Hookup the MediaStream glue for Adding and Removing tracks to an existing MediaStream.
https://code.google.com/p/webrtc/issues/detail?id=382
This cl refactor the way Chrome create the native repressentation for MediaStreams by splitting up creating MediaStreams and tracks in two functions, of for MediaStreams and one for Tracks (AddNativeLocalMediaTrack).
AddNativeLocalMediaTrack is hooked up to MediaStreamCenter::didAddMediaStreamTrack to allow adding tracks to existing MediaStreams.
Two content_browsertests are added for testing adding and removing tracks from MediaStreams.
Committed:
https://src.chromium.org/viewvc/chrome?view=rev&revision=193908