Bug 299438 [CommonNavigator] CNF viewer state non properly reset when NCEs are activated or deactivated
The map of the objects to the NCEs should be reset whenever the NCEs associated with the viewer to change to avoid having stale label information. This has shown up when looking at the CNF tests that change the viewer.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
*            <code>false</code> to only update labels as needed, assuming
	 *            that labels for existing elements are unchanged.
	 * 
	 * @since 2.0
	 */
	public void refresh(boolean updateLabels) {
		refresh(getRoot(), updateLabels);
	}
	/**
	 * Refreshes this viewer starting with the given element.
	 * <p>
	 * Unlike the <code>update</code> methods, this handles structural changes
	 * to the given element (e.g. addition or removal of children). If only the
	 * given element needs updating, it is more efficient to use the
	 * <code>update</code> methods.
	 * </p>
	 * 
	 * @param element
	 *            the element
	 */
	public void refresh(final Object element) {
		preservingSelection(new Runnable() {
			public void run() {
				internalRefresh(element);
			}
		});
	}
	/**
	 * Refreshes this viewer starting with the given element. Labels are updated
	 * as described in <code>refresh(boolean updateLabels)</code>.