Implement FallbackSignalStrategy.

remoting/webapp/crd/js/signal_strategy.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.
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /**
  * Abstract interface for various signaling mechanisms.
  *
  * @interface
  * @extends {base.Disposable}
  */
 remoting.SignalStrategy = function() {};
 
 /**
  * @enum {number} SignalStrategy states. Possible state transitions:
  *    NOT_CONNECTED -> CONNECTING (connect() called).
  *    CONNECTING -> HANDSHAKE (connected successfully).
  *    HANDSHAKE -> CONNECTED (authenticated successfully).
  *    CONNECTING -> FAILED (connection failed).
  *    HANDSHAKE -> FAILED (authentication failed).
  *    * -> CLOSED (dispose() called).
+ *
+ * Do not re-order these values without updating fallback_signal_strategy.js.
  */
 remoting.SignalStrategy.State = {
   NOT_CONNECTED: 0,
   CONNECTING: 1,
   HANDSHAKE: 2,
   CONNECTED: 3,
   FAILED: 4,
   CLOSED: 5
 };
 
@@ skipping 33 matching lines @@
 /**
  * Creates the appropriate signal strategy for the current environment.
  * @param {function(remoting.SignalStrategy.State): void} onStateChangedCallback
  * @return {remoting.SignalStrategy} New signal strategy object.
  */
 remoting.SignalStrategy.create = function(onStateChangedCallback) {
   // Only use XMPP when TCP API is available and TLS support is enabled. That's
   // not the case for V1 app (socket API is available only to platform apps)
   // and for Chrome releases before 38.
   if (chrome.socket && chrome.socket.secure) {
-    return new remoting.XmppConnection(onStateChangedCallback);
+    /**
+     * @param {function(remoting.SignalStrategy.State): void} onStateChanged
+     */
+    var xmppFactory = function(onStateChanged) {
+      return new remoting.XmppConnection(onStateChanged);
+    };
+
+    /**
+     * @param {function(remoting.SignalStrategy.State): void} onStateChanged
+     */
+    var wcsFactory = function(onStateChanged) {
+      return new remoting.WcsAdapter(onStateChanged);
+    };
+
+    /**
+     * @param {remoting.FallbackSignalStrategy.Progress} progress
+     */
+    var progressCallback = function(progress) {
+      console.log('FallbackSignalStrategy progress: ' + progress);
+    };
+
+    return new remoting.FallbackSignalStrategy(
+        xmppFactory, wcsFactory, onStateChangedCallback, progressCallback);
+
   } else {
     return new remoting.WcsAdapter(onStateChangedCallback);
   }
 };