Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/basic/mode-no-cors.js

+if (this.document === undefined) {
+  importScripts("/resources/testharness.js");
+  importScripts("../resources/utils.js");
+}
+
+function fetchNoCors(url, isOpaqueFiltered) {
+  var urlQuery = "?pipe=header(x-is-filtered,value)"
+  promise_test(function(test) {
+    if (isOpaqueFiltered)
+      return fetch(url + urlQuery, {"mode": "no-cors"}).then(function(resp) {
+        assert_equals(resp.status, 0, "Opaque filter: status is 0");
+        assert_equals(resp.statusText, "", "Opaque filter: statusText is \"\"");
+        assert_equals(resp.type , "opaque", "Opaque filter: response's type is opaque");
+        assert_equals(resp.headers.get("x-is-filtered"), null, "Header x-is-filtered is filtered");
+      });
+    else
+      return fetch(url + urlQuery, {"mode": "no-cors"}).then(function(resp) {
+        assert_equals(resp.status, 200, "HTTP status is 200");
+        assert_equals(resp.type , "basic", "Response's type is basic");
+        assert_equals(resp.headers.get("x-is-filtered"), "value", "Header x-is-filtered is not filtered");
+      });
+  }, "Fetch "+ url + " with no-cors mode");
+}
+
+fetchNoCors(RESOURCES_DIR + "top.txt", false);
+fetchNoCors("http://{{host}}:{{ports[http][0]}}/fetch/api/resources/top.txt", false);
+fetchNoCors("https://{{host}}:{{ports[https][0]}}/fetch/api/resources/top.txt", true);
+fetchNoCors("http://{{host}}:{{ports[http][1]}}/fetch/api/resources/top.txt", true);
+
+done();
+