MD Settings: Users: Fix add person validation and dialog focus

chrome/browser/resources/settings/people_page/users_page.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * 'settings-users-page' is the settings page for managing user accounts on
  * the device.
  */
 Polymer({
@@ skipping 34 matching lines @@
 
   /**
    * @param {!Event} e
    * @private
    */
   openAddUserDialog_: function(e) {
     e.preventDefault();
     this.$.addUserDialog.open();
   },
 
+  /** @private */
+  onAddUserDialogClose_: function() {
+    this.$$('#add-user-button a').focus();
+  },
+
   /**
    * @param {boolean} isOwner
    * @param {boolean} isWhitelistManaged
    * @private
    * @return {boolean}
    */
   isEditingDisabled_: function(isOwner, isWhitelistManaged) {
     return !isOwner || isWhitelistManaged;
   },
 
   /**
    * @param {boolean} isOwner
    * @param {boolean} isWhitelistManaged
    * @param {boolean} allowGuest
    * @private
    * @return {boolean}
    */
   isEditingUsersDisabled_: function(isOwner, isWhitelistManaged, allowGuest) {
     return !isOwner || isWhitelistManaged || allowGuest;
   }
 });