Show UI when a folder is empty.

ui/file_manager/file_manager/foreground/js/ui/file_manager_ui.js

 // Copyright 2014 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.
 
 /**
  * The root of the file manager's view managing the DOM of Files.app.
  *
  * @param {!HTMLElement} element Top level element of Files.app.
  * @param {!LaunchParam} launchParam Launch param.
  * @constructor
@@ skipping 135 matching lines @@
    * Search box.
    * @type {!SearchBox}
    * @const
    */
   this.searchBox = new SearchBox(
       this.element.querySelector('#search-box'),
       this.element.querySelector('#search-button'),
       this.element.querySelector('#no-search-results'));
 
   /**
+   * Empty folder UI.
+   * @type {!EmptyFolder}
+   * @const
+   */
+  this.emptyFolder = new EmptyFolder(
+      queryRequiredElement(this.element, '#empty-folder'));
+
+  /**
    * Toggle-view button.
    * @type {!Element}
    * @const
    */
   this.toggleViewButton = queryRequiredElement(this.element, '#view-button');
 
   /**
    * The button to open gear menu.
    * @type {!cr.ui.MenuButton}
    * @const
@@ skipping 267 matching lines @@
     },
 
     handleSplitterDragEnd: function(e) {
       Splitter.prototype.handleSplitterDragEnd.apply(this, arguments);
       this.ownerDocument.documentElement.classList.remove('col-resize');
     }
   };
 
   customSplitter.decorate(splitterElement);
 };