[web_dev_style] Changing :pseudo-element to ::pseudo-element to match

chrome/browser/resources/options/manage_profile_overlay.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. */
 
 #manage-profile-overlay {
   width: 512px;
 }
 
 .profile-icon-grid-item {
   height: 31px;
@@ skipping 68 matching lines @@
   padding: 0 10px;
 }
 
 #create-profile-icon-grid,
 #manage-profile-icon-grid {
   background-color: rgba(255, 255, 255, 0.75);
   padding: 2px;
 }
 
 /* Adds a grey horizontal line below content area  */
-#create-profile-content:after,
-#manage-profile-content:after {
+#create-profile-content::after,
+#manage-profile-content::after {
   background: #c0c0c0;
   content: '';
   display: block;
   height: 1px;
   margin-top: 25px;
   width: 100%;
 }
 
 #create-profile-content > :first-child {
   margin-bottom: 10px;
@@ skipping 37 matching lines @@
 }
 
 #delete-profile-message {
   -webkit-padding-start: 48px;
   background-repeat: no-repeat;
 }
 
 html[dir='rtl'] #delete-profile-message {
   background-position: right;