A spec concept named "focus delegate" has been introduced since, the current Element::focusDelegate() function is unrelated.
<rdar://problem/86287159>
Pull request: https://github.com/WebKit/WebKit/pull/2817
Committed 252926@main (511a0e0ebba7): <https://commits.webkit.org/252926@main> Reviewed commits have been landed. Closing PR #2817 and removing active labels.