chromium/chrome/test/data/web_apps/no_manifest.html

<!DOCTYPE html>
<html>

<head>
  <link rel="icon" href="basic-48.png">
</head>

<body>
  <h1>Web page with no manifest</h1>
  <p>
    This page is ideal for web app installations where all of the configuration is done in code, and thus a manifest
    link & update would overwrite the test setup.
  </p>
</body>

</html>