Enrollment recovery: Add UMA stats.

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

 /* Copyright 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.
  */
 
 #oauth-enrollment {
   min-height: 609px;
   padding: 70px 17px 21px;
   width: 722px;
 }
@@ skipping 59 matching lines @@
 #oauth-enroll-signin-right > div {
   -webkit-margin-before: 20px;
 }
 
 #oauth-enroll-learn-more-link,
 .oauth-enroll-explain-link {
   display: none;
 }
 
 #oauth-enrollment.mode-manual #oauth-enroll-learn-more-link,
-#oauth-enrollment.mode-forced #oauth-enroll-learn-more-link {
+#oauth-enrollment.mode-forced #oauth-enroll-learn-more-link,
+#oauth-enrollment.mode-recovery #oauth-enroll-learn-more-link {
   display: inline;
 }
 
 #oauth-enrollment.mode-auto .oauth-enroll-explain-link {
   display: inline;
 }
 
 .oauth-enroll-step-content {
   display: table-cell;
   vertical-align: middle;
@@ skipping 34 matching lines @@
   color: rgb(37, 79, 155);
   cursor: pointer;
   text-decoration: none;
 }
 
 .oauth-enroll-button {
   display: none;
 }
 
 .oauth-enroll-state-signin.mode-manual #oauth-enroll-cancel-button,
+.oauth-enroll-state-signin.mode-forced #oauth-enroll-back-button,
+.oauth-enroll-state-signin.mode-recovery #oauth-enroll-back-button,
 .oauth-enroll-state-working.mode-manual #oauth-enroll-cancel-button,
-.oauth-enroll-state-signin.mode-forced #oauth-enroll-back-button,
 .oauth-enroll-state-working.mode-forced #oauth-enroll-back-button,
+.oauth-enroll-state-working.mode-recovery #oauth-enroll-back-button,
 .oauth-enroll-state-error.mode-manual #oauth-enroll-cancel-button,
 .oauth-enroll-state-error.mode-auto #oauth-enroll-retry-button,
 .oauth-enroll-state-error.mode-forced #oauth-enroll-back-button,
+.oauth-enroll-state-error.mode-recovery #oauth-enroll-back-button,
 .oauth-enroll-state-explain #oauth-enroll-explain-retry-button,
 .oauth-enroll-state-success #oauth-enroll-done-button {
   display: inline;
 }
 
 #oobe.oauth-enrollment #header-oauth-enrollment {
   display: block;
 }
 
 #oauth-saml-notice-container {
@@ skipping 17 matching lines @@
   -webkit-padding-end: 17px;
 }
 
 #oauth-enrollment:not(.saml) #oauth-saml-notice-container {
   display: none;
 }
 
 #oauth-saml-notice-message {
   margin: 0 auto;
 }