assets/scripts/src/polyfill.js

// Source: https://gist.github.com/paulirish/1579671
(function () {
  let lastTime = 0;
  const vendors = ['ms', 'moz', 'webkit', 'o'];

  for (let x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
    window.requestAnimationFrame = window[`${vendors[x]}RequestAnimationFrame`];
    window.cancelAnimationFrame = window[`${vendors[x]}CancelAnimationFrame`] || window[`${vendors[x]}CancelRequestAnimationFrame`];
  }

  if (!window.requestAnimationFrame) {
    window.requestAnimationFrame = function (callback) {
      const currTime = new Date().getTime();
      const timeToCall = Math.max(0, 16 - (currTime - lastTime));
      const id = window.setTimeout(
        () => { callback(currTime + timeToCall); },
        timeToCall,
      );
      lastTime = currTime + timeToCall;
      return id;
    };
  }

  if (!window.cancelAnimationFrame) {
    window.cancelAnimationFrame = function (id) {
      clearTimeout(id);
    };
  }
}());