Rename for some supervised users ambiguity. Adding child account icon to the avatar menu bubble.

ui/login/account_picker/user_pod_row.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 user pods row of account picker UI.
  */
 
 podrow {
   /* Temporarily disabled because animation interferes with updating screen's
    size. */
@@ skipping 408 matching lines @@
   left: auto;
   right: 0;
 }
 
 .user-type-icon-image {
   height: 16px;
   margin: 5px;
   width: 16px;
 }
 
-.user-type-icon-area.supervised .user-type-icon-image {
-  background-image: url(chrome://theme/IDR_SUPERVISED_USER_ICON);
+.user-type-icon-area.legacySupervised .user-type-icon-image {
+  background-image: url(chrome://theme/IDR_LEGACY_SUPERVISED_USER_ICON);
 }
 
 .user-type-icon-area.child .user-type-icon-image {
   background-image: url(chrome://theme/IDR_CHILD_USER_ICON);
 }
 
 .user-type-icon-area.policy .user-type-icon-image {
   background-image: url(chrome://theme/IDR_CONTROLLED_SETTING_MANDATORY);
 }
 
@@ skipping 74 matching lines @@
 }
 
 .action-box-remove-user-warning {
   border-top: 1px solid lightgray;
   font-size: 12px;
   line-height: 18px;
   padding: 20px;
 }
 
 .action-box-remove-user-warning-text,
-.action-box-remove-supervised-user-warning-text {
+.action-box-remove-legacy-supervised-user-warning-text {
   padding-bottom: 20px;
 }
 
 .action-box-remove-user-warning .remove-warning-button {
   width: 100%;
 }
 
 .user-type-bubble {
   background-color: white;
   border: 1px solid lightgray;
@@ skipping 223 matching lines @@
   -webkit-animation: ellipsis-component2 1.5s infinite;
 }
 
 @-webkit-keyframes ellipsis-component2 {
   0% { opacity: 0; }
   25% { opacity: 0; }
   50% { opacity: 0; }
   75% { opacity: 1; }
   100% { opacity: 0; }
 }