[Sync] Add support for loading, updating and querying delete journals in

sync/syncable/base_transaction.h

 // Copyright (c) 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_SYNCABLE_BASE_TRANSACTION_H_
 #define SYNC_SYNCABLE_BASE_TRANSACTION_H_
 
 #include "base/location.h"
 #include "sync/syncable/syncable_id.h"
 
 namespace syncer {
 namespace syncable {
 
 class Directory;
 
 // A WriteTransaction has a writer tag describing which body of code is doing
 // the write. This is defined up here since WriteTransactionInfo also contains
 // one.
 enum WriterTag {
   INVALID,
   SYNCER,
   AUTHWATCHER,
   UNITTEST,
   VACUUM_AFTER_SAVE,
+  HANDLE_SAVE_FAILURE,
   PURGE_ENTRIES,
-  SYNCAPI
+  SYNCAPI,
 };
 
 // Make sure to update this if you update WriterTag.
 std::string WriterTagToString(WriterTag writer_tag);
 
 class BaseTransaction {
  public:
   inline Directory* directory() const { return directory_; }
   inline Id root_id() const { return Id(); }
 
@@ skipping 36 matching lines @@
 
  private:
   friend class Entry;
   DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_SYNCABLE_BASE_TRANSACTION_H_