[storage] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

storage/common/database/database_connections.h

 // Copyright (c) 2011 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 STORAGE_COMMON_DATABASE_DATABASE_CONNECTIONS_H_
 #define STORAGE_COMMON_DATABASE_DATABASE_CONNECTIONS_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "base/synchronization/lock.h"
 #include "storage/common/storage_common_export.h"
 
 namespace base {
-class MessageLoopProxy;
+class SingleThreadTaskRunner;
 }
 
 namespace storage {
 
 class STORAGE_COMMON_EXPORT DatabaseConnections {
  public:
   DatabaseConnections();
   ~DatabaseConnections();
 
   bool IsEmpty() const;
@@ skipping 55 matching lines @@
                          const base::string16& database_name);
   void RemoveOpenConnection(const std::string& origin_identifier,
                             const base::string16& database_name);
  private:
   ~DatabaseConnectionsWrapper();
   friend class base::RefCountedThreadSafe<DatabaseConnectionsWrapper>;
 
   bool waiting_for_dbs_to_close_;
   base::Lock open_connections_lock_;
   DatabaseConnections open_connections_;
-  scoped_refptr<base::MessageLoopProxy> main_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_;
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_COMMON_DATABASE_DATABASE_CONNECTIONS_H_