Function measure

packages/react-devtools-shared/src/PerformanceLoggingUtils.js:29–36

(markName: string)

}

function measure(markName: string): void {
  if (supportsUserTiming) {
    performance.mark(markName + '-end');
    performance.measure(markName, markName + '-start', markName + '-end');
    performance.clearMarks(markName + '-start');
    performance.clearMarks(markName + '-end');
  }
}

function now(): number {
  if (supportsPerformanceNow) {