1<!DOCTYPE html> 2<body> 3<pre id="log"></pre> 4<script src="../resources/runner.js"></script> 5<div id="sandbox" style="display:none"></div> 6<script> 7var sandbox = document.getElementById('sandbox'); 8var observing = false; 9 10var elems = []; 11for (var i = 0; i < 50000; ++i) 12 elems[i] = document.createElement('div'); 13var observer = new WebKitMutationObserver(listener); 14var tickledSpan = document.createElement('span'); 15observer.observe(tickledSpan, {attributes: true}); 16 17function resetState() { 18 window.start = null; 19 window.numRuns = 25; 20 window.times = []; 21} 22 23function runAgain() { 24 tickledSpan.setAttribute('data-foo', numRuns); 25} 26 27function listener(mutations) { 28 if (start) { 29 var time = Date.now() - start; 30 times.push(time); 31 PerfTestRunner.log(time); 32 } 33 if (numRuns-- >= 0) { 34 runAgain(); 35 if (observing) 36 observer.disconnect() 37 sandbox.innerHTML = ''; 38 if (observing) 39 observer.observe(sandbox, {childList: true}); 40 start = Date.now(); 41 for (var i = 0; i < elems.length; ++i) 42 sandbox.appendChild(elems[i]); 43 } else { 44 PerfTestRunner.logStatistics(times); 45 if (!observing) { 46 observing = true; 47 resetState(); 48 PerfTestRunner.log('\n------------\n'); 49 PerfTestRunner.log('Running ' + numRuns + ' times with observation'); 50 setTimeout(runAgain, 0); 51 } 52 } 53} 54 55resetState(); 56PerfTestRunner.log('Running ' + numRuns + ' times without observation'); 57window.addEventListener('load', runAgain); 58</script> 59</body> 60