chromium/third_party/blink/web_tests/fast/css/no-recalc-on-no-op-inline-style-changes.html

<!DOCTYPE html>
<div id="element"></div>

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
test(function () {
  if (!window.internals)
    assert_unreached('This test requires window.internals.');

  element.offsetTop;
  element.style.top = "0px";
  assert_equals(internals.updateStyleAndReturnAffectedElementCount(), 1);

  for (var i = 0; i < 100; i ++) {
    element.style.top = "0px";
    assert_equals(internals.updateStyleAndReturnAffectedElementCount(), 0);
  }
}, "Check that a no-op inline style change doesn't result in a recalc");
</script>