src/tools/perf/page_sets/layer_stress_tests/opacity.html

<!doctype html>
<html>
  <head>
    <title>Chrome 18 opacity test</title>
    <style>
      .ninety-nine{
        opacity: 0.99;
      }
    </style>
    <script>
        function toggleOpacity() {
            var pre = document.getElementById('label');
            if (document.body.className == '') {
                document.body.className='ninety-nine';
                pre.innerHTML = 'opacity: 0.99';
            } else {
                document.body.className='';
                pre.innerHTML = 'opacity: 1.0';
            }
            window.setTimeout("toggleOpacity();", 1000);
        }
        onload = toggleOpacity;
    </script>
  </head>
  <body>
    <div style="overflow: hidden">
      <div style="-webkit-perspective: 10px">
       Quite a lot of text: Opacity can be thought of as a postprocessing
       operation. Conceptually, after the element (including its descendants)
       is rendered into an RGBA offscreen image, the opacity setting specifies
       how to blend the offscreen rendering into the current composite rendering.
       The uniform opacity setting to be applied across an entire object. Any
       values outside the range 0.0 (fully transparent) to 1.0 (fully opaque)
       will be clamped to this range. If the object is a container element, then
       the effect is as if the contents of the container element were blended
       against the current background using a mask where the value of each pixel
       of the mask is the opacity value
      </div>
      <pre id="label"></pre>
    </div>
  </body>
</html>