This will be used for frame matching in a follow up CL. Bug: webrtc:10365 Change-Id: If29fd59f8fff4c30b4c509104ade0e4ff02b08b2 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/130489 Commit-Queue: Sebastian Jansson <srte@webrtc.org> Reviewed-by: Magnus Jedvert <magjed@webrtc.org> Cr-Commit-Position: refs/heads/master@{#27399}