MD Bookmarks: Show toolbar overlay when multiple items are selected

ui/webui/resources/cr_elements/cr_toolbar/cr_toolbar.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 Polymer({
   is: 'cr-toolbar',
 
   properties: {
     // Name to display in the toolbar, in titlecase.
     pageName: String,
@@ skipping 17 matching lines @@
 
     // Controls whether the menu button is shown at the start of the menu.
     showMenu: {type: Boolean, value: false},
 
     // Whether to show menu promo tooltip.
     showMenuPromo: {
       type: Boolean,
       value: false,
     },
 
+    // True when the toolbar is displaying in narrow mode.
+    narrow: {
+      type: Boolean,
+      reflectToAttribute: true,
+      readonly: true,
+      notify: true,
+    },
+
     closeMenuPromo: String,
 
     /** @private */
-    narrow_: {type: Boolean, reflectToAttribute: true},
-
-    /** @private */
     showingSearch_: {
       type: Boolean,
       reflectToAttribute: true,
     },
   },
 
   observers: [
     'possiblyShowMenuPromo_(showMenu, showMenuPromo, showingSearch_)',
   ],
 
@@ skipping 30 matching lines @@
 
   /**
    * @param {string} title
    * @param {boolean} showMenuPromo
    * @return {string} The title if the menu promo isn't showing, else "".
    */
   titleIfNotShowMenuPromo_: function(title, showMenuPromo) {
     return showMenuPromo ? '' : title;
   },
 });