[Athena] Extract Chrome OS authentication stack

chrome/browser/chromeos/login/managed/supervised_user_authentication.cc

 // Copyright 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.
 
 #include "chrome/browser/chromeos/login/managed/supervised_user_authentication.h"
 
 #include "base/base64.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/threading/sequenced_worker_pool.h"
-#include "chrome/browser/chromeos/login/auth/key.h"
 #include "chrome/browser/chromeos/login/managed/locally_managed_user_constants.h"
 #include "chrome/browser/chromeos/login/users/supervised_user_manager.h"
 #include "chrome/browser/chromeos/login/users/user.h"
 #include "chrome/browser/chromeos/login/users/user_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chromeos/cryptohome/signed_secret.pb.h"
+#include "chromeos/login/auth/key.h"
 #include "content/public/browser/browser_thread.h"
 #include "crypto/hmac.h"
 #include "crypto/random.h"
 #include "crypto/symmetric_key.h"
 
 namespace chromeos {
 
 namespace {
 
 // Byte size of hash salt.
@@ skipping 281 matching lines @@
     LOG(FATAL) << "HMAC::Sign failed";
 
   std::string raw_result(out_bytes, out_bytes + sizeof(out_bytes));
 
   std::string result;
   base::Base64Encode(raw_result, &result);
   return result;
 }
 
 }  // namespace chromeos