Bug 189490 [CommonNavigator] Go To->Resource won't enable
I0524 1. Open the Project Explorer in the Resource perspective 2. Create a vanilla project P 3. Create a folder F 4. Create a file resource R Open the Navigate->Go To file. "Resource..." will remain disabled.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
*/
	public INavigatorDnDService getDnDService() {
		if (navigatorDnDService == null) {
			navigatorDnDService = new NavigatorDnDService(this);
		}
		return navigatorDnDService;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.ui.navigator.INavigatorContentService#getActivationService()
	 */
	public INavigatorActivationService getActivationService() {
		if (navigatorActivationService == null) {
			navigatorActivationService = new NavigatorActivationService(this);
		}
		return navigatorActivationService;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.ui.navigator.INavigatorContentService#getSaveableService()
	 */
	public INavigatorSaveablesService getSaveablesService() {
		synchronized (this) {
			if (navigatorSaveablesService == null) {
				navigatorSaveablesService = new NavigatorSaveablesService(this);
				assistant.addListener(navigatorSaveablesService);