Function gio_sys::g_bus_watch_name_on_connection

pub unsafe extern fn g_bus_watch_name_on_connection(connection: *mut GDBusConnection,
                                                    name: *const c_char,
                                                    flags: GBusNameWatcherFlags,
                                                    name_appeared_handler: GBusNameAppearedCallback,
                                                    name_vanished_handler: GBusNameVanishedCallback,
                                                    user_data: gpointer,
                                                    user_data_free_func: GDestroyNotify)
                                                    -> c_uint