Remove ViE interface usage from VideoReceiveStream.

References channels and underlying objects directly instead of using
interfaces referenced with channel id. Channel creation is still done as
before for now.

BUG=1695
R=stefan@webrtc.org
TBR=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/46849004

Cr-Commit-Position: refs/heads/master@{#8958}
12 files changed