**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
"""Form widget used to display connection"""
    field_behaviours = json.dumps(ProvidersManager().field_behaviours)
class ConnectionModelView(AirflowModelView):
    """View to show records from Connections table"""
    route_base = '/connection'
    datamodel = AirflowModelView.CustomSQLAInterface(Connection)  
    class_permission_name = permissions.RESOURCE_CONNECTION
    method_permission_name = {
        'add': 'create',
        'list': 'read',
        'edit': 'edit',
        'delete': 'delete',
        'action_muldelete': 'delete',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]
    extra_fields = list(ProvidersManager().connection_form_widgets.keys())
    list_columns = [
        'conn_id',
        'conn_type',
        'description',
        'host',
        'port',
        'is_encrypted',
        'is_extra_encrypted',