FileWriterDelegate should not call URLRequest::Start() after Cancel().

webkit/fileapi/file_system_operation.h

Index: webkit/fileapi/file_system_operation.h
diff --git a/webkit/fileapi/file_system_operation.h b/webkit/fileapi/file_system_operation.h
index 380e3ee51803e2c639695a5acfab758316f63c56..fa16713b79078e4c3788ee83ba87927316c82556 100644
--- a/webkit/fileapi/file_system_operation.h
+++ b/webkit/fileapi/file_system_operation.h
@@ -175,7 +175,8 @@ class FileSystemOperation : public FileSystemOperationInterface {
                          bool recursive);
   void DoCopy(const StatusCallback& callback);
   void DoMove(const StatusCallback& callback);
-  void DoWrite();
+  void DoWrite(const GURL& blob_url,
+               const net::URLRequestContext* request_context);
   void DoTruncate(const StatusCallback& callback, int64 length);
   void DoOpenFile(const OpenFileCallback& callback, int file_flags);
 
@@ -220,7 +221,9 @@ class FileSystemOperation : public FileSystemOperationInterface {
                    bool created);
 
   // Helper for Write().
-  void OnFileOpenedForWrite(base::PlatformFileError rv,
+  void OnFileOpenedForWrite(const GURL& blob_url,
+                            const net::URLRequestContext* request_context,
+                            base::PlatformFileError rv,
                             base::PassPlatformFile file,
                             bool created);
 
@@ -254,7 +257,6 @@ class FileSystemOperation : public FileSystemOperationInterface {
   // These are all used only by Write().
   friend class FileWriterDelegate;
   scoped_ptr<FileWriterDelegate> file_writer_delegate_;
-  scoped_ptr<net::URLRequest> blob_request_;
 
   // write_callback is kept in this class for so that we can dispatch it when
   // the operation is cancelled. calcel_callback is kept for canceling a