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
popup.setVisible(true);
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.IContributionItem#update(java.lang.String)
	 */
	public void update(String propertyName) {
		if (coolItem != null) {	
			boolean sizeChanged = (propertyName == null) || propertyName.equals(CoolBarManager.SIZE);
			
			if (sizeChanged) {
				updateSize(true);
			}
			
		}
		 
		
		if (propertyName.equals(CoolBarManager.VISIBILITY)) {
			
			if (toolBarManager != null) {
				IContributionItem[] items = toolBarManager.getItems();
				boolean visibleItem = false;
				for (int i=0; i < items.length; i++) {
					if ((!items[i].isGroupMarker()) && (!items[i].isSeparator()) && (items[i].isVisible())) {
						visibleItem = true;
						break;
					}
				}
				if (!visibleItem) {
					setVisible(false);