This introduces a new class for encapsulating the QualityRampupExperiment
R=hbos@webrtc.org
Bug: webrtc:11553
Change-Id: If2f2347cdcbd0c79821355f90e2d7ad3171143b5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176363
Commit-Queue: Evan Shrubsole <eshr@google.com>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31531}