The timestamps used for sample division in SourceBuffer aren't being aligned with the same rounding margin used in SourceBuffer::sourceBufferPrivateDidReceiveSample().
Created attachment 454012 [details] Patch
Created attachment 454090 [details] Patch
Committed r291101 (248263@main): <https://commits.webkit.org/248263@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 454090 [details].
<rdar://problem/90090776>