Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/public/platform/WebWorkerFetchContext.h

+// 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.
+
+#ifndef WebWorkerFetchContext_h
+#define WebWorkerFetchContext_h
+
+namespace blink {
+
+class WebURLLoader;
+class WebURLRequest;
+
+// WebWorkerFetchContext is crated from WebWorkerFetchContextInfo to create a
+// new WebURLLoader instance in the worker thread.
+class WebWorkerFetchContext {

[kinuko, 2017/04/14 02:27:02]

I wonder if this could be implemented using WebServiceWorkerNetworkProvider
interface?  Platform::CreateURLLoader could return thread-local instance of
ResourceFetcher.  (Putting aside if that's better design, my main interest is if
it's possible to slim down the necessary changes in that way)

[kinuko, 2017/04/14 05:38:12]

This part could be probably cleaned up a bit but we agreed that this's not only
about SW-specific part so it might make sense to have this.

+ public:
+  virtual ~WebWorkerFetchContext() {}
+
+  // Returns a new WebURLLoader instance which is associated with the worker
+  // thread.
+  virtual WebURLLoader* CreateURLLoader() = 0;
+
+  // Called when a request is about to be sent out to modify the request to
+  // handle the rquest correctly in the loading stack later. (Example: service

[kinuko, 2017/04/14 02:27:02]

rquest -> request

[horo, 2017/04/14 07:22:45]

Done.

+  // worker)
+  virtual void WillSendRequest(WebURLRequest&) = 0;
+
+  // Whether the fetch context is controlled by a service worker.
+  virtual bool IsControlledByServiceWorker() const = 0;
+};
+
+}  // namespace blink
+
+#endif  // WebWorkerFetchContext_h