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 c3f4015d3500c60a8a4749c80099bd80460b9b8c..4d0ffa3bb4a3962aa345d4637bcdd43913029d27 100644
--- a/media/filters/audio_renderer_impl.h
+++ b/media/filters/audio_renderer_impl.h
@@ -83,17 +83,11 @@ 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();