Implement MediaSession on top of the WebMediaPlayerDelegate.

media/blink/webmediaplayer_impl.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_IMPL_H_
 #define MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 176 matching lines @@
   void OnPipelineError(PipelineStatus error);
   void OnPipelineMetadata(PipelineMetadata metadata);
   void OnPipelineBufferingStateChanged(BufferingState buffering_state);
   void OnDemuxerOpened();
   void OnAddTextTrack(const TextTrackConfig& config,
                       const AddTextTrackDoneCB& done_cb);
 
   // WebMediaPlayerDelegate::Observer implementation.
   void OnHidden() override;
   void OnShown() override;
+  void OnPlay() override;
+  void OnPause() override;
+  void OnVolumeMultiplierUpdate(double multiplier) override;
 
 #if defined(OS_ANDROID)  // WMPI_CAST
   bool isRemote() const override;
   void requestRemotePlayback() override;
   void requestRemotePlaybackControl() override;
 
   void SetMediaPlayerManager(
       RendererMediaPlayerManagerInterface* media_player_manager);
   void OnRemotePlaybackEnded();
   void OnDisconnectedFromRemoteDevice(double t);
@@ skipping 171 matching lines @@
   // |pending_seek_time_| is meaningless when |pending_seek_| is false.
   base::TimeDelta pending_seek_time_;
 
   // Tracks whether to issue time changed notifications during buffering state
   // changes.
   bool should_notify_time_changed_;
 
   blink::WebMediaPlayerClient* client_;
   blink::WebMediaPlayerEncryptedMediaClient* encrypted_client_;
 
+  // WebMediaPlayer notifies the |delegate_| of playback state changes using
+  // |delegate_id_|; an id provided after registering with the delegate.  The
+  // WebMediaPlayer may also receive directives (play, pause) from the delegate
+  // via the WebMediaPlayerDelegate::Observer interface after registration.
   base::WeakPtr<WebMediaPlayerDelegate> delegate_;
+  int delegate_id_;
 
   WebMediaPlayerParams::DeferLoadCB defer_load_cb_;
   WebMediaPlayerParams::Context3DCB context_3d_cb_;
 
   // Members for notifying upstream clients about internal memory usage.  The
   // |adjust_allocated_memory_cb_| must only be called on |main_task_runner_|.
   base::RepeatingTimer memory_usage_reporting_timer_;
   WebMediaPlayerParams::AdjustAllocatedMemoryCB adjust_allocated_memory_cb_;
   int64_t last_reported_memory_usage_;
 
@@ skipping 28 matching lines @@
 
   scoped_ptr<blink::WebContentDecryptionModuleResult> set_cdm_result_;
 
   // Whether a CDM has been successfully attached.
   bool is_cdm_attached_;
 
 #if defined(OS_ANDROID)  // WMPI_CAST
   WebMediaPlayerCast cast_impl_;
 #endif
 
+  // The last volume received by setVolume() and the last volume multiplier from
+  // OnVolumeMultiplierUpdate().  The multiplier is typical 1.0, but may be less
+  // if the WebMediaPlayerDelegate has requested a volume reduction (ducking)
+  // for a transient sound.  Playout volume is derived by volume * multiplier.
+  double volume_;
+  double volume_multiplier_;
+
   scoped_ptr<RendererFactory> renderer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_