Add Transient FileSystem which goes away after its snapsot file is gone

webkit/fileapi/isolated_mount_point_provider.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 WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_
 #define WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "webkit/fileapi/file_system_mount_point_provider.h"
 
@@ skipping 43 matching lines @@
   virtual FileSystemQuotaUtil* GetQuotaUtil() OVERRIDE;
   virtual void DeleteFileSystem(
       const GURL& origin_url,
       FileSystemType type,
       FileSystemContext* context,
       const DeleteFileSystemCallback& callback) OVERRIDE;
 
  private:
   scoped_ptr<AsyncFileUtilAdapter> isolated_file_util_;
   scoped_ptr<AsyncFileUtilAdapter> dragged_file_util_;
+  scoped_ptr<AsyncFileUtilAdapter> transient_file_util_;
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_