Change argument type for VideoProviderInterface::SetVideoPlayout.
Replace VideoMediaChannel::SetRenderer and VideoChannel::SetRenderer
by SetSink.
Alse deleted unused member variables VideoMediaChannel::renderer_ and
VideoChannel::renderer_.
BUG=webrtc:5426
Review URL: https://codereview.webrtc.org/1668493002
Cr-Commit-Position: refs/heads/master@{#11485}