third_party/blink/web_tests/fast/canvas/canvas-blending-image-over-gradient.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script type="text/javascript" src="canvas-blending-helpers.js"></script>
<script>
async_test(function(t) {
    function drawElement(context, i) {
        if (i >= blendModes.length) {
            t.done();
            return;
        }

        context.clearRect(0, 0, 10, 10);
        context.save();
        drawBackdropColorGradientInContext(context);
        context.globalCompositeOperation = blendModes[i];

        drawSourceColorImageInContext(context, function() {
            t.step(function () {
                checkBlendModeResult(i, context, 5);
            });
            context.restore();
            drawElement(context, ++i);
        });
    }

    var canvas = document.createElement('canvas');
    var sigma = 5;
    canvas.width = 10;
    canvas.height = 10;
    context = canvas.getContext('2d');
    drawElement(context, 0);

}, 'Series of tests to ensure correct results on applying different blend modes when drawing an image on top of a gradient.');
</script>