Move ProtocolExtensionManager from SessionConnector into its own class

remoting/webapp/crd/js/session_connector.js

 // Copyright 2014 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
  * Interface abstracting the SessionConnector functionality.
  */
 
 'use strict';
@@ skipping 80 matching lines @@
 remoting.SessionConnector.prototype.cancel = function() {};
 
 /**
  * Get host ID.
  *
  * @return {string}
  */
 remoting.SessionConnector.prototype.getHostId = function() {};
 
 /**
- * @param {remoting.ProtocolExtension} extension
- */
-remoting.SessionConnector.prototype.registerProtocolExtension =
-    function(extension) {};
-
-/**
  * Closes the session and removes the plugin element.
  */
 remoting.SessionConnector.prototype.closeSession = function() {};
 
 /**
  * @interface
  */
 remoting.SessionConnectorFactory = function() {};
 
 /**
  * @param {HTMLElement} clientContainer Container element for the client view.
  * @param {function(remoting.ConnectionInfo):void} onConnected Callback on
  *     success.
  * @param {function(!remoting.Error):void} onError Callback on error.
  * @param {function(!remoting.Error):void} onConnectionFailed Callback for when
  *     the connection fails.
  * @param {Array<string>} requiredCapabilities Connector capabilities
  *     required by this application.
  * @return {remoting.SessionConnector}
  */
 remoting.SessionConnectorFactory.prototype.createConnector =
     function(clientContainer, onConnected, onError,
              onConnectionFailed, requiredCapabilities) {};
 
 /**
  * @type {remoting.SessionConnectorFactory}
  */
 remoting.SessionConnector.factory = null;