Interfaceify ClientPlugin in preparation for mocking it.

remoting/webapp/client_plugin_impl.js

Index: remoting/webapp/client_plugin_impl.js
diff --git a/remoting/webapp/client_plugin.js b/remoting/webapp/client_plugin_impl.js
similarity index 74%
copy from remoting/webapp/client_plugin.js
copy to remoting/webapp/client_plugin_impl.js
index 197eeffd743adc58c351534895344d6494181be2..28a973d1edae21ec69f6d864e0e4497172742a36 100644
--- a/remoting/webapp/client_plugin.js
+++ b/remoting/webapp/client_plugin_impl.js
@@ -22,75 +22,130 @@ var remoting = remoting || {};
  *     protocol extension messages. Returns true if a message is recognized;
  *     false otherwise.
  * @constructor
+ * @implements {remoting.ClientPlugin}
  */
-remoting.ClientPlugin = function(container, onExtensionMessage) {
-  this.plugin_ = remoting.ClientPlugin.createPluginElement_();
+remoting.ClientPluginImpl = function(container, onExtensionMessage) {
+  this.plugin_ = remoting.ClientPluginImpl.createPluginElement_();
   this.plugin_.id = 'session-client-plugin';
   container.appendChild(this.plugin_);
 
   this.onExtensionMessage_ = onExtensionMessage;
 
-  this.desktopWidth = 0;
-  this.desktopHeight = 0;
-  this.desktopXDpi = 96;
-  this.desktopYDpi = 96;
+  /** @private */
+  this.desktopWidth_ = 0;
+  /** @private */
+  this.desktopHeight_ = 0;
+  /** @private */
+  this.desktopXDpi_ = 96;
+  /** @private */
+  this.desktopYDpi_ = 96;
 
-  /** @param {string} iq The Iq stanza received from the host. */
-  this.onOutgoingIqHandler = function (iq) {};
-  /** @param {string} message Log message. */
-  this.onDebugMessageHandler = function (message) {};
+  /**
+   * @param {string} iq The Iq stanza received from the host.
+   * @private
+   */
+  this.onOutgoingIqHandler_ = function (iq) {};
+  /**
+   * @param {string} message Log message.
+   * @private
+   */
+  this.onDebugMessageHandler_ = function (message) {};
   /**
    * @param {number} state The connection state.
    * @param {number} error The error code, if any.
+   * @private
    */
-  this.onConnectionStatusUpdateHandler = function(state, error) {};
-  /** @param {boolean} ready Connection ready state. */
-  this.onConnectionReadyHandler = function(ready) {};
+  this.onConnectionStatusUpdateHandler_ = function(state, error) {};
+  /**
+   * @param {boolean} ready Connection ready state.
+   * @private
+   */
+  this.onConnectionReadyHandler_ = function(ready) {};
 
   /**
    * @param {string} tokenUrl Token-request URL, received from the host.
    * @param {string} hostPublicKey Public key for the host.
    * @param {string} scope OAuth scope to request the token for.
+   * @private
    */
-  this.fetchThirdPartyTokenHandler = function(
+  this.fetchThirdPartyTokenHandler_ = function(
     tokenUrl, hostPublicKey, scope) {};
-  this.onDesktopSizeUpdateHandler = function () {};
-  /** @param {!Array.<string>} capabilities The negotiated capabilities. */
-  this.onSetCapabilitiesHandler = function (capabilities) {};
-  this.fetchPinHandler = function (supportsPairing) {};
-  /** @param {string} data Remote gnubbyd data. */
-  this.onGnubbyAuthHandler = function(data) {};
+  /** @private */
+  this.onDesktopSizeUpdateHandler_ = function () {};
+  /**
+   * @param {!Array.<string>} capabilities The negotiated capabilities.
+   * @private
+   */
+  this.onSetCapabilitiesHandler_ = function (capabilities) {};
+  /** @private */
+  this.fetchPinHandler_ = function (supportsPairing) {};
+  /**
+   * @param {string} data Remote gnubbyd data.
+   * @private
+   */
+  this.onGnubbyAuthHandler_ = function(data) {};
   /**
    * @param {string} url
    * @param {number} hotspotX
    * @param {number} hotspotY
+   * @private
    */
-  this.updateMouseCursorImage = function(url, hotspotX, hotspotY) {};
+  this.updateMouseCursorImage_ = function(url, hotspotX, hotspotY) {};
 
-  /** @param {string} data Remote cast extension message. */
-  this.onCastExtensionHandler = function(data) {};
+  /**
+   * @param {string} data Remote cast extension message.
+   * @private
+   */
+  this.onCastExtensionHandler_ = function(data) {};
 
-  /** @type {remoting.MediaSourceRenderer} */
+  /**
+   * @type {remoting.MediaSourceRenderer}
+   * @private
+   */
   this.mediaSourceRenderer_ = null;
 
-  /** @type {number} */
+  /**
+   * @type {number}
+   * @private
+   */
   this.pluginApiVersion_ = -1;
-  /** @type {Array.<string>} */
+  /**
+   * @type {Array.<string>}
+   * @private
+   */
   this.pluginApiFeatures_ = [];
-  /** @type {number} */
+  /**
+   * @type {number}
+   * @private
+   */
   this.pluginApiMinVersion_ = -1;
-  /** @type {!Array.<string>} */
+  /**
+   * @type {!Array.<string>}
+   * @private
+   */
   this.capabilities_ = [];
-  /** @type {boolean} */
+  /**
+   * @type {boolean}
+   * @private
+   */
   this.helloReceived_ = false;
-  /** @type {function(boolean)|null} */
+  /**
+   * @type {function(boolean)|null}
+   * @private
+   */
   this.onInitializedCallback_ = null;
-  /** @type {function(string, string):void} */
+  /**
+   * @type {function(string, string):void}
+   * @private
+   */
   this.onPairingComplete_ = function(clientId, sharedSecret) {};
-  /** @type {remoting.ClientSession.PerfStats} */
+  /**
+   * @type {remoting.ClientSession.PerfStats}
+   * @private
+   */
   this.perfStats_ = new remoting.ClientSession.PerfStats();
 
-  /** @type {remoting.ClientPlugin} */
+  /** @type {remoting.ClientPluginImpl} */
   var that = this;
   /** @param {Event} event Message event from the plugin. */
   this.plugin_.addEventListener('message', function(event) {
@@ -107,7 +162,7 @@ remoting.ClientPlugin = function(container, onExtensionMessage) {
  *
  * @return {remoting.ViewerPlugin} Plugin element
  */
-remoting.ClientPlugin.createPluginElement_ = function() {
+remoting.ClientPluginImpl.createPluginElement_ = function() {
   var plugin = /** @type {remoting.ViewerPlugin} */
       document.createElement('embed');
   if (remoting.settings.CLIENT_PLUGIN_TYPE == 'pnacl') {
@@ -127,42 +182,6 @@ remoting.ClientPlugin.createPluginElement_ = function() {
 }
 
 /**
- * Preloads the plugin to make instantiation faster when the user tries
- * to connect.
- */
-remoting.ClientPlugin.preload = function() {
-  if (remoting.settings.CLIENT_PLUGIN_TYPE != 'pnacl') {
-    return;
-  }
-
-  var plugin = remoting.ClientPlugin.createPluginElement_();
-  plugin.addEventListener(
-      'loadend', function() { document.body.removeChild(plugin); }, false);
-  document.body.appendChild(plugin);
-}
-
-/**
- * Set of features for which hasFeature() can be used to test.
- *
- * @enum {string}
- */
-remoting.ClientPlugin.Feature = {
-  INJECT_KEY_EVENT: 'injectKeyEvent',
-  NOTIFY_CLIENT_RESOLUTION: 'notifyClientResolution',
-  ASYNC_PIN: 'asyncPin',
-  PAUSE_VIDEO: 'pauseVideo',
-  PAUSE_AUDIO: 'pauseAudio',
-  REMAP_KEY: 'remapKey',
-  SEND_CLIPBOARD_ITEM: 'sendClipboardItem',
-  THIRD_PARTY_AUTH: 'thirdPartyAuth',
-  TRAP_KEY: 'trapKey',
-  PINLESS_AUTH: 'pinlessAuth',
-  EXTENSION_MESSAGE: 'extensionMessage',
-  MEDIA_SOURCE_RENDERING: 'mediaSourceRendering',
-  VIDEO_CONTROL: 'videoControl'
-};
-
-/**
  * Chromoting session API version (for this javascript).
  * This is compared with the plugin API version to verify that they are
  * compatible.
@@ -170,7 +189,7 @@ remoting.ClientPlugin.Feature = {
  * @const
  * @private
  */
-remoting.ClientPlugin.prototype.API_VERSION_ = 6;
+remoting.ClientPluginImpl.prototype.API_VERSION_ = 6;
 
 /**
  * The oldest API version that we support.
@@ -180,14 +199,97 @@ remoting.ClientPlugin.prototype.API_VERSION_ = 6;
  * @const
  * @private
  */
-remoting.ClientPlugin.prototype.API_MIN_VERSION_ = 5;
+remoting.ClientPluginImpl.prototype.API_MIN_VERSION_ = 5;
+
+/**
+ * @param {function(string):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setOnOutgoingIqHandler = function(handler) {
+  this.onOutgoingIqHandler_ = handler;
+};
+
+/**
+ * @param {function(string):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setOnDebugMessageHandler =
+    function(handler) {
+  this.onDebugMessageHandler_ = handler;
+};
+
+/**
+ * @param {function(number, number):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setConnectionStatusUpdateHandler =
+    function(handler) {
+  this.onConnectionStatusUpdateHandler_ = handler;
+};
+
+/**
+ * @param {function(boolean):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setConnectionReadyHandler =
+    function(handler) {
+  this.onConnectionReadyHandler_ = handler;
+};
+
+/**
+ * @param {function():void} handler
+ */
+remoting.ClientPluginImpl.prototype.setDesktopSizeUpdateHandler =
+    function(handler) {
+  this.onDesktopSizeUpdateHandler_ = handler;
+};
+
+/**
+ * @param {function(!Array.<string>):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setCapabilitiesHandler = function(handler) {
+  this.onSetCapabilitiesHandler_ = handler;
+};
+
+/**
+ * @param {function(string):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setGnubbyAuthHandler = function(handler) {
+  this.onGnubbyAuthHandler_ = handler;
+};
+
+/**
+ * @param {function(string):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setCastExtensionHandler =
+    function(handler) {
+  this.onCastExtensionHandler_ = handler;
+};
+
+/**
+ * @param {function(string, number, number):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setMouseCursorHandler = function(handler) {
+  this.updateMouseCursorImage_ = handler;
+};
+
+/**
+ * @param {function(string, string, string):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setFetchThirdPartyTokenHandler =
+    function(handler) {
+  this.fetchThirdPartyTokenHandler_ = handler;
+};
+
+/**
+ * @param {function(boolean):void} handler
+ */
+remoting.ClientPluginImpl.prototype.setFetchPinHandler = function(handler) {
+  this.fetchPinHandler_ = handler;
+};
 
 /**
  * @param {string|{method:string, data:Object.<string,*>}}
  *    rawMessage Message from the plugin.
  * @private
  */
-remoting.ClientPlugin.prototype.handleMessage_ = function(rawMessage) {
+remoting.ClientPluginImpl.prototype.handleMessage_ = function(rawMessage) {
   var message =
       /** @type {{method:string, data:Object.<string,*>}} */
       ((typeof(rawMessage) == 'string') ? jsonParseSafe(rawMessage)
@@ -209,7 +311,7 @@ remoting.ClientPlugin.prototype.handleMessage_ = function(rawMessage) {
  *    message Parsed message from the plugin.
  * @private
  */
-remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
+remoting.ClientPluginImpl.prototype.handleMessageMethod_ = function(message) {
   /**
    * Splits a string into a list of words delimited by spaces.
    * @param {string} str String that should be split.
@@ -285,24 +387,24 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
     }
 
   } else if (message.method == 'sendOutgoingIq') {
-    this.onOutgoingIqHandler(getStringAttr(message.data, 'iq'));
+    this.onOutgoingIqHandler_(getStringAttr(message.data, 'iq'));
 
   } else if (message.method == 'logDebugMessage') {
-    this.onDebugMessageHandler(getStringAttr(message.data, 'message'));
+    this.onDebugMessageHandler_(getStringAttr(message.data, 'message'));
 
   } else if (message.method == 'onConnectionStatus') {
     var state = remoting.ClientSession.State.fromString(
         getStringAttr(message.data, 'state'))
     var error = remoting.ClientSession.ConnectionError.fromString(
         getStringAttr(message.data, 'error'));
-    this.onConnectionStatusUpdateHandler(state, error);
+    this.onConnectionStatusUpdateHandler_(state, error);
 
   } else if (message.method == 'onDesktopSize') {
-    this.desktopWidth = getNumberAttr(message.data, 'width');
-    this.desktopHeight = getNumberAttr(message.data, 'height');
-    this.desktopXDpi = getNumberAttr(message.data, 'x_dpi', 96);
-    this.desktopYDpi = getNumberAttr(message.data, 'y_dpi', 96);
-    this.onDesktopSizeUpdateHandler();
+    this.desktopWidth_ = getNumberAttr(message.data, 'width');
+    this.desktopHeight_ = getNumberAttr(message.data, 'height');
+    this.desktopXDpi_ = getNumberAttr(message.data, 'x_dpi', 96);
+    this.desktopYDpi_ = getNumberAttr(message.data, 'y_dpi', 96);
+    this.onDesktopSizeUpdateHandler_();
 
   } else if (message.method == 'onPerfStats') {
     // Return value is ignored. These calls will throw an error if the value
@@ -331,7 +433,7 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
 
   } else if (message.method == 'onConnectionReady') {
     var ready = getBooleanAttr(message.data, 'ready');
-    this.onConnectionReadyHandler(ready);
+    this.onConnectionReadyHandler_(ready);
 
   } else if (message.method == 'fetchPin') {
     // The pairingSupported value in the dictionary indicates whether both
@@ -339,18 +441,18 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
     // then the value won't be there at all, so give it a default of false.
     var pairingSupported = getBooleanAttr(message.data, 'pairingSupported',
                                           false)
-    this.fetchPinHandler(pairingSupported);
+    this.fetchPinHandler_(pairingSupported);
 
   } else if (message.method == 'setCapabilities') {
     /** @type {!Array.<string>} */
     var capabilities = tokenize(getStringAttr(message.data, 'capabilities'));
-    this.onSetCapabilitiesHandler(capabilities);
+    this.onSetCapabilitiesHandler_(capabilities);
 
   } else if (message.method == 'fetchThirdPartyToken') {
     var tokenUrl = getStringAttr(message.data, 'tokenUrl');
     var hostPublicKey = getStringAttr(message.data, 'hostPublicKey');
     var scope = getStringAttr(message.data, 'scope');
-    this.fetchThirdPartyTokenHandler(tokenUrl, hostPublicKey, scope);
+    this.fetchThirdPartyTokenHandler_(tokenUrl, hostPublicKey, scope);
 
   } else if (message.method == 'pairingResponse') {
     var clientId = getStringAttr(message.data, 'clientId');
@@ -362,13 +464,13 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
     var extMsgData = getStringAttr(message.data, 'data');
     switch (extMsgType) {
       case 'gnubby-auth':
-        this.onGnubbyAuthHandler(extMsgData);
+        this.onGnubbyAuthHandler_(extMsgData);
         break;
       case 'test-echo-reply':
         console.log('Got echo reply: ' + extMsgData);
         break;
       case 'cast_message':
-        this.onCastExtensionHandler(extMsgData);
+        this.onCastExtensionHandler_(extMsgData);
         break;
       default:
         this.onExtensionMessage_(extMsgType, extMsgData);
@@ -397,7 +499,7 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
         (/** @type {ArrayBuffer} */ message.data['buffer']), keyframe);
 
   } else if (message.method == 'unsetCursorShape') {
-    this.updateMouseCursorImage('', 0, 0);
+    this.updateMouseCursorImage_('', 0, 0);
 
   } else if (message.method == 'setCursorShape') {
     var width = getNumberAttr(message.data, 'width');
@@ -425,14 +527,14 @@ remoting.ClientPlugin.prototype.handleMessageMethod_ = function(message) {
     }
 
     context.putImageData(imageData, 0, 0);
-    this.updateMouseCursorImage(canvas.toDataURL(), hotspotX, hotspotY);
+    this.updateMouseCursorImage_(canvas.toDataURL(), hotspotX, hotspotY);
   }
 };
 
 /**
  * Deletes the plugin.
  */
-remoting.ClientPlugin.prototype.cleanup = function() {
+remoting.ClientPluginImpl.prototype.dispose = function() {
   if (this.plugin_) {
     this.plugin_.parentNode.removeChild(this.plugin_);
     this.plugin_ = null;
@@ -442,14 +544,14 @@ remoting.ClientPlugin.prototype.cleanup = function() {
 /**
  * @return {HTMLEmbedElement} HTML element that corresponds to the plugin.
  */
-remoting.ClientPlugin.prototype.element = function() {
+remoting.ClientPluginImpl.prototype.element = function() {
   return this.plugin_;
 };
 
 /**
  * @param {function(boolean): void} onDone
  */
-remoting.ClientPlugin.prototype.initialize = function(onDone) {
+remoting.ClientPluginImpl.prototype.initialize = function(onDone) {
   if (this.helloReceived_) {
     onDone(true);
   } else {
@@ -460,7 +562,7 @@ remoting.ClientPlugin.prototype.initialize = function(onDone) {
 /**
  * @return {boolean} True if the plugin and web-app versions are compatible.
  */
-remoting.ClientPlugin.prototype.isSupportedVersion = function() {
+remoting.ClientPluginImpl.prototype.isSupportedVersion = function() {
   if (!this.helloReceived_) {
     console.error(
         "isSupportedVersion() is called before the plugin is initialized.");
@@ -474,7 +576,7 @@ remoting.ClientPlugin.prototype.isSupportedVersion = function() {
  * @param {remoting.ClientPlugin.Feature} feature The feature to test for.
  * @return {boolean} True if the plugin supports the named feature.
  */
-remoting.ClientPlugin.prototype.hasFeature = function(feature) {
+remoting.ClientPluginImpl.prototype.hasFeature = function(feature) {
   if (!this.helloReceived_) {
     console.error(
         "hasFeature() is called before the plugin is initialized.");
@@ -486,14 +588,14 @@ remoting.ClientPlugin.prototype.hasFeature = function(feature) {
 /**
  * @return {boolean} True if the plugin supports the injectKeyEvent API.
  */
-remoting.ClientPlugin.prototype.isInjectKeyEventSupported = function() {
+remoting.ClientPluginImpl.prototype.isInjectKeyEventSupported = function() {
   return this.pluginApiVersion_ >= 6;
 };
 
 /**
  * @param {string} iq Incoming IQ stanza.
  */
-remoting.ClientPlugin.prototype.onIncomingIq = function(iq) {
+remoting.ClientPluginImpl.prototype.onIncomingIq = function(iq) {
   if (this.plugin_ && this.plugin_.postMessage) {
     this.plugin_.postMessage(JSON.stringify(
         { method: 'incomingIq', data: { iq: iq } }));
@@ -521,7 +623,7 @@ remoting.ClientPlugin.prototype.onIncomingIq = function(iq) {
  * @param {string} clientPairedSecret For paired Me2Me connections, the
  *     paired secret for this client, as issued by the host.
  */
-remoting.ClientPlugin.prototype.connect = function(
+remoting.ClientPluginImpl.prototype.connect = function(
     hostJid, hostPublicKey, localJid, sharedSecret,
     authenticationMethods, authenticationTag,
     clientPairingId, clientPairedSecret) {
@@ -552,7 +654,7 @@ remoting.ClientPlugin.prototype.connect = function(
 /**
  * Release all currently pressed keys.
  */
-remoting.ClientPlugin.prototype.releaseAllKeys = function() {
+remoting.ClientPluginImpl.prototype.releaseAllKeys = function() {
   this.plugin_.postMessage(JSON.stringify(
       { method: 'releaseAllKeys', data: {} }));
 };
@@ -563,7 +665,7 @@ remoting.ClientPlugin.prototype.releaseAllKeys = function() {
  * @param {number} usbKeycode The USB-style code of the key to inject.
  * @param {boolean} pressed True to inject a key press, False for a release.
  */
-remoting.ClientPlugin.prototype.injectKeyEvent =
+remoting.ClientPluginImpl.prototype.injectKeyEvent =
     function(usbKeycode, pressed) {
   this.plugin_.postMessage(JSON.stringify(
       { method: 'injectKeyEvent', data: {
@@ -578,7 +680,7 @@ remoting.ClientPlugin.prototype.injectKeyEvent =
  * @param {number} fromKeycode The USB-style code of the key to remap.
  * @param {number} toKeycode The USB-style code to remap the key to.
  */
-remoting.ClientPlugin.prototype.remapKey =
+remoting.ClientPluginImpl.prototype.remapKey =
     function(fromKeycode, toKeycode) {
   this.plugin_.postMessage(JSON.stringify(
       { method: 'remapKey', data: {
@@ -593,7 +695,7 @@ remoting.ClientPlugin.prototype.remapKey =
  * @param {number} keycode The USB-style code of the key.
  * @param {Boolean} trap True to enable trapping, False to disable.
  */
-remoting.ClientPlugin.prototype.trapKey = function(keycode, trap) {
+remoting.ClientPluginImpl.prototype.trapKey = function(keycode, trap) {
   this.plugin_.postMessage(JSON.stringify(
       { method: 'trapKey', data: {
           'keycode': keycode,
@@ -606,7 +708,7 @@ remoting.ClientPlugin.prototype.trapKey = function(keycode, trap) {
  *
  * @return {remoting.ClientSession.PerfStats} The connection statistics.
  */
-remoting.ClientPlugin.prototype.getPerfStats = function() {
+remoting.ClientPluginImpl.prototype.getPerfStats = function() {
   return this.perfStats_;
 };
 
@@ -616,7 +718,7 @@ remoting.ClientPlugin.prototype.getPerfStats = function() {
  * @param {string} mimeType The MIME type of the clipboard item.
  * @param {string} item The clipboard item.
  */
-remoting.ClientPlugin.prototype.sendClipboardItem =
+remoting.ClientPluginImpl.prototype.sendClipboardItem =
     function(mimeType, item) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.SEND_CLIPBOARD_ITEM))
     return;
@@ -632,7 +734,7 @@ remoting.ClientPlugin.prototype.sendClipboardItem =
  * @param {number} height The available client height in DIPs.
  * @param {number} device_scale The number of device pixels per DIP.
  */
-remoting.ClientPlugin.prototype.notifyClientResolution =
+remoting.ClientPluginImpl.prototype.notifyClientResolution =
     function(width, height, device_scale) {
   if (this.hasFeature(remoting.ClientPlugin.Feature.NOTIFY_CLIENT_RESOLUTION)) {
     var dpi = Math.floor(device_scale * 96);
@@ -649,7 +751,7 @@ remoting.ClientPlugin.prototype.notifyClientResolution =
  *
  * @param {boolean} pause True to suspend video updates, false otherwise.
  */
-remoting.ClientPlugin.prototype.pauseVideo =
+remoting.ClientPluginImpl.prototype.pauseVideo =
     function(pause) {
   if (this.hasFeature(remoting.ClientPlugin.Feature.VIDEO_CONTROL)) {
     this.plugin_.postMessage(JSON.stringify(
@@ -665,7 +767,7 @@ remoting.ClientPlugin.prototype.pauseVideo =
  *
  * @param {boolean} pause True to suspend audio updates, false otherwise.
  */
-remoting.ClientPlugin.prototype.pauseAudio =
+remoting.ClientPluginImpl.prototype.pauseAudio =
     function(pause) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.PAUSE_AUDIO)) {
     return;
@@ -679,7 +781,7 @@ remoting.ClientPlugin.prototype.pauseAudio =
  *
  * @param {boolean} wantLossless True to request lossless encoding.
  */
-remoting.ClientPlugin.prototype.setLosslessEncode =
+remoting.ClientPluginImpl.prototype.setLosslessEncode =
     function(wantLossless) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.VIDEO_CONTROL)) {
     return;
@@ -693,7 +795,7 @@ remoting.ClientPlugin.prototype.setLosslessEncode =
  *
  * @param {boolean} wantLossless True to request lossless color.
  */
-remoting.ClientPlugin.prototype.setLosslessColor =
+remoting.ClientPluginImpl.prototype.setLosslessColor =
     function(wantLossless) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.VIDEO_CONTROL)) {
     return;
@@ -707,7 +809,7 @@ remoting.ClientPlugin.prototype.setLosslessColor =
  *
  * @param {string} pin The PIN.
  */
-remoting.ClientPlugin.prototype.onPinFetched =
+remoting.ClientPluginImpl.prototype.onPinFetched =
     function(pin) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.ASYNC_PIN)) {
     return;
@@ -719,7 +821,7 @@ remoting.ClientPlugin.prototype.onPinFetched =
 /**
  * Tells the plugin to ask for the PIN asynchronously.
  */
-remoting.ClientPlugin.prototype.useAsyncPinDialog =
+remoting.ClientPluginImpl.prototype.useAsyncPinDialog =
     function() {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.ASYNC_PIN)) {
     return;
@@ -734,7 +836,7 @@ remoting.ClientPlugin.prototype.useAsyncPinDialog =
  * @param {string} token The token received from the token URL.
  * @param {string} sharedSecret Shared secret received from the token URL.
  */
-remoting.ClientPlugin.prototype.onThirdPartyTokenFetched = function(
+remoting.ClientPluginImpl.prototype.onThirdPartyTokenFetched = function(
     token, sharedSecret) {
   this.plugin_.postMessage(JSON.stringify(
     { method: 'onThirdPartyTokenFetched',
@@ -748,7 +850,7 @@ remoting.ClientPlugin.prototype.onThirdPartyTokenFetched = function(
  * @param {function(string, string):void} onDone, Callback to receive the
  *     client id and shared secret when they are available.
  */
-remoting.ClientPlugin.prototype.requestPairing =
+remoting.ClientPluginImpl.prototype.requestPairing =
     function(clientName, onDone) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.PINLESS_AUTH)) {
     return;
@@ -764,7 +866,7 @@ remoting.ClientPlugin.prototype.requestPairing =
  * @param {string} type The message type.
  * @param {string} message The message payload.
  */
-remoting.ClientPlugin.prototype.sendClientMessage =
+remoting.ClientPluginImpl.prototype.sendClientMessage =
     function(type, message) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.EXTENSION_MESSAGE)) {
     return;
@@ -780,7 +882,7 @@ remoting.ClientPlugin.prototype.sendClientMessage =
  *
  * @param {remoting.MediaSourceRenderer} mediaSourceRenderer
  */
-remoting.ClientPlugin.prototype.enableMediaSourceRendering =
+remoting.ClientPluginImpl.prototype.enableMediaSourceRendering =
     function(mediaSourceRenderer) {
   if (!this.hasFeature(remoting.ClientPlugin.Feature.MEDIA_SOURCE_RENDERING)) {
     return;
@@ -790,13 +892,29 @@ remoting.ClientPlugin.prototype.enableMediaSourceRendering =
       { method: 'enableMediaSourceRendering', data: {} }));
 };
 
+remoting.ClientPluginImpl.prototype.getDesktopWidth = function() {
+  return this.desktopWidth_;
+}
+
+remoting.ClientPluginImpl.prototype.getDesktopHeight = function() {
+  return this.desktopHeight_;
+}
+
+remoting.ClientPluginImpl.prototype.getDesktopXDpi = function() {
+  return this.desktopXDpi_;
+}
+
+remoting.ClientPluginImpl.prototype.getDesktopYDpi = function() {
+  return this.desktopYDpi_;
+}
+
 /**
  * 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.ClientPlugin.prototype.showPluginForClickToPlay_ = function() {
+remoting.ClientPluginImpl.prototype.showPluginForClickToPlay_ = function() {
   if (!this.helloReceived_) {
     var width = 200;
     var height = 200;
@@ -815,10 +933,38 @@ remoting.ClientPlugin.prototype.showPluginForClickToPlay_ = function() {
  * Undo the CSS rules needed to make the plugin clickable for click-to-play.
  * @private
  */
-remoting.ClientPlugin.prototype.hidePluginForClickToPlay_ = function() {
+remoting.ClientPluginImpl.prototype.hidePluginForClickToPlay_ = function() {
   this.plugin_.style.width = '';
   this.plugin_.style.height = '';
   this.plugin_.style.top = '';
   this.plugin_.style.left = '';
   this.plugin_.style.position = '';
 };
+
+
+/**
+ * @constructor
+ * @implements {remoting.ClientPluginFactory}
+ */
+remoting.DefaultClientPluginFactory = function() {};
+
+/**
+ * @param {Element} container
+ * @param {function(string, string):boolean} onExtensionMessage
+ * @return {remoting.ClientPlugin}
+ */
+remoting.DefaultClientPluginFactory.prototype.createPlugin =
+    function(container, onExtensionMessage) {
+  return new remoting.ClientPluginImpl(container, onExtensionMessage);
+};
+
+remoting.DefaultClientPluginFactory.prototype.preloadPlugin = function() {
+  if (remoting.settings.CLIENT_PLUGIN_TYPE != 'pnacl') {
+    return;
+  }
+
+  var plugin = remoting.ClientPluginImpl.createPluginElement_();
+  plugin.addEventListener(
+      'loadend', function() { document.body.removeChild(plugin); }, false);
+  document.body.appendChild(plugin);
+};