[GTK] Annotate WebKitUserMessage getters as nullable
Created attachment 413709 [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 r269675: <https://trac.webkit.org/changeset/269675>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 413709 [details].