PerformanceTests/Layout/subtree-detaching.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <body>
 <script src="../resources/runner.js"></script>
 <script>
 function buildTree()
 {
     wrapper = document.createElement("div");
     for (i = 0; i < 1000; ++i) {
         var child = document.createElement("div");
         for (j = 0; j < 1000; ++j) {
             var grandChild = document.createElement("div");
             child.appendChild(grandChild);
         }
         wrapper.appendChild(child);
     }
     document.body.appendChild(wrapper);
 }

 function setup() {
     wrapper.style.display = "block";
     // Force a layout so that everything is up-to-date.
     wrapper.offsetTop;
 }

 function runTest() {
     setup();

     var now = PerfTestRunner.now();

     wrapper.style.display = "none";
     wrapper.offsetTop;

     return PerfTestRunner.now() - now;
 }

 buildTree();

 PerfTestRunner.measureTime({run: runTest, description: "This benchmark checks the time spend in detaching an tree." });
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<body>
	<script src="../resources/runner.js"></script>
	<script>
	function buildTree()
	{
	wrapper = document.createElement("div");
	for (i = 0; i < 1000; ++i) {
	var child = document.createElement("div");
	for (j = 0; j < 1000; ++j) {
	var grandChild = document.createElement("div");
	child.appendChild(grandChild);
	}
	wrapper.appendChild(child);
	}
	document.body.appendChild(wrapper);
	}

	function setup() {
	wrapper.style.display = "block";
	// Force a layout so that everything is up-to-date.
	wrapper.offsetTop;
	}

	function runTest() {
	setup();

	var now = PerfTestRunner.now();

	wrapper.style.display = "none";
	wrapper.offsetTop;

	return PerfTestRunner.now() - now;
	}

	buildTree();

	PerfTestRunner.measureTime({run: runTest, description: "This benchmark checks the time spend in detaching an tree." });
	</script>
	</body>
	</html>