This CL adds code for doing signal-dependent downmixing before the delay estimation in the multichannel case. As part of the CL, the unittests of the render delay controller are corrected. However, as that caused some of them to fail, the CL (for now) as well disables the failing test. Bug: webrtc:11153,chromium:1029740, webrtc:11161 Change-Id: I0b765c28fa5e547aabd6dfbd24b626ff9a16346f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161045 Commit-Queue: Per Åhgren <peah@webrtc.org> Reviewed-by: Sam Zackrisson <saza@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29980}