2ab9879af0
In the transition period when we have both VideoRenderer.Callbacks and VideoSinks, and VideoRenderer.I420Frames and VideoFrames, the adapters between them does not handle RGB frames correctly. This CL improves the situation somewhat, and at least gives clearer error messages. BUG=webrtc:7749 Review-Url: https://codereview.webrtc.org/3017433002 Cr-Commit-Position: refs/heads/master@{#19817}