**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/models/dag.py
f'{DEFAULT_VIEW_PRESETS}, but get {default_view}'
            )
        if orientation in ORIENTATION_PRESETS:
            self.orientation = orientation
        else:
            raise AirflowException(
                f'Invalid values of dag.orientation: only support '
                f'{ORIENTATION_PRESETS}, but get {orientation}'
            )
        self.catchup = catchup
        self.is_subdag = False  
        self.partial = False
        self.on_success_callback = on_success_callback
        self.on_failure_callback = on_failure_callback
        
        
        
        self.edge_info: Dict[str, Dict[str, EdgeInfoType]] = {}
        
        
        self.has_on_success_callback = self.on_success_callback is not None
        self.has_on_failure_callback = self.on_failure_callback is not None
        self.doc_md = doc_md
        self._access_control = DAG._upgrade_outdated_dag_access_control(access_control)
        self.is_paused_upon_creation = is_paused_upon_creation
        self.jinja_environment_kwargs = jinja_environment_kwargs
        self.render_template_as_native_obj = render_template_as_native_obj
        self.tags = tags
        self._task_group = TaskGroup.create_root(self)
    def __repr__(self):