Web Animations update - retire timed item events
Web Animations update - retire timed item events

Sync to latest Web Animations polyfill that does not have aliases Timeline or
specified, or timed item events.

We keep our SVG-specific patches.

smil-in-javascript/smil-in-javascript,smil-in-javascript/smil-in-javascript,smil-in-javascript/smil-in-javascript