Remove several unneeded includes from mojo/edk/test_utils.h.

mojo/edk/test/test_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_EDK_TEST_TEST_UTILS_H_
 #define MOJO_EDK_TEST_TEST_UTILS_H_
 
 #include <stddef.h>
-#include <stdio.h>
-
-#include <string>
 
 #include "mojo/edk/embedder/platform_handle.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/util/scoped_file.h"
 
 namespace mojo {
 namespace test {
 
 // On success, |bytes_written| is updated to the number of bytes written;
 // otherwise it is untouched.
@@ skipping 22 matching lines @@
 embedder::ScopedPlatformHandle PlatformHandleFromFILE(util::ScopedFILE fp);
 
 // Gets a (scoped) |FILE| from a (scoped) |PlatformHandle|.
 util::ScopedFILE FILEFromPlatformHandle(embedder::ScopedPlatformHandle h,
                                         const char* mode);
 
 }  // namespace test
 }  // namespace mojo
 
 #endif  // MOJO_EDK_TEST_TEST_UTILS_H_