Snippets

;(function(){
  var ifr = document.createElement('iframe');
  document.body.appendChild(ifr);
  var pure = Object.getOwnPropertyNames(ifr.contentWindow);
  document.body.removeChild(ifr);
  var cur = Object.getOwnPropertyNames(window);
  var diff = cur.filter(function(item){
    return pure.indexOf(item) == -1 && item !== '__commandLineAPI';
  });
  console.log(diff, diff.length);
})();