sync: Specialize functions that fetch type root

sync/internal_api/read_node.cc

 // 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.
 
 #include "sync/internal_api/public/read_node.h"
 
 #include "base/logging.h"
 #include "sync/internal_api/public/base_transaction.h"
 #include "sync/syncable/entry.h"
 #include "sync/syncable/syncable_base_transaction.h"
@@ skipping 59 matching lines @@
 }
 
 const syncable::Entry* ReadNode::GetEntry() const {
   return entry_;
 }
 
 const BaseTransaction* ReadNode::GetTransaction() const {
   return transaction_;
 }
 
-BaseNode::InitByLookupResult ReadNode::InitByTagLookup(
+BaseNode::InitByLookupResult ReadNode::InitByTagLookupForBookmarks(
     const std::string& tag) {
   DCHECK(!entry_) << "Init called twice";
   if (tag.empty())
     return INIT_FAILED_PRECONDITION;
   syncable::BaseTransaction* trans = transaction_->GetWrappedTrans();
-  entry_ = new syncable::Entry(trans, syncable::GET_BY_SERVER_TAG, tag);
+  entry_ = new syncable::Entry(trans,
+                               syncable::GET_BY_SERVER_TAG_DEPRECATED,
+                               tag);
   if (!entry_->good())
     return INIT_FAILED_ENTRY_NOT_GOOD;
   if (entry_->GetIsDel())
     return INIT_FAILED_ENTRY_IS_DEL;
   ModelType model_type = GetModelType();
-  LOG_IF(WARNING, model_type == UNSPECIFIED || model_type == TOP_LEVEL_FOLDER)
-      << "SyncAPI InitByTagLookup referencing unusually typed object.";
+  DCHECK_EQ(model_type, BOOKMARKS)
+      << "InitByTagLookup deprecated for all types except bookmarks.";
   return DecryptIfNecessary() ? INIT_OK : INIT_FAILED_DECRYPT_IF_NECESSARY;
 }
 
+BaseNode::InitByLookupResult ReadNode::InitTypeRoot(ModelType type) {
+  DCHECK(!entry_) << "Init called twice";
+  if (!IsRealDataType(type))
+    return INIT_FAILED_PRECONDITION;
+  syncable::BaseTransaction* trans = transaction_->GetWrappedTrans();
+  entry_ = new syncable::Entry(trans, syncable::GET_TYPE_ROOT, type);
+  if (!entry_->good())
+    return INIT_FAILED_ENTRY_NOT_GOOD;
+  if (entry_->GetIsDel())
+    return INIT_FAILED_ENTRY_IS_DEL;
+  ModelType found_model_type = GetModelType();
+  LOG_IF(WARNING, found_model_type == UNSPECIFIED ||
+                  found_model_type == TOP_LEVEL_FOLDER)
+      << "SyncAPI InitTypeRoot referencing unusually typed object.";
+  return DecryptIfNecessary() ? INIT_OK : INIT_FAILED_DECRYPT_IF_NECESSARY;
+}
+
 }  // namespace syncer