Bug 48452 Widget is disposed while closing cool bar
This is the problem that is occurring in the nightly builds. There is something happening where a cool bar is attempting to layout disposed cool bar items.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ToolBarContributionItem.java
/**
	 * A constant used by <code>setMinimumItemsToShow</code> and <code>getMinimumItemsToShow</code>
	 * to indicate that all tool items should be shown in the cool item.
	 */
	public static final int SHOW_ALL_ITEMS = -1;
	
	/**
	 * The tool bar manager used to manage the tool items contained in the cool item widget.
	 */
	private ToolBarManager toolBarManager = null;
	
	/**
	 * The pull down menu used to list all hidden tool items if the current size is less than
	 * the preffered size.
	 */
	private MenuManager chevronMenuManager = null;
	
	/**
	 * The context menu of the cool item. If one is not defined the the parents context menu
	 * is used.
	 */
	private MenuManager contextMenuManager = null;
	
	/**
	 * Mininum number of tool items to show in the cool item widget.
	 */