Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/basic/response-url.js

+if (this.document === undefined) {
+  importScripts("/resources/testharness.js");
+}
+
+function checkResponseURL(fetchedURL, expectedURL)
+{
+    promise_test(function() {
+        return fetch(fetchedURL).then(function(response) {
+            assert_equals(response.url, expectedURL);
+        });
+    }, "Testing response url getter with " +fetchedURL);
+}
+
+var baseURL = "http://{{host}}:{{ports[http][0]}}";
+checkResponseURL(baseURL + "/ada", baseURL + "/ada");
+checkResponseURL(baseURL + "/#", baseURL + "/");
+checkResponseURL(baseURL + "/#ada", baseURL + "/");
+checkResponseURL(baseURL + "#ada", baseURL + "/");
+
+done();
+