Issue 1727 - Fix WebSocket constructor without second argument in Chrome 47

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 388 matching lines @@
         detail: {url: url}
       }));
     }
 
     WebSocket = function WrappedWebSocket(url, protocols)
     {
       // Throw correct exceptions if the constructor is used improperly.
       if (!(this instanceof WrappedWebSocket)) return RealWebSocket();
       if (arguments.length < 1) return new RealWebSocket();
 
-      var websocket = new RealWebSocket(url, protocols);
+      var websocket = new RealWebSocket(url, protocols || []);
 
       checkRequest(websocket.url, function(blocked)
       {
         if (blocked)
           closeWebSocket(websocket);
       });
 
       return websocket;
     }.bind();
 
@@ skipping 194 matching lines @@
   }, true);
 
   return updateStylesheet;
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   window.updateStylesheet = init(document);
 }