Issue 1727 - Prevent circumvention via WebSocket

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 437 matching lines @@
 
       checkRequest(websocket.url, function(blocked)
       {
         if (blocked)
           closeWebSocket(websocket);
       });
 
       return websocket;
     }.bind();
 
-    var properties = Object.getOwnPropertyNames(RealWebSocket);
-    for (var i = 0; i < properties.length; i++)
-    {
-      var name = properties[i];
-      var desc = Object.getOwnPropertyDescriptor(RealWebSocket, name);
-      Object.defineProperty(WebSocket, name, desc);
-    }
+    Object.defineProperties(WebSocket, {
+      CONNECTING: {value: RealWebSocket.CONNECTING, enumerable: true},
+      OPEN: {value: RealWebSocket.OPEN, enumerable: true},
+      CLOSING: {value: RealWebSocket.CLOSING, enumerable: true},
+      CLOSED: {value: RealWebSocket.CLOSED, enumerable: true},
+      prototype: {value: RealWebSocket.prototype}
+    });
 
     RealWebSocket.prototype.constructor = WebSocket;
   }, eventName);
 }
 
 function init(document)
 {
   var shadow = null;
   var style = null;
   var observer = null;
@@ skipping 164 matching lines @@
   }, true);
 
   return updateStylesheet;
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   window.updateStylesheet = init(document);
 }