| // Copyright 2018 The Chromium Authors. All rights reserved. | 
 | // Use of this source code is governed by a BSD-style license that can be | 
 | // found in the LICENSE file. | 
 |  | 
 | #ifndef BASE_TASK_SCHEDULER_SCHEDULER_WORKER_OBSERVER_H_ | 
 | #define BASE_TASK_SCHEDULER_SCHEDULER_WORKER_OBSERVER_H_ | 
 |  | 
 | namespace base { | 
 |  | 
 | // Interface to observe entry and exit of the main function of a TaskScheduler | 
 | // worker. | 
 | class SchedulerWorkerObserver { | 
 |  public: | 
 |   virtual ~SchedulerWorkerObserver() = default; | 
 |  | 
 |   // Invoked at the beginning of the main function of a TaskScheduler worker, | 
 |   // before any task runs. | 
 |   virtual void OnSchedulerWorkerMainEntry() = 0; | 
 |  | 
 |   // Invoked at the end of the main function of a TaskScheduler worker, when it | 
 |   // can no longer run tasks. | 
 |   virtual void OnSchedulerWorkerMainExit() = 0; | 
 | }; | 
 |  | 
 | }  // namespace base | 
 |  | 
 | #endif  // BASE_TASK_SCHEDULER_SCHEDULER_WORKER_OBSERVER_H_ |