Add stub icons for playpen.

chrome/browser/resources/chromeos/login/screen_locally_managed_user_creation.css

 /* Copyright (c) 2013 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.
  *
  * This is the stylesheet used by the Locally managed user creation flow screen.
  */
 
-.screen-horizontal-splitter {
-  background: -webkit-linear-gradient(rgba(128,128,128,0),
-                                      rgba(128,128,128,0.3));
-  height: 10px;
-  width: 100%;
-}
-
 #managed-user-creation-flow {
   height: 488px;
   padding: 70px 17px 50px;
   width: 704px;
 }
 
 #managed-user-creation-flow-intro-title {
   font-size: x-large;
   text-align: center;
 }
@@ skipping 111 matching lines @@
 
 .manager-pod .managed-user-creation-flow-manager-name {
   color: #000;
   font-size: small;
 }
 .manager-pod .managed-user-creation-flow-manager-wrong-password {
   background: url('chrome://theme/IDR_WARNING') left top /24px no-repeat;
   color: red;
   padding-left: 28px;
 }