Use a direct include of strings headers in chromeos/.

chromeos/cryptohome/cryptohome_library.cc

 // 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.
 
 #include "chromeos/cryptohome/cryptohome_library.h"
 
 #include <map>
 
 #include "base/bind.h"
 #include "base/chromeos/chromeos_version.h"
 #include "base/memory/weak_ptr.h"
-#include "base/string_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "chromeos/dbus/cryptohome_client.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "crypto/encryptor.h"
 #include "crypto/nss_util.h"
 #include "crypto/sha2.h"
 #include "crypto/symmetric_key.h"
 
 namespace chromeos {
 
 namespace {
@@ skipping 322 matching lines @@
   CHECK(!g_test_cryptohome_library || !impl);
   g_test_cryptohome_library = impl;
 }
 
 // static
 CryptohomeLibrary* CryptohomeLibrary::GetTestImpl() {
   return new CryptohomeLibraryStubImpl();
 }
 
 } // namespace chromeos