MTrimBar topTrim = ((WorkbenchWindow) PlatformUI.getWorkbench()
    .getActiveWorkbenchWindow()).getTopTrim();
for (MTrimElement element : topTrim.getChildren()) {
    if (element instanceof MToolBar) {
        boolean any = false;
        List<MToolBarElement> children = ((MToolBar) element).getChildren();
        if (children != null && !children.isEmpty()) {
            for (MToolBarElement child : children) {
                if (child.isVisible()) {
                    any = true;
                    break;
                }
            }
        }
        if (!any) {
            element.setVisible(false);
        }
    }
}