Adding back removed methods to MockNonlinearBeamformer.

This is temporary, until downstream dependencies are updated.

TBR=aluebs@webrtc.org

Review-Url: https://codereview.webrtc.org/2121553002
Cr-Original-Commit-Position: refs/heads/master@{#13374}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: bb01781982c515f0100ea56d0e5cb62a52b67fcb
1 file changed