three.js/src/extras/MiscUtils.js

/**
 * @author greggman / http://greggman.com/
 */
 
if (!window.requestAnimationFrame) {
  window.requestAnimationFrame = (function() {
    return window.requestAnimationFrame ||
           window.webkitRequestAnimationFrame ||
           window.mozRequestAnimationFrame ||
           window.oRequestAnimationFrame ||
           window.msRequestAnimationFrame ||
           function(/* function FrameRequestCallback */ callback, /* DOMElement Element */ element) {
             window.setTimeout(callback, 1000/60);
           };
  })();
};