This property getter must be called with the PerformanceResourceTiming object as the receiver.
PerformanceResourceTiming
新增于: v18.2.0, v16.17.0
在调度 fetch 请求之前的高分辨率毫秒时间戳。如果资源未被 worker 拦截，则该属性始终返回 0。
fetch
【The high resolution millisecond timestamp at immediately before dispatching the fetch request. If the resource is not intercepted by a worker the property will always return 0.】