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

webkit/fileapi/file_system_url_request_job.h

Index: webkit/fileapi/file_system_url_request_job.h
diff --git a/webkit/fileapi/file_system_url_request_job.h b/webkit/fileapi/file_system_url_request_job.h
index bc25f75f29c328e33ced7bba59ee7db885e5b11c..9fa52de5ebc1222832788cf1005770edad784d43 100644
--- a/webkit/fileapi/file_system_url_request_job.h
+++ b/webkit/fileapi/file_system_url_request_job.h
@@ -17,6 +17,7 @@
 #include "net/base/completion_callback.h"
 #include "net/http/http_byte_range.h"
 #include "net/url_request/url_request_job.h"
+#include "webkit/fileapi/file_system_operation_context.h"
 
 class GURL;
 
@@ -75,6 +76,7 @@ class FileSystemURLRequestJob : public net::URLRequestJob {
   ScopedRunnableMethodFactory<FileSystemURLRequestJob> method_factory_;
   base::ScopedCallbackFactory<FileSystemURLRequestJob> callback_factory_;
   scoped_refptr<base::MessageLoopProxy> file_thread_proxy_;
+  scoped_ptr<FileSystemOperationContext> file_system_operation_context_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystemURLRequestJob);
 };