Revert "chromeos: Move files in //ash/common to //ash, part 3"

ash/session/session_state_delegate.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 "ash/session/session_state_delegate.h"
-
-namespace ash {
-
-bool SessionStateDelegate::IsInSecondaryLoginScreen() const {
-  return GetSessionState() == session_manager::SessionState::LOGIN_SECONDARY;
-}
-
-AddUserSessionPolicy SessionStateDelegate::GetAddUserSessionPolicy() const {
-  if (!IsMultiProfileAllowedByPrimaryUserPolicy())
-    return AddUserSessionPolicy::ERROR_NOT_ALLOWED_PRIMARY_USER;
-
-  if (NumberOfLoggedInUsers() >= GetMaximumNumberOfLoggedInUsers())
-    return AddUserSessionPolicy::ERROR_MAXIMUM_USERS_REACHED;
-
-  return AddUserSessionPolicy::ALLOWED;
-}
-
-}  // namespace ash