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/navigator/CommonNavigator.java
return this;
		} else if (adapter == ISHOW_IN_SOURCE_CLASS) {
            return getShowInSource();
        }
		return super.getAdapter(adapter);
	}
    /**
     * Returns the <code>IShowInSource</code> for this view.
     */
    private IShowInSource getShowInSource() {
        return new IShowInSource() {
            public ShowInContext getShowInContext() {
                return new ShowInContext(getCommonViewer().getInput(), getCommonViewer().getSelection());
            }
        };
    }
	/**
	 * @return The Navigator Content Service which populates this instance of
	 *         Common Navigator
	 */
	public NavigatorActionService getNavigatorActionService() {
		return commonManager.getNavigatorActionService();
	}
	/**
	 * <p>
	 * Constructs and returns an instance of {@link CommonViewer}. The ID of
	 * the Eclipse view part will be used to create the viewer. The ID is
	 * important as some extensions indicate they should only be used with a
	 * particular viewer ID.
	 * <p>