1<!DOCTYPE html> 2<html> 3<head> 4<script src="../resources/runner.js"></script> 5</head> 6<body> 7<iframe></iframe> 8</body> 9<script> 10 11function setup() { 12 var frame = document.getElementsByTagName("iframe")[0]; 13 var testDoc = frame.contentDocument; 14 var docText = ""; 15 docText += "<body><style>.foo {color:red}</style>"; 16 docText += "<div class='bar'>Foo</div>"; 17 for (var i = 0; i < 10000; ++i) 18 docText += "<div class='foo'>Foo</div>"; 19 testDoc.body.innerHTML = docText; 20 return testDoc; 21} 22 23PerfTestRunner.measureTime({run:function() { 24 var testDoc = setup(); 25 var start = PerfTestRunner.now(); 26 testDoc.body.offsetTop; 27 for (var i = 0; i < 50; i++) { 28 var styleElem = testDoc.createElement("style"); 29 styleElem.innerText = ".bar {color:green}"; 30 testDoc.body.insertBefore(styleElem, testDoc.body.firstChild); 31 } 32 testDoc.body.offsetTop; 33 return PerfTestRunner.now() - start; 34}}); 35</script> 36</html> 37