[Sync] Move network-related code from core/ to engine/net/.

components/sync/core/network_resources.h

-// Copyright 2013 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 COMPONENTS_SYNC_CORE_NETWORK_RESOURCES_H_
-#define COMPONENTS_SYNC_CORE_NETWORK_RESOURCES_H_
-
-#include <memory>
-
-#include "components/sync/core/network_time_update_callback.h"
-
-namespace net {
-class URLRequestContextGetter;
-}  // namespace net
-
-namespace syncer {
-
-class CancelationSignal;
-class HttpPostProviderFactory;
-
-class NetworkResources {
- public:
-  virtual ~NetworkResources() {}
-
-  virtual std::unique_ptr<HttpPostProviderFactory> GetHttpPostProviderFactory(
-      const scoped_refptr<net::URLRequestContextGetter>&
-          baseline_context_getter,
-      const NetworkTimeUpdateCallback& network_time_update_callback,
-      CancelationSignal* cancelation_signal) = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_SYNC_CORE_NETWORK_RESOURCES_H_