As part of the work on Scroll-driven Animations (bug 222295) we will need to support the `scroll-timeline` shorthand property and its longhands.
Pull request: https://github.com/WebKit/WebKit/pull/20864
Committed 271110@main (782243529167): <https://commits.webkit.org/271110@main> Reviewed commits have been landed. Closing PR #20864 and removing active labels.
<rdar://problem/118783919>
Re-opened since this is blocked by bug 265358
Pull request: https://github.com/WebKit/WebKit/pull/20924
Committed 271189@main (0f2aca5ad236): <https://commits.webkit.org/271189@main> Reviewed commits have been landed. Closing PR #20924 and removing active labels.