commit ce0ea49001238a2d624a54bdd6fefb4bae181961
author Henrik Boström <hbos@webrtc.org> Mon Jan 13 10:27:18 2020
committer Commit Bot <commit-bot@chromium.org> Mon Jan 13 11:14:04 2020
tree c11b950d228ad15d8cd97cb28038b14d6bcc9e48
parent d23820088285b76b4ec2ca4631e8474de24ed6e9

VideoStreamEncoder configuring source/sink with VideoSourceController.

This is part of the work for making VideoStreamEncoder responsible for
configuring its source/sink and limiting the responsibility of
OveruseFrameDetectorResourceAdaptationModule to only output relevant
VideoSourceRestrictions.

BEFORE THIS CL

Prior to this CL, OveruseFrameDetector was responsible for performing
AddOrUpdateSink() on the source, which it did using its nested class
VideoSourceProxy.

AddOrUpdateSink() could happen for both adaptation and non-adaptation
related reasons. For example:
- Adaptation related: AdaptUp() or AdaptDown() happens, causing updated
  VideoSourceRestrictions.
- Non-adaptation related: VideoStreamEncoder asks the module to
  reconfigure the source/sink for it, such as with
  SetMaxFramerateAndAlignment() or SetWantsRotationApplied().

AFTER THIS CL

AddOrUpdateSink() is performed by VideoSourceController, which is owned
by VideoStreamEncoder. Any reconfiguration has to go through the
VideoStreamEncoder. This means that:
- Non-adaptation related settings happen between VideoStreamEncoder and
  VideoSourceController directly (without going through the adaptation
  module).
- Adaptation related changes can be expressed in terms of
  VideoSourceRestrictions. OveruseFrameDetectorResourceAdaptationModule
  only has to output the restrictions and not know or care about other
  source/sink settings.

For now, VideoSourceController has to know about DegradationPreference.
In a future CL, the DegradationPreference logic should move back to
the adaptation module. The VideoSourceRestrictions are fully capable of
expressing all possible source/sink values without the "modifier" that
is the degradation preference.

Bug: webrtc:11222
Change-Id: I0f058c4700ca108e2d9f212e38b61f6f728aa419
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162802
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@google.com>
Cr-Commit-Position: refs/heads/master@{#30228}