[sync] Reland - Replace FakeServer's implementation with LoopbackServer invocations.

components/sync/test/fake_server/tombstone_entity.h

Index: components/sync/test/fake_server/tombstone_entity.h
diff --git a/components/sync/test/fake_server/tombstone_entity.h b/components/sync/test/fake_server/tombstone_entity.h
deleted file mode 100644
index 3ddb94d7a351f5babf954ca3c378290a3ec61c49..0000000000000000000000000000000000000000
--- a/components/sync/test/fake_server/tombstone_entity.h
+++ /dev/null
@@ -1,41 +0,0 @@
-// 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_TOMBSTONE_ENTITY_H_
-#define COMPONENTS_SYNC_TEST_FAKE_SERVER_TOMBSTONE_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 Sync entity that represents a deleted item.
-class TombstoneEntity : public FakeServerEntity {
- public:
-  ~TombstoneEntity() override;
-
-  // Factory function for TombstoneEntity.
-  static std::unique_ptr<FakeServerEntity> Create(
-      const std::string& id,
-      const std::string& client_defined_unique_tag);
-
-  // FakeServerEntity implementation.
-  bool RequiresParentId() const override;
-  std::string GetParentId() const override;
-  void SerializeAsProto(sync_pb::SyncEntity* proto) const override;
-  bool IsDeleted() const override;
-
- private:
-  TombstoneEntity(const std::string& id,
-                  const std::string& client_defined_unique_tag,
-                  const syncer::ModelType& model_type);
-};
-
-}  // namespace fake_server
-
-#endif  // COMPONENTS_SYNC_TEST_FAKE_SERVER_TOMBSTONE_ENTITY_H_