Introduce media::TimeSource.

media/filters/audio_renderer_impl.h

 // Copyright (c) 2012 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.
 
 // Audio rendering unit utilizing an AudioRendererSink to output data.
 //
 // This class lives inside three threads during it's lifetime, namely:
 // 1. Render thread
 //    Where the object is created.
 // 2. Media thread (provided via constructor)
@@ skipping 46 matching lines @@
   // |set_decryptor_ready_cb| is fired when the audio decryptor is available
   // (only applicable if the stream is encrypted and we have a decryptor).
   AudioRendererImpl(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       AudioRendererSink* sink,
       ScopedVector<AudioDecoder> decoders,
       const SetDecryptorReadyCB& set_decryptor_ready_cb,
       AudioHardwareConfig* hardware_params);
   virtual ~AudioRendererImpl();
 
+  // TimeSource implementation.
+  virtual void StartTicking() OVERRIDE;
+  virtual void StopTicking() OVERRIDE;
+  virtual void SetPlaybackRate(float rate) OVERRIDE;
+  virtual void SetMediaTimestamp(base::TimeDelta timestamp) OVERRIDE;
+  virtual base::TimeDelta CurrentMediaTimestamp() OVERRIDE;
+
   // AudioRenderer implementation.
   virtual void Initialize(DemuxerStream* stream,
                           const PipelineStatusCB& init_cb,
                           const StatisticsCB& statistics_cb,
-                          const TimeCB& time_cb,
                           const BufferingStateCB& buffering_state_cb,
                           const base::Closure& ended_cb,
                           const PipelineStatusCB& error_cb) OVERRIDE;
-  virtual void StartRendering() OVERRIDE;
-  virtual void StopRendering() OVERRIDE;
   virtual void Flush(const base::Closure& callback) OVERRIDE;
   virtual void Stop(const base::Closure& callback) OVERRIDE;
-  virtual void SetPlaybackRate(float rate) OVERRIDE;
-  virtual void StartPlayingFrom(base::TimeDelta timestamp) OVERRIDE;
+  virtual void StartPlaying() OVERRIDE;
   virtual void SetVolume(float volume) OVERRIDE;
 
  private:
   friend class AudioRendererImplTest;
 
   // Important detail: being in kPlaying doesn't imply that audio is being
   // rendered. Rather, it means that the renderer is ready to go. The actual
   // rendering of audio is controlled via Start/StopRendering().
   //
   //   kUninitialized
   //         | Initialize()
   //         |
   //         V
   //    kInitializing
   //         | Decoders initialized
   //         |
   //         V            Decoders reset
   //      kFlushed <------------------ kFlushing
-  //         | StartPlayingFrom()         ^
+  //         | StartPlaying()             ^
   //         |                            |
   //         |                            | Flush()
   //         `---------> kPlaying --------'
   enum State {
     kUninitialized,
     kInitializing,
     kFlushing,
     kFlushed,
     kPlaying,
     kStopped,
@@ skipping 137 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<AudioRendererImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_AUDIO_RENDERER_IMPL_H_