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.resources/src/org/eclipse/ui/internal/navigator/workingsets/WorkingSetsContentProvider.java
/**
	 * The extension id for the WorkingSet extension.
	 */
	public static final String EXTENSION_ID = "org.eclipse.ui.navigator.resources.workingSets"; 
	/**
	 * A key used by the Extension State Model to keep track of whether top level Working Sets or
	 * Projects should be shown in the viewer.
	 */
	public static final String SHOW_TOP_LEVEL_WORKING_SETS = EXTENSION_ID + ".showTopLevelWorkingSets"; 
	private static final Object[] NO_CHILDREN = new Object[0];
	 static final int WORKING_SETS = 0;
	 static final int PROJECTS = 1;
	private WorkingSetHelper helper;