Update ToLower/UpperASCII API

base/files/file_util_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
@@ skipping 408 matching lines @@
     // Delete the reparse points, and see that NormalizeFilePath() fails
     // to traverse them.
   }
 
   ASSERT_FALSE(NormalizeFilePath(to_sub_a.Append(FPL("file.txt")),
                                             &normalized_path));
 }
 
 TEST_F(FileUtilTest, DevicePathToDriveLetter) {
   // Get a drive letter.
-  std::wstring real_drive_letter = temp_dir_.path().value().substr(0, 2);
-  StringToUpperASCII(&real_drive_letter);
+  string16 real_drive_letter =
+      ToUpperASCII(temp_dir_.path().value().substr(0, 2));
   if (!isalpha(real_drive_letter[0]) || ':' != real_drive_letter[1]) {
     LOG(ERROR) << "Can't get a drive letter to test with.";
     return;
   }
 
   // Get the NT style path to that drive.
   wchar_t device_path[MAX_PATH] = {'\0'};
   ASSERT_TRUE(
       ::QueryDosDevice(real_drive_letter.c_str(), device_path, MAX_PATH));
   FilePath actual_device_path(device_path);
@@ skipping 2077 matching lines @@
   // Trying to close it should crash. This is important for security.
   EXPECT_DEATH(CloseWithScopedFD(fds[1]), "");
 #endif
 }
 
 #endif  // defined(OS_POSIX)
 
 }  // namespace
 
 }  // namespace base