Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/basic/scheme-others.js

+if (this.document === undefined) {
+  importScripts("/resources/testharness.js");
+  importScripts("../resources/utils.js");
+}
+
+function checkKoUrl(url, desc) {
+  if (!desc)
+    desc = "Fetching " + url.substring(0, 45) + " is KO"
+  promise_test(function(test) {
+    var promise = fetch(url);
+    return promise_rejects(test, new TypeError(), promise);
+  }, desc);
+}
+
+var urlWithoutScheme = "://{{host}}:{{ports[http][0]}}/";
+checkKoUrl("aaa" + urlWithoutScheme);
+checkKoUrl("cap" + urlWithoutScheme);
+checkKoUrl("cid" + urlWithoutScheme);
+checkKoUrl("dav" + urlWithoutScheme);
+checkKoUrl("dict" + urlWithoutScheme);
+checkKoUrl("dns" + urlWithoutScheme);
+checkKoUrl("geo" + urlWithoutScheme);
+checkKoUrl("im" + urlWithoutScheme);
+checkKoUrl("imap" + urlWithoutScheme);
+checkKoUrl("ipp" + urlWithoutScheme);
+checkKoUrl("ldap" + urlWithoutScheme);
+checkKoUrl("mailto" + urlWithoutScheme);
+checkKoUrl("nfs" + urlWithoutScheme);
+checkKoUrl("pop" + urlWithoutScheme);
+checkKoUrl("rtsp" + urlWithoutScheme);
+checkKoUrl("snmp" + urlWithoutScheme);
+
+done();