CGDisplayList image cache cannot cache images between layers
<rdar://problem/100336143>
Pull request: https://github.com/WebKit/WebKit/pull/4894
Committed 273240@main (e8c0db1780a3): <https://commits.webkit.org/273240@main> Reviewed commits have been landed. Closing PR #4894 and removing active labels.
Re-opened since this is blocked by bug 268062