chromium/third_party/blink/perf_tests/layout/layers_overlap_2d.html

<!DOCTYPE html>
<html>
    <head>
        <title>Performance tester for non-overlaping 2D layers</title>
        <style>
            .container {
                position: relative;
                width: 20px;
                height: 20px;
                border: 1px solid #AAA;
                margin: 0 auto 5px;
            }

            .box {
                width: 100%;
                height: 100%;
                position: absolute;
                background: red;
            }

            .composited {
                -webkit-transform: translateZ(1px);
            }
        </style>
        <script src="../resources/runner.js"></script>
    </head>
    <body>
        <pre id="log"></pre>
        <script>
            function createTestFunction(count) {
                return function() {
                    var container = document.createElement("div");
                    for(i = 0; i < count; ++i) {
                        var outer = document.createElement('div');
                        outer.className = 'container';
                        var inner = document.createElement('div');
                        inner.className = 'box';
                        if (i == 0) {
                            // Use at least one 3D layer to trigger the overlap map checking.
                            inner.className += " composited";
                        }
                        outer.appendChild(inner);
                        container.appendChild(outer);
                    }
                    document.body.appendChild(container);
                    PerfTestRunner.forceLayout();
                    container.remove();
                }
            }
            PerfTestRunner.measureTime({
                description: "Measures performance of non-overlapping 2D layers.",
                run: createTestFunction(5000)
            });
        </script>
    </body>
</html>