[Sync] Add context proto and directory support

sync/syncable/directory_backing_store.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_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 #define SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 152 matching lines @@
   bool MigrateVersion76To77();
   bool MigrateVersion77To78();
   bool MigrateVersion78To79();
   bool MigrateVersion79To80();
   bool MigrateVersion80To81();
   bool MigrateVersion81To82();
   bool MigrateVersion82To83();
   bool MigrateVersion83To84();
   bool MigrateVersion84To85();
   bool MigrateVersion85To86();
+  bool MigrateVersion86To87();
 
   scoped_ptr<sql::Connection> db_;
   sql::Statement save_meta_statment_;
   sql::Statement save_delete_journal_statment_;
   std::string dir_name_;
 
   // Set to true if migration left some old columns around that need to be
   // discarded.
   bool needs_column_refresh_;
 
  private:
   // Prepares |save_statement| for saving entries in |table|.
   void PrepareSaveEntryStatement(EntryTable table,
                                  sql::Statement* save_statement);
 
   DISALLOW_COPY_AND_ASSIGN(DirectoryBackingStore);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_