ChromeOS cryptohome should be able to use gaia id as user identifier.

chromeos/dbus/mock_cryptohome_client.h

 // 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.
 
 #ifndef CHROMEOS_DBUS_MOCK_CRYPTOHOME_CLIENT_H_
 #define CHROMEOS_DBUS_MOCK_CRYPTOHOME_CLIENT_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 22 matching lines @@
                void(const std::string& username,
                     const std::string& key,
                     const AsyncMethodCallback& callback));
   MOCK_METHOD4(AsyncMigrateKey,
                void(const std::string& username,
                     const std::string& from_key,
                     const std::string& to_key,
                     const AsyncMethodCallback& callback));
   MOCK_METHOD2(AsyncRemove, void(const std::string& username,
                                  const AsyncMethodCallback& callback));
+  MOCK_METHOD3(RenameCryptohome,
+               void(const cryptohome::AccountIdentifier& id_from,
+                    const cryptohome::AccountIdentifier& id_to,
+                    const ProtobufMethodCallback& callback));
+
   MOCK_METHOD1(GetSystemSalt, void(const GetSystemSaltCallback& callback));
   MOCK_METHOD2(GetSanitizedUsername,
                void(const std::string& username,
                     const StringDBusMethodCallback& callback));
   MOCK_METHOD1(BlockingGetSanitizedUsername,
                std::string(const std::string& username));
   MOCK_METHOD4(AsyncMount, void(const std::string& username,
                                 const std::string& key,
                                 int flags,
                                 const AsyncMethodCallback& callback));
@@ skipping 152 matching lines @@
                     const ProtobufMethodCallback& callback));
   MOCK_METHOD2(
       FlushAndSignBootAttributes,
       void(const cryptohome::FlushAndSignBootAttributesRequest& request,
            const ProtobufMethodCallback& callback));
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_MOCK_CRYPTOHOME_CLIENT_H_