Inject config when creating channels to override the existing one.

BUG=
R=xians@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/3239004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5116 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed