On random code inspection noticed that AnimationTimeline::relevantAnimations() and ::allAnimations() are copying into a new Vector. They don't need to. Moreover, allAnimations() isn't being used, so I was tempted to remove, but maybe it will be used soon?
Created attachment 398216 [details] Patch
Comment on attachment 398216 [details] Patch Clearing flags on attachment: 398216 Committed r261029: <https://trac.webkit.org/changeset/261029>
All reviewed patches have been landed. Closing bug.
<rdar://problem/62749337>