Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/external/wpt/html/editing/dnd/overlay/heavy-styling-001.html 

<!DOCTYPe html>
<meta charset='utf-8'>
<title>drag and drop – feedback overlay for heavily styled elements – 001</title>
<style>
a {
  display: block;
  height: 200px;
  width: 200px;
  background-color: blue;
  box-shadow: 10px 10px 10px gray;
}
</style>

<p>Drag the blue box below downwards. The drag placeholder should resemble the blue box. It may optionally also include the box's shadow.</p>

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