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

content/renderer/media/media_stream_renderer_factory_impl.cc

 // Copyright 2014 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_renderer_factory_impl.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "content/renderer/media/media_stream.h"
 #include "content/renderer/media/media_stream_audio_track.h"
 #include "content/renderer/media/media_stream_video_renderer_sink.h"
 #include "content/renderer/media/media_stream_video_track.h"
 #include "content/renderer/media/track_audio_renderer.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
+#include "content/renderer/media/webrtc/peer_connection_remote_audio_source.h"
 #include "content/renderer/media/webrtc_audio_renderer.h"
 #include "content/renderer/render_thread_impl.h"
 #include "media/base/audio_hardware_config.h"
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebMediaStreamRegistry.h"
 #include "third_party/webrtc/api/mediastreaminterface.h"
 
 namespace content {
 
@@ skipping 89 matching lines @@
       MediaStreamAudioTrack::From(audio_tracks[0]);
   if (!audio_track) {
     // This can happen if the track was cloned.
     // TODO(tommi, perkj): Fix cloning of tracks to handle extra data too.
     LOG(ERROR) << "No native track for WebMediaStreamTrack.";
     return nullptr;
   }
 
   // If the track has a local source, or is a remote track that does not use the
   // WebRTC audio pipeline, return a new TrackAudioRenderer instance.
-  //
-  // TODO(miu): In a soon up-coming change, I'll introduce a cleaner way (i.e.,
-  // rather than calling GetAudioAdapter()) to determine whether a remote source
-  // is via WebRTC or something else.
-  if (audio_track->is_local_track() || !audio_track->GetAudioAdapter()) {
+  if (!PeerConnectionRemoteAudioTrack::From(audio_track)) {
     // TODO(xians): Add support for the case where the media stream contains
     // multiple audio tracks.
     DVLOG(1) << "Creating TrackAudioRenderer for "
              << (audio_track->is_local_track() ? "local" : "remote")
              << " track.";
     return new TrackAudioRenderer(audio_tracks[0], render_frame_id,
                                   0 /* no session_id */, device_id,
                                   security_origin);
   }
 
@@ skipping 14 matching lines @@
         device_id, security_origin);
 
     if (!audio_device->SetAudioRenderer(renderer.get()))
       return nullptr;
   }
 
   return renderer->CreateSharedAudioRendererProxy(web_stream);
 }
 
 }  // namespace content