Introduce SystemNetworkContextManager.

content/public/network/network_service.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 CONTENT_PUBLIC_NETWORK_NETWORK_SERVICE_H_
+#define CONTENT_PUBLIC_NETWORK_NETWORK_SERVICE_H_
+
+#include <memory>
+
+#include "content/common/content_export.h"
+#include "content/public/common/network_service.mojom.h"
+
+namespace net {
+class URLRequestContext;
+class URLRequestContextBuilder;
+}  // namespace net
+
+namespace content {
+
+// Allows an in-process NetworkService to be set up.
+class CONTENT_EXPORT NetworkService : public mojom::NetworkService {
+ public:
+  // TODO(mmenke): Take in a NetworkServiceRequest.
+  static std::unique_ptr<NetworkService> Create();
+
+  // Can be used to seed a NetworkContext with a consumer-configured
+  // URLRequestContextBuilder, which |params| will then be applied to. The
+  // results URLRequestContext will be written to |url_request_context|, which
+  // is owned by the NetworkContext, and can be further modified before first
+  // use. The returned NetworkContext must be destroyed before the
+  // NetworkService.
+  //
+  // This method is intended to ease the transition to an out-of-process
+  // NetworkService, and will be removed once that ships.
+  virtual std::unique_ptr<mojom::NetworkContext>
+  CreateNetworkContextWithBuilder(
+      content::mojom::NetworkContextRequest request,
+      content::mojom::NetworkContextParamsPtr params,
+      std::unique_ptr<net::URLRequestContextBuilder> builder,
+      net::URLRequestContext** url_request_context) = 0;
+
+  ~NetworkService() override {}
+
+ protected:
+  NetworkService() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_NETWORK_NETWORK_SERVICE_H_