Move ProtocolExtensionManager from SessionConnector into its own class

remoting/webapp/crd/js/client_plugin_impl.js

Index: remoting/webapp/crd/js/client_plugin_impl.js
diff --git a/remoting/webapp/crd/js/client_plugin_impl.js b/remoting/webapp/crd/js/client_plugin_impl.js
index 3560e7b8df1070e6de590a79716a59e0322e7248..412568c77f7b8dcff688515e486232dd1aa399c1 100644
--- a/remoting/webapp/crd/js/client_plugin_impl.js
+++ b/remoting/webapp/crd/js/client_plugin_impl.js
@@ -93,9 +93,14 @@ remoting.ClientPluginImpl = function(container,
     window.setTimeout(this.showPluginForClickToPlay_.bind(this), 500);
   }
 
+  /** @private */
   this.hostDesktop_ = new remoting.ClientPlugin.HostDesktopImpl(
       this, this.postMessage_.bind(this));
 
+  /** @private */
+  this.extensions_ = new remoting.ProtocolExtensionManager(
+      this.sendClientMessage.bind(this));
+
   /** @private {remoting.CredentialsProvider} */
   this.credentials_ = null;
 
@@ -226,7 +231,11 @@ remoting.ClientPluginImpl.prototype.handleMessageMethod_ = function(message) {
       var error = remoting.ClientSession.ConnectionError.fromString(
           base.getStringAttr(message.data, 'error'));
       handler.onConnectionStatusUpdate(state, error);
-
+      // TODO(kelvinp): Refactor the ClientSession.State into its own file as

[garykac, 2015/04/07 22:14:16]

Or have an onConnected, onDisconnected,... message instead of just
onConnectionStatus.

[kelvinp, 2015/04/08 00:26:02]

Even if we break onConnectionStatus into OnConnected, etc, we still need to
compare the status against some predefined enum string. 
The problem here is that the enum string is defined in ClientSession, which is a
much concept that belongs to a higher layer than the plugin.

+      // the plugin should not depend on ClientSession.
+      if (state === remoting.ClientSession.State.CONNECTED) {
+        this.extensions_.start();
+      }
     } else if (message.method == 'onRouteChanged') {
       var channel = base.getStringAttr(message.data, 'channel');
       var connectionType = base.getStringAttr(message.data, 'connectionType');
@@ -245,7 +254,7 @@ remoting.ClientPluginImpl.prototype.handleMessageMethod_ = function(message) {
     } else if (message.method == 'extensionMessage') {
       var extMsgType = base.getStringAttr(message.data, 'type');
       var extMsgData = base.getStringAttr(message.data, 'data');
-      handler.onExtensionMessage(extMsgType, extMsgData);
+      this.extensions_.onProtocolExtensionMessage(extMsgType, extMsgData);

[garykac, 2015/04/07 22:14:16]

Since this no longer requires a connectionEventHandler, it should be moved out
of this if().

[kelvinp, 2015/04/08 00:26:02]

Done.

     }
   }
 
@@ -383,6 +392,9 @@ remoting.ClientPluginImpl.prototype.dispose = function() {
     this.plugin_.parentNode.removeChild(this.plugin_);
     this.plugin_ = null;
   }
+
+  base.dispose(this.extensions_);
+  this.extensions_ = null;
 };
 
 /**
@@ -791,6 +803,10 @@ remoting.ClientPluginImpl.prototype.hostDesktop = function() {
   return this.hostDesktop_;
 };
 
+remoting.ClientPluginImpl.prototype.extensions = function() {
+  return this.extensions_;
+};
+
 /**
  * If we haven't yet received a "hello" message from the plugin, change its
  * size so that the user can confirm it if click-to-play is enabled, or can