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

sync/notifier/invalidator_state.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_INVALIDATOR_STATE_H_
+#define SYNC_NOTIFIER_INVALIDATOR_STATE_H_
+
+#include "jingle/notifier/listener/push_client_observer.h"
+
+namespace syncer {
+
+enum InvalidatorState {
+  // Failure states
+  // --------------
+  // There is an underlying transient problem (e.g., network- or
+  // XMPP-related).
+  TRANSIENT_INVALIDATION_ERROR,
+  DEFAULT_INVALIDATION_ERROR = TRANSIENT_INVALIDATION_ERROR,
+  // Our credentials have been rejected.
+  INVALIDATION_CREDENTIALS_REJECTED,
+
+  // Invalidations are fully working.
+  INVALIDATIONS_ENABLED
+};
+
+const char* InvalidatorStateToString(InvalidatorState state);
+
+InvalidatorState FromNotifierReason(
+    notifier::NotificationsDisabledReason reason);
+
+// Should not be called when |state| == INVALIDATIONS_ENABLED.
+notifier::NotificationsDisabledReason ToNotifierReasonForTest(
+    InvalidatorState state);
+
+}  // namespace syncer
+
+#endif  // SYNC_NOTIFIER_INVALIDATOR_STATE_H_