Implement the Request/Response bits of Background Fetch

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledRequest.idl

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://wicg.github.io/background-fetch/#backgroundfetchsettledfetches
+// TODO(peter): Update either the above link or the name of this interface based
+// on the outcome of https://github.com/WICG/background-fetch/issues/32.
+
+[
+    Constructor(Request request, Response response),
+    Exposed=ServiceWorker,
+    RuntimeEnabled=BackgroundFetch
+] interface BackgroundFetchSettledRequest : BackgroundFetchRequest {
+    readonly attribute Response? response;
+};