Request animation frame

raf.js

define(function(){
  return window.requestAnimationFrame  ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame    ||
    window.oRequestAnimationFrame      ||
    window.msRequestAnimationFrame     ||
    function(/* function */ callback, /* DOMElement */ element){
      window.setTimeout(callback, 1000 / 60);
    };
});