That's another regression from https://bugs.webkit.org/show_bug.cgi?id=212324, I noticed that the previous device type check got removed...
Created attachment 432877 [details] Patch
Thanks for the patch. If this patch contains new public API please make sure it follows the guidelines for new WebKit2 GTK+ API. See https://trac.webkit.org/wiki/WebKitGTK/AddingNewWebKit2API
Hm yes, there's also a GTK3-only code path in PageClientImpl.cpp. I hoped I can get away without a GTK3 build as well. :)
Created attachment 432885 [details] Patch Updated that codepath as well.
Committed r279574 (239405@main): <https://commits.webkit.org/239405@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 432885 [details].