TaskScheduler: Make SchedulerWorkerThread own its delegate.

base/task_scheduler/scheduler_worker_thread.h

 // Copyright 2016 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_THREAD_H_
 #define BASE_TASK_SCHEDULER_SCHEDULER_WORKER_THREAD_H_
 
 #include <memory>
 
 #include "base/base_export.h"
@@ skipping 35 matching lines @@
 
     // Called when |sequence| isn't empty after the SchedulerWorkerThread pops a
     // Task from it. |sequence| is the last Sequence returned by GetWork().
     virtual void EnqueueSequence(scoped_refptr<Sequence> sequence) = 0;
   };
 
   // Creates a SchedulerWorkerThread with priority |thread_priority| that runs
   // Tasks from Sequences returned by |delegate|. |task_tracker| is used to
   // handle shutdown behavior of Tasks. Returns nullptr if creating the
   // underlying platform thread fails.
-  static std::unique_ptr<SchedulerWorkerThread> CreateSchedulerWorkerThread(
+  static std::unique_ptr<SchedulerWorkerThread> CreateWorkerThread(
       ThreadPriority thread_priority,
-      Delegate* delegate,
+      std::unique_ptr<Delegate> delegate,
       TaskTracker* task_tracker);
 
   // Destroying a SchedulerWorkerThread in production is not allowed; it is
   // always leaked. In tests, it can only be destroyed after JoinForTesting()
   // has returned.
   ~SchedulerWorkerThread() override;
 
   // Wakes up this SchedulerWorkerThread if it wasn't already awake. After this
   // is called, this SchedulerWorkerThread will run Tasks from Sequences
   // returned by the GetWork() method of its delegate until it returns nullptr.
   void WakeUp();
 
   // Joins this SchedulerWorkerThread. If a Task is already running, it will be
   // allowed to complete its execution. This can only be called once.
   void JoinForTesting();
 
  private:
   SchedulerWorkerThread(ThreadPriority thread_priority,
-                        Delegate* delegate,
+                        std::unique_ptr<Delegate> delegate,
                         TaskTracker* task_tracker);
 
   // PlatformThread::Delegate:
   void ThreadMain() override;
 
   bool ShouldExitForTesting() const;
 
   // Platform thread managed by this SchedulerWorkerThread.
   PlatformThreadHandle thread_handle_;
 
   // Event signaled to wake up this SchedulerWorkerThread.
   WaitableEvent wake_up_event_;
 
-  Delegate* const delegate_;
+  const std::unique_ptr<Delegate> delegate_;
   TaskTracker* const task_tracker_;
 
   // Synchronizes access to |should_exit_for_testing_|.
   mutable SchedulerLock should_exit_for_testing_lock_;
 
   // True once JoinForTesting() has been called.
   bool should_exit_for_testing_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerWorkerThread);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_SCHEDULER_WORKER_THREAD_H_