Componentize SigninIdAccountHelper.

components/signin/core/common/signin_pref_names.cc

 // Copyright 2014 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 "components/signin/core/common/signin_pref_names.h"
 
 namespace prefs {
 
 // String the identifies the last user that logged into sync and other
 // google services. As opposed to kGoogleServicesUsername, this value is not
 // cleared on signout, but while the user is signed in the two values will
 // be the same.
 const char kGoogleServicesLastUsername[] = "google.services.last_username";
 
+// Obfuscated account ID that identifies the current user logged into sync and
+// other google services.
+const char kGoogleServicesUserAccountId[] = "google.services.user_account_id";
+
 // String that identifies the current user logged into sync and other google
 // services.
 const char kGoogleServicesUsername[] = "google.services.username";
 
 // Boolean which stores if the user is allowed to signin to chrome.
 const char kSigninAllowed[] = "signin.allowed";
 
 }  // namespace prefs