Apply content-security-policy to the HTML options page. This is a

chrome/browser/resources/options/language_add_language_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.
-
-///////////////////////////////////////////////////////////////////////////////
-// AddLanguageOverlay class:
-
-cr.define('options', function() {
-  const OptionsPage = options.OptionsPage;
-
-  /**
-   * Encapsulated handling of ChromeOS add language overlay page.
-   * @constructor
-   */
-  function AddLanguageOverlay() {
-    OptionsPage.call(this, 'addLanguage',
-                     localStrings.getString('add_button'),
-                     'add-language-overlay-page');
-  }
-
-  cr.addSingletonGetter(AddLanguageOverlay);
-
-  AddLanguageOverlay.prototype = {
-    // Inherit AddLanguageOverlay from OptionsPage.
-    __proto__: OptionsPage.prototype,
-
-    /**
-     * Initializes AddLanguageOverlay page.
-     * Calls base class implementation to starts preference initialization.
-     */
-    initializePage: function() {
-      // Call base class implementation to starts preference initialization.
-      OptionsPage.prototype.initializePage.call(this);
-
-      // Set up the cancel button.
-      $('add-language-overlay-cancel-button').onclick = function(e) {
-        OptionsPage.closeOverlay();
-      };
-
-      // Create the language list with which users can add a language.
-      var addLanguageList = $('add-language-overlay-language-list');
-      var languageListData = templateData.languageList;
-      for (var i = 0; i < languageListData.length; i++) {
-        var language = languageListData[i];
-        var displayText = language.displayName;
-        // If the native name is different, add it.
-        if (language.displayName != language.nativeDisplayName) {
-          displayText += ' - ' + language.nativeDisplayName;
-        }
-        if (cr.isChromeOS) {
-          var button = document.createElement('button');
-          button.className = 'link-button';
-          button.textContent = displayText;
-          button.languageCode = language.code;
-          var li = document.createElement('li');
-          li.languageCode = language.code;
-          li.appendChild(button);
-          addLanguageList.appendChild(li);
-        } else {
-          var option = document.createElement('option');
-          option.value = language.code;
-          option.textContent = displayText;
-          addLanguageList.appendChild(option);
-        }
-      }
-    },
-  };
-
-  return {
-    AddLanguageOverlay: AddLanguageOverlay
-  };
-});