Add support for unmixed audio from remote WebRTC remote tracks.

content/renderer/media/media_stream_center.cc

 // 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.
 
 #include "content/renderer/media/media_stream_center.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 108 matching lines @@
   native_track->Stop();
   return true;
 }
 
 blink::WebAudioSourceProvider*
 MediaStreamCenter::createWebAudioSourceFromMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
   DVLOG(1) << "MediaStreamCenter::createWebAudioSourceFromMediaStreamTrack";
   MediaStreamTrack* media_stream_track =
       static_cast<MediaStreamTrack*>(track.extraData());
-  // Only local audio track is supported now.
-  // TODO(xians): Support remote audio track.
-  if (!media_stream_track || !media_stream_track->is_local_track()) {
-    NOTIMPLEMENTED();
-    return NULL;
+  if (!media_stream_track) {
+    DLOG(ERROR) << "Native track missing for webaudio source.";
+    return nullptr;
   }
 
   blink::WebMediaStreamSource source = track.source();
   DCHECK_EQ(source.type(), blink::WebMediaStreamSource::TypeAudio);
-  WebRtcLocalAudioSourceProvider* source_provider =
-      new WebRtcLocalAudioSourceProvider(track);
-  return source_provider;
+
+  // TODO(tommi): Rename WebRtcLocalAudioSourceProvider to
+  // WebRtcAudioSourceProvider since it's not specific to local.
+  return new WebRtcLocalAudioSourceProvider(track);
 }
 
 void MediaStreamCenter::didStopLocalMediaStream(
     const blink::WebMediaStream& stream) {
   DVLOG(1) << "MediaStreamCenter::didStopLocalMediaStream";
   MediaStream* native_stream = MediaStream::GetMediaStream(stream);
   if (!native_stream) {
     NOTREACHED();
     return;
   }
@@ skipping 28 matching lines @@
 
 bool MediaStreamCenter::didRemoveMediaStreamTrack(
     const blink::WebMediaStream& stream,
     const blink::WebMediaStreamTrack& track) {
   DVLOG(1) << "MediaStreamCenter::didRemoveMediaStreamTrack";
   MediaStream* native_stream = MediaStream::GetMediaStream(stream);
   return native_stream->RemoveTrack(track);
 }
 
 }  // namespace content