Add string for case when supervised user creation is disabled due to "only these users can log in" …

chrome/browser/resources/chromeos/login/screen_gaia_signin.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 Oobe signin screen implementation.
  */
 
 <include src="../../gaia_auth_host/gaia_auth_host.js"></include>
 
@@ skipping 251 matching lines @@
         reasonLabel.hidden = true;
       }
 
       $('createAccount').hidden = !data.createAccount;
       $('guestSignin').hidden = !data.guestSignin;
       $('createManagedUserPane').hidden = !data.managedUsersEnabled;
 
       $('createManagedUserLinkPlaceholder').hidden =
           !data.managedUsersCanCreate;
       $('createManagedUserNoManagerText').hidden = data.managedUsersCanCreate;
+      $('createManagedUserNoManagerText').textContent =
+          data.managedUsersRestrictionReason;
 
       // Allow cancellation of screen only when user pods can be displayed.
       this.cancelAllowed_ = data.isShowUsers && $('pod-row').pods.length;
       $('login-header-bar').allowCancel = this.cancelAllowed_;
 
       // Sign-in right panel is hidden if all of its items are hidden.
       var noRightPanel = $('gaia-signin-reason').hidden &&
                          $('createAccount').hidden &&
                          $('guestSignin').hidden &&
                          $('createManagedUserPane').hidden;
@@ skipping 152 matching lines @@
      * Handler for iframe's error notification coming from the outside.
      * For more info see C++ class 'SnifferObserver' which calls this method.
      * @param {number} error Error code.
      */
     onFrameError: function(error) {
       this.error_ = error;
       chrome.send('frameLoadingCompleted', [this.error_]);
     },
   };
 });