Block esc, back button and cancel button until gaia is loaded.

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

 // 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.
 
 login.createScreen('OAuthEnrollmentScreen', 'oauth-enrollment', function() {
   /** @const */ var STEP_SIGNIN = 'signin';
   /** @const */ var STEP_WORKING = 'working';
   /** @const */ var STEP_ERROR = 'error';
   /** @const */ var STEP_SUCCESS = 'success';
 
@@ skipping 25 matching lines @@
      * Opaque token used to correlate request and response while retrieving the
      * authenticated user's e-mail address from GAIA.
      */
     attemptToken_: null,
 
     /**
      * The help topic to show when the user clicks the learn more link.
      */
     learnMoreHelpTopicID_: null,
 
+    /**
+     * We block esc, back button and cancel button until gaia is loaded to
+     * prevent multiple cancel events.
+     */
+    isCancelDisabled_: null,
+
+    get isCancelDisabled() { return this.isCancelDisabled_ },
+    set isCancelDisabled(disabled) {
+      if (disabled == this.isCancelDisabled)
+        return;
+      this.isCancelDisabled_ = disabled;
+
+      $('oauth-enroll-back-button').disabled = disabled;
+      $('oauth-enroll-back-button').
+          classList.toggle('preserve-disabled-state', disabled);
+
+      $('oauth-enroll-cancel-button').disabled = disabled;
+      $('oauth-enroll-cancel-button').
+          classList.toggle('preserve-disabled-state', disabled);
+    },
+
     /** @override */
     decorate: function() {
       window.addEventListener('message',
                               this.onMessage_.bind(this), false);
       $('oauth-enroll-error-retry').addEventListener('click',
                                                      this.doRetry_.bind(this));
       $('oauth-enroll-learn-more-link').addEventListener(
           'click', this.launchLearnMoreHelp_.bind(this));
 
       this.updateLocalizedContent();
@@ skipping 43 matching lines @@
           loadTimeData.getString('oauthEnrollCancel'),
           function() {
             chrome.send('oauthEnrollClose', ['cancel']);
           });
 
       makeButton(
           'oauth-enroll-back-button',
           ['oauth-enroll-focus-on-error'],
           loadTimeData.getString('oauthEnrollBack'),
           function() {
-            $('oauth-enroll-back-button').disabled = true;
-
-            $('oauth-enroll-back-button').
-                classList.add('preserve-disabled-state');
-
+            this.isCancelDisabled = true;
             chrome.send('oauthEnrollClose', ['cancel']);
-          });
+          }.bind(this));
 
       makeButton(
           'oauth-enroll-retry-button',
           ['oauth-enroll-focus-on-error'],
           loadTimeData.getString('oauthEnrollRetry'),
           this.doRetry_.bind(this));
 
       makeButton(
           'oauth-enroll-done-button',
           ['oauth-enroll-focus-on-success'],
@@ skipping 14 matching lines @@
       this.signInParams_ = {};
       this.signInParams_['gaiaUrl'] = data.gaiaUrl;
       this.signInParams_['needPassword'] = false;
       this.signInUrl_ = data.signin_url;
       var modes = ['manual', 'forced', 'recovery'];
       for (var i = 0; i < modes.length; ++i) {
         this.classList.toggle('mode-' + modes[i],
                               data.enrollment_mode == modes[i]);
       }
       this.managementDomain_ = data.management_domain;
+      this.isCancelDisabled = true;
       this.doReload();
       this.learnMoreHelpTopicID_ = data.learn_more_help_topic_id;
       this.updateLocalizedContent();
       this.showStep(STEP_SIGNIN);
     },
 
     /**
      * Cancels enrollment and drops the user back to the login screen.
      */
     cancel: function() {
+      if (this.isCancelDisabled)
+        return;
+      this.isCancelDisabled = true;
       chrome.send('oauthEnrollClose', ['cancel']);
     },
 
     /**
      * Switches between the different steps in the enrollment flow.
      * @param {string} step the steps to show, one of "signin", "working",
      * "error", "success".
      */
     showStep: function(step) {
       this.classList.toggle('oauth-enroll-state-' + this.currentStep_, false);
@@ skipping 76 matching lines @@
               msg.domain);
         }
         this.classList.toggle('saml', msg.isSAML);
       }
 
       if (msg.method == 'resetAuthFlow') {
         this.classList.remove('saml');
       }
 
       if (msg.method == 'loginUILoaded' && this.currentStep_ == STEP_SIGNIN) {
-        $('oauth-enroll-back-button').disabled = false;
-
-        $('oauth-enroll-back-button').
-            classList.remove('preserve-disabled-state');
-
+        this.isCancelDisabled = false;
         chrome.send('frameLoadingCompleted', [0]);
       }
 
       if (msg.method == 'insecureContentBlocked') {
         this.showError(
             loadTimeData.getStringF('insecureURLEnrollmentError', msg.url),
             false);
       }
 
       if (msg.method == 'missingGaiaInfo') {
         this.showError(
             loadTimeData.getString('fatalEnrollmentError'),
             false);
       }
     },
 
     /**
      * Opens the learn more help topic.
      */
     launchLearnMoreHelp_: function() {
       if (this.learnMoreHelpTopicID_) {
         chrome.send('launchHelpApp', [this.learnMoreHelpTopicID_]);
       }
     }
   };
 });