shisama/performance_api.html

## performance_api.html
<!doctype html>
<html>
	<head>
	</head>
	<body>
		<div id="info"></div>
		<script>
			const markerNameA = "example-marker-a"
			const markerNameB = "example-marker-b"

			// いくつかのネストしたタイムアウトを実行し、それぞれに対して PerformanceMark を作成します。
			performance.mark(markerNameA);
			const c = performance.now();
			setTimeout(function() {
				performance.mark(markerNameB);
				setTimeout(function() {
					const d = performance.now();
					// using User Timing API. check devTools Perfomarnce tab
					performance.measure("measure a to b", markerNameA, markerNameB);
					// print console tab
					console.log(`measure c to d ${d - c}`);
					performance.clearMarks();
					performance.clearMeasures();
				}, 1000);
			}, 1000);
		</script>
	</body>
</html>
	<!doctype html>
	<html>
	<head>
	</head>
	<body>
	<div id="info"></div>
	<script>
	const markerNameA = "example-marker-a"
	const markerNameB = "example-marker-b"

	// いくつかのネストしたタイムアウトを実行し、それぞれに対して PerformanceMark を作成します。
	performance.mark(markerNameA);
	const c = performance.now();
	setTimeout(function() {
	performance.mark(markerNameB);
	setTimeout(function() {
	const d = performance.now();
	// using User Timing API. check devTools Perfomarnce tab
	performance.measure("measure a to b", markerNameA, markerNameB);
	// print console tab
	console.log(`measure c to d ${d - c}`);
	performance.clearMarks();
	performance.clearMeasures();
	}, 1000);
	}, 1000);
	</script>
	</body>
	</html>