REGRESSION(271415@main): Paint-on captions shift slightly during playback
<rdar://problem/120847946>
Pull request: https://github.com/WebKit/WebKit/pull/22664
Committed 272966@main (c2b79f5f2ba7): <https://commits.webkit.org/272966@main> Reviewed commits have been landed. Closing PR #22664 and removing active labels.