The purose of this cl is to remove dependency on cricket::VideoCapturer from WebRtcVideoChannel2. This cl change CPU adaptation to use a new VideoSinkWants.Resolution Cl is WIP and uploaded to start the discussion. Tested on a N5 with hw acceleration turned off. BUG=webrtc:5426 Review URL: https://codereview.webrtc.org/1695263002 Cr-Commit-Position: refs/heads/master@{#11804}