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

chrome/browser/ui/autofill/country_combobox_model.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_AUTOFILL_COUNTRY_COMBOBOX_MODEL_H_
 #define CHROME_BROWSER_UI_AUTOFILL_COUNTRY_COMBOBOX_MODEL_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_vector.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/base/models/combobox_model.h"
 
 namespace autofill {
 
 class AutofillCountry;
 
 // A model for countries to be used to enter addresses.
 class CountryComboboxModel : public ui::ComboboxModel {
  public:
   CountryComboboxModel();
@@ skipping 12 matching lines @@
   // The countries to show in the model, including NULL for entries that are
   // not countries (the separator entry).
   ScopedVector<AutofillCountry> countries_;
 
   DISALLOW_COPY_AND_ASSIGN(CountryComboboxModel);
 };
 
 }  // namespace autofill
 
 #endif  // CHROME_BROWSER_UI_AUTOFILL_COUNTRY_COMBOBOX_MODEL_H_