a #GstObject
the property name in object to control
a #GstObject to forward all #GstControlBinding requests to
the property_name in ref_object to control
a new #GstControlBinding that proxies the control interface between properties on different #GstObject's
#GstProxyControlBinding forwards all access to data or sync_values() requests from property_name on object to the control binding at ref_property_name on ref_object.