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

sync/notifier/invalidator_registrar.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_REGISTRAR_H_
 #define SYNC_NOTIFIER_INVALIDATOR_REGISTRAR_H_
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 37 matching lines @@
 
   // Returns the set of all IDs that are registered to some handler (even
   // handlers that have been unregistered).
   ObjectIdSet GetAllRegisteredIds() const;
 
   // Sorts incoming invalidations into a bucket for each handler and then
   // dispatches the batched invalidations to the corresponding handler.
   // Invalidations for IDs with no corresponding handler are dropped, as are
   // invalidations for handlers that are not added.
   void DispatchInvalidationsToHandlers(const ObjectIdStateMap& id_state_map,
-                                       IncomingNotificationSource source);
+                                       IncomingInvalidationSource source);
 
-  // Calls the given handler method for each handler that has registered IDs.
-  void EmitOnNotificationsEnabled();
-  void EmitOnNotificationsDisabled(NotificationsDisabledReason reason);
+  // Updates the invalidator state to the given one and then notifies
+  // all handlers.  Note that the order is important; handlers that
+  // call GetInvalidatorState() when notified will see the new state.
+  void UpdateInvalidatorState(InvalidatorState state);
+
+  // Returns the current invalidator state.  When called from within
+  // InvalidationHandler::OnInvalidatorStateChange(), this returns the
+  // updated state.
+  InvalidatorState GetInvalidatorState() const;
 
   bool IsHandlerRegisteredForTest(InvalidationHandler* handler) const;
 
   // Needed for death tests.
   void DetachFromThreadForTest();
 
  private:
   typedef std::map<invalidation::ObjectId, InvalidationHandler*,
                    ObjectIdLessThan>
       IdHandlerMap;
 
   InvalidationHandler* ObjectIdToHandler(const invalidation::ObjectId& id);
 
   base::ThreadChecker thread_checker_;
   ObserverList<InvalidationHandler> handlers_;
   IdHandlerMap id_to_handler_map_;
+  InvalidatorState state_;
 
   DISALLOW_COPY_AND_ASSIGN(InvalidatorRegistrar);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_INVALIDATOR_REGISTRAR_H_