chrome中的消息通信

https://justcode.ikeepstudying.com/2017/05/chrome-extension-%E4%BA%8B%E4%BB%B6%E4%BA%A4%E4%BA%92%E5%AE%9E%E4%BE%8B-%EF%BC%88sendmessage%EF%BC%8Cconnect%EF%BC%8Conconnect%EF%BC%8Conmessage%EF%BC%89/