devicemotion_outer.html

Enable keyboard shortcuts

<!DOCTYPE HTML>

<html>

<body>

<script>

var total = 50;

var loaded = 0;

for (var i = 0; i < total; i++) {

  var f = document.createElement("iframe");

  document.body.appendChild(f);

  f.onload = function() {

                    loaded++;

                    if (loaded == total - 1)

                      document.location.replace("about:blank");

  f.setAttribute('src', 'devicemotion_inner.html');

</script>

</body>

</html>