During my investigation, it was hard to figure out what ShouldAllowExternalSchemes implied.
Renaming ShouldAllowExternalSchemes to ShouldAllowExternalSchemesButNotAppLinks should clarify what this enum value is for.
Created attachment 409048 [details]
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
Committed r267203: <https://trac.webkit.org/changeset/267203>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 409048 [details].