Media Remoting: Add RemotingController.

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
@@ skipping 179 matching lines @@
 
     // Whether the WebMediaPlayer supports overlay fullscreen video mode. When
     // this is true, the video layer will be removed from the layer tree when
     // entering fullscreen, and the WebMediaPlayer is responsible for displaying
     // the video in enteredFullscreen().
     virtual bool supportsOverlayFullscreenVideo() { return false; }
     // Inform WebMediaPlayer when the element has entered/exited fullscreen.
     virtual void enteredFullscreen() { }
     virtual void exitedFullscreen() { }
 
+    // These are called when any ancestor enters/exits full screen.
+    virtual void ancestorEnteredFullscreen() {}
+    virtual void ancestorExitedFullscreen() {}

[xhwang, 2016/10/01 07:12:15]

See my previous comment on this. What if there are other elements sharing the
same ancestor with the media element?

You need someone who's more familiar with blink/elements/fullscreen to review
this.

[xjz, 2016/10/03 22:31:09]

Only one video element can start remoting successfully at one time. The current
logic is the first come first serve. We may improve this logic in future change.

[xhwang, 2016/10/04 06:30:29]

Could you put this comment somewhere in the code? Just in case people may ask
again.

[xjz, 2016/10/04 19:21:28]

Done.

+
     virtual void enabledAudioTracksChanged(const WebVector<TrackId>& enabledTrackIds) { }
     // |selectedTrackId| is null if no track is selected.
     virtual void selectedVideoTrackChanged(TrackId* selectedTrackId) { }
 };
 
 } // namespace blink
 
 #endif