AVSampleBufferRenderSynchronizer timeline sometimes goes backwards when playback begins
rdar://91117803
Created attachment 457835 [details] Patch
Created attachment 457942 [details] Patch for landing
Committed r293170 (249852@main): <https://commits.webkit.org/249852@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 457942 [details].