Bug 128293 [Contributions] visible/enabled: Object contributions contributed to submenus do not show up
bundles/org.eclipse.jface/src/org/eclipse/jface/action/SubMenuManager.java
/* (non-Javadoc)
     * @see org.eclipse.jface.action.IContributionItem#isEnabled()
     */
    public boolean isEnabled() {
        return isVisible() && getParentMenuManager().isEnabled();
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.action.IContributionItem#isGroupMarker()
     */
    public boolean isGroupMarker() {
        return getParentMenuManager().isGroupMarker();
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.action.IContributionItem#isSeparator()
     */
    public boolean isSeparator() {
        return getParentMenuManager().isSeparator();
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.action.SubContributionManager#isVisible()
     */
    public boolean isVisible() {
        return super.isVisible() && getParentMenuManager().isVisible();
    }
    /**
     * Remove all contribution items.
     */
    public void removeAll() {
        super.removeAll();
        if (mapMenuToWrapper != null) {