MediaStream audio: Refactor 3 separate "glue" implementations into one.

content/renderer/media/webrtc_local_audio_source_provider.h

Index: content/renderer/media/webrtc_local_audio_source_provider.h
diff --git a/content/renderer/media/webrtc_local_audio_source_provider.h b/content/renderer/media/webrtc_local_audio_source_provider.h
index d9432805b4078227d58c68dcf985276796a245d2..f5a867fc9495fbb7d1fc645689ecf700de4e5768 100644
--- a/content/renderer/media/webrtc_local_audio_source_provider.h
+++ b/content/renderer/media/webrtc_local_audio_source_provider.h
@@ -34,11 +34,15 @@ class WebAudioSourceProviderClient;
 
 namespace content {
 
+// TODO(miu): This implementation should be renamed to WebAudioMediaStreamSink,
+// as it should work as a provider for WebAudio from ANY MediaStreamAudioTrack.
+// http://crbug.com/577874
+//
 // WebRtcLocalAudioSourceProvider provides a bridge between classes:
-//     WebRtcLocalAudioTrack ---> blink::WebAudioSourceProvider
+//     MediaStreamAudioTrack ---> blink::WebAudioSourceProvider
 //
-// WebRtcLocalAudioSourceProvider works as a sink to the WebRtcLocalAudioTrack
-// and store the capture data to a FIFO. When the media stream is connected to
+// WebRtcLocalAudioSourceProvider works as a sink to the MediaStreamAudioTrack
+// and stores the capture data to a FIFO. When the media stream is connected to
 // WebAudio MediaStreamAudioSourceNode as a source provider,
 // MediaStreamAudioSourceNode will periodically call provideInput() to get the
 // data from the FIFO.