Add Stop() to AudioDecoder.

media/filters/audio_renderer_impl.h

Index: media/filters/audio_renderer_impl.h
diff --git a/media/filters/audio_renderer_impl.h b/media/filters/audio_renderer_impl.h
index 851e52b81551f43eb7b7e0e020d6bb85e2c9922f..0e91e7ba5dc193e6905d23601d5b3d31e5486b84 100644
--- a/media/filters/audio_renderer_impl.h
+++ b/media/filters/audio_renderer_impl.h
@@ -183,6 +183,13 @@ class MEDIA_EXPORT AudioRendererImpl
   // Called when the |decoder_|.Reset() has completed.
   void ResetDecoderDone();
 
+  // Calls |decoder_|.Stop() and arranges for StopDecoderDone() to get
+  // called when the stop completes.
+  void StopDecoder();
+
+  // Called when the |decoder_|.Stop() has completed.
+  void StopDecoderDone();
+
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::WeakPtrFactory<AudioRendererImpl> weak_factory_;
   base::WeakPtr<AudioRendererImpl> weak_this_;
@@ -211,6 +218,7 @@ class MEDIA_EXPORT AudioRendererImpl
   base::Closure ended_cb_;
   base::Closure disabled_cb_;
   PipelineStatusCB error_cb_;
+  base::Closure stop_cb_;
 
   // Callback provided to Flush().
   base::Closure flush_cb_;