[Blink>Media] Add heuristic for dominant video detection for Android

third_party/WebKit/public/platform/WebMediaPlayer.h

Index: third_party/WebKit/public/platform/WebMediaPlayer.h
diff --git a/third_party/WebKit/public/platform/WebMediaPlayer.h b/third_party/WebKit/public/platform/WebMediaPlayer.h
index dd88518fb0a277a27ae0762c2e3c46d9364c81f4..c18baf7f4e57e4aa95cbcd3d47ccf2a5d39809a4 100644
--- a/third_party/WebKit/public/platform/WebMediaPlayer.h
+++ b/third_party/WebKit/public/platform/WebMediaPlayer.h
@@ -272,6 +272,11 @@ class WebMediaPlayer {
   // WebMediaPlayerClient::activateViewportIntersectionMonitoring().
   virtual void becameDominantVisibleContent(bool isDominant) {}

[miu, 2017/02/24 22:44:39]

Can the old heuristic be removed? It seems the new one should work for our use
case as well as yours. :)

If you want to address that in a separate change, please put a TODO comment here
and file a crbug for tracking (cc'ing me and xjz).

Also, feel free to send us a patch and we can test it out on our end to make
sure all's well.

[Zhiqiang Zhang (Slow), 2017/02/25 18:48:27]

Filed a bug and added TODO :)

 
+  // Inform WebMediaPlayer when the element starts/stops being the effectively
+  // fullscreen video, i.e. being the fullscreen element or child of the
+  // fullscreen element, and being dominant in the viewport.
+  virtual void setIsEffectivelyFullscreen(bool) {}
+
   virtual void enabledAudioTracksChanged(
       const WebVector<TrackId>& enabledTrackIds) {}
   // |selectedTrackId| is null if no track is selected.