Recent versions of GTK+ now warns at runtime when a deprecated property or signal is used. A diagnostic mode was added that is enabled by default, but that can be disabled by setting G_ENABLE_DIAGNOSTIC=0, see https://bugzilla.gnome.org/show_bug.cgi?id=601686
Created attachment 235735 [details] Patch
Committed r171794: <http://trac.webkit.org/changeset/171794>