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

chrome/browser/importer/nss_decryptor_mac.h

 // Copyright (c) 2011 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_IMPORTER_NSS_DECRYPTOR_MAC_H_
 #define CHROME_BROWSER_IMPORTER_NSS_DECRYPTOR_MAC_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 
 namespace base {
 class FilePath;
 }
 
 // The following declarations of functions and types are from Firefox
 // NSS library.
 // source code:
 //   security/nss/lib/util/seccomon.h
 //   security/nss/lib/nss/nss.h
@@ skipping 130 matching lines @@
   PK11SDRDecryptFunc PK11SDR_Decrypt;
   SECITEMFreeItemFunc SECITEM_FreeItem;
 
   // True if NSS_Init() has been called
   bool is_nss_initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(NSSDecryptor);
 };
 
 #endif  // CHROME_BROWSER_IMPORTER_NSS_DECRYPTOR_MAC_H_