Ensure that privates are private.

extensions/renderer/resources/messaging.js

 // Copyright 2014 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.
 
 // chrome.runtime.messaging API implementation.
 
   // TODO(kalman): factor requiring chrome out of here.
   var chrome = requireNative('chrome').GetChrome();
   var Event = require('event_bindings').Event;
   var lastError = require('lastError');
@@ skipping 382 matching lines @@
   function sendMessageUpdateArguments(functionName, hasOptionsArgument) {
     // skip functionName and hasOptionsArgument
     var args = $Array.slice(arguments, 2);
     var alignedArgs = messagingUtils.alignSendMessageArguments(args,
         hasOptionsArgument);
     if (!alignedArgs)
       throw new Error('Invalid arguments to ' + functionName + '.');
     return alignedArgs;
   }
 
-var Port = utils.expose('Port', PortImpl, { functions: [
-    'disconnect',
-    'postMessage'
-  ],
-  properties: [
-    'name',
-    'onDisconnect',
-    'onMessage'
-  ] });
+  function Port() {
+    privates(Port).constructPrivate(this, arguments);
+  }
+  utils.expose(Port, PortImpl, {
+    functions: [
+      'disconnect',
+      'postMessage',
+    ],
+    properties: [
+      'name',
+      'onDisconnect',
+      'onMessage',
+    ],
+  });
 
 exports.$set('kRequestChannel', kRequestChannel);
 exports.$set('kMessageChannel', kMessageChannel);
 exports.$set('kNativeMessageChannel', kNativeMessageChannel);
 exports.$set('Port', Port);
 exports.$set('createPort', createPort);
 exports.$set('sendMessageImpl', sendMessageImpl);
 exports.$set('sendMessageUpdateArguments', sendMessageUpdateArguments);
 
 // For C++ code to call.
 exports.$set('hasPort', hasPort);
 exports.$set('dispatchOnConnect', dispatchOnConnect);
 exports.$set('dispatchOnDisconnect', dispatchOnDisconnect);
 exports.$set('dispatchOnMessage', dispatchOnMessage);