<!DOCTYPE html>
<style>
div {
  position: absolute;
  transform: skew(-45deg);
  transform-origin: left top;
  top: 50px;
  left: 500px;
  height: 500px;
}
#skewed {
  width: 200px;
  background-color: green;
}
#indicator {
  width: 200px;
  background-color: red;
}
</style>
Tests paint invalidation when a skewed element is resized. Passes if there is no red. 
<div id="indicator"></div>
<div id="skewed"></div>