Add button to reset auto-open pref in Chrome OS settings

chrome/browser/resources/options/browser_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.
 
 cr.define('options', function() {
   var OptionsPage = options.OptionsPage;
   var ArrayDataModel = cr.ui.ArrayDataModel;
   var RepeatingButton = cr.ui.RepeatingButton;
   var HotwordSearchSettingIndicator = options.HotwordSearchSettingIndicator;
 
@@ skipping 420 matching lines @@
       };
       $('language-button').onclick = showLanguageOptions;
       $('manage-languages').onclick = showLanguageOptions;
 
       // Downloads section.
       Preferences.getInstance().addEventListener('download.default_directory',
           this.onDefaultDownloadDirectoryChanged_.bind(this));
       $('downloadLocationChangeButton').onclick = function(event) {
         chrome.send('selectDownloadLocation');
       };
-      if (!cr.isChromeOS) {
-        $('autoOpenFileTypesResetToDefault').onclick = function(event) {
-          chrome.send('autoOpenFileTypesAction');
-        };
-      } else {
+      if (cr.isChromeOS) {
         $('disable-drive-row').hidden =
             UIAccountTweaks.loggedInAsLocallyManagedUser();
       }
+      $('autoOpenFileTypesResetToDefault').onclick = function(event) {
+        chrome.send('autoOpenFileTypesAction');
+      };
 
       // HTTPS/SSL section.
       if (cr.isWindows || cr.isMac) {
         $('certificatesManageButton').onclick = function(event) {
           chrome.send('showManageSSLCertificates');
         };
       } else {
         $('certificatesManageButton').onclick = function(event) {
           OptionsPage.navigateToPage('certificates');
           chrome.send('coreOptionsUserMetricsAction',
@@ skipping 996 matching lines @@
       }
     },
 
     /**
      * Shows/hides the autoOpenFileTypesResetToDefault button and label, with
      * animation.
      * @param {boolean} display Whether to show the button and label or not.
      * @private
      */
     setAutoOpenFileTypesDisplayed_: function(display) {
-      if (cr.isChromeOS)
-        return;
-
       if ($('advanced-settings').hidden) {
         // If the Advanced section is hidden, don't animate the transition.
         $('auto-open-file-types-section').hidden = !display;
       } else {
         if (display) {
           this.showSectionWithAnimation_(
               $('auto-open-file-types-section'),
               $('auto-open-file-types-container'));
         } else {
           this.hideSectionWithAnimation_(
@@ skipping 259 matching lines @@
     BrowserOptions.getLoggedInUsername = function() {
       return BrowserOptions.getInstance().username_;
     };
   }
 
   // Export
   return {
     BrowserOptions: BrowserOptions
   };
 });