[Sync] Propagate XMPP auth errors to SyncNotifierObservers

sync/notifier/sync_notifier_observer.h

Index: sync/notifier/sync_notifier_observer.h
diff --git a/sync/notifier/sync_notifier_observer.h b/sync/notifier/sync_notifier_observer.h
index 06855287477fb6e59df981f626bc06b569dd2fb4..2ca07c8633605f54c0f935d6de3171c97a21b938 100644
--- a/sync/notifier/sync_notifier_observer.h
+++ b/sync/notifier/sync_notifier_observer.h
@@ -6,9 +6,8 @@
 #define SYNC_NOTIFIER_SYNC_NOTIFIER_OBSERVER_H_
 #pragma once
 
-#include <string>
-
 #include "sync/internal_api/public/syncable/model_type_payload_map.h"
+#include "sync/notifier/sync_notifier_state.h"
 
 namespace sync_notifier {
 
@@ -24,7 +23,8 @@ class SyncNotifierObserver {
   virtual void OnIncomingNotification(
       const syncable::ModelTypePayloadMap& type_payloads,
       IncomingNotificationSource source) = 0;
-  virtual void OnNotificationStateChange(bool notifications_enabled) = 0;
+  virtual void OnSyncNotifierStateChange(
+      SyncNotifierState sync_notifier_state) = 0;
 
  protected:
   virtual ~SyncNotifierObserver() {}