[Video] MediaSession API event handlers can resume background video.

media/blink/webmediaplayer_delegate.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BLINK_WEBMEDIAPLAYER_DELEGATE_H_
 #define MEDIA_BLINK_WEBMEDIAPLAYER_DELEGATE_H_
 
 namespace blink {
 class WebMediaPlayer;
 }
@@ skipping 44 matching lines @@
     // where 1 indicates normal (non-ducked) playback.
     virtual void OnVolumeMultiplierUpdate(double multiplier) = 0;
   };
 
   // Returns true if the host frame is hidden or closed.
   virtual bool IsFrameHidden() = 0;
 
   // Returns true if the host frame is closed.
   virtual bool IsFrameClosed() = 0;
 
-  // Returns |true| if background video playback permission has been granted,
-  // for example by a media session 'play' command.
-  virtual bool IsBackgroundVideoPlaybackUnlocked() = 0;
-
   // Subscribe to observer callbacks. A player must use the returned |player_id|
   // for the rest of the calls below.
   virtual int AddObserver(Observer* observer) = 0;
 
   // Unsubscribe from observer callbacks.
   virtual void RemoveObserver(int player_id) = 0;
 
   // Notify playback started. This will request appropriate wake locks and, if
   // applicable, show a pause button in external controls.
   //
@@ skipping 38 matching lines @@
   virtual bool IsStale(int player_id) = 0;
 
  protected:
   WebMediaPlayerDelegate() = default;
   virtual ~WebMediaPlayerDelegate() = default;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBMEDIAPLAYER_DELEGATE_H_