Ensure ExternalSurface is idle in fullscreen video mode

content/browser/media/android/browser_media_player_manager.cc

Index: content/browser/media/android/browser_media_player_manager.cc
diff --git a/content/browser/media/android/browser_media_player_manager.cc b/content/browser/media/android/browser_media_player_manager.cc
index 2b75e3bab66fc1b9943323787f465ae608a9b307..055bf79c392a207d1cd2b3a6a3fc3fcd90a81636 100644
--- a/content/browser/media/android/browser_media_player_manager.cc
+++ b/content/browser/media/android/browser_media_player_manager.cc
@@ -321,13 +321,16 @@ void BrowserMediaPlayerManager::DetachExternalVideoSurface(int player_id) {
 }
 
 void BrowserMediaPlayerManager::OnFrameInfoUpdated() {

[Hugo Holgersson, 2015/01/29 15:24:18]

I added a print here. In fullscreen video playback, OnFrameInfoUpdated() runs
once the info layer updates (second ticks/progress bar advances/fades in/out).
OnFrameInfoUpdated() does not run at all in a paused state.

To make this clear, in the CL description I'd rather write: "When the progress
layer updates itself (second ticks/progress bar advances/fades in/out) on top of
fullscreen video playback, we do not need to send OnFrameInfoUpdated() to video
hole surface because it is hidden behind the fullscreen surface."

(Tested in com.android.browser with --force-use-overlay-embedded-video.)

+  if (fullscreen_player_id_ != kInvalidMediaPlayerId)
+    return;
+
   if (external_video_surface_container_)
     external_video_surface_container_->OnFrameInfoUpdated();
 }
 
 void BrowserMediaPlayerManager::OnNotifyExternalSurface(
     int player_id, bool is_request, const gfx::RectF& rect) {
-  if (!web_contents_)
+  if (!web_contents_ || fullscreen_player_id_ != kInvalidMediaPlayerId)

[qinmin, 2015/01/28 19:31:04]

What happens if we exit fullscreen? The external surface view will showing up in
a wrong position?

[william.xie1, 2015/01/28 23:33:22]

Hi Min, if we exit fullscreen, the external surface view will show up in the
original position before enter fullscreen, which is the correct behavior. 
This change is target to skip to notify external surface during the process of
entering to full screen (message is sent from
RendererMediaPlayerManager::DidCommitCompositorFrame()).

[qinmin, 2015/02/02 17:45:07]

what if user wrote a script to scroll the page while entering fullscreen?
Shouldn't we update the external surface position if scroll position changes?

     return;
 
   if (is_request) {