https://custom2048.github.io/js/animframe_polyfill.js

1(function() {
2  var lastTime = 0;
3  var vendors = ['webkit', 'moz'];
4  for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
5    window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
6    window.cancelAnimationFrame =
7    window[vendors[x]+'CancelAnimationFrame'] || window[vendors[x]+'CancelRequestAnimationFrame'];
8  }
9
10  if (!window.requestAnimationFrame) {
11    window.requestAnimationFrame = function(callback, element) {
12      var currTime = new Date().getTime();
13      var timeToCall = Math.max(0, 16 - (currTime - lastTime));
14      var id = window.setTimeout(function() { callback(currTime + timeToCall); },
15      timeToCall);
16      lastTime = currTime + timeToCall;
17      return id;
18    };
19  }
20
21  if (!window.cancelAnimationFrame) {
22    window.cancelAnimationFrame = function(id) {
23      clearTimeout(id);
24    };
25  }
26}());