**Description**

For a DAG that looks like this:

```
A >> B
```

If A fails, B goes into "upstream_failed" state. If a user then marks A "success", B will remain in "upstream_failed" state. It will not automatically start running. This scenario often happens if the failure of A is dealt with outside of Airflow and the user does not want Airflow to run A again. But he usually expect Airflow to run B after A is marked "success".

**Use case / motivation**

After A is marked "success", its downstream tasks B should be cleared automatically and get ready to be scheduled. To avoid changing this behaviour completely, there can be a toggle button next to "Success" that lets the user decide if he wants Airflow to automatically clear downstream tasks that are in "upstream_failed" state.
airflow/www/views.py
status_count_paused = is_paused_count.get(True, 0)
            all_dags_count = status_count_active + status_count_paused
            if arg_status_filter == 'active':
                current_dags = active_dags
                num_of_all_dags = status_count_active
            elif arg_status_filter == 'paused':
                current_dags = paused_dags
                num_of_all_dags = status_count_paused
            else:
                current_dags = all_dags
                num_of_all_dags = all_dags_count
            dags = (
                current_dags.order_by(DagModel.dag_id)
                .options(joinedload(DagModel.tags))
                .offset(start)
                .limit(dags_per_page)
                .all()
            )
            user_permissions = current_app.appbuilder.sm.get_current_user_permissions()
            all_dags_editable = (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG) in user_permissions
            can_create_dag_run = (
                permissions.ACTION_CAN_CREATE,
                permissions.RESOURCE_DAG_RUN,
            ) in user_permissions
            can_delete_dag = (
                permissions.ACTION_CAN_DELETE,
                permissions.RESOURCE_DAG,
            ) in user_permissions
            for dag in dags:
                if all_dags_editable: