Make rendering timeouts work even if paint data received early

content/renderer/render_frame_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 2717 matching lines @@
     // it needs to set RenderViewImpl's pointer for the main frame to itself
     // and ensure RenderWidget is no longer in swapped out mode.
     if (is_main_frame_) {
       CHECK(!render_view_->main_render_frame_);
       render_view_->main_render_frame_ = this;
       if (render_view_->is_swapped_out())
         render_view_->SetSwappedOut(false);
     }
   }
 
+  // For new page navigations, the browser process needs to be notified of the
+  // first paint of that page, so it can cancel the timer that waits for it.

[Charlie Reis, 2015/10/01 21:26:39]

nit: (or skip the timer if the paint IPC is handled before the navigation commit
IPC).

[kenrb, 2015/10/02 13:24:40]

Done.

+  if (is_main_frame_ && !navigation_state->WasWithinSamePage()) {
+    render_view_->QueueMessage(

[Charlie Reis, 2015/10/01 21:26:39]

There's some magic here I don't fully understand, but the comments on it in
RenderWidget make it sound like the right thing.

+        new ViewHostMsg_DidFirstPaintAfterLoad(render_view_->routing_id_),
+        MESSAGE_DELIVERY_POLICY_WITH_VISUAL_STATE);
+  }
+
   // When we perform a new navigation, we need to update the last committed
   // session history entry with state for the page we are leaving. Do this
   // before updating the HistoryController state.
   render_view_->SendUpdateState();
 
   render_view_->history_controller()->UpdateForCommit(
       this, item, commit_type, navigation_state->WasWithinSamePage());
 
   InternalDocumentStateData* internal_data =
       InternalDocumentStateData::FromDocumentState(document_state);
@@ skipping 2426 matching lines @@
   mojo::ServiceProviderPtr service_provider;
   mojo::URLRequestPtr request(mojo::URLRequest::New());
   request->url = mojo::String::From(url);
   mojo_shell_->ConnectToApplication(request.Pass(), GetProxy(&service_provider),
                                     nullptr, nullptr,
                                     base::Bind(&OnGotContentHandlerID));
   return service_provider.Pass();
 }
 
 }  // namespace content