Ensures that WebRTC works for device selection using a different sample rate than default

content/renderer/media/media_stream_dependency_factory.cc

Index: content/renderer/media/media_stream_dependency_factory.cc
diff --git a/content/renderer/media/media_stream_dependency_factory.cc b/content/renderer/media/media_stream_dependency_factory.cc
index 69a35727ac7c413317e4292452788668680f0e03..7512cce0caff59ba1a22375bc147c1f9fd37d36a 100644
--- a/content/renderer/media/media_stream_dependency_factory.cc
+++ b/content/renderer/media/media_stream_dependency_factory.cc
@@ -190,6 +190,7 @@ void MediaStreamDependencyFactory::CreateNativeMediaSources(
     const WebKit::WebMediaConstraints& video_constraints,
     WebKit::WebMediaStreamDescriptor* description,
     const MediaSourcesCreatedCallback& sources_created) {
+  DVLOG(1) << "MediaStreamDependencyFactory::CreateNativeMediaSources()";
   if (!EnsurePeerConnectionFactory()) {
     sources_created.Run(description, false);
     return;
@@ -223,11 +224,59 @@ void MediaStreamDependencyFactory::CreateNativeMediaSources(
                           &native_video_constraints));
     source_observer->AddSource(source_data->video_source());
   }
+
+  // Do additional source initialization if the audio source is a valid
+  // microphone.
+  WebKit::WebVector<WebKit::WebMediaStreamComponent> audio_components;
+  description->audioSources(audio_components);
+  for (size_t i = 0; i < audio_components.size(); ++i) {
+    const WebKit::WebMediaStreamSource& source = audio_components[i].source();
+    MediaStreamSourceExtraData* source_data =
+        static_cast<MediaStreamSourceExtraData*>(source.extraData());

[perkj_chrome, 2013/01/15 09:00:19]

Will WebAudio also end up here? Fix comment in that case.

[henrika (OOO until Aug 14), 2013/01/16 16:49:00]

Do you mean for the MediaStreamDestination case (not yet in Chrome)?

+    if (!source_data) {
+      // TODO(henrika): Implement support for sources from remote MediaStreams.
+      NOTIMPLEMENTED();
+      continue;
+    }
+
+    const MediaStreamDevice device = source_data->device_info().device;
+    if (device.type == content::MEDIA_DEVICE_AUDIO_CAPTURE) {
+      // Initialize the source using audio parameters for the selected
+      // capture device.
+      WebRtcAudioCapturer* capturer = GetWebRtcAudioDevice()->capturer();
+      // TODO(henrika): refactor \content\public\common\media_stream_request.h
+      // to allow dependency of media::ChannelLayout and avoid static_cast.
+      if (!capturer->Initialize(
+          static_cast<media::ChannelLayout>(device.channel_layout),
+          device.sample_rate)) {
+        // The capturer does not support all possible sample rates.

[perkj_chrome, 2013/01/15 09:00:19]

nit: all possible ? I don't understand the comment- does it add any value here?
All we care about is if the source was successfully initialized.

[henrika (OOO until Aug 14), 2013/01/16 16:49:00]

Refactored + fixed.

+        sources_created.Run(description, false);
+        return;
+      }
+
+      // Specify which capture device to use. The acquired session id is used
+      // for identification.
+      // TODO(henrika): the current design does not support a uniqe source
+      // for each audio track.
+      if (source_data->device_info().session_id <= 0) {
+        LOG(ERROR) << "Invalid audio session id";
+        sources_created.Run(description, false);
+        return;
+      }
+      capturer->SetDevice(source_data->device_info().session_id);
+    } else {
+      DLOG(WARNING) << "Unsupported audio source";

[perkj_chrome, 2013/01/15 09:00:19]

nit: NOTREACHED ?

[henrika (OOO until Aug 14), 2013/01/16 16:49:00]

See if you like new proposal better.

+      sources_created.Run(description, false);
+      return;
+    }
+  }
+
   source_observer->StartObservering();
 }
 
 void MediaStreamDependencyFactory::CreateNativeLocalMediaStream(
     WebKit::WebMediaStreamDescriptor* description) {
+  DVLOG(1) << "MediaStreamDependencyFactory::CreateNativeLocalMediaStream()";
   DCHECK(PeerConnectionFactoryCreated());
 
   std::string label = UTF16ToUTF8(description->label());
@@ -253,10 +302,6 @@ void MediaStreamDependencyFactory::CreateNativeLocalMediaStream(
         CreateLocalAudioTrack(UTF16ToUTF8(source.id()), NULL));
     native_stream->AddTrack(audio_track);
     audio_track->set_enabled(audio_components[i].isEnabled());
-    // TODO(xians): This set the source of all audio tracks to the same
-    // microphone. Implement support for setting the source per audio track
-    // instead.
-    SetAudioDeviceSessionId(source_data->device_info().session_id);
   }
 
   // Add video tracks.
@@ -295,6 +340,7 @@ void MediaStreamDependencyFactory::CreateNativeLocalMediaStream(
 }
 
 bool MediaStreamDependencyFactory::CreatePeerConnectionFactory() {
+  DVLOG(1) << "MediaStreamDependencyFactory::CreatePeerConnectionFactory()";
   if (!pc_factory_.get()) {
     DCHECK(!audio_device_);
     audio_device_ = new WebRtcAudioDeviceImpl();
@@ -389,10 +435,6 @@ MediaStreamDependencyFactory::GetWebRtcAudioDevice() {
   return audio_device_;
 }
 
-void MediaStreamDependencyFactory::SetAudioDeviceSessionId(int session_id) {
-  audio_device_->SetSessionId(session_id);
-}
-
 void MediaStreamDependencyFactory::InitializeWorkerThread(
     talk_base::Thread** thread,
     base::WaitableEvent* event) {