This CL corrects the bug that only looked at narrowband render signals above 900 Hz and only assumed that the influence of such lasted for 6 blocks, which resulted in filter divergence and echo leakage. Bug: webrtc:9008,chromium:821670 Change-Id: I9b2635d24b260e9d9a8c5c088ab663e03fb93c42 Reviewed-on: https://webrtc-review.googlesource.com/61800 Commit-Queue: Per Åhgren <peah@webrtc.org> Reviewed-by: Ivo Creusen <ivoc@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22434}