Enable brightness controls for all ChromeOS builds. Make brightness controls auto-repeat.

chrome/browser/resources/options/chromeos/system_options.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.
 
 cr.define('options', function() {
 
   var OptionsPage = options.OptionsPage;
+  var RepeatingButton = cr.ui.RepeatingButton;
+
   /////////////////////////////////////////////////////////////////////////////
   // SystemOptions class:
 
   /**
    * Encapsulated handling of ChromeOS system options page.
    * @constructor
    */
 
   function SystemOptions() {
     OptionsPage.call(this, 'system', templateData.systemPageTabTitle,
@@ skipping 38 matching lines @@
       $('language-button').onclick = function(event) {
         OptionsPage.navigateToPage('language');
       };
       $('modifier-keys-button').onclick = function(event) {
         OptionsPage.navigateToPage('languageCustomizeModifierKeysOverlay');
       };
       $('accesibility-check').onchange = function(event) {
         chrome.send('accessibilityChange',
                     [String($('accesibility-check').checked)]);
       };
-
-      if (cr.isTouch) {
-        initializeBrightnessButton_('brightness-decrease-button',
-            'decreaseScreenBrightness');
-        initializeBrightnessButton_('brightness-increase-button',
-            'increaseScreenBrightness');
-      }
+      initializeBrightnessButton_('brightness-decrease-button',
+          'decreaseScreenBrightness');
+      initializeBrightnessButton_('brightness-increase-button',
+          'increaseScreenBrightness');
     }
   };
 
   /**
-   * Initializes a button for controlling screen brightness on touch builds of
-   * ChromeOS.
+   * Initializes a button for controlling screen brightness.
    * @param {string} id Button ID.
    * @param {string} callback Name of the callback function.
    */
   function initializeBrightnessButton_(id, callback) {
-    // TODO(kevers): Make brightness buttons auto-repeat if held.
-    $(id).onclick = function(event) {
+    var button = $(id);
+    cr.ui.decorate(button, RepeatingButton);
+    button.onButtonHeldAction = function() {
       chrome.send(callback);
-    }
+    };
   }
 
   /**
    * Scan for bluetooth devices.
    * @private
    */
   function findBluetoothDevices_() {
     setVisibility_('bluetooth-scanning-label', true);
     setVisibility_('bluetooth-scanning-icon', true);
 
@@ skipping 65 matching lines @@
       setVisibility_('bluetooth-scanning-icon', false);
     }, 2000);
   }
 
   // Export
   return {
     SystemOptions: SystemOptions
   };
 
 });