[Sync] Refactoring polling to be reliable.

sync/internal_api/sync_rollback_manager_base.h

 // Copyright 2014 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_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 #define SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 23 matching lines @@
  public:
   SyncRollbackManagerBase();
   ~SyncRollbackManagerBase() override;
 
   // SyncManager implementation.
   ModelTypeSet InitialSyncEndedTypes() override;
   ModelTypeSet GetTypesWithEmptyProgressMarkerToken(
       ModelTypeSet types) override;
   bool PurgePartiallySyncedTypes() override;
   void UpdateCredentials(const SyncCredentials& credentials) override;
-  void StartSyncingNormally(const ModelSafeRoutingInfo& routing_info) override;
+  void StartSyncingNormally(const ModelSafeRoutingInfo& routing_info,
+                            base::Time last_poll_time) override;
   void ConfigureSyncer(ConfigureReason reason,
                        ModelTypeSet to_download,
                        ModelTypeSet to_purge,
                        ModelTypeSet to_journal,
                        ModelTypeSet to_unapply,
                        const ModelSafeRoutingInfo& new_routing_info,
                        const base::Closure& ready_task,
                        const base::Closure& retry_task) override;
   void SetInvalidatorEnabled(bool invalidator_enabled) override;
   void OnIncomingInvalidation(
@@ skipping 80 matching lines @@
   bool initialized_;
 
   base::WeakPtrFactory<SyncRollbackManagerBase> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncRollbackManagerBase);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_