The following newly imported W3C ref-test is failing: http/tests/w3c/html/semantics/embedded-content/the-video-element/video_initially_paused.html is failing The video frame does not show. It seems to show when run in the browser but not in the context of the layout tests so this may be a timing issue.
<rdar://problem/22588320>
All browsers are failing this test case: https://wpt.fyi/results/html/semantics/embedded-content/the-video-element/video_initially_paused.html?label=experimental&label=master&aligned= though looks like 70 px difference rather than actual failure etc. So might need to be fixed upstream in WPT repo.