Since https://webrtc-review.googlesource.com/c/src/+/161447,
frame_extra_info_ is modified from both the encoder thread and the
callback thread.
Bug: None
Change-Id: Idece4d19cae6d8363428234721616f6ca6f85832
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/184121
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Mirta Dvornicic <mirtad@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32095}
8452ea86c5