MediaStream audio sourcing: Bypass audio processing for non-WebRTC cases.

content/renderer/media/media_stream_center.cc

Index: content/renderer/media/media_stream_center.cc
diff --git a/content/renderer/media/media_stream_center.cc b/content/renderer/media/media_stream_center.cc
index ad7f8ddf6f1c2281a6f693fab87fab0b419e3cd0..54c5499bb84476a52a175058cd07fde02a4cad09 100644
--- a/content/renderer/media/media_stream_center.cc
+++ b/content/renderer/media/media_stream_center.cc
@@ -15,9 +15,11 @@
 #include "content/public/renderer/media_stream_audio_sink.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/media/media_stream.h"
+#include "content/renderer/media/media_stream_audio_track.h"
 #include "content/renderer/media/media_stream_source.h"
 #include "content/renderer/media/media_stream_video_source.h"
 #include "content/renderer/media/media_stream_video_track.h"
+#include "content/renderer/media/webaudio_media_stream_source.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
 #include "content/renderer/media/webrtc_local_audio_source_provider.h"
 #include "third_party/WebKit/public/platform/WebMediaConstraints.h"
@@ -40,14 +42,25 @@ namespace {
 void CreateNativeAudioMediaStreamTrack(
     const blink::WebMediaStreamTrack& track,
     PeerConnectionDependencyFactory* factory) {
-  DCHECK(!track.extraData());
+  DCHECK(!MediaStreamAudioTrack::Get(track));
   blink::WebMediaStreamSource source = track.source();
   DCHECK_EQ(source.type(), blink::WebMediaStreamSource::TypeAudio);
-  if (source.remote()) {
-    factory->CreateRemoteAudioTrack(track);
+
+  if (!source.extraData()) {
+    // TODO(miu): This needs to be moved to an appropriate location.  The source
+    // should have been created before this method was called.
+    if (source.requiresAudioConsumer()) {
+      DVLOG(1) << "Creating WebAudio media stream source.";
+      source.setExtraData(new WebAudioMediaStreamSource(source));
+    }
   } else {
-    factory->CreateLocalAudioTrack(track);
+    NOTREACHED()
+        << "WebMediaStreamSource missing its MediaStreamAudioSource.";
+    return;
   }
+
+  static_cast<MediaStreamAudioSource*>(source.extraData())
+      ->ConnectToTrack(track);
 }
 
 void CreateNativeVideoMediaStreamTrack(
@@ -104,35 +117,31 @@ void MediaStreamCenter::didCreateMediaStreamTrack(
 
 void MediaStreamCenter::didEnableMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
-  MediaStreamTrack* native_track =
-      MediaStreamTrack::GetTrack(track);
-  if (native_track)
+  if (MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track))
     native_track->SetEnabled(true);
 }
 
 void MediaStreamCenter::didDisableMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
-  MediaStreamTrack* native_track =
-      MediaStreamTrack::GetTrack(track);
-  if (native_track)
+  if (MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track))
     native_track->SetEnabled(false);
 }
 
 bool MediaStreamCenter::didStopMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
   DVLOG(1) << "MediaStreamCenter::didStopMediaStreamTrack";
-  MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track);
-  native_track->Stop();
-  return true;
+  if (MediaStreamTrack* native_track = MediaStreamTrack::GetTrack(track)) {
+    native_track->Stop();
+    return true;
+  }
+  return false;
 }
 
 blink::WebAudioSourceProvider*
 MediaStreamCenter::createWebAudioSourceFromMediaStreamTrack(
     const blink::WebMediaStreamTrack& track) {
   DVLOG(1) << "MediaStreamCenter::createWebAudioSourceFromMediaStreamTrack";
-  MediaStreamTrack* media_stream_track =
-      static_cast<MediaStreamTrack*>(track.extraData());
-  if (!media_stream_track) {
+  if (!MediaStreamAudioTrack::Get(track)) {
     DLOG(ERROR) << "Native track missing for webaudio source.";
     return nullptr;
   }