basic-border-3.https-expected.html | Explore in Territory

<body>
  <iframe
      style="width: 100%; height: 300px; border: 3px solid black;"
      srcdoc="<body style='margin: 0px'><div style='background: red; width: 20px; height: 20px'></div></body>"></iframe>
</body>

chromium/third_party/blink/web_tests/http/tests/fenced_frame/basic-border-3.https-expected.html