1./core/util/perf.js
import { inBrowser } from './env' //运行环境在浏览器为true export let mark //window.performance.mark export let measure //重写了window.performance.measure函数
1./core/util/perf.js
import { inBrowser } from './env' //运行环境在浏览器为true export let mark //window.performance.mark export let measure //重写了window.performance.measure函数