[Sync] Move //components/sync_driver to //components/sync/driver.

components/sync_driver/backend_migrator.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 COMPONENTS_SYNC_DRIVER_BACKEND_MIGRATOR_H_
-#define COMPONENTS_SYNC_DRIVER_BACKEND_MIGRATOR_H_
-
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "base/observer_list.h"
-#include "components/sync/base/model_type.h"
-#include "components/sync_driver/data_type_manager.h"
-
-namespace syncer {
-struct UserShare;
-}  // namespace syncer
-
-namespace sync_driver {
-class SyncService;
-}
-
-namespace browser_sync {
-
-// Interface for anything that wants to know when the migrator's state
-// changes.
-class MigrationObserver {
- public:
-  virtual void OnMigrationStateChange() = 0;
-
- protected:
-  virtual ~MigrationObserver();
-};
-
-// A class to perform migration of a datatype pursuant to the 'MIGRATION_DONE'
-// code in the sync protocol definition (protocol/sync.proto).
-class BackendMigrator {
- public:
-  enum State {
-    IDLE,
-    WAITING_TO_START,   // Waiting for previous configuration to finish.
-    DISABLING_TYPES,    // Exit criteria: SYNC_CONFIGURE_DONE for
-                        // enabled types _excluding_ |to_migrate_| and
-                        // empty download progress markers for types
-                        // in |to_migrate_|.
-    REENABLING_TYPES,   // Exit criteria: SYNC_CONFIGURE_DONE for enabled
-                        // types.
-  };
-
-  // TODO(akalin): Remove the dependency on |user_share|.
-  BackendMigrator(const std::string& name,
-                  syncer::UserShare* user_share,
-                  sync_driver::SyncService* service,
-                  sync_driver::DataTypeManager* manager,
-                  const base::Closure &migration_done_callback);
-  virtual ~BackendMigrator();
-
-  // Starts a sequence of events that will disable and reenable |types|.
-  void MigrateTypes(syncer::ModelTypeSet types);
-
-  void AddMigrationObserver(MigrationObserver* observer);
-  bool HasMigrationObserver(const MigrationObserver* observer) const;
-  void RemoveMigrationObserver(MigrationObserver* observer);
-
-  State state() const;
-
-  // Called from ProfileSyncService to notify us of configure done.
-  // Note: We receive these notificiations only when our state is not IDLE.
-  void OnConfigureDone(
-      const sync_driver::DataTypeManager::ConfigureResult& result);
-
-  // Returns the types that are currently pending migration (if any).
-  syncer::ModelTypeSet GetPendingMigrationTypesForTest() const;
-
- private:
-  void ChangeState(State new_state);
-
-  // Must be called only in state WAITING_TO_START.  If ready to
-  // start, meaning the data type manager is configured, calls
-  // RestartMigration() and returns true.  Otherwise, does nothing and
-  // returns false.
-  bool TryStart();
-
-  // Restarts migration, interrupting any existing migration.
-  void RestartMigration();
-
-  // Called by OnConfigureDone().
-  void OnConfigureDoneImpl(
-      const sync_driver::DataTypeManager::ConfigureResult& result);
-
-  const std::string name_;
-  syncer::UserShare* user_share_;
-  sync_driver::SyncService* service_;
-  sync_driver::DataTypeManager* manager_;
-
-  State state_;
-
-  base::ObserverList<MigrationObserver> migration_observers_;
-
-  syncer::ModelTypeSet to_migrate_;
-
-  base::Closure migration_done_callback_;
-
-  base::WeakPtrFactory<BackendMigrator> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(BackendMigrator);
-};
-
-}  // namespace browser_sync
-
-#endif  // COMPONENTS_SYNC_DRIVER_BACKEND_MIGRATOR_H_