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
synchronized (this) {
			if (labelProvider == null) {
				labelProvider = new NavigatorContentServiceLabelProvider(this);
			}
			labelProviderInitialized = true;
		}
		return labelProvider;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @seeorg.eclipse.ui.navigator.INavigatorContentService#
	 * createCommonDescriptionProvider()
	 */
	public IDescriptionProvider createCommonDescriptionProvider() {
		if (descriptionProvider != null) {
			return descriptionProvider;
		}
		synchronized (this) {
			if (descriptionProvider == null) {
				descriptionProvider = new NavigatorContentServiceDescriptionProvider(
						this);
			}
		}
		return descriptionProvider;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.navigator.INavigatorContentService#dispose()