Fix some migration-related bugs

chrome/browser/sync/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 CHROME_BROWSER_SYNC_BACKEND_MIGRATOR_H_
 #define CHROME_BROWSER_SYNC_BACKEND_MIGRATOR_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
@@ skipping 15 matching lines @@
 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 content::NotificationObserver {
+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,
                   sync_api::UserShare* user_share,
                   ProfileSyncService* service,
                   DataTypeManager* manager);
   virtual ~BackendMigrator();
 
   // Starts a sequence of events that will disable and reenable |types|.
   void MigrateTypes(syncable::ModelTypeSet types);
 
   void AddMigrationObserver(MigrationObserver* observer);
   bool HasMigrationObserver(MigrationObserver* observer) const;
   void RemoveMigrationObserver(MigrationObserver* observer);
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  State state() const;
 
-  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 DataTypeManager::ConfigureResult& result);
 
   // Returns the types that are currently pending migration (if any).
   syncable::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 Observe().
-  void OnConfigureDone(const DataTypeManager::ConfigureResult& result);
+  // Called by OnConfigureDone().
+  void OnConfigureDoneImpl(const DataTypeManager::ConfigureResult& result);
 
   const std::string name_;
   sync_api::UserShare* user_share_;
   ProfileSyncService* service_;
   DataTypeManager* manager_;
 
   State state_;
 
-  content::NotificationRegistrar registrar_;
-
   ObserverList<MigrationObserver> migration_observers_;
 
   syncable::ModelTypeSet to_migrate_;
 
   base::WeakPtrFactory<BackendMigrator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BackendMigrator);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_BACKEND_MIGRATOR_H_