Intended to make it easier to wire up cpu-adaptation experiments.
To setup the circular references between OveruseFrameDetector and
VideoStreamEncoder, let the AdaptationObserverInterface pointer be
an argument to StartCheckForOveruse.
Bug: webrtc:8504
Change-Id: Ifcf7655ec65e637819d77f507552cb22a6aa5f0f
Reviewed-on: https://webrtc-review.googlesource.com/33340
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22006}