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

base/task_scheduler/scheduler_worker_pool_impl.cc

 // 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.
 
 #include "base/task_scheduler/scheduler_worker_pool_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 392 matching lines @@
 void SchedulerWorkerPoolImpl::PostTaskWithSequenceNow(
     std::unique_ptr<Task> task,
     scoped_refptr<Sequence> sequence,
     SchedulerWorker* worker) {
   DCHECK(task);
   DCHECK(sequence);
   DCHECK(!worker || ContainsWorker(workers_, worker));
 
   // Confirm that |task| is ready to run (its delayed run time is either null or
   // in the past).
-  DCHECK_LE(task->delayed_run_time, delayed_task_manager_->Now());
+  DCHECK_LE(task->delayed_run_time, TimeTicks::Now());
 
   // Because |worker| belongs to this worker pool, we know that the type
   // of its delegate is SchedulerWorkerDelegateImpl.
   PriorityQueue* const priority_queue =
       worker
           ? static_cast<SchedulerWorkerDelegateImpl*>(worker->delegate())
                 ->single_threaded_priority_queue()
           : &shared_priority_queue_;
   DCHECK(priority_queue);
 
@@ skipping 332 matching lines @@
   AutoSchedulerLock auto_lock(idle_workers_stack_lock_);
   idle_workers_stack_.Remove(worker);
 }
 
 bool SchedulerWorkerPoolImpl::CanWorkerDetachForTesting() {
   return !worker_detachment_disallowed_.IsSet();
 }
 
 }  // namespace internal
 }  // namespace base