[Athena] Extract Chrome OS authentication stack

chromeos/login/user_names.cc

+// Copyright (c) 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 "chromeos/login/user_names.h"
+
+#include "google_apis/gaia/gaia_auth_util.h"
+
+namespace chromeos {
+
+namespace login {
+
+const char* kStubUser = "stub-user@example.com";
+
+const char* kSignInUser = "sign-in-user-id";
+
+// Should match cros constant in platform/libchromeos/chromeos/cryptohome.h
+const char* kGuestUserName = "$guest";
+
+const char* kLocallyManagedUserDomain = "locally-managed.localhost";
+
+const char* kRetailModeUserName = "demouser@";
+
+std::string CanonicalizeUserID(const std::string& user_id) {
+  if (user_id == chromeos::login::kGuestUserName)
+    return user_id;
+  return gaia::CanonicalizeEmail(user_id);
+}
+
+}  // namespace login
+
+}  // namespace chromeos