Remove media::AudioRendererImpl::SignalEndOfStream() and some other minor cleanup.

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 0a6d660d6d5b384b569289388a4cbbfe85e330c2..b3c014ff0d432479425545f915c208279c80e8d0 100644
--- a/media/filters/audio_renderer_impl.h
+++ b/media/filters/audio_renderer_impl.h
@@ -85,17 +85,11 @@ class MEDIA_EXPORT AudioRendererImpl
   // should the filled buffer be played. If FillBuffer() is called as the audio
   // hardware plays the buffer, then |playback_delay| should be zero.
   //
-  // FillBuffer() calls SignalEndOfStream() when it reaches end of stream.
-  //
   // Safe to call on any thread.
   uint32 FillBuffer(uint8* dest,
                     uint32 requested_frames,
                     const base::TimeDelta& playback_delay);
 
-  // Called at the end of stream when all the hardware buffers become empty
-  // (i.e. when all the data written to the device has been played).
-  void SignalEndOfStream();
-
   // Get the playback rate of |algorithm_|.
   float GetPlaybackRate();