[SyncFS] Rename LevelDBWrapper::Operation not to be confusing

chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_LEVELDB_WRAPPER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_LEVELDB_WRAPPER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 20 matching lines @@
 };
 
 // LevelDBWrapper class wraps leveldb::DB and leveldb::WriteBatch to provide
 // transparent access to pre-commit data.
 // Put() and Delete() update data on memory, and Get() can access to those data
 // and also data on disk.  Those data on memory are written down on disk when
 // Commit() is called.
 class LevelDBWrapper {
  private:
   enum Operation {
-    DB_PUT,
-    DB_DELETE,
+    PUT_OPERATION,
+    DELETE_OPERATION,
   };
   typedef std::pair<Operation, std::string> Transaction;
   typedef std::map<std::string, Transaction, SliceComparator>
       PendingOperationMap;
 
  public:
   class Iterator {
    public:
     explicit Iterator(LevelDBWrapper* db);
     ~Iterator();
@@ skipping 42 matching lines @@
 
   PendingOperationMap pending_;
 
   DISALLOW_COPY_AND_ASSIGN(LevelDBWrapper);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_LEVELDB_WRAPPER_H_