Hide/Disable several (meaningless) options in Settings uber-page for Guest.

chrome/browser/resources/options2/language_options.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.
 
 // TODO(kochi): Generalize the notification as a component and put it
 // in js/cr/ui/notification.js .
 
 cr.define('options', function() {
   const OptionsPage = options.OptionsPage;
   const LanguageList = options.LanguageList;
@@ skipping 343 matching lines @@
         // currently in use.
         uiLanguageButton.textContent =
             localStrings.getString('is_displayed_in_this_language');
         // Make it look like a text label.
         uiLanguageButton.className = 'text-button';
         // Remove the event listner.
         uiLanguageButton.onclick = undefined;
       } else if (languageCode in templateData.uiLanguageCodeSet) {
         // If the language is supported as UI language, users can click on
         // the button to change the UI language.
-        if (cr.commandLine && cr.commandLine.options['--bwsi']) {
+        if (cr.isChromeOS && AccountsOptions.loggedInAsGuest()) {
           // In the guest mode for ChromeOS, changing UI language does not make
           // sense because it does not take effect after browser restart.
           uiLanguageButton.hidden = true;
         } else {
           uiLanguageButton.textContent =
               localStrings.getString('display_in_this_language');
           uiLanguageButton.className = '';
           // Send the change request to Chrome.
           uiLanguageButton.onclick = function(e) {
             chrome.send('uiLanguageChange', [languageCode]);
@@ skipping 438 matching lines @@
   LanguageOptions.uiLanguageSaved = function() {
     $('language-options-ui-language-button').style.display = 'none';
     $('language-options-ui-notification-bar').style.display = 'block';
   };
 
   // Export
   return {
     LanguageOptions: LanguageOptions
   };
 });