Ensure that privates are private.

chrome/renderer/resources/extensions/platform_keys/key.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.
 
 var utils = require('utils');
 
 /**
  * Enum of possible key types (subset of WebCrypto.KeyType).
  * @enum {string}
  */
@@ skipping 31 matching lines @@
 
 var KeyBase = function() {};
 
 Object.defineProperty(KeyBase.prototype, 'algorithm', {
   enumerable: true,
   get: function() {
     return utils.deepCopy(privates(this).impl.algorithm);
   }
 });
 
-var Key = utils.expose(
-    'Key',
-    KeyImpl,
-    {superclass: KeyBase, readonly: ['extractable', 'type', 'usages']});
+function Key() {
+  privates(Key).constructPrivate(this, arguments);
+}
+utils.expose(Key, KeyImpl, {
+  superclass: KeyBase,
+  readonly: [
+    'extractable',
+    'type',
+    'usages',
+  ],
+});
 
 /**
  * Returns |key|'s Subject Public Key Info. Throws an exception if |key| is not
  * a valid Key object.
  * @param {Key} key
  * @return {ArrayBuffer} The Subject Public Key Info in DER encoding of |key|.
  */
 function getSpki(key) {
   if (!privates(key))
     throw new Error('Invalid key object.');
   var keyImpl = privates(key).impl;
   if (!keyImpl || !keyImpl.spki)
     throw new Error('Invalid key object.');
   return keyImpl.spki;
 }
 
 exports.$set('Key', Key);
 exports.$set('KeyType', KeyType);
 exports.$set('KeyUsage', KeyUsage);
 exports.$set('getSpki', getSpki);