sync: Specialize functions that fetch type root

sync/internal_api/sync_rollback_manager_base.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/internal_api/sync_rollback_manager_base.h"
 
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/internal_components_factory.h"
 #include "sync/internal_api/public/read_node.h"
 #include "sync/internal_api/public/read_transaction.h"
@@ skipping 260 matching lines @@
           NULL));
   return syncable::OPENED ==
       share_.directory->Open(
           "backup", this,
           MakeWeakHandle(weak_ptr_factory_.GetWeakPtr()));
 }
 
 bool SyncRollbackManagerBase::InitTypeRootNode(ModelType type) {
   WriteTransaction trans(FROM_HERE, &share_);
   ReadNode root(&trans);
-  if (BaseNode::INIT_OK == root.InitByTagLookup(ModelTypeToRootTag(type)))
+  if (BaseNode::INIT_OK == root.InitTypeRoot(type))
     return true;
 
   syncable::MutableEntry entry(trans.GetWrappedWriteTrans(),
                                syncable::CREATE_NEW_UPDATE_ITEM,
                                syncable::Id::CreateFromServerId(
                                    ModelTypeToString(type)));
   if (!entry.good())
     return false;
 
   entry.PutParentId(syncable::Id());
   entry.PutBaseVersion(1);
   entry.PutUniqueServerTag(ModelTypeToRootTag(type));
   entry.PutNonUniqueName(ModelTypeToString(type));
   entry.PutIsDel(false);
   entry.PutIsDir(true);
 
   sync_pb::EntitySpecifics specifics;
   AddDefaultFieldValue(type, &specifics);
   entry.PutSpecifics(specifics);
 
   return true;
 }
 
 void SyncRollbackManagerBase::InitBookmarkFolder(const std::string& folder) {
   WriteTransaction trans(FROM_HERE, &share_);
   syncable::Entry bookmark_root(trans.GetWrappedTrans(),
-                                syncable::GET_BY_SERVER_TAG,
-                                ModelTypeToRootTag(BOOKMARKS));
+                                syncable::GET_TYPE_ROOT,
+                                BOOKMARKS);
   if (!bookmark_root.good())
     return;
 
   syncable::MutableEntry entry(trans.GetWrappedWriteTrans(),
                                syncable::CREATE_NEW_UPDATE_ITEM,
                                syncable::Id::CreateFromServerId(folder));
   if (!entry.good())
     return;
 
   entry.PutParentId(bookmark_root.GetId());
@@ skipping 17 matching lines @@
 
 void SyncRollbackManagerBase::UnregisterDirectoryTypeDebugInfoObserver(
     syncer::TypeDebugInfoObserver* observer) {}
 
 bool SyncRollbackManagerBase::HasDirectoryTypeDebugInfoObserver(
     syncer::TypeDebugInfoObserver* observer) { return false; }
 
 void SyncRollbackManagerBase::RequestEmitDebugInfo() {}
 
 }  // namespace syncer