Use a direct include of strings headers in ui/, part 3.

ui/views/controls/menu/native_menu_win.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.
 
 #ifndef UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_
 #define UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/views/controls/menu/menu_wrapper.h"
 #include "ui/views/views_export.h"
 
 namespace ui {
 class MenuModel;
 }
 
 namespace views {
 
 // A Windows implementation of MenuWrapper.
@@ skipping 134 matching lines @@
   // has a menu open, because our hook function that receives keyboard
   // events doesn't have a mechanism to get a user data pointer.
   static NativeMenuWin* open_native_menu_win_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeMenuWin);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_