gtk_widget_set_rc_style(gArrowWidget);
ensure_arrow_widget(){    if (!gArrowWidget) {        gDropdownButtonWidget = gtk_button_new();        setup_widget_prototype(gDropdownButtonWidget);        gArrowWidget = gtk_arrow_new(GTK_ARROW_DOWN, GTK_SHADOW_OUT);        gtk_container_add(GTK_CONTAINER(gDropdownButtonWidget), gArrowWidget);        gtk_widget_set_rc_style(gArrowWidget);        gtk_widget_realize(gArrowWidget);    }    return MOZ_GTK_SUCCESS;}