Use a direct include of strings headers in chrome/browser/ui/a*/.

chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.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 CHROME_BROWSER_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_
 
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/gfx/image/image.h"
 
 // A description for a menu item. It contains the menu item description as well
 // as the function which gets executed upon menu item click.
 class ChromeLauncherAppMenuItem {
  public:
   // To insert a separator before this item set |has_leading_separator|.
   ChromeLauncherAppMenuItem(const string16 title,
                             const gfx::Image* icon,
                             bool has_leading_separator);
@@ skipping 23 matching lines @@
  private:
   const string16 title_;
   const gfx::Image icon_;
 
   // True if the item has a separator in front of it.
   const bool has_leading_separator_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeLauncherAppMenuItem);
 };
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_CHROME_LAUNCHER_APP_MENU_ITEM_H_