Implement "Add" and "Remove" buttons in Language and Input page.

chrome/browser/resources/options/chromeos_language_add_language_overlay.js

+// Copyright (c) 2010 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.language', function() {
+
+  const OptionsPage = options.OptionsPage;
+
+  /**
+   * Encapsulated handling of ChromeOS add language overlay page.
+   * @constructor
+   */
+  function AddLanguageOverlay() {
+    OptionsPage.call(this, 'addLanguageOverlay',
+                     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.clearOverlays();
+      };
+
+      // Create the language list with which users can add a language.
+      // Note that we have about 40 languages.
+      var addLanguageList = $('add-language-overlay-language-list');
+      var languageListData = templateData.languageList;
+      for (var i = 0; i < languageListData.length; i++) {
+        var language = languageListData[i];
+        var button = document.createElement('button');
+        button.className = 'link-button';
+        button.textContent = language.displayName;
+        button.languageCode = language.code;
+        // Listen to user clicks.
+        button.addEventListener('click',
+                                cr.bind(this.handleLanguageClick_, this));
+        var li = document.createElement('li');
+        li.languageCode = language.code;
+        li.appendChild(button);
+        addLanguageList.appendChild(li);
+      }
+    },
+  };
+
+  return {
+    AddLanguageOverlay: AddLanguageOverlay
+  };
+});