LayoutTests/applicationmanifest/multiple-links.html

<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
}
</script>
<link rel="manifest" href="urlscheme://1" media="print">
<link rel="manifest" href="urlscheme://2">
<script>
if (window.testRunner) {
    (async () => {
        const success = await testRunner.getApplicationManifest();
        outputdiv.innerHTML = `manifest fetch success: ${success}`;
        testRunner.notifyDone();
    })();
}
</script>
<div id=outputdiv></div>