Implement audio constraints for PeerConneciton API

content/renderer/media/media_stream_source_extra_data.h

Index: content/renderer/media/media_stream_source_extra_data.h
diff --git a/content/renderer/media/media_stream_source_extra_data.h b/content/renderer/media/media_stream_source_extra_data.h
index 9b334a14ce12814de33ab3f9b037ff251aad3040..a5fb9ad2d53e6a72ad697e0820faf97e1eaa1b44 100644
--- a/content/renderer/media/media_stream_source_extra_data.h
+++ b/content/renderer/media/media_stream_source_extra_data.h
@@ -33,14 +33,27 @@ class CONTENT_EXPORT MediaStreamSourceExtraData
     video_source_ = source;
   }
 
+  void SetLocalAudioSource(webrtc::AudioSourceInterface* source) {
+    local_audio_source_ = source;
+  }
+
   webrtc::VideoSourceInterface* video_source() { return video_source_; }
   media::AudioCapturerSource* audio_source() { return audio_source_; }
+  webrtc::AudioSourceInterface* local_audio_source() {
+    return local_audio_source_;
+  }
 
  private:
   StreamDeviceInfo device_info_;
   scoped_refptr<webrtc::VideoSourceInterface> video_source_;
   scoped_refptr<media::AudioCapturerSource> audio_source_;
 
+  // This member holds an instance of webrtc::LocalAudioSource. This is used
+  // as a container for audio options.
+  // TODO(hclam): This should be merged with |audio_source_| such that it
+  // carries audio options.
+  scoped_refptr<webrtc::AudioSourceInterface> local_audio_source_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaStreamSourceExtraData);
 };