AddMigrationObserver   60 chrome/browser/sync/backend_migrator.h   void AddMigrationObserver(MigrationObserver* observer);
AddMigrationObserver  125 chrome/browser/sync/backend_migrator_unittest.cc   migrator()->AddMigrationObserver(&migration_observer);
AddMigrationObserver   83 chrome/browser/sync/test/integration/migration_test.cc     migrator->AddMigrationObserver(this);