PerformanceTests/Layout/subtree-detaching.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>