Make client tag IDs consistent in sync fake server

sync/test/fake_server/unique_client_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 "sync/test/fake_server/unique_client_entity.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/guid.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/test/fake_server/fake_server_entity.h"
 #include "sync/test/fake_server/permanent_entity.h"
 
 using std::string;
 
 using syncer::ModelType;
 
 namespace fake_server {
 
 UniqueClientEntity::~UniqueClientEntity() { }
 
 // static
 FakeServerEntity* UniqueClientEntity::CreateNew(

[pval...(no longer on Chromium), 2014/07/23 23:54:15]

CreateNew and CreateUpdatedVersion look pretty similar now. What do you think
about simplifying them down to just one method?

[rlarocque, 2014/07/24 00:18:40]

I hadn't noticed that until now.  Good point.  I'll update this CL.

     const sync_pb::SyncEntity& client_entity) {
   CHECK(client_entity.has_client_defined_unique_tag())
       << "A UniqueClientEntity must have a client-defined unique tag.";
   ModelType model_type =
       syncer::GetModelTypeFromSpecifics(client_entity.specifics());
-  string id = client_entity.version() == 0 ?
-      FakeServerEntity::CreateId(model_type, base::GenerateGUID()) :
-      client_entity.id_string();
+  string id = EffectiveIdForClientTaggedEntity(client_entity);
   return new UniqueClientEntity(id,
                                 model_type,
                                 client_entity.version(),
                                 client_entity.name(),
                                 client_entity.client_defined_unique_tag(),
                                 client_entity.specifics(),
                                 client_entity.ctime(),
                                 client_entity.mtime());
 }
 
 // static
 FakeServerEntity* UniqueClientEntity::CreateUpdatedVersion(
     const sync_pb::SyncEntity& client_entity,
     FakeServerEntity* current_server_entity) {
-  return new UniqueClientEntity(client_entity.id_string(),
+  string id = EffectiveIdForClientTaggedEntity(client_entity);
+  return new UniqueClientEntity(id,
                                 current_server_entity->GetModelType(),
                                 client_entity.version(),
                                 client_entity.name(),
                                 client_entity.client_defined_unique_tag(),
                                 client_entity.specifics(),
                                 client_entity.ctime(),
                                 client_entity.mtime());
 }
 
+// static
+std::string UniqueClientEntity::EffectiveIdForClientTaggedEntity(
+    const sync_pb::SyncEntity& entity) {
+  return FakeServerEntity::CreateId(
+      syncer::GetModelTypeFromSpecifics(entity.specifics()),
+      entity.client_defined_unique_tag());
+}
+
 UniqueClientEntity::UniqueClientEntity(
     const string& id,
     const ModelType& model_type,
     int64 version,
     const string& name,
     const string& client_defined_unique_tag,
     const sync_pb::EntitySpecifics& specifics,
     int64 creation_time,
     int64 last_modified_time)
     : FakeServerEntity(id, model_type, version, name),
@@ skipping 25 matching lines @@
 
 bool UniqueClientEntity::IsDeleted() const {
   return false;
 }
 
 bool UniqueClientEntity::IsFolder() const {
   return false;
 }
 
 }  // namespace fake_server