
+    }
+  }
+  uint32_t triggeringSandboxFlags = 0;
+  if (mBrowsingContext) {
+    triggeringSandboxFlags = aContent->OwnerDoc()->GetSandboxFlags();
+  }
+
+  uint32_t flags = INTERNAL_LOAD_FLAGS_NONE;
+  bool elementCanHaveNoopener = ElementCanHaveNoopener(aContent);
+  bool triggeringPrincipalIsSystemPrincipal =
+      aLoadState->TriggeringPrincipal()->IsSystemPrincipal();
+  if (elementCanHaveNoopener) {
+    MOZ_ASSERT(aContent->IsHTMLElement() || aContent->IsSVGElement());
+    nsAutoString relString;
+    aContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::rel,
+                                   relString);
+    nsWhitespaceTokenizerTemplate<nsContentUtils::IsHTMLWhitespace> tok(
+        relString);
+
+    bool targetBlank = aLoadState->Target().LowerCaseEqualsLiteral("_blank");
+    bool explicitOpenerSet = false;
+
+    // The opener behaviour follows a hierarchy, such that if a higher
+    // priority behaviour is specified, it always takes priority. That
+    // priority is currently: norefrerer > noopener > opener > default
+
+    while (tok.hasMoreTokens()) {
+      const nsAString& token = tok.nextToken();
+      if (token.LowerCaseEqualsLiteral("noreferrer")) {
+        flags |= INTERNAL_LOAD_FLAGS_DONT_SEND_REFERRER |
+                 INTERNAL_LOAD_FLAGS_NO_OPENER;
+        // noreferrer cannot be overwritten by a 'rel=opener'.
+        explicitOpenerSet = true;
+        break;
+      }
+
+      if (token.LowerCaseEqualsLiteral("noopener")) {
+        flags |= INTERNAL_LOAD_FLAGS_NO_OPENER;
+        explicitOpenerSet = true;
+      }
+
+      if (targetBlank && StaticPrefs::dom_targetBlankNoOpener_enabled() &&
+          token.LowerCaseEqualsLiteral("opener") && !explicitOpenerSet) {
+        explicitOpenerSet = true;
+      }
+    }
+
+    if (targetBlank && StaticPrefs::dom_targetBlankNoOpener_enabled() &&
+        !explicitOpenerSet && !triggeringPrincipalIsSystemPrincipal) {
+      flags |= INTERNAL_LOAD_FLAGS_NO_OPENER;
+    }
+
+    if (aNoOpenerImplied) {
+      flags |= INTERNAL_LOAD_FLAGS_NO_OPENER;
+    }
+  }
+
+  // Get the owner document of the link that was clicked, this will be
+  // the document that the link is in, or the last document that the
+  // link was in. From that document, we'll get the URI to use as the
+  // referrer, since the current URI in this docshell may be a
+  // new document that we're in the process of loading.
+  RefPtr<Document> referrerDoc = aContent->OwnerDoc();
+
+  // Now check that the referrerDoc's inner window is the current inner
+  // window for mScriptGlobal.  If it's not, then we don't want to
+  // follow this link.
+  nsPIDOMWindowInner* referrerInner = referrerDoc->GetInnerWindow();
+  if (!mScriptGlobal || !referrerInner ||
+      mScriptGlobal->GetCurrentInnerWindow() != referrerInner) {
+    // We're no longer the current inner window
+    return NS_OK;
+  }
+
+  // referrer could be null here in some odd cases, but that's ok,
+  // we'll just load the link w/o sending a referrer in those cases.
+
+  // If this is an anchor element, grab its type property to use as a hint
+  nsAutoString typeHint;
+  RefPtr<HTMLAnchorElement> anchor = HTMLAnchorElement::FromNode(aContent);
+  if (anchor) {
+    anchor->GetType(typeHint);
+    NS_ConvertUTF16toUTF8 utf8Hint(typeHint);
+    nsAutoCString type, dummy;
+    NS_ParseRequestContentType(utf8Hint, type, dummy);
+    CopyUTF8toUTF16(type, typeHint);
+  }
+
+  // Link click (or form submission) can be triggered inside an onload
+  // handler, and we don't want to add history entry in this case.
+  bool inOnLoadHandler = false;
+  GetIsExecutingOnLoadHandler(&inOnLoadHandler);
+  uint32_t loadType = inOnLoadHandler ? LOAD_NORMAL_REPLACE : LOAD_LINK;
+
+  nsCOMPtr<nsIReferrerInfo> referrerInfo =
+      elementCanHaveNoopener ? new ReferrerInfo(*aContent->AsElement())
+                             : new ReferrerInfo(*referrerDoc);
+  RefPtr<WindowContext> context = mBrowsingContext->GetCurrentWindowContext();
+
+  aLoadState->SetTriggeringSandboxFlags(triggeringSandboxFlags);
+  aLoadState->SetReferrerInfo(referrerInfo);
+  aLoadState->SetInternalLoadFlags(flags);
+  aLoadState->SetTypeHint(NS_ConvertUTF16toUTF8(typeHint));
+  aLoadState->SetLoadType(loadType);
+  aLoadState->SetSourceBrowsingContext(mBrowsingContext);
+  aLoadState->SetHasValidUserGestureActivation(
+      context && context->HasValidTransientUserGestureActivation());
+
+  nsresult rv = InternalLoad(aLoadState);
+
+  if (NS_SUCCEEDED(rv)) {
+    nsPingListener::DispatchPings(this, aContent, aLoadState->URI(),
+                                  referrerInfo);
+  }
+
+  return rv;
+}
+
+nsresult nsDocShell::OnOverLink(nsIContent* aContent, nsIURI* aURI,
+                                const nsAString& aTargetSpec) {
+  if (aContent->IsEditable()) {
+    return NS_OK;
+  }
+
+  nsresult rv = NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIWebBrowserChrome> browserChrome = do_GetInterface(mTreeOwner);
+  if (!browserChrome) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIURI> exposableURI = nsIOService::CreateExposableURI(aURI);
+  nsAutoCString spec;
+  rv = exposableURI->GetDisplaySpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ConvertUTF8toUTF16 uStr(spec);
+
+  PredictorPredict(aURI, mCurrentURI, nsINetworkPredictor::PREDICT_LINK,
+                   aContent->NodePrincipal()->OriginAttributesRef(), nullptr);
+
+  rv = browserChrome->SetLinkStatus(uStr);
+  return rv;
+}
+
+nsresult nsDocShell::OnLeaveLink() {
+  nsCOMPtr<nsIWebBrowserChrome> browserChrome(do_GetInterface(mTreeOwner));
+  nsresult rv = NS_ERROR_FAILURE;
+
+  if (browserChrome) {
+    rv = browserChrome->SetLinkStatus(u""_ns);
+  }
+  return rv;
+}
+
+bool nsDocShell::ShouldBlockLoadingForBackButton() {
+  if (!(mLoadType & LOAD_CMD_HISTORY) ||
+      UserActivation::IsHandlingUserInput() ||
+      !Preferences::GetBool("accessibility.blockjsredirection")) {
+    return false;
+  }
+
+  bool canGoForward = false;
+  GetCanGoForward(&canGoForward);
+  return canGoForward;
+}
+
+bool nsDocShell::PluginsAllowedInCurrentDoc() {
+  if (!mContentViewer) {
+    return false;
+  }
+
+  Document* doc = mContentViewer->GetDocument();
+  if (!doc) {
+    return false;
+  }
+
+  return doc->GetAllowPlugins();
+}
+
+//----------------------------------------------------------------------
+// Web Shell Services API
+
+// This functions is only called when a new charset is detected in loading a
+// document.
+nsresult nsDocShell::CharsetChangeReloadDocument(
+    mozilla::NotNull<const mozilla::Encoding*> aEncoding, int32_t aSource) {
+  // XXX hack. keep the aCharset and aSource wait to pick it up
+  nsCOMPtr<nsIContentViewer> cv;
+  NS_ENSURE_SUCCESS(GetContentViewer(getter_AddRefs(cv)), NS_ERROR_FAILURE);
+  if (cv) {
+    int32_t source;
+    Unused << cv->GetReloadEncodingAndSource(&source);
+    if (aSource > source) {
+      cv->SetReloadEncodingAndSource(aEncoding, aSource);
+      if (eCharsetReloadRequested != mCharsetReloadState) {
+        mCharsetReloadState = eCharsetReloadRequested;
+        switch (mLoadType) {
+          case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
+            return Reload(LOAD_FLAGS_CHARSET_CHANGE | LOAD_FLAGS_BYPASS_CACHE |
+                          LOAD_FLAGS_BYPASS_PROXY);
+          case LOAD_RELOAD_BYPASS_CACHE:
+            return Reload(LOAD_FLAGS_CHARSET_CHANGE | LOAD_FLAGS_BYPASS_CACHE);
+          default:
+            return Reload(LOAD_FLAGS_CHARSET_CHANGE);
+        }
+      }
+    }
+  }
+  // return failure if this request is not accepted due to mCharsetReloadState
+  return NS_ERROR_DOCSHELL_REQUEST_REJECTED;
+}
+
+nsresult nsDocShell::CharsetChangeStopDocumentLoad() {
+  if (eCharsetReloadRequested != mCharsetReloadState) {
+    Stop(nsIWebNavigation::STOP_ALL);
+    return NS_OK;
+  }
+  // return failer if this request is not accepted due to mCharsetReloadState
+  return NS_ERROR_DOCSHELL_REQUEST_REJECTED;
+}
+
+NS_IMETHODIMP nsDocShell::ExitPrintPreview() {
+#if NS_PRINT_PREVIEW
+  nsCOMPtr<nsIWebBrowserPrint> viewer = do_QueryInterface(mContentViewer);
+  return viewer->ExitPrintPreview();
+#else
+  return NS_OK;
+#endif
+}
+
+/* [infallible] */
+NS_IMETHODIMP nsDocShell::GetIsTopLevelContentDocShell(
+    bool* aIsTopLevelContentDocShell) {
+  *aIsTopLevelContentDocShell = false;
+
+  if (mItemType == typeContent) {
+    *aIsTopLevelContentDocShell = mBrowsingContext->IsTopContent();
+  }
+
+  return NS_OK;
+}
+
+// Implements nsILoadContext.originAttributes
+NS_IMETHODIMP
+nsDocShell::GetScriptableOriginAttributes(JSContext* aCx,
+                                          JS::MutableHandle<JS::Value> aVal) {
+  return mBrowsingContext->GetScriptableOriginAttributes(aCx, aVal);
+}
+
+// Implements nsIDocShell.GetOriginAttributes()
+NS_IMETHODIMP
+nsDocShell::GetOriginAttributes(JSContext* aCx,
+                                JS::MutableHandle<JS::Value> aVal) {
+  return mBrowsingContext->GetScriptableOriginAttributes(aCx, aVal);
+}
+
+bool nsDocShell::ServiceWorkerAllowedToControlWindow(nsIPrincipal* aPrincipal,
+                                                     nsIURI* aURI) {
+  MOZ_ASSERT(aPrincipal);
+  MOZ_ASSERT(aURI);
+
+  if (UsePrivateBrowsing() || mBrowsingContext->GetSandboxFlags()) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> parent;
+  GetInProcessSameTypeParent(getter_AddRefs(parent));
+  nsPIDOMWindowOuter* parentOuter = parent ? parent->GetWindow() : nullptr;
+  nsPIDOMWindowInner* parentInner =
+      parentOuter ? parentOuter->GetCurrentInnerWindow() : nullptr;
+
+  StorageAccess storage =
+      StorageAllowedForNewWindow(aPrincipal, aURI, parentInner);
+
+  // If the partitioned service worker is enabled, service worker is allowed to
+  // control the window if partition is enabled.
+  if (StaticPrefs::privacy_partition_serviceWorkers() && parentInner) {
+    RefPtr<Document> doc = parentInner->GetExtantDoc();
+
+    if (doc && StoragePartitioningEnabled(storage, doc->CookieJarSettings())) {
+      return true;
+    }
+  }
+
+  return storage == StorageAccess::eAllow;
+}
+
+nsresult nsDocShell::SetOriginAttributes(const OriginAttributes& aAttrs) {
+  MOZ_ASSERT(!mIsBeingDestroyed);
+  return mBrowsingContext->SetOriginAttributes(aAttrs);
+}
+
+NS_IMETHODIMP
+nsDocShell::ResumeRedirectedLoad(uint64_t aIdentifier, int32_t aHistoryIndex) {
+  RefPtr<nsDocShell> self = this;
+  RefPtr<ChildProcessChannelListener> cpcl =
+      ChildProcessChannelListener::GetSingleton();
+
+  // Call into InternalLoad with the pending channel when it is received.
+  cpcl->RegisterCallback(
+      aIdentifier, [self, aHistoryIndex](
+                       nsDocShellLoadState* aLoadState,
+                       nsTArray<Endpoint<extensions::PStreamFilterParent>>&&
+                           aStreamFilterEndpoints,
+                       nsDOMNavigationTiming* aTiming) {
+        MOZ_ASSERT(aLoadState->GetPendingRedirectedChannel());
+        if (NS_WARN_IF(self->mIsBeingDestroyed)) {
+          aLoadState->GetPendingRedirectedChannel()->CancelWithReason(
+              NS_BINDING_ABORTED, "nsDocShell::mIsBeingDestroyed"_ns);
+          return NS_BINDING_ABORTED;
+        }
+
+        self->mLoadType = aLoadState->LoadType();
+        nsCOMPtr<nsIURI> previousURI;
+        uint32_t previousFlags = 0;
+        ExtractLastVisit(aLoadState->GetPendingRedirectedChannel(),
+                         getter_AddRefs(previousURI), &previousFlags);
+        self->SaveLastVisit(aLoadState->GetPendingRedirectedChannel(),
+                            previousURI, previousFlags);
+
+        if (aTiming) {
+          self->mTiming = new nsDOMNavigationTiming(self, aTiming);
+          self->mBlankTiming = false;
+        }
+
+        // If we're performing a history load, locate the correct history entry,
+        // and set the relevant bits on our loadState.
+        if (aHistoryIndex >= 0 && self->GetSessionHistory() &&
+            !mozilla::SessionHistoryInParent()) {
+          nsCOMPtr<nsISHistory> legacySHistory =
+              self->GetSessionHistory()->LegacySHistory();
+
+          nsCOMPtr<nsISHEntry> entry;
+          nsresult rv = legacySHistory->GetEntryAtIndex(aHistoryIndex,
+                                                        getter_AddRefs(entry));
+          if (NS_SUCCEEDED(rv)) {
+            legacySHistory->InternalSetRequestedIndex(aHistoryIndex);
+            aLoadState->SetLoadType(LOAD_HISTORY);
+            aLoadState->SetSHEntry(entry);
+          }
+        }
+
+        self->InternalLoad(aLoadState);
+
+        if (aLoadState->GetOriginalURIString().isSome()) {
+          // Save URI string in case it's needed later when
+          // sending to search engine service in EndPageLoad()
+          self->mOriginalUriString = *aLoadState->GetOriginalURIString();
+        }
+
+        for (auto& endpoint : aStreamFilterEndpoints) {
+          extensions::StreamFilterParent::Attach(
+              aLoadState->GetPendingRedirectedChannel(), std::move(endpoint));
+        }
+
+        // If the channel isn't pending, then it means that InternalLoad
+        // never connected it, and we shouldn't try to continue. This
+        // can happen even if InternalLoad returned NS_OK.
+        bool pending = false;
+        aLoadState->GetPendingRedirectedChannel()->IsPending(&pending);
+        NS_ASSERTION(pending, "We should have connected the pending channel!");
+        if (!pending) {
+          return NS_BINDING_ABORTED;
+        }
+        return NS_OK;
+      });
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::SetOriginAttributes(JS::Handle<JS::Value> aOriginAttributes,
+                                JSContext* aCx) {
+  OriginAttributes attrs;
+  if (!aOriginAttributes.isObject() || !attrs.Init(aCx, aOriginAttributes)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return SetOriginAttributes(attrs);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetAsyncPanZoomEnabled(bool* aOut) {
+  if (PresShell* presShell = GetPresShell()) {
+    *aOut = presShell->AsyncPanZoomEnabled();
+    return NS_OK;
+  }
+
+  // If we don't have a presShell, fall back to the default platform value of
+  // whether or not APZ is enabled.
+  *aOut = gfxPlatform::AsyncPanZoomEnabled();
+  return NS_OK;
+}
+
+bool nsDocShell::HasUnloadedParent() {
+  for (WindowContext* wc = GetBrowsingContext()->GetParentWindowContext(); wc;
+       wc = wc->GetParentWindowContext()) {
+    if (!wc->IsCurrent() || wc->IsDiscarded() ||
+        wc->GetBrowsingContext()->IsDiscarded()) {
+      // If a parent is OOP and the parent WindowContext is no
+      // longer current, we can assume the parent was unloaded.
+      return true;
+    }
+
+    if (wc->GetBrowsingContext()->IsInProcess() &&
+        (!wc->GetBrowsingContext()->GetDocShell() ||
+         wc->GetBrowsingContext()->GetDocShell()->GetIsInUnload())) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/* static */
+bool nsDocShell::ShouldUpdateGlobalHistory(uint32_t aLoadType) {
+  return !(aLoadType == LOAD_BYPASS_HISTORY || aLoadType == LOAD_ERROR_PAGE ||
+           aLoadType & LOAD_CMD_HISTORY);
+}
+
+void nsDocShell::UpdateGlobalHistoryTitle(nsIURI* aURI) {
+  if (!mBrowsingContext->GetUseGlobalHistory() || UsePrivateBrowsing()) {
+    return;
+  }
+
+  // Global history is interested into sub-frame visits only for link-coloring
+  // purposes, thus title updates are skipped for those.
+  //
+  // Moreover, some iframe documents (such as the ones created via
+  // document.open()) inherit the document uri of the caller, which would cause
+  // us to override a previously set page title with one from the subframe.
+  if (IsSubframe()) {
+    return;
+  }
+
+  if (nsCOMPtr<IHistory> history = components::History::Service()) {
+    history->SetURITitle(aURI, mTitle);
+  }
+}
+
+bool nsDocShell::IsInvisible() { return mInvisible; }
+
+void nsDocShell::SetInvisible(bool aInvisible) { mInvisible = aInvisible; }
+
+// The caller owns |aAsyncCause| here.
+void nsDocShell::NotifyJSRunToCompletionStart(const char* aReason,
+                                              const nsAString& aFunctionName,
+                                              const nsAString& aFilename,
+                                              const uint32_t aLineNumber,
+                                              JS::Handle<JS::Value> aAsyncStack,
+                                              const char* aAsyncCause) {
+  // If first start, mark interval start.
+  if (mJSRunToCompletionDepth == 0 && TimelineConsumers::HasConsumer(this)) {
+    TimelineConsumers::AddMarkerForDocShell(
+        this, mozilla::MakeUnique<JavascriptTimelineMarker>(
+                  aReason, aFunctionName, aFilename, aLineNumber,
+                  MarkerTracingType::START, aAsyncStack, aAsyncCause));
+  }
+
+  mJSRunToCompletionDepth++;
+}
+
+void nsDocShell::NotifyJSRunToCompletionStop() {
+  mJSRunToCompletionDepth--;
+
+  // If last stop, mark interval end.
+  if (mJSRunToCompletionDepth == 0 && TimelineConsumers::HasConsumer(this)) {
+    TimelineConsumers::AddMarkerForDocShell(this, "Javascript",
+                                            MarkerTracingType::END);
+  }
+}
+
+/* static */
+void nsDocShell::MaybeNotifyKeywordSearchLoading(const nsString& aProvider,
+                                                 const nsString& aKeyword) {
+  if (aProvider.IsEmpty()) {
+    return;
+  }
+  nsresult rv;
+  nsCOMPtr<nsISupportsString> isupportsString =
+      do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  rv = isupportsString->SetData(aProvider);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIObserverService> obsSvc = services::GetObserverService();
+  if (obsSvc) {
+    // Note that "keyword-search" refers to a search via the url
+    // bar, not a bookmarks keyword search.
+    obsSvc->NotifyObservers(isupportsString, "keyword-search", aKeyword.get());
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::ShouldPrepareForIntercept(nsIURI* aURI, nsIChannel* aChannel,
+                                      bool* aShouldIntercept) {
+  return mInterceptController->ShouldPrepareForIntercept(aURI, aChannel,
+                                                         aShouldIntercept);
+}
+
+NS_IMETHODIMP
+nsDocShell::ChannelIntercepted(nsIInterceptedChannel* aChannel) {
+  return mInterceptController->ChannelIntercepted(aChannel);
+}
+
+bool nsDocShell::InFrameSwap() {
+  RefPtr<nsDocShell> shell = this;
+  do {
+    if (shell->mInFrameSwap) {
+      return true;
+    }
+    shell = shell->GetInProcessParentDocshell();
+  } while (shell);
+  return false;
+}
+
+UniquePtr<ClientSource> nsDocShell::TakeInitialClientSource() {
+  return std::move(mInitialClientSource);
+}
+
+NS_IMETHODIMP
+nsDocShell::GetEditingSession(nsIEditingSession** aEditSession) {
+  if (!NS_SUCCEEDED(EnsureEditorData())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aEditSession = do_AddRef(mEditorData->GetEditingSession()).take();
+  return *aEditSession ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetScriptableBrowserChild(nsIBrowserChild** aBrowserChild) {
+  *aBrowserChild = GetBrowserChild().take();
+  return *aBrowserChild ? NS_OK : NS_ERROR_FAILURE;
+}
+
+already_AddRefed<nsIBrowserChild> nsDocShell::GetBrowserChild() {
+  nsCOMPtr<nsIBrowserChild> tc = do_QueryReferent(mBrowserChild);
+  return tc.forget();
+}
+
+nsCommandManager* nsDocShell::GetCommandManager() {
+  NS_ENSURE_SUCCESS(EnsureCommandHandler(), nullptr);
+  return mCommandManager;
+}
+
+NS_IMETHODIMP_(void)
+nsDocShell::GetOriginAttributes(mozilla::OriginAttributes& aAttrs) {
+  mBrowsingContext->GetOriginAttributes(aAttrs);
+}
+
+HTMLEditor* nsIDocShell::GetHTMLEditor() {
+  nsDocShell* docShell = static_cast<nsDocShell*>(this);
+  return docShell->GetHTMLEditorInternal();
+}
+
+nsresult nsIDocShell::SetHTMLEditor(HTMLEditor* aHTMLEditor) {
+  nsDocShell* docShell = static_cast<nsDocShell*>(this);
+  return docShell->SetHTMLEditorInternal(aHTMLEditor);
+}
+
+#define MATRIX_LENGTH 20
+
+NS_IMETHODIMP
+nsDocShell::SetColorMatrix(const nsTArray<float>& aMatrix) {
+  if (aMatrix.Length() == MATRIX_LENGTH) {
+    mColorMatrix.reset(new gfx::Matrix5x4());
+    static_assert(
+        MATRIX_LENGTH * sizeof(float) == sizeof(mColorMatrix->components),
+        "Size mismatch for our memcpy");
+    memcpy(mColorMatrix->components, aMatrix.Elements(),
+           sizeof(mColorMatrix->components));
+  } else if (aMatrix.Length() == 0) {
+    mColorMatrix.reset();
+  } else {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  PresShell* presShell = GetPresShell();
+  if (!presShell) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsIFrame* frame = presShell->GetRootFrame();
+  if (!frame) {
+    return NS_ERROR_FAILURE;
+  }
+
+  frame->SchedulePaint();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetColorMatrix(nsTArray<float>& aMatrix) {
+  if (mColorMatrix) {
+    aMatrix.SetLength(MATRIX_LENGTH);
+    static_assert(
+        MATRIX_LENGTH * sizeof(float) == sizeof(mColorMatrix->components),
+        "Size mismatch for our memcpy");
+    memcpy(aMatrix.Elements(), mColorMatrix->components,
+           MATRIX_LENGTH * sizeof(float));
+  }
+
+  return NS_OK;
+}
+
+#undef MATRIX_LENGTH
+
+NS_IMETHODIMP
+nsDocShell::GetIsForceReloading(bool* aForceReload) {
+  *aForceReload = IsForceReloading();
+  return NS_OK;
+}
+
+bool nsDocShell::IsForceReloading() { return IsForceReloadType(mLoadType); }
+
+NS_IMETHODIMP
+nsDocShell::GetBrowsingContextXPCOM(BrowsingContext** aBrowsingContext) {
+  *aBrowsingContext = do_AddRef(mBrowsingContext).take();
+  return NS_OK;
+}
+
+BrowsingContext* nsDocShell::GetBrowsingContext() { return mBrowsingContext; }
+
+bool nsDocShell::GetIsAttemptingToNavigate() {
+  // XXXbz the document.open spec says to abort even if there's just a
+  // queued navigation task, sort of.  It's not clear whether browsers
+  // actually do that, and we didn't use to do it, so for now let's
+  // not do that.
+  // https://github.com/whatwg/html/issues/3447 tracks the spec side of this.
+  if (mDocumentRequest) {
+    // There's definitely a navigation in progress.
+    return true;
+  }
+
+  // javascript: channels have slightly weird behavior: they're LOAD_BACKGROUND
+  // until the script runs, which means they're not sending loadgroup
+  // notifications and hence not getting set as mDocumentRequest.  Look through
+  // our loadgroup for document-level javascript: loads.
+  if (!mLoadGroup) {
+    return false;
+  }
+
+  nsCOMPtr<nsISimpleEnumerator> requests;
+  mLoadGroup->GetRequests(getter_AddRefs(requests));
+  bool hasMore = false;
+  while (NS_SUCCEEDED(requests->HasMoreElements(&hasMore)) && hasMore) {
+    nsCOMPtr<nsISupports> elem;
+    requests->GetNext(getter_AddRefs(elem));
+    nsCOMPtr<nsIScriptChannel> scriptChannel(do_QueryInterface(elem));
+    if (!scriptChannel) {
+      continue;
+    }
+
+    if (scriptChannel->GetIsDocumentLoad()) {
+      // This is a javascript: load that might lead to a new document,
+      // hence a navigation.
+      return true;
+    }
+  }
+
+  return mCheckingSessionHistory;
+}
+
+void nsDocShell::SetLoadingSessionHistoryInfo(
+    const mozilla::dom::LoadingSessionHistoryInfo& aLoadingInfo,
+    bool aNeedToReportActiveAfterLoadingBecomesActive) {
+  // FIXME Would like to assert this, but can't yet.
+  // MOZ_ASSERT(!mLoadingEntry);
+  MOZ_LOG(gSHLog, LogLevel::Debug,
+          ("Setting the loading entry on nsDocShell %p to %s", this,
+           aLoadingInfo.mInfo.GetURI()->GetSpecOrDefault().get()));
+  mLoadingEntry = MakeUnique<LoadingSessionHistoryInfo>(aLoadingInfo);
+  mNeedToReportActiveAfterLoadingBecomesActive =
+      aNeedToReportActiveAfterLoadingBecomesActive;
+}
+
+void nsDocShell::MoveLoadingToActiveEntry(bool aPersist, bool aExpired,
+                                          uint32_t aCacheKey,
+                                          nsIURI* aPreviousURI) {
+  MOZ_ASSERT(mozilla::SessionHistoryInParent());
+
+  MOZ_LOG(gSHLog, LogLevel::Debug,
+          ("nsDocShell %p MoveLoadingToActiveEntry", this));
+
+  UniquePtr<SessionHistoryInfo> previousActiveEntry(mActiveEntry.release());
+  mozilla::UniquePtr<mozilla::dom::LoadingSessionHistoryInfo> loadingEntry;
+  mActiveEntryIsLoadingFromSessionHistory =
+      mLoadingEntry && mLoadingEntry->mLoadIsFromSessionHistory;
+  if (mLoadingEntry) {
+    MOZ_LOG(gSHLog, LogLevel::Debug,
+            ("Moving the loading entry to the active entry on nsDocShell %p "
+             "to %s",
+             this, mLoadingEntry->mInfo.GetURI()->GetSpecOrDefault().get()));
+    mActiveEntry = MakeUnique<SessionHistoryInfo>(mLoadingEntry->mInfo);
+    mLoadingEntry.swap(loadingEntry);
+    if (!mActiveEntryIsLoadingFromSessionHistory) {
+      if (mNeedToReportActiveAfterLoadingBecomesActive) {
+        // Needed to pass various history length WPTs.
+        mBrowsingContext->SetActiveSessionHistoryEntry(
+            mozilla::Nothing(), mActiveEntry.get(), mLoadType,
+            /* aUpdatedCacheKey = */ 0, false);
+      }
+      mBrowsingContext->IncrementHistoryEntryCountForBrowsingContext();
+    }
+  }
+  mNeedToReportActiveAfterLoadingBecomesActive = false;
+
+  if (mActiveEntry) {
+    if (aCacheKey != 0) {
+      mActiveEntry->SetCacheKey(aCacheKey);
+    }
+    MOZ_ASSERT(loadingEntry);
+    uint32_t loadType =
+        mLoadType == LOAD_ERROR_PAGE ? mFailedLoadType : mLoadType;
+
+    if (loadingEntry->mLoadId != UINT64_MAX) {
+      // We're passing in mCurrentURI, which could be null. SessionHistoryCommit
+      // does require a non-null uri if this is for a refresh load of the same
+      // URI, but in that case mCurrentURI won't be null here.
+      mBrowsingContext->SessionHistoryCommit(
+          *loadingEntry, loadType, aPreviousURI, previousActiveEntry.get(),
+          aPersist, false, aExpired, aCacheKey);
+    }
+  }
+}
+
+static bool IsFaviconLoad(nsIRequest* aRequest) {
+  nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
+  if (!channel) {
+    return false;
+  }
+
+  nsCOMPtr<nsILoadInfo> li = channel->LoadInfo();
+  return li && li->InternalContentPolicyType() ==
+                   nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON;
+}
+
+void nsDocShell::RecordSingleChannelId(bool aStartRequest,
+                                       nsIRequest* aRequest) {
+  // Ignore favicon loads, they don't need to block caching.
+  if (IsFaviconLoad(aRequest)) {
+    return;
+  }
+
+  MOZ_ASSERT_IF(!aStartRequest, mRequestForBlockingFromBFCacheCount > 0);
+
+  mRequestForBlockingFromBFCacheCount += aStartRequest ? 1 : -1;
+
+  if (mBrowsingContext->GetCurrentWindowContext()) {
+    // We have three states: no request, one request with an id and
+    // eiher one request without an id or multiple requests. Nothing() is no
+    // request, Some(non-zero) is one request with an id and Some(0) is one
+    // request without an id or multiple requests.
+    Maybe<uint64_t> singleChannelId;
+    if (mRequestForBlockingFromBFCacheCount > 1) {
+      singleChannelId = Some(0);
+    } else if (mRequestForBlockingFromBFCacheCount == 1) {
+      nsCOMPtr<nsIIdentChannel> identChannel;
+      if (aStartRequest) {
+        identChannel = do_QueryInterface(aRequest);
+      } else {
+        // aChannel is the channel that's being removed, but we need to check if
+        // the remaining channel in the loadgroup has an id.
+        nsCOMPtr<nsISimpleEnumerator> requests;
+        mLoadGroup->GetRequests(getter_AddRefs(requests));
+        for (const auto& request : SimpleEnumerator<nsIRequest>(requests)) {
+          if (!IsFaviconLoad(request) &&
+              !!(identChannel = do_QueryInterface(request))) {
+            break;
+          }
+        }
+      }
+
+      if (identChannel) {
+        singleChannelId = Some(identChannel->ChannelId());
+      } else {
+        singleChannelId = Some(0);
+      }
+    } else {
+      MOZ_ASSERT(mRequestForBlockingFromBFCacheCount == 0);
+      singleChannelId = Nothing();
+    }
+
+    if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+      nsAutoCString uri("[no uri]");
+      if (mCurrentURI) {
+        uri = mCurrentURI->GetSpecOrDefault();
+      }
+      if (singleChannelId.isNothing()) {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s doesn't have any requests relevant for "
+                 "blocking BFCache",
+                 uri.get()));
+      } else if (singleChannelId.value() == 0) {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s has multiple requests relevant for blocking "
+                 "BFCache",
+                 uri.get()));
+      } else {
+        MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+                ("Loadgroup for %s has one request with id %" PRIu64
+                 " relevant for blocking BFCache",
+                 uri.get(), singleChannelId.value()));
+      }
+    }
+
+    if (mSingleChannelId != singleChannelId) {
+      mSingleChannelId = singleChannelId;
+      WindowGlobalChild* wgc =
+          mBrowsingContext->GetCurrentWindowContext()->GetWindowGlobalChild();
+      if (wgc) {
+        wgc->SendSetSingleChannelId(singleChannelId);
+      }
+    }
+  }
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStartRequest(nsIRequest* aRequest) {
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+    nsAutoCString uri("[no uri]");
+    if (mCurrentURI) {
+      uri = mCurrentURI->GetSpecOrDefault();
+    }
+    nsAutoCString name;
+    aRequest->GetName(name);
+    MOZ_LOG(gSHIPBFCacheLog, LogLevel::Verbose,
+            ("Adding request %s to loadgroup for %s", name.get(), uri.get()));
+  }
+  RecordSingleChannelId(true, aRequest);
+  return nsDocLoader::OnStartRequest(aRequest);
+}
+
+NS_IMETHODIMP
+nsDocShell::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
+  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gSHIPBFCacheLog, LogLevel::Verbose))) {
+    nsAutoCString uri("[no uri]");
+    if (mCurrentURI) {
+      uri = mCurrentURI->GetSpecOrDefault();
+    }
+    nsAutoCString name;
+    aRequest->GetName(name);
+    MOZ_LOG(
+        gSHIPBFCacheLog, LogLevel::Verbose,
+        ("Removing request %s from loadgroup for %s", name.get(), uri.get()));
+  }
+  RecordSingleChannelId(false, aRequest);
+  return nsDocLoader::OnStopRequest(aRequest, aStatusCode);
+}
+
+void nsDocShell::MaybeDisconnectChildListenersOnPageHide() {
+  MOZ_RELEASE_ASSERT(XRE_IsContentProcess());
+
+  if (mChannelToDisconnectOnPageHide != 0 && mLoadGroup) {
+    nsCOMPtr<nsISimpleEnumerator> requests;
+    mLoadGroup->GetRequests(getter_AddRefs(requests));
+    for (const auto& request : SimpleEnumerator<nsIRequest>(requests)) {
+      RefPtr<DocumentChannel> channel = do_QueryObject(request);
+      if (channel && channel->ChannelId() == mChannelToDisconnectOnPageHide) {
+        static_cast<DocumentChannelChild*>(channel.get())
+            ->DisconnectChildListeners(NS_BINDING_ABORTED, NS_BINDING_ABORTED);
+      }
+    }
+    mChannelToDisconnectOnPageHide = 0;
+  }
+}