bookmarklet to send a jsperf test to all webpagetest's IEs

jsperf-bookmarklet.js

(function(){

  var key = localStorage.wpt_key;
  if (!key) {
    var prompt = window.__proto__.prompt;
    key = prompt('Your WebPagetest API key, please?');
    if (!key) {
      return gameOver();
    }
    localStorage.wpt_key = key;
  }

  // base params
  var wpt = 'http://www.webpagetest.org/runtest.php?';
  var params = {
    k: key,
    time: 60,
    runs: 1,
    fvonly: 1,
    url: 'http://jsperf.com' + location.pathname + '#run'
  };
  Object
    .keys(params)
    .forEach(function(key) {
      wpt += key + '=' + encodeURIComponent(params[key]) + '&';
    });

  var locations = localStorage.wpt_locations;
  if (!locations) {
    locations = ['Dulles_IE6', 'Dulles_IE7', 'Dulles_IE8', 'Dulles_IE9', 'Dulles_IE10'];
  }
  
  // pop some windows up
  var open = window.__proto__.open;
  locations.forEach(function(loco){
    open(wpt + 'location=' + encodeURIComponent(loco));
  });

  gameOver();

  function gameOver() {
    console.log('JSPerf bookmarklet help: http://phpied.com/jsperf-bookmarklet');
    console.log('If broken, check your localStorage.wpt_key and wpt_locations');
  }

}());

Line 28 should be:
var locations = localStorage.wpt_locations && localStorage.wpt_locations.split(',');