More thorough refactoring work is planned for RTCVideoFrame (see webrtc:7785), and this CL just unblocks removing the old interface from webrtc::VideoFrameBuffer.
Bug: webrtc:7632,webrtc:7785
Change-Id: I351536c5ca454c2acd8944bbc2ebb1d1439dc50c
Reviewed-on: https://chromium-review.googlesource.com/530231
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18553}