As an additional step towards broad support for custom properties in animations (bug 241842), we need to account for custom properties in Animation.commitStyles().
Pull request: https://github.com/WebKit/WebKit/pull/1810
Committed 251858@main (8161c9767ffb): <https://commits.webkit.org/251858@main> Reviewed commits have been landed. Closing PR #1810 and removing active labels.
<rdar://problem/95939301>