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

components/autofill/browser/autocheckout_manager.h

 // Copyright (c) 2013 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 COMPONENTS_AUTOFILL_BROWSER_AUTOCHECKOUT_MANAGER_H_
 #define COMPONENTS_AUTOFILL_BROWSER_AUTOCHECKOUT_MANAGER_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/threading/thread_checker.h"
 #include "components/autofill/browser/autocheckout_page_meta_data.h"
 #include "components/autofill/common/autocheckout_status.h"
 
 class GURL;
 
 namespace content {
 struct SSLStatus;
 }
 
@@ skipping 127 matching lines @@
   base::WeakPtrFactory<AutocheckoutManager> weak_ptr_factory_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(AutocheckoutManager);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_BROWSER_AUTOCHECKOUT_MANAGER_H_