This eliminates a lot of warnings when running AudioMixer unittests. Bug: None Change-Id: I978e859e8904bb382843a9c23a35ace1884aa4b4 Reviewed-on: https://webrtc-review.googlesource.com/58981 Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Commit-Queue: Sebastian Jansson <srte@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22245}