Add CreateFileSystemOperation() method to FileSystemContext

webkit/fileapi/file_system_operation_interface.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_FILE_SYSTEM_OPERATION_INTERFACE_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_OPERATION_INTERFACE_H_
 
 #include "base/process.h"
 
 namespace base {
 class Time;
 }  // namespace base
 
 namespace net {
 class URLRequest;
 class URLRequestContext;
 }  // namespace net
 
 class GURL;
 
 namespace fileapi {
 
 class FileSystemCallbackDispatcher;
+class FileSystemOperation;
 
 // The interface class for FileSystemOperation implementations.
 //
 // This interface defines file system operations required to implement
 // "File API: Directories and System"
 // http://www.w3.org/TR/file-system-api/
 //
 // DESIGN NOTES
 //
 // This class is designed to
@@ skipping 104 matching lines @@
   // values of base::PlatformFileFlags.
   //
   // |peer_handle| is the process handle of a pepper plugin process, which
   // is necessary for underlying IPC calls with Pepper plugins.
   //
   // This function is used only by Pepper as of writing.
   virtual void OpenFile(
       const GURL& path,
       int file_flags,
       base::ProcessHandle peer_handle) = 0;
+
+  // For downcasting to FileSystemOperation.
+  // TODO(kinuko): this hack should go away once appropriate upload-stream
+  // handling based on element types is supported.
+  virtual FileSystemOperation* AsFileSystemOperation() = 0;
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_OPERATION_INTERFACE_H_