chromium/content/test/data/gpu/pixel_canvas2d_webgl.html

<!DOCTYPE HTML>
<html>
<head>
<title>Accelerated Retina Canvas 2D and WebGL Test: Red Box and Green Triangle over Black Background</title>
<style type="text/css">
.nomargin {
  margin: 0px auto;
}
</style>

<script src="pixel_webgl_util.js"></script>

<script>
var g_swapsBeforeAck = 15;
var gl;

function main()
{
  var canvas = document.getElementById("c");
  canvas.style.width = canvas.style.height = "150px";
  var c2d = canvas.getContext("2d");
  c2d.clearRect(0, 0, canvas.width, canvas.height);
  c2d.fillStyle = "rgba(255, 0, 0, 0.5)";
  c2d.fillRect(50, 50, 100, 100);

  var webglCanvas = document.getElementById("c2");
  gl = initGL(webglCanvas);
  if (!gl) {
    console.log('Failed to initialize GL from canvas: ' + webglCanvas);
    domAutomationController.send("FAILURE");
    return;
  }

  if (!setup(gl)) {
    console.log('Failed to set up GL: ' + gl);
    domAutomationController.send("FAILURE");
    return;
  }

  gl.viewport(0, 0, 50, 50);

  waitForFinish();
}

function waitForFinish()
{
  if (g_swapsBeforeAck == 0) {
    domAutomationController.send("SUCCESS");
  } else {
    g_swapsBeforeAck--;
    document.getElementById('container').style.zIndex = g_swapsBeforeAck + 1;
    drawTriangle(gl);
    window.requestAnimationFrame(waitForFinish);
  }
}
</script>
</head>
<body onload="main()">
<div style="position:relative; width:300px; height:300px; background-color:black">
</div>
<div id="container" style="position:absolute; top:0px; left:0px">
<canvas id="c2" width="50" height="50" class="nomargin"></canvas>
<!--
Canvas acceleration requires that the canvas be at least 256x257.
-->
<canvas id="c" width="300" height="300" class="nomargin"></canvas>
</div>
</body>
</html>