|  | // 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_ |