Replace TOUCH_UI condition in WebUI with dynamic flag.

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;
 
@@ skipping 30 matching lines @@
       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 && !cr.isTouch) {
+        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
   };
 });