chromium/src/third_party/blink/web_tests/http/tests/download/inherited-encoding-form-submission-result.html

<meta charset="koi8-r">
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.setCustomPolicyDelegate(true, true);
    testRunner.waitForPolicyDelegate();
}
</script>
<p>Downloaded file name should be "SUóóåSS.txt" (letters "CCE" are Cyrillic).</p>
<form action="resources/literal-koi8-r.php">
</form>

<script>
document.forms[0].submit();
</script>