Move RunScriptsAtDocumentStart for the empty document to Dispatcher

Extensions code wants to run scripts on the initial empty document,
so instead of adding a duplicate call to all ContentRendererClients
(both RenderFrameCreated and RunScriptsAtDocumentStart) we can have
the extensions code do the right thing with the RenderFrameCreated
signal.

R=dcheng@chromium.org, reillyg@chromium.org

Bug: 1158869
Change-Id: I11a969e8b84933f13a5ceadb6e6d3943a5fb5d9e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627690Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Shimi Zhang <ctzsm@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844203}

android_webview/renderer/aw_content_renderer_client.cc

@@ -205,15 +205,7 @@ void AwContentRendererClient::RunScriptsAtDocumentStart(
     content::RenderFrame* render_frame) {
   js_injection::JsCommunication* communication =
       js_injection::JsCommunication::Get(render_frame);
-  // We will get RunScriptsAtDocumentStart() event even before we received
-  // RenderFrameCreated() for that |render_frame|. This is because Blink code
-  // does initialization work on the main frame, which is not related to any
-  // real navigation. If the communication is nullptr, it means we haven't
-  // received RenderFrameCreated() yet, we simply ignore this event for
-  // JsCommunication since that is not the right time to run the script and
-  // the script may not reach renderer from browser yet.
-  if (communication)
-    communication->RunScriptsAtDocumentStart();
+  communication->RunScriptsAtDocumentStart();
 }
 
 void AwContentRendererClient::AddSupportedKeySystems(

content/renderer/render_frame_impl.cc

@@ -2069,9 +2069,6 @@ void RenderFrameImpl::Initialize(blink::WebFrame* parent) {
   // We delay calling this until we have the WebFrame so that any observer or
   // embedder can call GetWebFrame on any RenderFrame.
   GetContentClient()->renderer()->RenderFrameCreated(this);
-  // Dispatch events for the initial empty document after all frame observers
-  // have been created.
-  RunScriptsAtDocumentElementAvailable();
 
   // blink::WebAudioOutputIPCFactory::io_task_runner_ may be null in tests.
   auto& factory = blink::WebAudioOutputIPCFactory::GetInstance();

extensions/renderer/dispatcher.cc

@@ -289,6 +289,11 @@ void Dispatcher::OnRenderThreadStarted(content::RenderThread* thread) {
 void Dispatcher::OnRenderFrameCreated(content::RenderFrame* render_frame) {
   script_injection_manager_->OnRenderFrameCreated(render_frame);
   content_watcher_->OnRenderFrameCreated(render_frame);
+
+  // The RenderFrame comes with the initial empty document already created.
+  DidCreateDocumentElement(render_frame->GetWebFrame());
+  // We run scripts on the empty document.
+  RunScriptsAtDocumentStart(render_frame);
 }
 
 bool Dispatcher::IsExtensionActive(const std::string& extension_id) const {

extensions/renderer/extension_frame_helper.cc

@@ -118,9 +118,6 @@ ExtensionFrameHelper::ExtensionFrameHelper(content::RenderFrame* render_frame,
     // Manages its own lifetime.
     new AutomationApiHelper(render_frame);
   }
-  // The RenderFrame comes with the initial empty document already created, and
-  // we want to act on it in the same way as a new document.
-  DidCreateDocumentElement();
 }
 
 ExtensionFrameHelper::~ExtensionFrameHelper() {

extensions/renderer/extension_frame_helper.h

@@ -174,10 +174,12 @@ class ExtensionFrameHelper
 
   Dispatcher* extension_dispatcher_;
 
-  // Whether or not the current document element has been created.
+  // Whether or not the current document element has been created. This starts
+  // true as the initial empty document is already created when this class is
+  // instantiated.
   // TODO(danakj): Does this still need to be tracked? We now have consisitent
   // notifications for initial empty documents on all frames.
-  bool did_create_current_document_element_ = false;
+  bool did_create_current_document_element_ = true;
 
   // Callbacks to be run at the next RunScriptsAtDocumentStart notification.
   std::vector<base::OnceClosure> document_element_created_callbacks_;