Done in preparation for the child CL which adds an alternative implementation. Bug: webrtc:7494 Change-Id: I4963376afc917eae434a0d0ccee18f21880eefe0 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/214125 Reviewed-by: Jakob Ivarsson <jakobi@webrtc.org> Commit-Queue: Alessio Bazzica <alessiob@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33646}