Move bulk of media::AudioRendererImpl::Render() logic to media thread.

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 135 matching lines @@
   //
   // Render() updates the pipeline's playback timestamp. If Render() is
   // not called at the same rate as audio samples are played, then the reported
   // timestamp in the pipeline will be ahead of the actual audio playback. In
   // this case |audio_delay_milliseconds| should be used to indicate when in the
   // future should the filled buffer be played.
   virtual int Render(AudioBus* audio_bus,
                      int audio_delay_milliseconds) OVERRIDE;
   virtual void OnRenderError() OVERRIDE;
 
+  // Contains result of the last call to Render(). Used to update |audio_clock_|
+  // and changes in buffering state.
+  struct RenderResult {
+    RenderResult();
+
+    int requested_frames;
+    int delay_frames;
+    int frames_written;
+    float playback_rate;
+    base::TimeDelta endpoint_timestamp;
+  };
+  void DidRender(RenderResult result);

[DaleCurtis, 2014/07/10 23:37:00]

const&

+
   // Helper methods that schedule an asynchronous read from the decoder as long
   // as there isn't a pending read.
   //
   // Must be called on |task_runner_|.
-  void AttemptRead();
   void AttemptRead_Locked();
-  bool CanRead_Locked();
   void ChangeState_Locked(State new_state);
 
   // Returns true if the data in the buffer is all before |start_timestamp_|.
   // This can only return true while in the kPlaying state.
   bool IsBeforeStartTime(const scoped_refptr<AudioBuffer>& buffer);
 
   // Called upon AudioBufferStream initialization, or failure thereof (indicated
   // by the value of |success|).
   void OnAudioBufferStreamInitialized(bool succes);
 
   // Used to initiate the flush operation once all pending reads have
   // completed.
   void DoFlush_Locked();
 
   // Calls |decoder_|.Reset() and arranges for ResetDecoderDone() to get
   // called when the reset completes.
   void ResetDecoder();
 
   // Called when the |decoder_|.Reset() has completed.
   void ResetDecoderDone();
 
   // Called by the AudioBufferStream when a splice buffer is demuxed.
   void OnNewSpliceBuffer(base::TimeDelta);
 
   // Called by the AudioBufferStream when a config change occurs.
   void OnConfigChange();
 
   // Updates |buffering_state_| and fires |buffering_state_cb_|.
-  void SetBufferingState_Locked(BufferingState buffering_state);
+  void SetBufferingState(BufferingState buffering_state);
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   scoped_ptr<AudioSplicer> splicer_;
   scoped_ptr<AudioBufferConverter> buffer_converter_;
 
   // Whether or not we expect to handle config changes.
   bool expecting_config_changes_;
 
   // The sink (destination) for rendered audio. |sink_| must only be accessed
@@ skipping 54 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_