Add a menu option for the right-hand Ctrl -> Meta mapping.

remoting/webapp/base/js/client_plugin_impl.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.
 
 /**
  * @fileoverview
  * Class that wraps low-level details of interacting with the client plugin.
  *
  * This abstracts a <embed> element and controls the plugin which does
  * the actual remoting work. It also handles differences between
@@ skipping 532 matching lines @@
 /**
  * Sets and stores the key remapping setting for the current host.
  *
  * @param {!Object} remappings
  */
 remoting.ClientPluginImpl.prototype.setRemapKeys =
     function(remappings) {
   // Cancel any existing remappings and apply the new ones.
   this.applyRemapKeys_(this.keyRemappings_, false);
   this.applyRemapKeys_(remappings, true);
-  this.keyRemappings_ = remappings;
+  this.keyRemappings_ = /** @type {!Object} */ (base.deepCopy(remappings));
 };
 
 /**
  * Applies the configured key remappings to the session, or resets them.
  *
  * @param {!Object} remappings
  * @param {boolean} apply True to apply remappings, false to cancel them.
  * @private
  */
 remoting.ClientPluginImpl.prototype.applyRemapKeys_ =
@@ skipping 323 matching lines @@
 remoting.DefaultClientPluginFactory.prototype.preloadPlugin = function() {
   if (remoting.settings.CLIENT_PLUGIN_TYPE != 'pnacl') {
     return;
   }
 
   var plugin = remoting.ClientPluginImpl.createPluginElement_();
   plugin.addEventListener(
       'loadend', function() { document.body.removeChild(plugin); }, false);
   document.body.appendChild(plugin);
 };