Convert //mojo/file_utils to use SynchronousInterfacePtr.

mojo/file_utils/file_util.h

 // Copyright 2015 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.
 
 // This file contains utility functions around the mojo files service.
 
 #ifndef MOJO_FILE_UTILS_FILE_UTIL_H_
 #define MOJO_FILE_UTILS_FILE_UTIL_H_
 
 #include <string>
 
-#include "mojo/services/files/interfaces/directory.mojom.h"
+#include "mojo/public/cpp/bindings/interface_handle.h"
+#include "mojo/public/cpp/bindings/synchronous_interface_ptr.h"
+#include "mojo/services/files/interfaces/directory.mojom-sync.h"
 #include "mojo/services/files/interfaces/file.mojom.h"
 
 namespace file_utils {
 
 // Creates a new temp file, placed in the (input) directory |directory| along
 // with the (output) file location in |path_name|. This function blocks the
 // calling thread, and there must not be any calls pending on the |directory|
 // when this function is called.
 // Returns a FilePtr on success, and null on failure.
 // On failure, |path_name| is unchanged.
-mojo::files::FilePtr CreateTemporaryFileInDir(
-    mojo::files::DirectoryPtr* directory,
+mojo::InterfaceHandle<mojo::files::File> CreateTemporaryFileInDir(
+    mojo::SynchronousInterfacePtr<mojo::files::Directory>* directory,
     std::string* path_name);
 
 }  // namespace file_utils
 
 #endif  // MOJO_FILE_UTILS_FILE_UTIL_H_