X-Frame-Options HTTP headers with an empty value are incorrectly being ignored.
Pull request: https://github.com/WebKit/WebKit/pull/4097
Committed 254245@main (8c97181d7559): <https://commits.webkit.org/254245@main> Reviewed commits have been landed. Closing PR #4097 and removing active labels.
<rdar://problem/99660826>