Always use TaskScheduler::InitParams to initialize a TaskScheduler.

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 247 matching lines @@
         num_wake_ups_before_start_ +
         (params.standby_thread_policy() ==
                  SchedulerWorkerPoolParams::StandbyThreadPolicy::ONE
              ? 1
              : 0);
 
     // Create workers in reverse order of index so that the worker with the
     // highest index is at the bottom of the idle stack.
     for (int index = params.max_threads() - 1; index >= 0; --index) {
       workers_[index] = make_scoped_refptr(new SchedulerWorker(
-          params.priority_hint(),
+          priority_hint_,
           MakeUnique<SchedulerWorkerDelegateImpl>(
               this, re_enqueue_sequence_callback_, index),
           task_tracker_, params.backward_compatibility(),
           index < num_alive_workers ? SchedulerWorker::InitialState::ALIVE
                                     : SchedulerWorker::InitialState::DETACHED));
 
       // Put workers that won't be woken up at the end of this method on the
       // idle stack.
       if (index >= num_wake_ups_before_start_)
         idle_workers_stack_.Push(workers_[index].get());
@@ skipping 330 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