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chromium/third_party/blink/web_tests/fast/css/outline-around-empty-box.html 

<!DOCTYPE html>
Tests paint invalidation and painting of outline around an empty box.
Passes if there is a green square.
<div id="target" style="position: absolute; top: 200px; left: 200px; outline: 50px solid red"></div>
<script src="../../resources/run-after-layout-and-paint.js"></script>
<script>
runAfterLayoutAndPaint(function() {
  target.style.outlineColor = 'green';
}, true);
</script>