JoinForTesting() in ScopedAsyncTaskScheduler.

base/test/scoped_async_task_scheduler.cc

 // Copyright 2017 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/test/scoped_async_task_scheduler.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/task_scheduler.h"
+#include "base/task_scheduler/task_scheduler_impl.h"
 
 namespace base {
 namespace test {
 
 ScopedAsyncTaskScheduler::ScopedAsyncTaskScheduler() {
   DCHECK(!TaskScheduler::GetInstance());
   constexpr int kMaxThreads = 1;
   const TimeDelta kSuggestedReclaimTime = TimeDelta::Max();
   std::vector<SchedulerWorkerPoolParams> worker_pool_params_vector;
   worker_pool_params_vector.emplace_back(
       "ScopedAsyncTaskScheduler", ThreadPriority::NORMAL,
       SchedulerWorkerPoolParams::StandbyThreadPolicy::LAZY, kMaxThreads,
       kSuggestedReclaimTime);
   TaskScheduler::CreateAndSetDefaultTaskScheduler(
       worker_pool_params_vector,
       Bind([](const TaskTraits&) -> size_t { return 0; }));
   task_scheduler_ = TaskScheduler::GetInstance();
 }
 
 ScopedAsyncTaskScheduler::~ScopedAsyncTaskScheduler() {
   DCHECK_EQ(TaskScheduler::GetInstance(), task_scheduler_);
   TaskScheduler::GetInstance()->Shutdown();
+  static_cast<internal::TaskSchedulerImpl*>(TaskScheduler::GetInstance())
+      ->JoinForTesting();
   TaskScheduler::SetInstance(nullptr);
 }
 
 }  // namespace test
 }  // namespace base