vue项目在IE9下报错 “requestAnimationFrame”未定义

(function () {
var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];
for (var 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, element) {
var currTime = new Date().getTime();
var timeToCall = Math.max(0, 16 - (currTime - lastTime));
var id = window.setTimeout(function () { callback(currTime + timeToCall); },
timeToCall);
lastTime = currTime + timeToCall;
return id;
};
} if (!window.cancelAnimationFrame) {
window.cancelAnimationFrame = function (id) {
clearTimeout(id);
};
}
}());