[Sync] Introduce ModelError for USS error handling.

components/sync/device_info/device_info_sync_bridge.h

 // Copyright 2015 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 COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_BRIDGE_H_
 #define COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_BRIDGE_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "components/sync/device_info/device_info_tracker.h"
 #include "components/sync/device_info/local_device_info_provider.h"
 #include "components/sync/model/model_type_store.h"
 #include "components/sync/model/model_type_sync_bridge.h"
 
 namespace sync_pb {
 class DeviceInfoSpecifics;
 }  // namespace sync_pb
 
 namespace syncer {
 
-class SyncError;
-
 // Sync bridge implementation for DEVICE_INFO model type. Handles storage of
 // device info and associated sync metadata, applying/merging foreign changes,
 // and allows public read access.
 class DeviceInfoSyncBridge : public ModelTypeSyncBridge,
                              public DeviceInfoTracker {
  public:
   typedef base::Callback<void(const ModelTypeStore::InitCallback& callback)>
       StoreFactoryFunction;
 
   DeviceInfoSyncBridge(LocalDeviceInfoProvider* local_device_info_provider,
                        const StoreFactoryFunction& callback,
                        const ChangeProcessorFactory& change_processor_factory);
   ~DeviceInfoSyncBridge() override;
 
   // ModelTypeSyncBridge implementation.
   std::unique_ptr<MetadataChangeList> CreateMetadataChangeList() override;
-  SyncError MergeSyncData(
+  ModelError MergeSyncData(
       std::unique_ptr<MetadataChangeList> metadata_change_list,
       EntityDataMap entity_data_map) override;
-  SyncError ApplySyncChanges(
+  ModelError ApplySyncChanges(
       std::unique_ptr<MetadataChangeList> metadata_change_list,
       EntityChangeList entity_changes) override;
   void GetData(StorageKeyList storage_keys, DataCallback callback) override;
   void GetAllData(DataCallback callback) override;
   std::string GetClientTag(const EntityData& entity_data) override;
   std::string GetStorageKey(const EntityData& entity_data) override;
   void DisableSync() override;
 
   // DeviceInfoTracker implementation.
   bool IsSyncing() const override;
@@ skipping 23 matching lines @@
   void NotifyObservers();
 
   // Used as callback given to LocalDeviceInfoProvider.
   void OnProviderInitialized();
 
   // Methods used as callbacks given to DataTypeStore.
   void OnStoreCreated(ModelTypeStore::Result result,
                       std::unique_ptr<ModelTypeStore> store);
   void OnReadAllData(ModelTypeStore::Result result,
                      std::unique_ptr<ModelTypeStore::RecordList> record_list);
-  void OnReadAllMetadata(SyncError error,
+  void OnReadAllMetadata(ModelError error,
                          std::unique_ptr<MetadataBatch> metadata_batch);
   void OnCommit(ModelTypeStore::Result result);
 
   // Load metadata if the data is loaded and the provider is initialized.
   void LoadMetadataIfReady();
 
   // Performs reconciliation between the locally provided device info and the
   // stored device info data. If the sets of data differ, then we consider this
   // a local change and we send it to the processor.
   void ReconcileLocalAndStored();
 
   // Stores the updated version of the local copy of device info in durable
   // storage, in memory, and informs sync of the change. Should not be called
   // before the provider and processor have initialized.
   void SendLocalData();
 
   // Persists the changes in the given aggregators and notifies observers if
   // indicated to do as such.
   void CommitAndNotify(std::unique_ptr<ModelTypeStore::WriteBatch> batch,
                        bool should_notify);
 
   // Counts the number of active devices relative to |now|. The activeness of a
   // device depends on the amount of time since it was updated, which means
   // comparing it against the current time. |now| is passed into this method to
   // allow unit tests to control expected results.
   int CountActiveDevices(const base::Time now) const;
 
-  // Report an error starting up to sync if it tries to connect to this
-  // datatype, since these errors prevent us from knowing if sync is enabled.
-  void ReportStartupErrorToSync(const std::string& msg);
-
   // |local_device_info_provider_| isn't owned.
   const LocalDeviceInfoProvider* const local_device_info_provider_;
 
   ClientIdToSpecifics all_data_;
 
   // Registered observers, not owned.
   base::ObserverList<Observer, true> observers_;
 
   // Used to listen for provider initialization. If the provider is already
   // initialized during our constructor then the subscription is never used.
   std::unique_ptr<LocalDeviceInfoProvider::Subscription> subscription_;
 
   // In charge of actually persiting changes to disk, or loading previous data.
   std::unique_ptr<ModelTypeStore> store_;
 
   // If |local_device_info_provider_| has initialized.
   bool has_provider_initialized_ = false;
   // If data has been loaded from the store.
   bool has_data_loaded_ = false;
 
   // Used to update our local device info once every pulse interval.
   base::OneShotTimer pulse_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceInfoSyncBridge);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_BRIDGE_H_