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

chromeos/dbus/mock_cryptohome_client.h

Index: chromeos/dbus/mock_cryptohome_client.h
diff --git a/chromeos/dbus/mock_cryptohome_client.h b/chromeos/dbus/mock_cryptohome_client.h
index 4382d35415a77cdafba11e84d4245bd5622630da..60433da23ae5710a44c97b55ba6b5915daee8902 100644
--- a/chromeos/dbus/mock_cryptohome_client.h
+++ b/chromeos/dbus/mock_cryptohome_client.h
@@ -40,6 +40,11 @@ class MockCryptohomeClient : public CryptohomeClient {
                     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,