[MediaSession] Add playbackState attribute to Blink MediaSession and use it to determine playback s…

content/browser/media/session/media_session_impl.h

 // Copyright 2015 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 CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_IMPL_H_
 #define CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 158 matching lines @@
 
   // MediaSessionService-related methods
 
   // Called when a MediaSessionService is created, which registers itself to
   // this session.
   void OnServiceCreated(MediaSessionServiceImpl* service);
   // Called when a MediaSessionService is destroyed, which unregisters itself
   // from this session.
   void OnServiceDestroyed(MediaSessionServiceImpl* service);
 
+  // Called when the playback state of a MediaSessionService has
+  // changed. Will notify observers of media session state change.
+  void OnMediaSessionPlaybackStateChanged(MediaSessionServiceImpl* service);
+
   // Called when the metadata of a MediaSessionService has changed. Will notify
   // observers if the service is currently routed.
   void OnMediaSessionMetadataChanged(MediaSessionServiceImpl* service);
   // Called when the actions of a MediaSessionService has changed. Will notify
   // observers if the service is currently routed.
   void OnMediaSessionActionsChanged(MediaSessionServiceImpl* service);
 
   // Called when a MediaSessionAction is received. The action will be forwarded
   // to blink::MediaSession corresponding to the current routed service.
   void DidReceiveAction(blink::mojom::MediaSessionAction action) override;
@@ skipping 118 matching lines @@
   ServicesMap services_;
   // The currently routed service (non-owned pointer).
   MediaSessionServiceImpl* routed_service_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSessionImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_IMPL_H_