- // Blocks until canceled. Signals |task_done_signal| when finished.
- void Run(base::WaitableEvent* task_done_signal);
+ // Blocks until canceled. Signals |task_done_signal| when finished (either
+ // via early cancel or cancel after start). Signals |task_start_signal| if
+ // and when the task starts successfully (which will not happen if the task
+ // was cancelled early).
+ void Run(base::WaitableEvent* task_start_signal,
+ base::WaitableEvent* task_done_signal);