Now that plugins are obsolete, this code should never be able to run. See https://github.com/whatwg/html/pull/6281. No tests as I'm not sure how web-platform-tests can test this.
<rdar://problem/73348091>
I'm no longer able to relevant code. Unless someone knows something this can probably be closed.
I looked at this again, grepped for objectTag and could not find anything relevant. And HTMLObjectElement only seemed to have form stuff that was still relevant, apart from one minor thing which I'll remove.
Pull request: https://github.com/WebKit/WebKit/pull/16098
Committed 266319@main (a6c7c6f6984d): <https://commits.webkit.org/266319@main> Reviewed commits have been landed. Closing PR #16098 and removing active labels.