Cleaned up the WebRtcAudioCapturer a bit.

content/renderer/media/rtc_peer_connection_handler.cc

Index: content/renderer/media/rtc_peer_connection_handler.cc
diff --git a/content/renderer/media/rtc_peer_connection_handler.cc b/content/renderer/media/rtc_peer_connection_handler.cc
index 08f71c064b371d3c20beba4ae47d339b8d7c67a9..306c6c7ac35ae92690335372dc4f2cbf2ed5c62e 100644
--- a/content/renderer/media/rtc_peer_connection_handler.cc
+++ b/content/renderer/media/rtc_peer_connection_handler.cc
@@ -15,6 +15,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/common/content_switches.h"
 #include "content/renderer/media/media_stream_dependency_factory.h"
+#include "content/renderer/media/media_stream_source_extra_data.h"
 #include "content/renderer/media/peer_connection_tracker.h"
 #include "content/renderer/media/remote_media_stream_impl.h"
 #include "content/renderer/media/rtc_data_channel_handler.h"
@@ -549,13 +550,16 @@ bool RTCPeerConnectionHandler::addStream(
         this, stream, PeerConnectionTracker::SOURCE_LOCAL);
 
   // A media stream is connected to a peer connection, enable the
-  // peer connection mode for the capturer.
-  WebRtcAudioDeviceImpl* audio_device =
-      dependency_factory_->GetWebRtcAudioDevice();
-  if (audio_device) {
-    WebRtcAudioCapturer* capturer = audio_device->GetDefaultCapturer();
-    if (capturer)
-      capturer->EnablePeerConnectionMode();
+  // peer connection mode for the sources.
+  blink::WebVector<blink::WebMediaStreamTrack> audio_tracks;
+  stream.audioTracks(audio_tracks);
+  for (size_t i = 0; i < audio_tracks.size(); ++i) {
+    const blink::WebMediaStreamSource& source = audio_tracks[i].source();
+    MediaStreamSourceExtraData* extra_data =
+        static_cast<MediaStreamSourceExtraData*>(source.extraData());
+    DCHECK_EQ(source.type(), blink::WebMediaStreamSource::TypeAudio);

[perkj_chrome, 2014/01/12 21:53:06]

no need for dcheck

[no longer working on chromium, 2014/01/13 16:59:59]

Done.

+    if (extra_data->GetAudioCapturer())
+      extra_data->GetAudioCapturer()->EnablePeerConnectionMode();

[perkj_chrome, 2014/01/12 21:53:06]

Is EnablePeerConnectionMode() needed?

[no longer working on chromium, 2014/01/13 16:59:59]

Yes. the capturer might be setup for WebAudio, in such case, it might run with a
packet size smaller than 10ms chunk. When the peer connnection is hooked up, we
need to make sure the capturer is running at 10ms packet size to have the peer
connection working properly.

   }
 
   return AddStream(stream, &constraints);