Created attachment 432898 [details]
I've opened a separate https://bugs.webkit.org/show_bug.cgi?id=227691 since that's a different issue and will require a deeper rework (and is not GTK4-specific), but the code was also never ported to GTK4 to begin with, so we can do at least that for now.
Hmm, it depends on https://bugs.webkit.org/show_bug.cgi?id=227678 (not really, but there's a merge conflict otherwise)
Committed r279580 (239411@main): <https://commits.webkit.org/239411@main>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 432898 [details].