third_party/WebKit/LayoutTests/scrollbars/basic-scrollbar.html

<head>
<style>
div::-webkit-scrollbar {
  width:17px;
  height:17px;
  background-color:grey;
}

div::-webkit-scrollbar-button {
  display:block;
  width: 17px;
  height: 17px;
  background-color:lightblue;
  border:2px solid black;
}

div::-webkit-scrollbar-thumb {
  background-color: navy;
  border:2px solid #cccccc;
}
</style>
</head>
<body>
<div style="width:200px; height:200px; overflow:auto">
Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>Hello<br>
Hello<br>Hello<br>Hello<br>
</div>