1 files changed, 279 insertions, 0 deletions
diff --git a/dom/base/nsFrameLoaderOwner.cpp b/dom/base/nsFrameLoaderOwner.cpp
new file mode 100644
index 0000000000..dc2c8c70d3
--- /dev/null
+++ b/dom/base/nsFrameLoaderOwner.cpp
@@ -0,0 +1,279 @@
+/* -*- 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 "nsFrameLoaderOwner.h"
+#include "nsFrameLoader.h"
+#include "nsFocusManager.h"
+#include "nsNetUtil.h"
+#include "nsSubDocumentFrame.h"
+#include "nsQueryObject.h"
+#include "mozilla/AsyncEventDispatcher.h"
+#include "mozilla/dom/BrowsingContext.h"
+#include "mozilla/dom/FrameLoaderBinding.h"
+#include "mozilla/dom/HTMLIFrameElement.h"
+#include "mozilla/dom/MozFrameLoaderOwnerBinding.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/dom/BrowserBridgeChild.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/BrowserBridgeHost.h"
+#include "mozilla/dom/BrowserHost.h"
+#include "mozilla/StaticPrefs_fission.h"
+#include "mozilla/EventStateManager.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+already_AddRefed<nsFrameLoader> nsFrameLoaderOwner::GetFrameLoader() {
+  return do_AddRef(mFrameLoader);
+}
+
+void nsFrameLoaderOwner::SetFrameLoader(nsFrameLoader* aNewFrameLoader) {
+  mFrameLoader = aNewFrameLoader;
+}
+
+mozilla::dom::BrowsingContext* nsFrameLoaderOwner::GetBrowsingContext() {
+  if (mFrameLoader) {
+    return mFrameLoader->GetBrowsingContext();
+  }
+  return nullptr;
+}
+
+mozilla::dom::BrowsingContext* nsFrameLoaderOwner::GetExtantBrowsingContext() {
+  if (mFrameLoader) {
+    return mFrameLoader->GetExtantBrowsingContext();
+  }
+  return nullptr;
+}
+
+bool nsFrameLoaderOwner::UseRemoteSubframes() {
+  RefPtr<Element> owner = do_QueryObject(this);
+
+  nsILoadContext* loadContext = owner->OwnerDoc()->GetLoadContext();
+  MOZ_DIAGNOSTIC_ASSERT(loadContext);
+
+  return loadContext->UseRemoteSubframes();
+}
+
+nsFrameLoaderOwner::ChangeRemotenessContextType
+nsFrameLoaderOwner::ShouldPreserveBrowsingContext(
+    bool aIsRemote, bool aReplaceBrowsingContext) {
+  if (aReplaceBrowsingContext) {
+    return ChangeRemotenessContextType::DONT_PRESERVE;
+  }
+
+  if (XRE_IsParentProcess()) {
+    // Don't preserve for remote => parent loads.
+    if (!aIsRemote) {
+      return ChangeRemotenessContextType::DONT_PRESERVE;
+    }
+
+    // Don't preserve for parent => remote loads.
+    if (mFrameLoader && !mFrameLoader->IsRemoteFrame()) {
+      return ChangeRemotenessContextType::DONT_PRESERVE;
+    }
+  }
+
+  // We will preserve our browsing context if either fission is enabled, or the
+  // `preserve_browsing_contexts` pref is active.
+  if (UseRemoteSubframes() ||
+      StaticPrefs::fission_preserve_browsing_contexts()) {
+    return ChangeRemotenessContextType::PRESERVE;
+  }
+  return ChangeRemotenessContextType::DONT_PRESERVE;
+}
+
+void nsFrameLoaderOwner::ChangeRemotenessCommon(
+    const ChangeRemotenessContextType& aContextType,
+    bool aSwitchingInProgressLoad, bool aIsRemote, BrowsingContextGroup* aGroup,
+    std::function<void()>& aFrameLoaderInit, mozilla::ErrorResult& aRv) {
+  MOZ_ASSERT_IF(aGroup, aContextType != ChangeRemotenessContextType::PRESERVE);
+
+  RefPtr<mozilla::dom::BrowsingContext> bc;
+  bool networkCreated = false;
+
+  // In this case, we're not reparenting a frameloader, we're just destroying
+  // our current one and creating a new one, so we can use ourselves as the
+  // owner.
+  RefPtr<Element> owner = do_QueryObject(this);
+  MOZ_ASSERT(owner);
+
+  // When we destroy the original frameloader, it will stop blocking the parent
+  // document's load event, and immediately trigger the load event if there are
+  // no other blockers. Since we're going to be adding a new blocker as soon as
+  // we recreate the frame loader, this is not what we want, so add our own
+  // blocker until the process is complete.
+  Document* doc = owner->OwnerDoc();
+  doc->BlockOnload();
+  auto cleanup = MakeScopeExit([&]() { doc->UnblockOnload(false); });
+
+  {
+    // Introduce a script blocker to ensure no JS is executed during the
+    // nsFrameLoader teardown & recreation process. Unload listeners will be run
+    // for the previous document, and the load will be started for the new one,
+    // at the end of this block.
+    nsAutoScriptBlocker sb;
+
+    // If we already have a Frameloader, destroy it, possibly preserving its
+    // browsing context.
+    if (mFrameLoader) {
+      // Calling `GetBrowsingContext` here will force frameloader
+      // initialization if it hasn't already happened, which we neither need
+      // or want, so we use the initial (possibly pending) browsing context
+      // directly, instead.
+      bc = mFrameLoader->GetMaybePendingBrowsingContext();
+      if (aContextType == ChangeRemotenessContextType::PRESERVE) {
+        mFrameLoader->SetWillChangeProcess();
+      }
+
+      // Preserve the networkCreated status, as nsDocShells created after a
+      // process swap may shouldn't change their dynamically-created status.
+      networkCreated = mFrameLoader->IsNetworkCreated();
+      mFrameLoader->Destroy(aSwitchingInProgressLoad);
+      mFrameLoader = nullptr;
+    }
+
+    mFrameLoader = nsFrameLoader::Recreate(
+        owner, bc, aGroup, aIsRemote, networkCreated,
+        aContextType == ChangeRemotenessContextType::PRESERVE);
+    if (NS_WARN_IF(!mFrameLoader)) {
+      aRv.Throw(NS_ERROR_FAILURE);
+      return;
+    }
+
+    // Invoke the frame loader initialization callback to perform setup on our
+    // new nsFrameLoader. This may cause our ErrorResult to become errored, so
+    // double-check after calling.
+    aFrameLoaderInit();
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+  }
+
+  // Now that we've got a new FrameLoader, we need to reset our
+  // nsSubDocumentFrame to use the new FrameLoader.
+  if (nsSubDocumentFrame* ourFrame = do_QueryFrame(owner->GetPrimaryFrame())) {
+    ourFrame->ResetFrameLoader();
+  }
+
+  // If the element is focused, or the current mouse over target then
+  // we need to update that state for the new BrowserParent too.
+  if (nsFocusManager* fm = nsFocusManager::GetFocusManager()) {
+    if (fm->GetFocusedElement() == owner) {
+      fm->ActivateRemoteFrameIfNeeded(*owner,
+                                      nsFocusManager::GenerateFocusActionId());
+    }
+  }
+
+  if (owner->GetPrimaryFrame()) {
+    EventStateManager* eventManager =
+        owner->GetPrimaryFrame()->PresContext()->EventStateManager();
+    eventManager->RecomputeMouseEnterStateForRemoteFrame(*owner);
+  }
+
+  if (owner->IsXULElement()) {
+    // Assuming this element is a XULFrameElement, once we've reset our
+    // FrameLoader, fire an event to act like we've recreated ourselves, similar
+    // to what XULFrameElement does after rebinding to the tree.
+    // ChromeOnlyDispatch is turns on to make sure this isn't fired into
+    // content.
+    (new mozilla::AsyncEventDispatcher(owner, u"XULFrameLoaderCreated"_ns,
+                                       mozilla::CanBubble::eYes,
+                                       mozilla::ChromeOnlyDispatch::eYes))
+        ->RunDOMEventWhenSafe();
+  }
+}
+
+void nsFrameLoaderOwner::ChangeRemoteness(
+    const mozilla::dom::RemotenessOptions& aOptions, mozilla::ErrorResult& rv) {
+  bool isRemote = !aOptions.mRemoteType.IsEmpty();
+
+  std::function<void()> frameLoaderInit = [&] {
+    if (isRemote) {
+      mFrameLoader->ConfigRemoteProcess(aOptions.mRemoteType, nullptr);
+    }
+
+    if (aOptions.mPendingSwitchID.WasPassed()) {
+      mFrameLoader->ResumeLoad(aOptions.mPendingSwitchID.Value());
+    } else {
+      mFrameLoader->LoadFrame(false);
+    }
+  };
+
+  auto shouldPreserve = ShouldPreserveBrowsingContext(
+      isRemote, /* replaceBrowsingContext */ false);
+  ChangeRemotenessCommon(shouldPreserve, aOptions.mSwitchingInProgressLoad,
+                         isRemote, /* group */ nullptr, frameLoaderInit, rv);
+}
+
+void nsFrameLoaderOwner::ChangeRemotenessWithBridge(BrowserBridgeChild* aBridge,
+                                                    mozilla::ErrorResult& rv) {
+  MOZ_ASSERT(XRE_IsContentProcess());
+  if (NS_WARN_IF(!mFrameLoader)) {
+    rv.Throw(NS_ERROR_UNEXPECTED);
+    return;
+  }
+
+  std::function<void()> frameLoaderInit = [&] {
+    RefPtr<BrowserBridgeHost> host = aBridge->FinishInit(mFrameLoader);
+    mFrameLoader->mPendingBrowsingContext->SetEmbedderElement(
+        mFrameLoader->GetOwnerContent());
+    mFrameLoader->mRemoteBrowser = host;
+  };
+
+  ChangeRemotenessCommon(ChangeRemotenessContextType::PRESERVE,
+                         /* inProgress */ true,
+                         /* isRemote */ true, /* group */ nullptr,
+                         frameLoaderInit, rv);
+}
+
+void nsFrameLoaderOwner::ChangeRemotenessToProcess(
+    ContentParent* aContentParent, bool aReplaceBrowsingContext,
+    BrowsingContextGroup* aGroup, mozilla::ErrorResult& rv) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT_IF(aGroup, aReplaceBrowsingContext);
+  bool isRemote = aContentParent != nullptr;
+
+  std::function<void()> frameLoaderInit = [&] {
+    if (isRemote) {
+      mFrameLoader->ConfigRemoteProcess(aContentParent->GetRemoteType(),
+                                        aContentParent);
+    }
+  };
+
+  auto shouldPreserve =
+      ShouldPreserveBrowsingContext(isRemote, aReplaceBrowsingContext);
+  ChangeRemotenessCommon(shouldPreserve, /* inProgress */ true, isRemote,
+                         aGroup, frameLoaderInit, rv);
+}
+
+void nsFrameLoaderOwner::SubframeCrashed() {
+  MOZ_ASSERT(XRE_IsContentProcess());
+
+  std::function<void()> frameLoaderInit = [&] {
+    RefPtr<nsFrameLoader> frameLoader = mFrameLoader;
+    nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
+        "nsFrameLoaderOwner::SubframeCrashed", [frameLoader]() {
+          nsCOMPtr<nsIURI> uri;
+          nsresult rv = NS_NewURI(getter_AddRefs(uri), "about:blank");
+          if (NS_WARN_IF(NS_FAILED(rv))) {
+            return;
+          }
+
+          RefPtr<nsDocShell> docShell =
+              frameLoader->GetDocShell(IgnoreErrors());
+          if (NS_WARN_IF(!docShell)) {
+            return;
+          }
+          bool displayed = false;
+          docShell->DisplayLoadError(NS_ERROR_FRAME_CRASHED, uri,
+                                     u"about:blank", nullptr, &displayed);
+        }));
+  };
+
+  ChangeRemotenessCommon(ChangeRemotenessContextType::PRESERVE,
+                         /* inProgress */ false, /* isRemote */ false,
+                         /* group */ nullptr, frameLoaderInit, IgnoreErrors());
+}