Sync: Don't set/use Parent ID for non-hierarchical sync data types.

sync/engine/syncer_proto_util.h

 // Copyright 2012 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 SYNC_ENGINE_SYNCER_PROTO_UTIL_H_
 #define SYNC_ENGINE_SYNCER_PROTO_UTIL_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
@@ skipping 40 matching lines @@
   // Returns true on success.  Also handles store birthday verification: will
   // produce a SyncError if the birthday is incorrect.
   // NOTE: This will add all fields that must be sent on every request, which
   // includes store birthday, protocol version, client chips, api keys, etc.
   static SyncerError PostClientToServerMessage(
       sync_pb::ClientToServerMessage* msg,
       sync_pb::ClientToServerResponse* response,
       sessions::SyncSession* session,
       ModelTypeSet* partial_failure_data_types);
 
+  // Specifies where entity's position should be updated from the data in
+  // GetUpdates message.
   static bool ShouldMaintainPosition(const sync_pb::SyncEntity& sync_entity);
 
+  // Specifies where entity's parent ID should be updated from the data in
+  // GetUpdates message.
+  static bool ShouldMaintainHierarchy(const sync_pb::SyncEntity& sync_entity);
+
   // Extract the name field from a sync entity.
   static const std::string& NameFromSyncEntity(
       const sync_pb::SyncEntity& entry);
 
   // Extract the name field from a commit entry response.
   static const std::string& NameFromCommitEntryResponse(
       const sync_pb::CommitResponse_EntryResponse& entry);
 
   // Persist the bag of chips if it is present in the response.
   static void PersistBagOfChips(
@@ skipping 58 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, VerifyResponseBirthday);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingNoDatatypes);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, HandleThrottlingWithDatatypes);
 
   DISALLOW_COPY_AND_ASSIGN(SyncerProtoUtil);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_PROTO_UTIL_H_