Added JsonMessage to the control channel.

remoting/webapp/client_plugin_async.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 295 matching lines @@
     var scope = /** @type {string} */ message.data['scope'];
     this.fetchThirdPartyTokenHandler(tokenUrl, hostPublicKey, scope);
   } else if (message.method == 'pairingResponse') {
     var clientId = /** @type {string} */ message.data['clientId'];
     var sharedSecret = /** @type {string} */ message.data['sharedSecret'];
     if (typeof clientId != 'string' || typeof sharedSecret != 'string') {
       console.error('Received incorrect pairingResponse message.');
       return;
     }
     this.onPairingComplete_(clientId, sharedSecret);
+  } else if (message.method == 'extensionMessage') {
+    // No messages currently supported.
+    console.log('Unexpected message received: ' +
+                message.data.type + ': ' + message.data.data);
   }
 };
 
 /**
  * Deletes the plugin.
  */
 remoting.ClientPluginAsync.prototype.cleanup = function() {
   this.plugin.parentNode.removeChild(this.plugin);
 };
 
@@ skipping 274 matching lines @@
     function(clientName, onDone) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.PINLESS_AUTH)) {
     return;
   }
   this.onPairingComplete_ = onDone;
   this.plugin.postMessage(JSON.stringify(
       { method: 'requestPairing', data: { clientName: clientName } }));
 };
 
 /**
+ * Send an extension message to the host.
+ *
+ * @param {string} type The message type.
+ * @param {Object} message The message payload.
+ */
+remoting.ClientPluginAsync.prototype.sendClientMessage =
+    function(type, message) {
+  if (!this.hasFeature(remoting.ClientPlugin.Feature.EXTENSION_MESSAGE)) {
+    return;
+  }
+  this.plugin.postMessage(JSON.stringify(
+    { method: 'extensionMessage',
+      data: { type: type, data: JSON.stringify(message) } }));
+
+};
+
+/**
  * 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
  * see the "this plugin is disabled" message if it is actually disabled.
  * @private
  */
 remoting.ClientPluginAsync.prototype.showPluginForClickToPlay_ = function() {
   if (!this.helloReceived_) {
     var width = 200;
     var height = 200;
     this.plugin.width = width;
     this.plugin.height = height;
     // Center the plugin just underneath the "Connnecting..." dialog.
     var parentNode = this.plugin.parentNode;
     var dialog = document.getElementById('client-dialog');
     var dialogRect = dialog.getBoundingClientRect();
     parentNode.style.top = (dialogRect.bottom + 16) + 'px';
     parentNode.style.left = (window.innerWidth - width) / 2 + 'px';
   }
 };