[Invalidations] Add GetInvalidatorState() to Invalidator{,Frontend}

sync/notifier/notifications_disabled_reason.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 SYNC_NOTIFIER_NOTIFICATIONS_DISABLED_REASON_H_
-#define SYNC_NOTIFIER_NOTIFICATIONS_DISABLED_REASON_H_
-
-#include "jingle/notifier/listener/push_client_observer.h"
-
-namespace syncer {
-
-enum NotificationsDisabledReason {
-  // There is an underlying transient problem (e.g., network- or
-  // XMPP-related).
-  TRANSIENT_NOTIFICATION_ERROR,
-  DEFAULT_NOTIFICATION_ERROR = TRANSIENT_NOTIFICATION_ERROR,
-  // Our credentials have been rejected.
-  NOTIFICATION_CREDENTIALS_REJECTED,
-  // No error (useful as a default value or to avoid keeping a
-  // separate bool for notifications enabled/disabled).
-  NO_NOTIFICATION_ERROR
-};
-
-const char* NotificationsDisabledReasonToString(
-    NotificationsDisabledReason reason);
-
-NotificationsDisabledReason FromNotifierReason(
-    notifier::NotificationsDisabledReason reason);
-
-notifier::NotificationsDisabledReason ToNotifierReasonForTest(
-    NotificationsDisabledReason reason);
-
-}  // namespace syncer
-
-#endif  // SYNC_NOTIFIER_NOTIFICATIONS_DISABLED_REASON_H_