Add a 'remote' property to MediaSourceInterface. Also adding an implementation to the relevant sour…

talk/app/webrtc/peerconnectionfactory.cc

Index: talk/app/webrtc/peerconnectionfactory.cc
diff --git a/talk/app/webrtc/peerconnectionfactory.cc b/talk/app/webrtc/peerconnectionfactory.cc
index 672355085a6b775e57264dd92a241f64295260e3..0d2c493ae0f42822c053dc661e245ef740cb1fe9 100644
--- a/talk/app/webrtc/peerconnectionfactory.cc
+++ b/talk/app/webrtc/peerconnectionfactory.cc
@@ -225,8 +225,8 @@ PeerConnectionFactory::CreateVideoSource(
     cricket::VideoCapturer* capturer,
     const MediaConstraintsInterface* constraints) {
   RTC_DCHECK(signaling_thread_->IsCurrent());
-  rtc::scoped_refptr<VideoSource> source(
-      VideoSource::Create(channel_manager_.get(), capturer, constraints));
+  rtc::scoped_refptr<VideoSource> source(VideoSource::Create(
+      channel_manager_.get(), capturer, constraints, false));
   return VideoSourceProxy::Create(signaling_thread_, source);
 }
 
@@ -330,6 +330,7 @@ PeerConnectionFactory::CreateVideoTrack(
     const std::string& id,
     VideoSourceInterface* source) {
   RTC_DCHECK(signaling_thread_->IsCurrent());
+  RTC_DCHECK(!source || !source->remote());

[perkj_webrtc, 2015/12/14 15:55:03]

I think this currently can be a remote source. It would be like cloning a track.
The remote source implementation is not very nice but I think it works.  (This
"feature" is not used in Chrome or anywhere else that I am aware of though) 

[tommi, 2015/12/14 16:38:25]

I see.  The same is not true for CreateAudioTrack at the moment.  The reason is
that remote audio sources do not have AddSink/RemoveSink functionality in the
AudioSourceInterface.  I guess I could add it and then make the audio part
agnostic to whether the source is remote or local too?  If I do that, we don't
really need a RemoteAudioTrack and I can just move the functionality from there
into AudioTrack.

   rtc::scoped_refptr<VideoTrackInterface> track(
       VideoTrack::Create(id, source));
   return VideoTrackProxy::Create(signaling_thread_, track);