Notify WebMediaPlayer when its ancestor enters/exists fullscreen.

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 87c058c8da7cf3760c0fa3293db6c6c03b65dd3d..26e7b7e5e041a7c09702967782ae4c3ecc798ed1 100644
--- a/third_party/WebKit/public/platform/WebMediaPlayer.h
+++ b/third_party/WebKit/public/platform/WebMediaPlayer.h
@@ -227,6 +227,16 @@ class WebMediaPlayer {
   virtual void enteredFullscreen() {}
   virtual void exitedFullscreen() {}
 
+  // Inform WebMediaPlayer when its ancestor enters full screen and the element
+  // covers most of the window.
+  virtual void enterFullWindow() {}
+  // Whether its ancestor entered full screen and the element covers most of
+  // of the window.
+  virtual bool isFullWindow() { return false; }
+  // Inform WebMediaPlayer when isFullWindow() is true and its ancestor exits
+  // full screen.
+  virtual void exitFullWindow() {}
+
   virtual void enabledAudioTracksChanged(
       const WebVector<TrackId>& enabledTrackIds) {}
   // |selectedTrackId| is null if no track is selected.