Stackable file_util for FileAPIs. Sample code for discussion. Incomplete. Cannot be compiled.

webkit/fileapi/file_system_operation.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 WEBKIT_FILEAPI_FILE_SYSTEM_OPERATION_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_OPERATION_H_
 
 #include <vector>
 
 #include "base/file_path.h"
 #include "base/file_util_proxy.h"
 #include "base/message_loop_proxy.h"
 #include "base/platform_file.h"
 #include "base/ref_counted.h"
 #include "base/scoped_callback_factory.h"
 #include "base/scoped_ptr.h"
 #include "googleurl/src/gurl.h"
+#include "webkit/fileapi/file_system_operation_context.h"
 #include "webkit/fileapi/file_system_types.h"
 
 namespace base {
 class Time;
 }
 
 namespace net {
 class URLRequest;
 class URLRequestContext;
 }  // namespace net
@@ skipping 138 matching lines @@
   OperationType pending_operation_;
 #endif
 
   // Proxy for calling file_util_proxy methods.
   scoped_refptr<base::MessageLoopProxy> proxy_;
 
   scoped_ptr<FileSystemCallbackDispatcher> dispatcher_;
 
   scoped_refptr<FileSystemContext> file_system_context_;
 
+  scoped_ptr<FileSystemOperationContext> file_system_operation_context_;
+
   base::ScopedCallbackFactory<FileSystemOperation> callback_factory_;
 
   // These are all used only by Write().
   friend class FileWriterDelegate;
   scoped_ptr<FileWriterDelegate> file_writer_delegate_;
   scoped_ptr<net::URLRequest> blob_request_;
   scoped_ptr<FileSystemOperation> cancel_operation_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemOperation);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_OPERATION_H_