Created a blocking copy to temporary file function.

mojo/data_pipe_utils/data_pipe_utils.h

 // Copyright 2014 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 MOJO_DATA_PIPE_UTILS_DATA_PIPE_UTILS_H_
 #define MOJO_DATA_PIPE_UTILS_DATA_PIPE_UTILS_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
+#include "base/files/scoped_file.h"
 #include "base/threading/platform_thread.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace base {
 class FilePath;
 class TaskRunner;
 }
 
 namespace mojo {
 namespace common {
@@ skipping 14 matching lines @@
 
 // Copies the data from |source| into |contents| and returns true on success and
 // false on error.  In case of I/O error, |contents| holds the data that could
 // be read from source before the error occurred.
 bool BlockingCopyToString(ScopedDataPipeConsumerHandle source,
                           std::string* contents);
 
 bool BlockingCopyFromString(const std::string& source,
                             const ScopedDataPipeProducerHandle& destination);
 
-// Synchronously copies data from source to the destination file returning true
-// on success and false on error.  In case of an error, |destination| holds the
-// data that could be read from the source before the error occured.
-bool BlockingCopyToFile(ScopedDataPipeConsumerHandle source,
-                        const base::FilePath& destination);
+// Synchronously copies source data to a temporary file, returning a file
+// pointer on success and NULL on error. The temporary file is unlinked
+// immediately so that it is only accessible by file pointer (and removed once
+// closed or the creating process dies).
+base::ScopedFILE BlockingCopyToTempFile(ScopedDataPipeConsumerHandle source);
 
 }  // namespace common
 }  // namespace mojo
 
 #endif  // MOJO_DATA_PIPE_UTILS_DATA_PIPE_UTILS_H_