[Sync] Print out notification state explicitly in about:sync

sync/internal_api/sync_manager_impl.h

Index: sync/internal_api/sync_manager_impl.h
diff --git a/sync/internal_api/sync_manager_impl.h b/sync/internal_api/sync_manager_impl.h
index bdbc223bb046dc8453d650f5b75f1aec30da0de6..ddb86b50e8e0abd88651d854f6ac557903d85794 100644
--- a/sync/internal_api/sync_manager_impl.h
+++ b/sync/internal_api/sync_manager_impl.h
@@ -20,6 +20,7 @@
 #include "sync/internal_api/js_sync_manager_observer.h"
 #include "sync/internal_api/public/sync_manager.h"
 #include "sync/js/js_backend.h"
+#include "sync/notifier/notifications_disabled_reason.h"
 #include "sync/notifier/sync_notifier_observer.h"
 #include "sync/syncable/directory_change_delegate.h"
 #include "sync/util/cryptographer.h"
@@ -297,10 +298,16 @@ class SyncManagerImpl : public SyncManager,
   void BindJsMessageHandler(
     const std::string& name, UnboundJsMessageHandler unbound_message_handler);
 
+  // Helper function used by OnNotifications{Enabled,Disabled}().
+  void OnNotificationStateChange(NotificationsDisabledReason reason);
+
   // Returned pointer is owned by the caller.
   static DictionaryValue* NotificationInfoToValue(
       const NotificationInfoMap& notification_info);
 
+  static std::string NotificationInfoToString(
+      const NotificationInfoMap& notification_info);
+
   // JS message handlers.
   JsArgList GetNotificationState(const JsArgList& args);
   JsArgList GetNotificationInfo(const JsArgList& args);
@@ -380,6 +387,8 @@ class SyncManagerImpl : public SyncManager,
 
   bool observing_ip_address_changes_;
 
+  NotificationsDisabledReason notifications_disabled_reason_;
+
   // Map used to store the notification info to be displayed in
   // about:sync page.
   NotificationInfoMap notification_info_map_;