Warning: React depends on requestAnimationFrame. Make sure that you load a polyfill in older brow...

react写的项目，用ie9打开报错，如下图所示：

image.png

报错信息：
Warning: React depends on requestAnimationFrame. Make sure that you load a polyfill in older browsers.

解决方法：
在项目入口文件index.js中引入raf/polyfill，如下：

import 'raf/polyfill';