This CL adds delay headroom when an external delay estimator is used. Tested: audioproc_f --aec=1 is bitexact on a large number of aecdumps Bug: b/158455753 Change-Id: I56de44e841bb8162e302181c6c386ad7fbb00dee Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/186703 Commit-Queue: Sam Zackrisson <saza@webrtc.org> Reviewed-by: Per Åhgren <peah@webrtc.org> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32323}