Revert of [Sync] IWYU cleanup.

components/sync/engine_impl/loopback_server/persistent_permanent_entity.cc

 // 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.
 
 #include "components/sync/engine_impl/loopback_server/persistent_permanent_entity.h"
 
+#include <memory>
+#include <string>
+
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "components/sync/base/model_type.h"
+#include "components/sync/engine_impl/loopback_server/loopback_server_entity.h"
+#include "components/sync/protocol/sync.pb.h"
 
 using std::string;
 
 using syncer::ModelType;
 
 namespace {
 // The parent tag for children of the root entity. Entities with this parent are
 // referred to as top level enities.
 static const char kRootParentTag[] = "0";
 }  // namespace
@@ skipping 93 matching lines @@
 bool PersistentPermanentEntity::IsPermanent() const {
   return true;
 }
 
 sync_pb::LoopbackServerEntity_Type
 PersistentPermanentEntity::GetLoopbackServerEntityType() const {
   return sync_pb::LoopbackServerEntity_Type_PERMANENT;
 }
 
 }  // namespace syncer