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 (rootContentProviders == null) {
				rootContentProviders = extractContentProviders(findRootContentExtensions(anElement));
			}
		}
		return rootContentProviders;
	}
	/**
	 * 
	 * Return all of the label providers that are enabled for the given element.
	 * A label provider is 'enabled' if its corresponding content provider
	 * returned the element, or the element is described in the content
	 * extension's <b>possibleChild</b> expression.
	 * 
	 * @param anElement
	 *            An element from the tree (any element contributed to the
	 *            tree).
	 * @return The set of label providers that may be able to provide a valid
	 *         (non-null) label.
	 */
	public ILabelProvider[] findRelevantLabelProviders(Object anElement) {
		return extractLabelProviders(findContentExtensionsWithPossibleChild(
				anElement, false));
	}
	/**
	 * Search for extensions that declare the given element in their
	 * <b>triggerPoints</b> expression.
	 * 
	 * @param anElement