Remove -webkit-*-before/after in:

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

 /* 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.
  *
  * This is the stylesheet used by the Locally managed user creation flow screen.
  */
 
 #supervised-user-creation {
   height: 609px; /* Same size as GAIA sign in screen.*/
   padding: 0 0;  /* Some screens have elements right next to borders. */
@@ skipping 193 matching lines @@
 #supervised-user-creation .hidden-on-import {
   display: none;
 }
 
 #supervised-user-creation-error {
   padding: 175px 120px 0;
   text-align: center;
 }
 
 #supervised-user-creation-error .error-icon {
-  -webkit-margin-after: 50px;
+  margin-bottom: 50px;
 }
 
 #supervised-user-creation-error  .error-message-paragraph {
-  -webkit-margin-after: 40px;
-  -webkit-margin-before: 30px;
+  margin-bottom: 40px;
+  margin-top: 30px;
 }
 
 .screen-control-button {
   margin-left: 10px !important;
 }
 
 .import-pod {
   height: 32px;
   opacity: 0.8;
   padding: 20px;
@@ skipping 312 matching lines @@
   margin-left: -22px;
   margin-top: -22px;
   position: absolute;
   top: 50%;
   width: 44px;
 }
 
 .camera.live:not(.online) .supervised-user-creation-image-stream-area .spinner {
   display: block;
 }