<!DOCTYPE html>
<html>
<head>
  <title>Overriding postMessage and dispatchEvent bindings</title>
  <script type="application/javascript">
    window.postMessage = function (evt) {
      window.parent.postMessage("FAIL overridden postMessage called", "*");
    };

    var count = 0;

    function receiveMessage(evt) {
      count++;
      if (count == 2) {
        window.dispatchEvent = function(evt) {
          window.parent.postMessage("FAIL", "*");
          throw "dispatchEvent threw";
        };
      }

      window.parent.postMessage(evt.data, "http://mochi.test:8888");
    }

    function setup() {
      var target = document.getElementById("location");
      target.textContent = location.hostname + ":" + (location.port || 80);
    }

    window.addEventListener("message", receiveMessage);

    window.addEventListener("load", setup);
  </script>
</head>
<body>
<h1 id="location">No location!</h1>
</body>
</html>
