[web-animations] marker-start should support discrete animation
Created attachment 454571 [details] Patch
Created attachment 454587 [details] [fast-cq] Patch for landing
Committed r291228 (248383@main): <https://commits.webkit.org/248383@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 454587 [details].
<rdar://problem/90244310>