[GTK] Fix build after r209558
Created attachment 296651 [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 http://trac.webkit.org/wiki/WebKitGTK/AddingNewWebKit2API
Committed r209604: <http://trac.webkit.org/changeset/209604>