chromium/chrome/test/data/extensions/api_test/tab_capture/fullscreen_test/fullscreen_test.html

<html>
  <head>
    <script src="fullscreen_test.js"></script>
    <style>
      body {
        width: 100%;
        height: 100%;
        margin: 0px;
        padding: 0px;
        background-color: #f33;
        foreground-color: #3ff;
        font-size: xx-large;
      }
    </style>
  </head>
  <body>
    Click anywhere to toggle fullscreen.
  </body>
</html>