[menu.js] Menu.menuItemSelector has to be set before decoration

ui/webui/resources/js/cr/ui/menu.js

Index: ui/webui/resources/js/cr/ui/menu.js
diff --git a/ui/webui/resources/js/cr/ui/menu.js b/ui/webui/resources/js/cr/ui/menu.js
index 81a57ae4e8dde70ec3394b96ab3d1983aa9263e0..6784910acb732879261b9cd2c02c6b67698bd4a5 100644
--- a/ui/webui/resources/js/cr/ui/menu.js
+++ b/ui/webui/resources/js/cr/ui/menu.js
@@ -27,11 +27,6 @@ cr.define('cr.ui', function() {
     contextElement: null,
 
     /**
-     * Selector for children which are menu items.
-     */
-    menuItemSelector: '*',
-
-    /**
      * Initializes the menu element.
      */
     decorate: function() {
@@ -119,7 +114,7 @@ cr.define('cr.ui', function() {
     },
 
     get menuItems() {
-      return this.querySelectorAll(this.menuItemSelector);
+      return this.querySelectorAll(this.menuItemSelector || '*');
     },
 
     /**
@@ -272,6 +267,11 @@ cr.define('cr.ui', function() {
   cr.defineProperty(Menu, 'selectedIndex', cr.PropertyKind.JS,
       selectedIndexChanged);
 
+  /**
+   * Selector for children which are menu items.
+   */
+  cr.defineProperty(Menu, 'menuItemSelector', cr.PropertyKind.ATTR);
+
   // Export
   return {
     Menu: Menu