This CL changes the behavior when the main filter diverges. Instead of entering non-linear mode, the AEC continues to operate in linear mode but estimates the residual echo differently. R2 is S2 scaled by a factor of 10. Bug: chromium:857018,webrtc:9462 Change-Id: I41212efe164ad319cf38a163cdf9d3ea151e0997 Reviewed-on: https://webrtc-review.googlesource.com/85981 Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org> Reviewed-by: Jesus de Vicente Pena <devicentepena@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23772}