Not all form controls care about "readonly" attribute.
Pull request: https://github.com/WebKit/WebKit/pull/8356
Committed 258621@main (05578471c16e): <https://commits.webkit.org/258621@main> Reviewed commits have been landed. Closing PR #8356 and removing active labels.
<rdar://problem/103992639>
Re-opened since this is blocked by bug 250600
Remanded in https://commits.webkit.org/258964@main