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
}
			return navigatorSaveablesService;
		}
	}
	/**
	 * Not API as of 3.3.
	 * 
	 * @return The extension state service for this content service.
	 * 
	 */
	public NavigatorExtensionStateService getExtensionStateService() {
		if (navigatorExtensionStateService == null) {
			navigatorExtensionStateService = new NavigatorExtensionStateService(
					this);
		}
		return navigatorExtensionStateService;
	}
	/**
	 * Non-API method to return a shell.
	 * 
	 * @return A shell associated with the current viewer (if any) or
	 *         <b>null</b>.
	 */
	public Shell getShell() {
		if (structuredViewerManager != null
				&& structuredViewerManager.getViewer() != null) {
			return structuredViewerManager.getViewer().getControl().getShell();
		}
		return null;
	}