Revert of [sync] Replace FakeServer's implementation with LoopbackServer invocations.

components/sync/test/fake_server/permanent_entity.h

+// Copyright 2014 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_TEST_FAKE_SERVER_PERMANENT_ENTITY_H_
+#define COMPONENTS_SYNC_TEST_FAKE_SERVER_PERMANENT_ENTITY_H_
+
+#include <memory>
+#include <string>
+
+#include "components/sync/base/model_type.h"
+#include "components/sync/protocol/sync.pb.h"
+#include "components/sync/test/fake_server/fake_server_entity.h"
+
+namespace fake_server {
+
+// A server-created, permanent entity.
+class PermanentEntity : public FakeServerEntity {
+ public:
+  ~PermanentEntity() override;
+
+  // Factory function for PermanentEntity. |server_tag| should be a globally
+  // unique identifier.
+  static std::unique_ptr<FakeServerEntity> Create(
+      const syncer::ModelType& model_type,
+      const std::string& server_tag,
+      const std::string& name,
+      const std::string& parent_server_tag);
+
+  // Factory function for a top level PermanentEntity. Top level means that the
+  // entity's parent is the root entity (no PermanentEntity exists for root).
+  static std::unique_ptr<FakeServerEntity> CreateTopLevel(
+      const syncer::ModelType& model_type);
+
+  // Factory function for creating an updated version of a PermanentEntity.
+  // This function should only be called for the Nigori entity.
+  static std::unique_ptr<FakeServerEntity> CreateUpdatedNigoriEntity(
+      const sync_pb::SyncEntity& client_entity,
+      const FakeServerEntity& current_server_entity);
+
+  // FakeServerEntity implementation.
+  bool RequiresParentId() const override;
+  std::string GetParentId() const override;
+  void SerializeAsProto(sync_pb::SyncEntity* proto) const override;
+  bool IsFolder() const override;
+  bool IsPermanent() const override;
+
+ private:
+  PermanentEntity(const std::string& id,
+                  const syncer::ModelType& model_type,
+                  const std::string& name,
+                  const std::string& parent_id,
+                  const std::string& server_defined_unique_tag,
+                  const sync_pb::EntitySpecifics& entity_specifics);
+
+  // All member values have equivalent fields in SyncEntity.
+  std::string server_defined_unique_tag_;
+  std::string parent_id_;
+};
+
+}  // namespace fake_server
+
+#endif  // COMPONENTS_SYNC_TEST_FAKE_SERVER_PERMANENT_ENTITY_H_