Use a direct include of strings headers in ui/, part 1.

ui/base/l10n/l10n_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 localized
 // content.
 
 #ifndef UI_BASE_L10N_L10N_UTIL_H_
 #define UI_BASE_L10N_L10N_UTIL_H_
 
 #include <string>
 #include <vector>
 
-#include "base/string16.h"
-#include "base/string_util.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_util.h"
 #include "ui/base/ui_export.h"
 
 #if defined(OS_MACOSX)
 #include "ui/base/l10n/l10n_util_mac.h"
 #endif  // OS_MACOSX
 
 namespace l10n_util {
 
 // This method is responsible for determining the locale as defined below. In
 // nearly all cases you shouldn't call this, rather use GetApplicationLocale
@@ skipping 121 matching lines @@
     const std::string& display_locale,
     std::vector<std::string>* locale_codes);
 
 // Returns the preferred size of the contents view of a window based on
 // designer given constraints which might dependent on the language used.
 UI_EXPORT int GetLocalizedContentsWidthInPixels(int pixel_resource_id);
 
 }  // namespace l10n_util
 
 #endif  // UI_BASE_L10N_L10N_UTIL_H_