Add a Record button to the web-app if the host supports video recording.

remoting/webapp/client_session.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 handling creation and teardown of a remoting client session.
  *
  * The ClientSession class controls lifetime of the client plugin
  * object and provides the plugin with the functionality it needs to
@@ skipping 158 matching lines @@
   this.shrinkToFitButton_ = document.getElementById('screen-shrink-to-fit');
   /** @type {HTMLElement} @private */
   this.fullScreenButton_ = document.getElementById('toggle-full-screen');
 
   /** @type {remoting.GnubbyAuthHandler} @private */
   this.gnubbyAuthHandler_ = null;
 
   /** @type {remoting.CastExtensionHandler} @private */
   this.castExtensionHandler_ = null;
 
+  /** @type {remoting.VideoFrameRecorder} @private */
+  this.videoFrameRecorder_ = null;
+
   if (this.mode_ == remoting.ClientSession.Mode.IT2ME) {
     // Resize-to-client is not supported for IT2Me hosts.
     this.resizeToClientButton_.hidden = true;
   } else {
     this.resizeToClientButton_.hidden = false;
   }
 
   this.fullScreenButton_.addEventListener(
       'click', this.callToggleFullScreen_, false);
+
   this.defineEvents(Object.keys(remoting.ClientSession.Events));
 };
 
 base.extend(remoting.ClientSession, base.EventSource);
 
 /** @enum {string} */
 remoting.ClientSession.Events = {
   stateChanged: 'stateChanged',
   videoChannelStateChanged: 'videoChannelStateChanged',
   bumpScrollStarted: 'bumpScrollStarted',
@@ skipping 849 matching lines @@
   }
 
   this.capabilities_ = capabilities;
   if (this.hasCapability_(
       remoting.ClientSession.Capability.SEND_INITIAL_RESOLUTION)) {
     var clientArea = this.getClientArea_();
     this.plugin_.notifyClientResolution(clientArea.width,
                                         clientArea.height,
                                         window.devicePixelRatio);
   }
+  if (this.hasCapability_(
+      remoting.ClientSession.Capability.VIDEO_RECORDER)) {
+    this.videoFrameRecorder_ = new remoting.VideoFrameRecorder(this.plugin_);
+  }
 };
 
 /**
  * @private
  * @param {remoting.ClientSession.State} newState The new state for the session.
  * @return {void} Nothing.
  */
 remoting.ClientSession.prototype.setState_ = function(newState) {
   var oldState = this.state_;
   this.state_ = newState;
@@ skipping 519 matching lines @@
  * Create a CastExtensionHandler and inform the host that cast extension
  * is supported.
  * @private
  */
 remoting.ClientSession.prototype.createCastExtensionHandler_ = function() {
   if (remoting.enableCast && this.mode_ == remoting.ClientSession.Mode.ME2ME) {
     this.castExtensionHandler_ = new remoting.CastExtensionHandler(this);
   }
 };
 
+/**
+ * Returns true if the ClientSession can record video frames to a file.
+ * @return {boolean}
+ */
+remoting.ClientSession.prototype.canRecordVideo = function() {
+  return !!this.videoFrameRecorder_;
+}
+
+/**
+ * Returns true if the ClientSession is currently recording video frames.
+ * @return {boolean}
+ */
+remoting.ClientSession.prototype.isRecordingVideo = function() {
+  if (!this.videoFrameRecorder_) {
+    return false;
+  }
+  return this.videoFrameRecorder_.isRecording();
+}
+
+/**
+ * Starts or stops recording of video frames.
+ */
+remoting.ClientSession.prototype.startStopRecording = function() {
+  if (this.videoFrameRecorder_) {
+    this.videoFrameRecorder_.startStopRecording();
+  }
+}
+
+/**
+ * Handles protocol extension messages.
+ * @param {string} type Type of extension message.
+ * @param {string} data Contents of the extension message.
+ * @return {boolean} True if the message was recognized, false otherwise.
+ */
+remoting.ClientSession.prototype.handleExtensionMessage =
+    function(type, data) {
+  if (this.videoFrameRecorder_) {
+    return this.videoFrameRecorder_.handleMessage(type, data);
+  }
+  return false;
+}