sync: Specialize functions that fetch type root

sync/internal_api/public/write_node.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_INTERNAL_API_PUBLIC_WRITE_NODE_H_
 #define SYNC_INTERNAL_API_PUBLIC_WRITE_NODE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 67 matching lines @@
   // you want to fetch using client_tag. Note that the behavior of these
   // items is slightly different than that of normal items.
   // Most importantly, if it exists locally, this function will
   // actually undelete it
   // Client unique tagged nodes must NOT be folders.
   InitUniqueByCreationResult InitUniqueByCreation(
       ModelType model_type,
       const BaseNode& parent,
       const std::string& client_tag);
 
-  // Each server-created permanent node is tagged with a unique string.
-  // Look up the node with the particular tag.  If it does not exist,
-  // return false.
-  InitByLookupResult InitByTagLookup(const std::string& tag);
+  // Looks up the type's root folder.  This is usually created by the sync
+  // server during initial sync, though we do eventually wish to remove it from
+  // the protocol and have the client "fake it" instead.
+  InitByLookupResult InitTypeRoot(ModelType type);
 
   // These Set() functions correspond to the Get() functions of BaseNode.
   void SetIsFolder(bool folder);
   void SetTitle(const std::string& title);
 
   // External ID is a client-only field, so setting it doesn't cause the item to
   // be synced again.
   void SetExternalId(int64 external_id);
 
   // Remove this node and its children and sync deletion to server.
@@ skipping 99 matching lines @@
 
   // The sync API transaction that is the parent of this node.
   WriteTransaction* transaction_;
 
   DISALLOW_COPY_AND_ASSIGN(WriteNode);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_WRITE_NODE_H_