This CL adds functionality in AEC3 that allows the computational complexity to be reduced when the output of APM is not used. Bug: b/177830919 Change-Id: I08121364bf966f34311f54ffa5affbfd8b4db1e2 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/211341 Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Commit-Queue: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33476}