Wire up webrtc::RateAllocation to RtcVideoEncoder.

This will be necessary in order to properly use temporal and spatial
scalability in hardware accelerated video codecs.

Bug: chromium:794608
Change-Id: I029e044a33c95eb4bcc9db04b028d04a3cb7f922
Reviewed-on: https://chromium-review.googlesource.com/1016900
Commit-Queue: Erik Språng <[email protected]>
Reviewed-by: Kentaro Hara <[email protected]>
Reviewed-by: Dale Curtis <[email protected]>
Reviewed-by: Emircan Uysaler <[email protected]>
Cr-Commit-Position: refs/heads/master@{#560254}
9 files changed