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
blankLabelProviderOverride(OVERRIDDEN, NULL, PLAIN);
	}
	public void testBlankLabelProviderOverride2() throws Exception {
		blankLabelProviderOverride(OVERRIDING, BLANK, "");
	}
	public void testNullLabelProviderOverride2() throws Exception {
		blankLabelProviderOverride(OVERRIDING, NULL, "");
	}
	public void testPlainBlankLabelProviderOverride2() throws Exception {
		blankLabelProviderOverride(OVERRIDING, BLANK, PLAIN);
	}
	public void testPlainNullLabelProviderOverride2() throws Exception {
		blankLabelProviderOverride(OVERRIDING, NULL, PLAIN);
	}
	public void testBlankLabelProviderBoth() throws Exception {
		blankLabelProviderOverride(BOTH, BLANK, "");
	}
	public void testNullLabelProviderBoth() throws Exception {
		blankLabelProviderOverride(BOTH, NULL, "");
	}
	public void testPlainBlankLabelProviderBoth() throws Exception {
		blankLabelProviderOverride(BOTH, BLANK, PLAIN);
	}
	public void testPlainNullLabelProviderBoth() throws Exception {
		blankLabelProviderOverride(BOTH, NULL, PLAIN);
	}
	
	public void testSimpleResFirst() throws Exception {
		_contentService.bindExtensions(new String[] { TEST_CONTENT_OVERRIDDEN1,
				TEST_CONTENT_OVERRIDE1 }, false);