IndexedDB: Added UMA stat to measure time to close backing store.

content/browser/indexed_db/leveldb/leveldb_database.h

 // Copyright (c) 2013 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 CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_DATABASE_H_
 #define CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_DATABASE_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
@@ skipping 83 matching lines @@
   const LevelDBComparator* Comparator() const;
   void Compact(const base::StringPiece& start, const base::StringPiece& stop);
   void CompactAll();
 
  protected:
   LevelDBDatabase();
 
  private:
   friend class LevelDBSnapshot;
 
+  void CloseDatabase();
+
   scoped_ptr<leveldb::Env> env_;
   scoped_ptr<leveldb::Comparator> comparator_adapter_;
   scoped_ptr<leveldb::DB> db_;
   scoped_ptr<const leveldb::FilterPolicy> filter_policy_;
   const LevelDBComparator* comparator_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_DATABASE_H_