Refactor VideoTracks to forward all sinks to its source
This remove the use of VideoTrackRenderers within VideoTrack and instead all its sinks are passed to VideoSource.
That means that the source will handle all sinks and can (if the source implement it) handle different SinkWants for each sink.
The VideoBroadcaster is updated to produce black frames instead of as is today the deprecated VideoTrackRenderers.
BUG=webrtc:5426
R=nisse@webrtc.org, pthatcher@webrtc.org
Review URL: https://codereview.webrtc.org/1779063003 .
Cr-Original-Commit-Position: refs/heads/master@{#12028}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: d6c395441bf2866e2a99d726912292f67928999f
13 files changed
