Bug 1457139 [wpt PR 10657] - Align Request.destination to spec, a=testonly

Automatic update from web-platform-testsAlign Request.destination to spec

Currently `Request.destination` is set to "unknown" prefetch,
but that was recently changed:
Issue: whatwg/fetch#658
PR: whatwg/fetch#659

This CL aligns the destination values to the spec change.

Bug: 832105
Change-Id: Ib9f21dcc6cf0ace27b7a810d3670cddc45b3b74f
Reviewed-on: https://chromium-review.googlesource.com/1029858
Commit-Queue: Yoav Weiss <[email protected]>
Reviewed-by: Charlie Harrison <[email protected]>
Reviewed-by: Yutaka Hirano <[email protected]>
Cr-Commit-Position: refs/heads/master@{#554341}

--

wpt-commits: 3c940291e9e8c30e8c7c401426160e3531639403
wpt-pr: 10657

Author: yoavweiss

testing/web-platform/meta/MANIFEST.json

@@ -558229,7 +558229,7 @@
    "testharness"
   ],
   "fetch/api/request/destination/fetch-destination.https.html": [
-   "5b7276e8a10bf91ee7d2a92917176b8e62c3255d",
+   "29e22bbe11b501fa354e90dde671f5f500fcaab3",
    "testharness"
   ],
   "fetch/api/request/destination/resources/dummy": [

testing/web-platform/tests/fetch/api/request/destination/fetch-destination.https.html

@@ -425,4 +425,18 @@
   });
 }, 'HTMLLinkElement with rel=preload and as=manifest fetches with a "manifest" Request.destination');
 
+// HTMLLinkElement with rel=prefetch - empty string destination
+promise_test(async t => {
+  await new Promise((resolve, reject) => {
+      let node = frame.contentWindow.document.createElement("link");
+      node.rel = "prefetch";
+      node.onload = resolve;
+      node.onerror = reject;
+      node.href = "dummy?dest=";
+      frame.contentWindow.document.body.appendChild(node);
+  }).catch(() => {
+      assert_unreached("Fetch errored.");
+  });
+}, 'HTMLLinkElement with rel=prefetch fetches with an empty string Request.destination');
+
 </script>