Change system settings based on when mouse/touchpad is connected/disconnected.

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;
 
   /////////////////////////////////////////////////////////////////////////////
@@ skipping 170 matching lines @@
   /**
    * Hides the scanning label and icon that are used to indicate that a device
    * search is in progress.
    */
   SystemOptions.notifyBluetoothSearchComplete = function() {
     setVisibility_('bluetooth-scanning-label', false);
     setVisibility_('bluetooth-scanning-icon', false);
   };
 
   /**
-   * Displays the Touchpad Controls section when we detect a touchpad.
+   * Displays the touchpad controls section when we detect a touchpad, hides it
+   * otherwise.
    */
-  SystemOptions.showTouchpadControls = function() {
-    $('touchpad-controls').hidden = false;
+  SystemOptions.showTouchpadControls = function(show) {
+    $('touchpad-controls').hidden = !show;
+  };
+
+  /**
+   * Displays the mouse controls section when we detect a mouse, hides it
+   * otherwise.
+   */
+  SystemOptions.showMouseControls = function(show) {
+    $('mouse-controls').hidden = !show;
   };
 
   // Export
   return {
     SystemOptions: SystemOptions
   };
 
 });