Add VideoTrackSink interface to content/public

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 4c2f046dfc64994e0b207df63c6dcbed8411b2af..9ddf38a12fbcccbd819fa7c21e9318ba41f1b54b 100644
--- a/content/renderer/media/media_stream_dependency_factory.cc
+++ b/content/renderer/media/media_stream_dependency_factory.cc
@@ -12,6 +12,7 @@
 #include "content/public/common/content_switches.h"
 #include "content/renderer/media/media_stream_source_extra_data.h"
 #include "content/renderer/media/media_stream_track_extra_data.h"
+#include "content/renderer/media/media_stream_video_track.h"
 #include "content/renderer/media/peer_connection_identity_service.h"
 #include "content/renderer/media/rtc_media_constraints.h"
 #include "content/renderer/media/rtc_peer_connection_handler.h"
@@ -914,7 +915,13 @@ void MediaStreamDependencyFactory::AddNativeTrackToBlinkTrack(
     const blink::WebMediaStreamTrack& webkit_track) {
   DCHECK(!webkit_track.isNull() && !webkit_track.extraData());
   blink::WebMediaStreamTrack track = webkit_track;
-  track.setExtraData(new MediaStreamTrackExtraData(native_track));
+
+  if (track.source().type() == blink::WebMediaStreamSource::TypeVideo) {
+    track.setExtraData(new MediaStreamVideoTrack(
+        static_cast<webrtc::VideoTrackInterface*> (native_track)));
+  } else {
+    track.setExtraData(new MediaStreamTrackExtraData(native_track));
+  }
 }
 
 webrtc::MediaStreamInterface*