/**
 * Implements hook_field_storage_delete_instance().
 */
function {{ machine_name }}_field_storage_delete_instance($instance) {
  $field = field_info_field($instance['field_name']);
  $table_name = _field_sql_storage_tablename($field);
  $revision_name = _field_sql_storage_revision_tablename($field);
  db_update($table_name)
    ->fields(array('deleted' => 1))
    ->condition('entity_type', $instance['entity_type'])
    ->condition('bundle', $instance['bundle'])
    ->execute();
  db_update($revision_name)
    ->fields(array('deleted' => 1))
    ->condition('entity_type', $instance['entity_type'])
    ->condition('bundle', $instance['bundle'])
    ->execute();
}