Add remoting.ClientPlugin class that wraps the client plugin.

The new class will hide differences between various client plugin version
from the remoting.ClientScreen class.

BUG=86353


Review URL: http://codereview.chromium.org/9369056

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@121585 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 317 insertions, 136 deletions

diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index ab5b31b..8e65062 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -108,6 +108,7 @@
       'resources/icon_warning.png',
       'webapp/choice.css',
       'webapp/choice.html',
+      'webapp/client_plugin.js',
       'webapp/client_screen.js',
       'webapp/client_session.js',
       'webapp/cs_oauth2_trampoline.js',
diff --git a/remoting/webapp/choice.html b/remoting/webapp/choice.html
index cfe18b3..1e897e9 100644
--- a/remoting/webapp/choice.html
+++ b/remoting/webapp/choice.html
@@ -15,6 +15,7 @@ found in the LICENSE file.
     <link rel="stylesheet" href="main.css" />
     <link rel="stylesheet" href="choice.css" />
     <link rel="stylesheet" href="toolbar.css" />
+    <script src="client_plugin.js"></script>
     <script src="client_screen.js"></script>
     <script src="client_session.js"></script>
     <script src="debug_log.js"></script>
diff --git a/remoting/webapp/client_plugin.js b/remoting/webapp/client_plugin.js
new file mode 100644
index 0000000..9430115
--- /dev/null
+++ b/remoting/webapp/client_plugin.js
@@ -0,0 +1,239 @@
+// 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
+ * client plugins versions when it is necessary.
+ */
+
+'use strict';
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+
+/**
+ * @param {Element} container The element to add the plugin to.
+ * @param {string} id Id to use for the plugin element .
+ * @constructor
+ */
+remoting.ClientPlugin = function(container, id) {
+  this.plugin = /** @type {remoting.ViewerPlugin} */
+      document.createElement('embed');
+
+  this.plugin.id = id;
+  this.plugin.src = 'about://none';
+  this.plugin.type = 'application/vnd.chromium.remoting-viewer';
+  this.plugin.width = 0;
+  this.plugin.height = 0;
+  this.plugin.tabIndex = 0;  // Required, otherwise focus() doesn't work.
+  container.appendChild(this.plugin);
+
+  this.desktopWidth = 0;
+  this.desktopHeight = 0;
+
+  /** @param {string} iq The Iq stanza received from the host. */
+  this.onOutgoingIqHandler = function (iq) {};
+  /** @param {string} message Log message. */
+  this.onDebugMessageHandler = function (message) {};
+  /**
+   * @param {number} status The plugin status.
+   * @param {number} error The plugin error status, if any.
+   */
+  this.onConnectionStatusUpdateHandler = function(status, error) {};
+  this.onDesktopSizeUpdateHandler = function () {};
+
+  // Connect Event Handlers
+
+  /** @type {remoting.ClientPlugin} */
+  var that = this;
+
+  /** @param {string} iq The IQ stanza to send. */
+  this.plugin.sendIq = function(iq) { that.onSendIq_(iq); };
+
+  /** @param {string} msg The message to log. */
+  this.plugin.debugInfo = function(msg) { that.onDebugInfo_(msg); };
+
+  /**
+   * @param {number} status The plugin status.
+   * @param {number} error The plugin error status, if any.
+   */
+  this.plugin.connectionInfoUpdate = function(status, error) {
+    that.onConnectionInfoUpdate_(status, error);
+  };
+  this.plugin.desktopSizeUpdate = function() { that.onDesktopSizeUpdate_(); };
+};
+
+/** @param {string} iq The Iq stanza received from the host. */
+remoting.ClientPlugin.prototype.onSendIq_ = function(iq) {
+  this.onOutgoingIqHandler(iq);
+}
+
+  /** @param {string} message The IQ stanza to send. */
+remoting.ClientPlugin.prototype.onDebugInfo_ = function(message) {
+  this.onDebugMessageHandler(message);
+}
+
+/**
+ * @param {number} status The plugin status.
+ * @param {number} error The plugin error status, if any.
+ */
+remoting.ClientPlugin.prototype.onConnectionInfoUpdate_=
+    function(status, error) {
+  // Old plugins didn't pass the status and error values, so get
+  // them directly. Note that there is a race condition inherent in
+  // this approach.
+  if (typeof(status) == 'undefined')
+    status = this.plugin.status;
+  if (typeof(error) == 'undefined')
+    error = this.plugin.error;
+  this.onConnectionStatusUpdateHandler(status, error);
+};
+
+remoting.ClientPlugin.prototype.onDesktopSizeUpdate_ = function() {
+    this.desktopWidth = this.plugin.desktopWidth;
+    this.desktopHeight = this.plugin.desktopHeight;
+    this.onDesktopSizeUpdateHandler();
+}
+
+/**
+ * Chromoting session API version (for this javascript).
+ * This is compared with the plugin API version to verify that they are
+ * compatible.
+ *
+ * @const
+ * @private
+ */
+remoting.ClientPlugin.prototype.API_VERSION_ = 4;
+
+/**
+ * The oldest API version that we support.
+ * This will differ from the |API_VERSION_| if we maintain backward
+ * compatibility with older API versions.
+ *
+ * @const
+ * @private
+ */
+remoting.ClientPlugin.prototype.API_MIN_VERSION_ = 2;
+
+
+/**
+ * Deletes the plugin.
+ */
+remoting.ClientPlugin.prototype.cleanup = function() {
+  this.plugin.parentNode.removeChild(this.plugin);
+};
+
+/**
+ * @return {HTMLElement} HTML element that correspods to the plugin.
+ */
+remoting.ClientPlugin.prototype.element = function() {
+  return this.plugin;
+};
+
+/**
+ * @return {boolean} True if the plugin was loaded succesfully.
+ */
+remoting.ClientPlugin.prototype.isLoaded = function() {
+  return typeof this.plugin.connect === 'function';
+}
+
+/**
+ * @return {boolean} True if the plugin and web-app versions are compatible.
+ */
+remoting.ClientPlugin.prototype.isSupportedVersion = function() {
+  return this.API_VERSION_ >= this.plugin.apiMinVersion &&
+      this.plugin.apiVersion >= this.API_MIN_VERSION_;
+};
+
+/**
+ * @return {boolean} True if the plugin supports high-quality scaling.
+ */
+remoting.ClientPlugin.prototype.isHiQualityScalingSupported = function() {
+  return this.plugin.apiVersion >= 3;
+};
+
+/**
+ * @param {string} iq Incoming IQ stanza.
+ */
+remoting.ClientPlugin.prototype.onIncomingIq = function(iq) {
+  if (this.plugin && this.plugin.onIq) {
+    this.plugin.onIq(iq);
+  } else {
+    // plugin.onIq may not be set after the plugin has been shut
+    // down. Particularly this happens when we receive response to
+    // session-terminate stanza.
+    remoting.debug.log(
+        'plugin.onIq is not set so dropping incoming message.');
+  }
+};
+
+/**
+ * @param {string} hostJid The jid of the host to connect to.
+ * @param {string} hostPublicKey The base64 encoded version of the host's
+ *     public key.
+ * @param {string} clientJid Local jid.
+ * @param {string} sharedSecret The access code for IT2Me or the PIN
+ *     for Me2Me.
+ * @param {string} authenticationMethods Comma-separated list of
+ *     authentication methods the client should attempt to use.
+ * @param {string} authenticationTag A host-specific tag to mix into
+ *     authentication hashes.
+ */
+remoting.ClientPlugin.prototype.connect = function(
+    hostJid, hostPublicKey, clientJid, sharedSecret,
+    authenticationMethods, authenticationTag) {
+  if (this.plugin.apiVersion < 4) {
+    // Client plugin versions prior to 4 didn't support the last two
+    // parameters.
+    this.plugin.connect(hostJid, hostPublicKey, clientJid, sharedSecret);
+  } else {
+    this.plugin.connect(hostJid, hostPublicKey, clientJid, sharedSecret,
+                        authenticationMethods, authenticationTag);
+  }
+}
+
+/**
+ * @param {boolean} scaleToFit True if scale-to-fit should be enabled.
+ */
+remoting.ClientPlugin.prototype.setScaleToFit = function(scaleToFit) {
+  // scaleToFit() will be removed in future versions of the plugin.
+  if (!!this.plugin && typeof this.plugin.setScaleToFit === 'function')
+    this.plugin.setScaleToFit(scaleToFit);
+};
+
+
+/**
+ *
+ */
+remoting.ClientPlugin.prototype.releaseAllKeys = function() {
+  this.plugin.releaseAllKeys();
+};
+
+/**
+ * Returns an associative array with a set of stats for this connection.
+ *
+ * @return {Object.<string, number>} The connection statistics.
+ */
+remoting.ClientPlugin.prototype.getPerfStats = function() {
+  var dict = {};
+  dict[remoting.ClientSession.STATS_KEY_VIDEO_BANDWIDTH] =
+      this.plugin.videoBandwidth;
+  dict[remoting.ClientSession.STATS_KEY_VIDEO_FRAME_RATE] =
+      this.plugin.videoFrameRate;
+  dict[remoting.ClientSession.STATS_KEY_CAPTURE_LATENCY] =
+      this.plugin.videoCaptureLatency;
+  dict[remoting.ClientSession.STATS_KEY_ENCODE_LATENCY] =
+      this.plugin.videoEncodeLatency;
+  dict[remoting.ClientSession.STATS_KEY_DECODE_LATENCY] =
+      this.plugin.videoDecodeLatency;
+  dict[remoting.ClientSession.STATS_KEY_RENDER_LATENCY] =
+      this.plugin.videoRenderLatency;
+  dict[remoting.ClientSession.STATS_KEY_ROUNDTRIP_LATENCY] =
+      this.plugin.roundTripLatency;
+  return dict;
+};
diff --git a/remoting/webapp/client_screen.js b/remoting/webapp/client_screen.js
index 7479ace..45edbcb 100644
--- a/remoting/webapp/client_screen.js
+++ b/remoting/webapp/client_screen.js
@@ -397,7 +397,7 @@ function updateStatistics_() {
       remoting.clientSession.state != remoting.ClientSession.State.CONNECTED) {
     return;
   }
-  var stats = remoting.clientSession.stats();
+  var stats = remoting.clientSession.getPerfStats();
   remoting.debug.updateStatistics(stats);
   remoting.clientSession.logStatistics(stats);
   // Update the stats once per second.
diff --git a/remoting/webapp/client_session.js b/remoting/webapp/client_session.js
index 9977d58..f6d2e2e 100644
--- a/remoting/webapp/client_session.js
+++ b/remoting/webapp/client_session.js
@@ -6,9 +6,15 @@
  * @fileoverview
  * Class handling creation and teardown of a remoting client session.
  *
- * This abstracts a <embed> element and controls the plugin which does the
- * actual remoting work.  There should be no UI code inside this class.  It
- * should be purely thought of as a controller of sorts.
+ * The ClientSession class controls lifetime of the client plugin
+ * object and provides the plugin with the functionality it needs to
+ * establish connection. Specifically it:
+ *  - Delivers incoming/otgoing signaling messages,
+ *  - Adjusts plugin size and position when destop resolution changes,
+ *
+ * This class should not access the plugin directly, instead it should
+ * do it through ClientPlugin class which abstracts plugin version
+ * differences.
  */
 
 'use strict';
@@ -47,7 +53,7 @@ remoting.ClientSession = function(hostJid, hostPublicKey, sharedSecret,
   this.mode = mode;
   this.clientJid = '';
   this.sessionId = '';
-  /** @type {remoting.ViewerPlugin} */
+  /** @type {remoting.ClientPlugin} */
   this.plugin = null;
   this.scaleToFit = false;
   this.logToServer = new remoting.LogToServer();
@@ -55,7 +61,7 @@ remoting.ClientSession = function(hostJid, hostPublicKey, sharedSecret,
   /** @type {remoting.ClientSession} */
   var that = this;
   /** @type {function():void} @private */
-  this.refocusPlugin_ = function() { that.plugin.focus(); };
+  this.refocusPlugin_ = function() { that.plugin.element().focus(); };
 };
 
 // Note that the positive values in both of these enums are copied directly
@@ -114,26 +120,6 @@ remoting.ClientSession.prototype.error =
     remoting.ClientSession.ConnectionError.NONE;
 
 /**
- * Chromoting session API version (for this javascript).
- * This is compared with the plugin API version to verify that they are
- * compatible.
- *
- * @const
- * @private
- */
-remoting.ClientSession.prototype.API_VERSION_ = 4;
-
-/**
- * The oldest API version that we support.
- * This will differ from the |API_VERSION_| if we maintain backward
- * compatibility with older API versions.
- *
- * @const
- * @private
- */
-remoting.ClientSession.prototype.API_MIN_VERSION_ = 2;
-
-/**
  * The id of the client plugin
  *
  * @const
@@ -158,56 +144,49 @@ remoting.ClientSession.prototype.onStateChange =
  */
 remoting.ClientSession.prototype.createPluginAndConnect =
     function(container, oauth2AccessToken) {
-  this.plugin = /** @type {remoting.ViewerPlugin} */
-      document.createElement('embed');
-  this.plugin.id = this.PLUGIN_ID;
-  this.plugin.src = 'about://none';
-  this.plugin.type = 'application/vnd.chromium.remoting-viewer';
-  this.plugin.width = 0;
-  this.plugin.height = 0;
-  this.plugin.tabIndex = 0;  // Required, otherwise focus() doesn't work.
-  container.appendChild(this.plugin);
-
-  this.plugin.focus();
-  this.plugin.addEventListener('blur', this.refocusPlugin_, false);
-
-  if (!this.isPluginVersionSupported_(this.plugin)) {
-    // TODO(ajwong): Remove from parent.
+  this.plugin = new remoting.ClientPlugin(container, this.PLUGIN_ID);
+
+  this.plugin.element().focus();
+  this.plugin.element().addEventListener('blur', this.refocusPlugin_, false);
+
+  if (!this.plugin.isLoaded()) {
+    remoting.debug.log('ERROR: remoting plugin not loaded');
+    this.plugin.cleanup();
+    delete this.plugin;
+    this.setState_(remoting.ClientSession.State.UNKNOWN_PLUGIN_ERROR);
+    return;
+  }
+
+  if (!this.plugin.isSupportedVersion()) {
+    this.plugin.cleanup();
     delete this.plugin;
     this.setState_(remoting.ClientSession.State.BAD_PLUGIN_VERSION);
     return;
   }
 
   // Enable scale-to-fit if the plugin is new enough for high-quality scaling.
-  this.setScaleToFit(this.plugin.apiVersion >= 3);
+  this.setScaleToFit(this.plugin.isHiQualityScalingSupported());
 
   /** @type {remoting.ClientSession} */ var that = this;
   /** @param {string} msg The IQ stanza to send. */
-  this.plugin.sendIq = function(msg) { that.sendIq_(msg); };
+  this.plugin.onOutgoingIqHandler = function(msg) { that.sendIq_(msg); };
   /** @param {string} msg The message to log. */
-  this.plugin.debugInfo = function(msg) {
+  this.plugin.onDebugMessageHandler = function(msg) {
     remoting.debug.log('plugin: ' + msg);
   };
 
-  // TODO(ajwong): Is it even worth having this class handle these events?
-  // Or would it be better to just allow users to pass in their own handlers
-  // and leave these blank by default?
   /**
    * @param {number} status The plugin status.
    * @param {number} error The plugin error status, if any.
    */
-  this.plugin.connectionInfoUpdate = function(status, error) {
-    that.connectionInfoUpdateCallback(status, error);
+  this.plugin.onConnectionStatusUpdateHandler = function(status, error) {
+    that.connectionStatusUpdateCallback(status, error);
+  };
+  this.plugin.onDesktopSizeUpdateHandler = function() {
+    that.onDesktopSizeChanged_();
   };
-  this.plugin.desktopSizeUpdate = function() { that.onDesktopSizeChanged_(); };
 
-  // TODO(garykac): Clean exit if |connect| isn't a function.
-  if (typeof this.plugin.connect === 'function') {
-    this.connectPluginToWcs_(oauth2AccessToken);
-  } else {
-    remoting.debug.log('ERROR: remoting plugin not loaded');
-    this.setState_(remoting.ClientSession.State.UNKNOWN_PLUGIN_ERROR);
-  }
+  this.connectPluginToWcs_(oauth2AccessToken);
 };
 
 /**
@@ -219,9 +198,9 @@ remoting.ClientSession.prototype.createPluginAndConnect =
  */
 remoting.ClientSession.prototype.removePlugin = function() {
   if (this.plugin) {
-    this.plugin.removeEventListener('blur', this.refocusPlugin_, false);
-    var parentNode = this.plugin.parentNode;
-    parentNode.removeChild(this.plugin);
+    this.plugin.element().removeEventListener(
+        'blur', this.refocusPlugin_, false);
+    this.plugin.cleanup();
     this.plugin = null;
   }
 };
@@ -307,16 +286,6 @@ remoting.ClientSession.prototype.sendIq_ = function(msg) {
 };
 
 /**
- * @private
- * @param {remoting.ViewerPlugin} plugin The embed element for the plugin.
- * @return {boolean} True if the plugin and web-app versions are compatible.
- */
-remoting.ClientSession.prototype.isPluginVersionSupported_ = function(plugin) {
-  return this.API_VERSION_ >= plugin.apiMinVersion &&
-      plugin.apiVersion >= this.API_MIN_VERSION_;
-};
-
-/**
  * Connects the plugin to WCS.
  *
  * @private
@@ -333,29 +302,14 @@ remoting.ClientSession.prototype.connectPluginToWcs_ =
   /** @type {remoting.ClientSession} */
   var that = this;
   /** @param {string} stanza The IQ stanza received. */
-  var onIq = function(stanza) {
+  var onIncomingIq = function(stanza) {
     remoting.debug.logIq(false, stanza);
-    if (that.plugin.onIq) {
-      that.plugin.onIq(stanza);
-    } else {
-      // plugin.onIq may not be set after the plugin has been shut
-      // down. Particularly this happens when we receive response to
-      // session-terminate stanza.
-      remoting.debug.log(
-          'plugin.onIq is not set so dropping incoming message.');
-    }
-  }
-  remoting.wcs.setOnIq(onIq);
-  if (that.plugin.apiVersion < 4) {
-    // Client plugin versions prior to 4 didn't support the last two
-    // parameters.
-    that.plugin.connect(this.hostJid, this.hostPublicKey, this.clientJid,
-                        this.sharedSecret);
-  } else {
-    that.plugin.connect(this.hostJid, this.hostPublicKey, this.clientJid,
-                        this.sharedSecret, this.authenticationMethods,
-                        this.authenticationTag);
+    that.plugin.onIncomingIq(stanza);
   }
+  remoting.wcs.setOnIq(onIncomingIq);
+  that.plugin.connect(this.hostJid, this.hostPublicKey, this.clientJid,
+                      this.sharedSecret, this.authenticationMethods,
+                      this.authenticationTag);
 };
 
 /**
@@ -365,20 +319,11 @@ remoting.ClientSession.prototype.connectPluginToWcs_ =
  * @param {number} status The plugin's status.
  * @param {number} error The plugin's error state, if any.
  */
-remoting.ClientSession.prototype.connectionInfoUpdateCallback =
+remoting.ClientSession.prototype.connectionStatusUpdateCallback =
     function(status, error) {
-  // Old plugins didn't pass the status and error values, so get them directly.
-  // Note that there is a race condition inherent in this approach.
-  if (typeof(status) == 'undefined') {
-    status = this.plugin.status;
-  }
-  if (typeof(error) == 'undefined') {
-    error = this.plugin.error;
-  }
-
-  if (status == this.plugin.STATUS_CONNECTED) {
+  if (status == remoting.ClientSession.State.CONNECTED) {
     this.onDesktopSizeChanged_();
-  } else if (status == this.plugin.STATUS_FAILED) {
+  } else if (status == remoting.ClientSession.State.CONNECTION_FAILED) {
     this.error = /** @type {remoting.ClientSession.ConnectionError} */ (error);
   }
   this.setState_(/** @type {remoting.ClientSession.State} */ (status));
@@ -430,39 +375,47 @@ remoting.ClientSession.prototype.onDesktopSizeChanged_ = function() {
  */
 remoting.ClientSession.prototype.updateDimensions = function() {
   if (this.plugin.desktopWidth == 0 ||
-      this.plugin.desktopHeight == 0)
+      this.plugin.desktopHeight == 0) {
     return;
+  }
 
   var windowWidth = window.innerWidth;
   var windowHeight = window.innerHeight;
   var scale = 1.0;
 
   if (this.getScaleToFit()) {
-    var scaleFitHeight = 1.0 * windowHeight / this.plugin.desktopHeight;
     var scaleFitWidth = 1.0 * windowWidth / this.plugin.desktopWidth;
+    var scaleFitHeight = 1.0 * windowHeight / this.plugin.desktopHeight;
     scale = Math.min(1.0, scaleFitHeight, scaleFitWidth);
   }
 
+  var width = this.plugin.desktopWidth * scale;
+  var height = this.plugin.desktopHeight * scale;
+
   // Resize the plugin if necessary.
-  this.plugin.width = this.plugin.desktopWidth * scale;
-  this.plugin.height = this.plugin.desktopHeight * scale;
+  this.plugin.element().width = width;
+  this.plugin.element().height = height;
 
   // Position the container.
   // TODO(wez): We should take into account scrollbars when positioning.
-  var parentNode = this.plugin.parentNode;
-  if (this.plugin.width < windowWidth)
-    parentNode.style.left = (windowWidth - this.plugin.width) / 2 + 'px';
-  else
+  var parentNode = this.plugin.element().parentNode;
+
+  if (width < windowWidth) {
+    parentNode.style.left = (windowWidth - width) / 2 + 'px';
+  } else {
     parentNode.style.left = '0';
-  if (this.plugin.height < windowHeight)
-    parentNode.style.top = (windowHeight - this.plugin.height) / 2 + 'px';
-  else
+  }
+
+  if (height < windowHeight) {
+    parentNode.style.top = (windowHeight - height) / 2 + 'px';
+  } else {
     parentNode.style.top = '0';
+  }
 
   remoting.debug.log('plugin dimensions: ' +
                      parentNode.style.left + ',' +
                      parentNode.style.top + '-' +
-                     this.plugin.width + 'x' + this.plugin.height + '.');
+                     width + 'x' + height + '.');
   this.plugin.setScaleToFit(this.getScaleToFit());
 };
 
@@ -471,23 +424,8 @@ remoting.ClientSession.prototype.updateDimensions = function() {
  *
  * @return {Object.<string, number>} The connection statistics.
  */
-remoting.ClientSession.prototype.stats = function() {
-  var dict = {};
-  dict[remoting.ClientSession.STATS_KEY_VIDEO_BANDWIDTH] =
-      this.plugin.videoBandwidth;
-  dict[remoting.ClientSession.STATS_KEY_VIDEO_FRAME_RATE] =
-      this.plugin.videoFrameRate;
-  dict[remoting.ClientSession.STATS_KEY_CAPTURE_LATENCY] =
-      this.plugin.videoCaptureLatency;
-  dict[remoting.ClientSession.STATS_KEY_ENCODE_LATENCY] =
-      this.plugin.videoEncodeLatency;
-  dict[remoting.ClientSession.STATS_KEY_DECODE_LATENCY] =
-      this.plugin.videoDecodeLatency;
-  dict[remoting.ClientSession.STATS_KEY_RENDER_LATENCY] =
-      this.plugin.videoRenderLatency;
-  dict[remoting.ClientSession.STATS_KEY_ROUNDTRIP_LATENCY] =
-      this.plugin.roundTripLatency;
-  return dict;
+remoting.ClientSession.prototype.getPerfStats = function() {
+  return this.plugin.getPerfStats();
 };
 
 /**
diff --git a/remoting/webapp/viewer_plugin_proto.js b/remoting/webapp/viewer_plugin_proto.js
index 7ed0b57..df725a5 100644
--- a/remoting/webapp/viewer_plugin_proto.js
+++ b/remoting/webapp/viewer_plugin_proto.js
@@ -11,14 +11,11 @@ var remoting = remoting || {};
 /** @constructor
  *  @extends HTMLElement
  */
-remoting.ViewerPlugin = function() {};
+remoting.ViewerPlugin = function() { };
 
 /** @param {string} iq The Iq stanza received from the host. */
 remoting.ViewerPlugin.prototype.onIq = function(iq) {};
 
-/** @param {boolean} scale True to enable scaling, false to disable. */
-remoting.ViewerPlugin.prototype.setScaleToFit = function(scale) {};
-
 /** Release all keys currently pressed by this client. */
 remoting.ViewerPlugin.prototype.releaseAllKeys = function() {};
 
@@ -38,6 +35,11 @@ remoting.ViewerPlugin.prototype.connect =
     function(hostJid, hostPublicKey, clientJid, sharedSecret,
              authenticationMethod, authenticationTag) {};
 
+/**
+ * @param {boolean} scaleToFit New scaleToFit value.
+ */
+remoting.ViewerPlugin.prototype.setScaleToFit = function(scaleToFit) {};
+
 /** @type {function(number, number): void} State change callback function. */
 remoting.ViewerPlugin.prototype.connectionInfoUpdate;