The poorly named SetEncoderStartBitrate() is renamed
SetEncoderTargetBitrate() and added to the abstract resource adaptation
module interface.
The so-called "start bitrate" was updated to match the target bitrate,
so this was only ever a "start bitrate" until we had any estimates. The
variable is renamed in VideoStreamEncoder as well, and usage of optional
types are introduced to avoid magical values in a few places in the
existing code.
Bug: webrtc:11222
Change-Id: Idde92f68f34616aa3c34ab77a791fdbe7ea7af26
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166880
Reviewed-by: Evan Shrubsole <eshr@google.com>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30347}