Fix playback rate w/o audio. Remove unused SetPlaybackRate().

media/base/audio_renderer_sink.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.
 
 #ifndef MEDIA_BASE_AUDIO_RENDERER_SINK_H_
 #define MEDIA_BASE_AUDIO_RENDERER_SINK_H_
 
 #include <vector>
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
@@ skipping 37 matching lines @@
 
   // Stops audio playback.
   virtual void Stop() = 0;
 
   // Pauses playback.
   virtual void Pause(bool flush) = 0;
 
   // Resumes playback after calling Pause().
   virtual void Play() = 0;
 
-  // Called to inform the sink of a change in playback rate. Override if
-  // subclass needs the playback rate.
-  virtual void SetPlaybackRate(float rate) {}
-
   // Sets the playback volume, with range [0.0, 1.0] inclusive.
   // Returns |true| on success.
   virtual bool SetVolume(double volume) = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<AudioRendererSink>;
   virtual ~AudioRendererSink() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_RENDERER_SINK_H_