Remove webkit prefixes for CSS Animation in chrome/ styles

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

 /* 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. */
 
 #error-message {
   width: 650px;
 }
 
 .show-with-ui-state-update,
 .show-with-ui-state-signin,
@@ skipping 94 matching lines @@
 
 .ui-state-auto-enrollment-error .error-guest-signin {
   display: none;
 }
 
 .ui-state-auto-enrollment-error.allow-guest-signin
     .error-guest-signin-fix-network {
   display: block;
 }
 
-@-webkit-keyframes connecting-indicator-ellipsis {
+@keyframes connecting-indicator-ellipsis {
   0% {
     opacity: 0;
   }
   10% {
     opacity: 1;
   }
   50% {
     opacity: .8;
   }
   100% {
     opacity: 0;
   }
 }
 
 #connecting-indicator-ellipsis-1 {
-  -webkit-animation: connecting-indicator-ellipsis 3s 0 infinite;
+  animation: connecting-indicator-ellipsis 3s 0 infinite;
 }
 
 #connecting-indicator-ellipsis-2 {
-  -webkit-animation: connecting-indicator-ellipsis 3s 500ms infinite;
+  animation: connecting-indicator-ellipsis 3s 500ms infinite;
 }
 
 #connecting-indicator-ellipsis-3 {
-  -webkit-animation: connecting-indicator-ellipsis 3s 1s infinite;
+  animation: connecting-indicator-ellipsis 3s 1s infinite;
 }
 
 #error-navigation {
   color: rgba(0, 0, 0, .54);
   left: 0;
   position: absolute;
   right: 0;
   top: 0;
   z-index: 1;
 }