third_party/WebKit/LayoutTests/fast/canvas/canvas-large-pattern.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>

test(function(t) {
    var canvas = document.createElement('canvas');
    canvas.width = 40000;
    var context = canvas.getContext('2d');
    context.fillStyle = '#0f0';
    context.fillRect(0, 0, 1, 1);

    var dstCanvas = document.createElement('canvas');
    var dstContext = dstCanvas.getContext('2d');
    var pattern = dstContext.createPattern(canvas, 'repeat');
    dstContext.fillStyle = pattern;
    dstContext.fillRect(0, 0, dstCanvas.width, dstCanvas.height);

    // This test does not currently succeed because skia does not handle
    // canvases more than 32k pixels wide. For now, this test serves the
    // purpose of verifying that this use case does not crash the browser.
    // Crasher bug: crbug.com/281504.
    // The result, if Skia handled large canvases, would be [0, 255, 0, 255]
    assert_array_equals(dstContext.getImageData(0, 0, 1, 1).data, [0, 0, 0, 0]);
    
    assert_array_equals(dstContext.getImageData(1, 0, 1, 1).data, [0, 0, 0, 0]);
    assert_array_equals(dstContext.getImageData(0, 1, 1, 1).data, [0, 0, 0, 0]);
    
}, 'Tests createPattern using a source image that is a canvas 40k pixels wide.');
</script>