This CL introduces the ability to control the usage of the shadow filter output in the echo canceller output. Bug: webrtc:9694,chromium:879451 Change-Id: I01f90de60de1799b32892051c176bda5e1a8d33e Reviewed-on: https://webrtc-review.googlesource.com/97020 Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Commit-Queue: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#24506}