<!DOCTYPE html>
<style>
.green {
  background-color: green;
}
.box {
  width: 200px;
  height: 200px;
  position: absolute;
  left: 300px;
}
.drop-shadowed {
  -webkit-filter: drop-shadow(100px 100px 10px red);
}
</style>
<!--
    This test checks that we correctly invalidate filters when they are removed.
    There should be no red below.
-->
<div class="green box" id="box"></div>