chromium/third_party/blink/web_tests/http/tests/navigation/error404-subframeload.html

<script type="text/javascript" src="resources/testcode.js"></script>
<script>
    runLoadChildFrameTest("resources/error404.pl");
</script>
This page just kicks off a test, and should not appear in the expected test output.
The files in the resources dir have comments about the tests.