third_party/WebKit/LayoutTests/fast/css/no-recalc-on-no-op-inline-style-changes.html

   1 <!DOCTYPE html>
   2 <div id="element"></div>
   3
   4 <script src="../../resources/testharness.js"></script>
   5 <script src="../../resources/testharnessreport.js"></script>
   6 <script>
   7 test(function () {
   8   if (!window.internals)
   9     assert_unreached('This test requires window.internals.');
  10
  11   assert_greater_than(internals.updateStyleAndReturnAffectedElementCount(), 1);
  12
  13   element.style.top = "0px";
  14   assert_equals(internals.updateStyleAndReturnAffectedElementCount(), 1);
  15
  16   for (var i = 0; i < 100; i ++) {
  17     element.style.top = "0px";
  18     assert_equals(internals.updateStyleAndReturnAffectedElementCount(), 0);
  19   }
  20 }, "Check that a no-op inline style change doesn't result in a recalc");
  21 </script>