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chromium/third_party/blink/web_tests/paint/invalidation/box/margin.html 

<!DOCTYPE HTML>
<script src="../resources/text-based-repaint.js"></script>
<script>
function repaintTest()
{
    // Margin change will visually move the content of the div.
    // Should repaint the old position and the new position.
    document.getElementById('target').style.margin = '20px';
}
window.onload = runRepaintAndPixelTest;
</script>
<style>
body {
    margin: 0;
}
div {
    width: 100px;
    height: 100px;
    position: absolute;
    background-color: green;
}
</style>
<div id="target"></div>