chromium/third_party/blink/web_tests/external/wpt/html/editing/dnd/overlay/heavy-styling-008.html

<!DOCTYPe html>
<meta charset='utf-8'>
<title>drag and drop – feedback overlay for heavily styled elements – 008</title>
<style>
a {
  display: block;
  height: 200px;
  width: 200px;
  background-color: green;
  position: absolute;
  top: 100px;
  left: 10px;
  z-index: 1;
}

a + a {
  background-color: red;
  position: absolute;
  top: 150px;
  left: 20px;
  z-index: 2;
}


</style>

<p>Drag the green box below downwards. The drag placeholder should resemble the green box, including the text within it. It may optionally be a complete square, or the same shape as the visible part of the green box. There should be no red in the drag placeholder.</p>

<a draggable="true" ondragstart="event.dataTransfer.effectAllowed ='copy'">TEST</a>

<a href='#'>TEST</a>