Implement the infrastructure of creating WorkerFetchContext in worker global scope.

content/common/worker_url_loader_factory_provider.mojom

+// 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.
+
+module content.mojom;
+
+import "url_loader_factory.mojom";
+
+interface ServiceWorkerWorkerClient {

[kinuko, 2017/04/18 08:00:31]

can we also have an interface-level comment for this one too, a very simple one
is fine (e.g. "A renderer-side interface that is returned by
CreateWorkerFetchContext for the browser to notify the renderer process when
there's a controller change")

[horo, 2017/04/18 12:53:34]

Done.

+  // Called when the ServiceWorkerWorkerClient (which is a dedicated worker or
+  // a shared worker) is controlled by a new service worker.
+  SetControllerServiceWorker(int64 controller_version_id);
+};
+
+// An interface which provides URLLoaderFactory for worker context.

[kinuko, 2017/04/18 08:00:31]

nit: can you make it clear about the IPC direction, e.g. "A browser-side
interface which..." "worker contexts in the renderer process"

[horo, 2017/04/18 12:53:34]

Done.

+interface WorkerURLLoaderFactoryProvider {
+  // Called from a dedicated (or shared) worker thread to create a worker fetch
+  // context. The browser process returns a URLLoaderFactory for the worker.
+  // SetControllerServiceWorker method of the passed ServiceWorkerWorkerClient
+  // interface will be called when the parent frame and the worker context is
+  // controlled by a service worker. |service_worker_provider_id| is the service
+  // worker provider id of the parent frame.
+  CreateWorkerFetchContext(associated URLLoaderFactory& loader,
+                           associated ServiceWorkerWorkerClient client,
+                           int32 service_worker_provider_id);
+
+  // Called from the service worker thread to get the URLLoaderFactory.
+  GetURLLoaderFactory(associated URLLoaderFactory& loader);
+};