Bug 299210 [CommonNavigator] Test improvements
tests/org.eclipse.ui.tests.navigator/src/org/eclipse/ui/tests/navigator/NavigatorTestBase.java
protected void showNavigator() throws PartInitException {
		EditorTestHelper.showView(_navigatorInstanceId, true);
		IWorkbenchWindow activeWindow = PlatformUI.getWorkbench()
				.getActiveWorkbenchWindow();
		IWorkbenchPage activePage = activeWindow.getActivePage();
		_commonNavigator = (CommonNavigator) activePage
				.findView(_navigatorInstanceId);
		_commonNavigator.setFocus();
		_viewer = (CommonViewer) _commonNavigator
				.getAdapter(CommonViewer.class);
	}
	
	protected void tearDown() throws Exception {
		clearAll();
		
		EditorTestHelper.showView(_navigatorInstanceId, false);
	}
	protected void clearAll() throws Exception {
		IProject[] projects = ResourcesPlugin.getWorkspace().getRoot()
				.getProjects();
		for (int i = 0; i < projects.length; i++) {
			projects[i].delete(true, null);
		}
	}
	
	
	
	
	protected void refreshViewer() {
		try {