When a bandwidth decrease to the estimated throughput would lead to the "critical low" region we allow dropping to the link capacity estimate instead (if it is higher). Also moved BweInitialBackOffInterval config to the same field trial string. Bug: webrtc:10462 Change-Id: I4d6ee020a9ab8cede035b64253e3b3b1e2fb92b1 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/129920 Reviewed-by: Sebastian Jansson <srte@webrtc.org> Commit-Queue: Christoffer Rodbro <crodbro@webrtc.org> Cr-Commit-Position: refs/heads/master@{#27325}