This CL generalizes the hysteresis behavior on the AEC3 delay estimator to be two-sided and easier to configure. Bug: webrtc:8671 Change-Id: Ife21c1511416e32eb3618c81178deefe332ac1e8 Reviewed-on: https://webrtc-review.googlesource.com/39267 Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Commit-Queue: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21604}