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
IMenuManager {
    /**
     * Maps each submenu in the manager to a wrapper.  The wrapper is used to
     * monitor additions and removals.  If the visibility of the manager is modified
     * the visibility of the submenus is also modified.
     */
    private Map mapMenuToWrapper;
    /**
     * List of registered menu listeners (element type: <code>IMenuListener</code>).
     */
    private ListenerList menuListeners = new ListenerList();
    /**
     * The menu listener added to the parent.  Lazily initialized