Add close button to the supervised user pages.

chrome/browser/resources/chromeos/login/header_bar.js

 // Copyright (c) 2012 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 Login UI header bar implementation.
  */
 
 cr.define('login', function() {
   /**
@@ skipping 334 matching lines @@
           supervisedUserCreationDialogIsActiveAndNotIntro;
       $('more-settings-header-bar-item').hidden =
           !this.showCreateSupervised_ ||
           isNewGaiaScreenWithBackButton ||
           supervisedUserCreationDialogIsActive;
       $('cancel-add-user-button').hidden =
           ((gaiaIsActive || isPasswordChangedUI) && this.isNewGaiaFlow_) ||
           accountPickerIsActive ||
           !this.allowCancel_ ||
           wrongHWIDWarningIsActive ||
-          isMultiProfilesUI;
+          isMultiProfilesUI ||
+          supervisedUserCreationDialogIsActive;
       $('guest-user-header-bar-item').hidden =
           (gaiaIsActive && !this.isNewGaiaFlow_) ||
           supervisedUserCreationDialogIsActiveAndNotIntro ||
           !this.showGuest_ ||
           wrongHWIDWarningIsActive ||
           isSamlPasswordConfirm ||
           isMultiProfilesUI ||
           isNewGaiaScreenWithBackButton;
       $('restart-header-bar-item').hidden = !this.showReboot_;
       $('shutdown-header-bar-item').hidden = !this.showShutdown_;
@@ skipping 75 matching lines @@
    * Convenience wrapper of animateIn.
    */
   HeaderBar.animateIn = function(fast, callback) {
     $('login-header-bar').animateIn(fast, callback);
   };
 
   return {
     HeaderBar: HeaderBar
   };
 });