Use a direct include of strings headers in base/.

base/file_util.h

 // 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.
 
 // This file contains utility functions for dealing with the local
 // filesystem.
 
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 
@@ skipping 10 matching lines @@
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 
 #if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #endif
 
 namespace base {
 class Time;
 
@@ skipping 402 matching lines @@
 
 // Attempts determine the FileSystemType for |path|.
 // Returns false if |path| doesn't exist.
 BASE_EXPORT bool GetFileSystemType(const base::FilePath& path,
                                    FileSystemType* type);
 #endif
 
 }  // namespace file_util
 
 #endif  // BASE_FILE_UTIL_H_