third_party/WebKit/LayoutTests/fast/layers/opacity-change-stacking-context.html

   1 <!DOCTYPE html>
   2
   3 <script src="../../resources/js-test.js"></script>
   4
   5 <style>
   6 #target {
   7   top: 40px;
   8   width: 150px;
   9   height: 75px;
  10   background-color: yellow;
  11   transform: translateZ(0);
  12   opacity: 0;
  13 }
  14 </style>
  15
  16 <div id="target"></div>
  17
  18 <script>
  19 description("Test that opacity changes from less than 1 to 1 don't cause layout if the layer remains a stacking context");
  20 var div = document.getElementById('target');
  21 div.offsetTop;
  22 div.style.opacity = 1;
  23 shouldBe("internals.updateStyleAndReturnAffectedElementCount()", "1");
  24 shouldBe("internals.needsLayoutCount()", "0");
  25 </script>