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

base/task_scheduler/task.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/task.h"
 
 namespace base {
 namespace internal {
 
 Task::Task(const tracked_objects::Location& posted_from,
            const Closure& task,
            const TaskTraits& traits,
            const TimeDelta& delay)
     : PendingTask(posted_from,
                   task,
                   delay.is_zero() ? TimeTicks() : TimeTicks::Now() + delay,
                   false),  // Not nestable.
       // Prevent a delayed BLOCK_SHUTDOWN task from blocking shutdown before
       // being scheduled by changing its shutdown behavior to SKIP_ON_SHUTDOWN.
       traits(!delay.is_zero() &&
                      traits.shutdown_behavior() ==
                          TaskShutdownBehavior::BLOCK_SHUTDOWN
                  ? TaskTraits(traits).WithShutdownBehavior(
                        TaskShutdownBehavior::SKIP_ON_SHUTDOWN)
-                 : traits) {}
+                 : traits),
+      delay(delay) {}
 
 Task::~Task() = default;
 
 }  // namespace internal
 }  // namespace base