TaskScheduler: Replace the SchedulerServiceThread with a base::Thread.

base/task_scheduler/scheduler_worker_pool_impl.h

Index: base/task_scheduler/scheduler_worker_pool_impl.h
diff --git a/base/task_scheduler/scheduler_worker_pool_impl.h b/base/task_scheduler/scheduler_worker_pool_impl.h
index a621f797a53473b2096170a07689e456d5c3f2de..6ce3f1b4c569a1827755f9dfead17e9c61f60c7f 100644
--- a/base/task_scheduler/scheduler_worker_pool_impl.h
+++ b/base/task_scheduler/scheduler_worker_pool_impl.h
@@ -39,7 +39,6 @@ class TimeDelta;
 
 namespace internal {
 
-class DelayedTaskManager;
 class TaskTracker;
 
 // A pool of workers that run Tasks. This class is thread-safe.
@@ -57,14 +56,14 @@ class BASE_EXPORT SchedulerWorkerPoolImpl : public SchedulerWorkerPool {
   // Creates a SchedulerWorkerPoolImpl following the |worker_pool_params|
   // specification. |re_enqueue_sequence_callback| will be invoked after a
   // worker of this worker pool tries to run a Task. |task_tracker| is used to
-  // handle shutdown behavior of Tasks. |delayed_task_manager| handles Tasks
-  // posted with a delay. Returns nullptr on failure to create a worker pool
-  // with at least one thread.
+  // handle shutdown behavior of Tasks. |service_thread_task_runner| handles
+  // Tasks posted with a delay. Returns nullptr on failure to create a worker
+  // pool with at least one thread.
   static std::unique_ptr<SchedulerWorkerPoolImpl> Create(
       const SchedulerWorkerPoolParams& params,
       const ReEnqueueSequenceCallback& re_enqueue_sequence_callback,
       TaskTracker* task_tracker,
-      DelayedTaskManager* delayed_task_manager);
+      scoped_refptr<TaskRunner> service_thread_task_runner);
 
   // Waits until all workers are idle.
   void WaitForAllWorkersIdleForTesting();
@@ -89,7 +88,8 @@ class BASE_EXPORT SchedulerWorkerPoolImpl : public SchedulerWorkerPool {
                          const SequenceSortKey& sequence_sort_key) override;
   bool PostTaskWithSequence(std::unique_ptr<Task> task,
                             scoped_refptr<Sequence> sequence,
-                            SchedulerWorker* worker) override;
+                            SchedulerWorker* worker,
+                            TimeDelta delay) override;
   void PostTaskWithSequenceNow(std::unique_ptr<Task> task,
                                scoped_refptr<Sequence> sequence,
                                SchedulerWorker* worker) override;
@@ -102,12 +102,12 @@ class BASE_EXPORT SchedulerWorkerPoolImpl : public SchedulerWorkerPool {
   class SchedulerSingleThreadTaskRunner;
   class SchedulerWorkerDelegateImpl;
 
-  SchedulerWorkerPoolImpl(StringPiece name,
-                          SchedulerWorkerPoolParams::IORestriction
-                              io_restriction,
-                          const TimeDelta& suggested_reclaim_time,
-                          TaskTracker* task_tracker,
-                          DelayedTaskManager* delayed_task_manager);
+  SchedulerWorkerPoolImpl(
+      StringPiece name,
+      SchedulerWorkerPoolParams::IORestriction io_restriction,
+      const TimeDelta& suggested_reclaim_time,
+      TaskTracker* task_tracker,
+      scoped_refptr<TaskRunner> service_thread_task_runner);
 
   bool Initialize(
       ThreadPriority priority_hint,
@@ -194,7 +194,7 @@ class BASE_EXPORT SchedulerWorkerPoolImpl : public SchedulerWorkerPool {
           {};
 
   TaskTracker* const task_tracker_;
-  DelayedTaskManager* const delayed_task_manager_;
+  const scoped_refptr<TaskRunner> service_thread_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerWorkerPoolImpl);
 };