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

ui/views/controls/menu/menu_delegate.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_MENU_DELEGATE_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_DELEGATE_H_
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 
 using ui::OSExchangeData;
 
 namespace gfx {
 class Font;
 }
 
@@ skipping 201 matching lines @@
                                         int* left_margin,
                                         int* right_margin) const;
   // Returns true if the labels should reserve additional spacing for e.g.
   // submenu indicators at the end of the line.
   virtual bool ShouldReserveSpaceForSubmenuIndicator() const;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_DELEGATE_H_