Convert GetDisplayStringInLTRDirectionality from wstring to string16.

base/i18n/rtl.h

 // Copyright (c) 2010 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 BASE_I18N_RTL_H_
 #define BASE_I18N_RTL_H_
 #pragma once
 
+#include "base/compiler_specific.h"
 #include "base/string16.h"
 #include "build/build_config.h"
 
 class FilePath;
 
 namespace base {
 namespace i18n {
 
 const char16 kRightToLeftMark = 0x200F;
 const char16 kLeftToRightMark = 0x200E;
@@ skipping 109 matching lines @@
 // Wraps file path to get it to display correctly in RTL UI. All filepaths
 // should be passed through this function before display in UI for RTL locales.
 void WrapPathWithLTRFormatting(const FilePath& path,
                                string16* rtl_safe_path);
 
 // Given the string in |text|, this function returns the adjusted string having
 // LTR directionality for display purpose. Which means that in RTL locale the
 // string is wrapped with LRE (Left-To-Right Embedding) and PDF (Pop
 // Directional Formatting) marks and returned. In LTR locale, the string itself
 // is returned.
-std::wstring GetDisplayStringInLTRDirectionality(std::wstring* text);
+string16 GetDisplayStringInLTRDirectionality(const string16& text) 
+    WARN_UNUSED_RESULT;
 
 // Strip the beginning (U+202A..U+202B, U+202D..U+202E) and/or ending (U+202C)
 // explicit bidi control characters from |text|, if there are any. Otherwise,
 // return the text itself. Explicit bidi control characters display and have
 // semantic effect. They can be deleted so they might not always appear in a
 // pair.
-const string16 StripWrappingBidiControlCharacters(const string16& text);
+const string16 StripWrappingBidiControlCharacters(const string16& text)
+    WARN_UNUSED_RESULT;
 
 }  // namespace i18n
 }  // namespace base
 
 #endif  // BASE_I18N_RTL_H_