This fixes an issue which can happen if fec is used. The protection
rate may fluctuate and each such change would trigger a new allocation
limit to be signaled. For each such update, the probe controller could
initiate a new probe.
We work around this by both quantizing the protection fraction and by
not sending a new probe unless the max allocated bitrate has increased
significantly (or we are in ALR).
Bug: webrtc:10070
Change-Id: I328963da23aedbcbedeb877aec46f5955cd2b88d
Reviewed-on: https://webrtc-review.googlesource.com/c/113525
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25971}
00672b1ddc