Options: Remove the hidden class, since we override the hidden attribute to set

chrome/browser/resources/options/sync_setup_overlay.js

 // Copyright (c) 2011 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.
 
 cr.define('options', function() {
   const OptionsPage = options.OptionsPage;
 
   // Variable to track if a captcha challenge was issued. If this gets set to
   // true, it stays that way until we are told about successful login from
   // the browser.  This means subsequent errors (like invalid password) are
@@ skipping 382 matching lines @@
 
     // Called once, when this html/js is loaded.
     showConfigure_: function(args) {
       var datatypeSelect = document.getElementById('sync-select-datatypes');
       var self = this;
       datatypeSelect.onchange = function() {
         var syncAll = this.selectedIndex == 0;
         self.setCheckboxesToKeepEverythingSynced_(syncAll);
       };
 
-      $('sync-setup-configure').classList.remove('hidden');
+      $('sync-setup-configure').hidden = false;
 
       if (args) {
         if (!args['encryptionEnabled'])
-          $('customize-sync-encryption').classList.add('hidden');
+          $('customize-sync-encryption').hidden = true;
         this.setCheckboxesAndErrors_(args);
 
         // Whether to display the 'Sync everything' confirmation page or the
         // customize data types page.
         var showSyncEverythingPage = args['showSyncEverythingPage'];
         var keepEverythingSynced = args['keepEverythingSynced'];
         this.usePassphrase_ = args['usePassphrase'];
         if (showSyncEverythingPage == false ||
             keepEverythingSynced == false || this.usePassphrase_) {
           this.showCustomizePage_(keepEverythingSynced);
@@ skipping 44 matching lines @@
       if (page == 'settingUp') {
         this.setThrobbersVisible_(true);
         return;
       } else {
         this.setThrobbersVisible_(false);
       }
 
       // Hide an existing visible overlay.
       var overlay = $('sync-setup-overlay');
       for (var i = 0; i < overlay.children.length; i++)
-        overlay.children[i].classList.add('hidden');
+        overlay.children[i].hidden = true;
 
       this.setInputElementsDisabledState_(false);
 
       if (page == 'login')
         this.showGaiaLogin_(args);
       else if (page == 'configure')
         this.showConfigure_(args);
       else if (page == 'passphrase')
         this.showPassphrase_(args);
 
       if (page == 'done')
         this.closeOverlay_();
       else
         this.showOverlay_();
     },
 
     setThrobbersVisible_: function(visible) {
       var throbbers = document.getElementsByClassName("throbber");
         for (var i = 0; i < throbbers.length; i++)
           throbbers[i].style.visibility = visible ? "visible" : "hidden";
     },
 
     showPassphrase_: function(args) {
-      $('sync-setup-passphrase').classList.remove('hidden');
+      $('sync-setup-passphrase').hidden = false;
 
       $('passphrase-rejected-body').style.display = "none";
       $('normal-body').style.display = "none";
       $('incorrect-passphrase').style.display = "none";
 
       if (args["passphrase_creation_rejected"]) {
         $('passphrase-rejected-body').style.display = "block";
       } else {
         $('normal-body').style.display = "block";
       }
@@ skipping 44 matching lines @@
       // It's showtime for the captcha now.
       this.setElementDisplay_("captcha-div", "block");
       document.getElementById('gaia-email').disabled = true;
       document.getElementById('gaia-passwd').disabled = false;
       document.getElementById('captcha-value').disabled = false;
       document.getElementById('captcha-wrapper').style.backgroundImage =
           url(args.captchaUrl);
     },
 
     showGaiaLogin_: function(args) {
-      $('sync-setup-login').classList.remove('hidden');
+      $('sync-setup-login').hidden = false;
 
       document.getElementById('gaia-email').disabled = false;
       document.getElementById('gaia-passwd').disabled = false;
 
       var f = $('gaia-login-form');
       var email = $('gaia-email');
       var passwd = $('gaia-passwd');
       if (f) {
         if (args.user != undefined) {
           if (email.value != args.user)
@@ skipping 116 matching lines @@
 
     showSuccessAndSettingUp_: function() {
       $('sign-in').value = localStrings.getString('settingUp');
     },
 
     /** @inheritDoc */
     shouldClose: function() {
       if (!$('cancel-warning-box').hidden) {
         chrome.send('SyncSetupPassphraseCancel', ['']);
         return true;
-      } else if (!$('sync-setup-passphrase').classList.contains('hidden')) {
+      } else if (!$('sync-setup-passphrase').hidden) {
         // The Passphrase page is showing, and the use has pressed escape.
         // Activate the cancel logic in this case.
         this.showCancelWarning_();
         return false;
       }
 
       return true;
     },
   };
 
@@ skipping 11 matching lines @@
 
   SyncSetupOverlay.showSuccessAndSettingUp = function() {
     SyncSetupOverlay.getInstance().showSuccessAndSettingUp_();
   };
 
   // Export
   return {
     SyncSetupOverlay: SyncSetupOverlay
   };
 });