chromium/third_party/blink/web_tests/accessibility/platform-name.html

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html>
<head>
<script src="../resources/js-test.js"></script>
</head>
<body id="body">
<p id="description"></p>
<div id="console"></div>
<script>
description("This test just prints the name of the current platform.");
if (window.testRunner) {
  testRunner.dumpAsText();

  debug("Platform name: " + testRunner.platformName);
}
</script>
</body>
</html>