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

third_party/WebKit/public/platform/WebMediaPlayer.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
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   // Inform WebMediaPlayer when the element has entered/exited fullscreen.
   virtual void enteredFullscreen() {}
   virtual void exitedFullscreen() {}
 
   // Inform WebMediaPlayer when the element starts/stops being the dominant
   // visible content. This will only be called after the monitoring of the
   // intersection with viewport is activated by calling
   // WebMediaPlayerClient::activateViewportIntersectionMonitoring().
   virtual void becameDominantVisibleContent(bool isDominant) {}
 
+  // 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.
+  //
+  // TODO(zqzhang): merge with becameDominantVisibleContent(). See
+  // https://crbug.com/696211
+  virtual void setIsEffectivelyFullscreen(bool) {}
+
   virtual void enabledAudioTracksChanged(
       const WebVector<TrackId>& enabledTrackIds) {}
   // |selectedTrackId| is null if no track is selected.
   virtual void selectedVideoTrackChanged(TrackId* selectedTrackId) {}
 };
 
 }  // namespace blink
 
 #endif