Make rendering timeouts work even if paint data received early

The initial implementation of the browser paint timer for a new page
load assumed that the DidCommitProvisionalLoad IPC would be received
before any compositor frame generated from rendering the new page.

This turns out to be false. This CL adds a new IPC that is queued to
be sent when a new compositor frame is generated, and can be handled by
the browser even if it arrives too early. In that case, a flag is set
that tells RenderWidgetHost to not set the timer.

BUG=535375

Review URL: https://codereview.chromium.org/1376003002

Cr-Commit-Position: refs/heads/master@{#352028}

1 files changed, 8 insertions, 0 deletions

diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 045540d..ff5d269 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -2740,6 +2740,14 @@ void RenderFrameImpl::didCommitProvisionalLoad(
     }
   }
 
+  // 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.
+  if (is_main_frame_ && !navigation_state->WasWithinSamePage()) {
+    render_view_->QueueMessage(
+        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.