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.
tests/org.eclipse.ui.tests.navigator/src/org/eclipse/ui/tests/navigator/LabelProviderTest.java
if (false)
			DisplayHelper.sleep(10000000);
		TreeItem[] rootItems = _viewer.getTree().getItems();
		checkItems(rootItems, TestLabelProviderCyan.instance);
	}
	
	public void XXXtestChangeActivation() throws Exception {
		TreeItem[] rootItems = _viewer.getTree().getItems();
		checkItems(rootItems, TestLabelProviderStyledGreen.instance);
		_contentService.bindExtensions(new String[] { TEST_CONTENT_OVERRIDDEN2,
				TEST_CONTENT_OVERRIDE2 }, false);
		_contentService.getActivationService().activateExtensions(
				new String[] { TEST_CONTENT_OVERRIDDEN2, TEST_CONTENT_OVERRIDE2 }, true);
		_viewer.expandAll();
		
		
		DisplayHelper.sleep(1000);
		if (false)
			DisplayHelper.sleep(10000000);
		
		rootItems = _viewer.getTree().getItems();
		checkItems(rootItems, TestLabelProviderCyan.instance);
	}
	
	
	
	
	public void testUsingOverriddenLabelProvider() throws Exception {
		_contentService.bindExtensions(new String[] { TEST_CONTENT_OVERRIDDEN2,
				TEST_CONTENT_OVERRIDE2_BLANK }, true);