Use CreateAndSetDefaultTaskScheduler() in ScopedTaskScheduler.

A TaskScheduler created by CreateAndSetSimpleTaskScheduler() can't
be joined.

TBR=gab@chromium.org,danakj@chromium.org
BUG=553459

Review-Url: https://codereview.chromium.org/2528173002
Cr-Commit-Position: refs/heads/master@{#434538}

base/test/scoped_task_scheduler.cc

@@ -4,7 +4,13 @@
 
 #include "base/test/scoped_task_scheduler.h"
 
+#include <vector>
+
+#include "base/bind.h"
+#include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/task_scheduler.h"
+#include "base/threading/platform_thread.h"
+#include "base/time/time.h"
 
 namespace base {
 namespace test {
@@ -14,7 +20,15 @@ ScopedTaskScheduler::ScopedTaskScheduler() {
 
   // Create a TaskScheduler with a single thread to make tests deterministic.
   constexpr int kMaxThreads = 1;
-  TaskScheduler::CreateAndSetSimpleTaskScheduler(kMaxThreads);
+  std::vector<SchedulerWorkerPoolParams> worker_pool_params_vector;
+  worker_pool_params_vector.emplace_back(
+      "Simple", ThreadPriority::NORMAL,
+      SchedulerWorkerPoolParams::IORestriction::ALLOWED,
+      SchedulerWorkerPoolParams::StandbyThreadPolicy::LAZY, kMaxThreads,
+      TimeDelta::Max());
+  TaskScheduler::CreateAndSetDefaultTaskScheduler(
+      worker_pool_params_vector,
+      Bind([](const TaskTraits&) -> size_t { return 0; }));
   task_scheduler_ = TaskScheduler::GetInstance();
 }