Remove the |max_threads| argument from CreateAndSetSimpleTaskScheduler().

base/task_scheduler/task_scheduler.cc

Index: base/task_scheduler/task_scheduler.cc
diff --git a/base/task_scheduler/task_scheduler.cc b/base/task_scheduler/task_scheduler.cc
index 00ca4f15ce9c12b8f8f3331c314cdd7418bd6028..592d6f4a15ecb97f79f890cbd66ee9001c82f596 100644
--- a/base/task_scheduler/task_scheduler.cc
+++ b/base/task_scheduler/task_scheduler.cc
@@ -4,8 +4,11 @@
 
 #include "base/task_scheduler/task_scheduler.h"
 
+#include <algorithm>
+
 #include "base/bind.h"
 #include "base/logging.h"
+#include "base/sys_info.h"
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/task_scheduler_impl.h"
 #include "base/threading/platform_thread.h"
@@ -20,17 +23,21 @@ TaskScheduler* g_task_scheduler = nullptr;
 
 }  // namespace
 
+#if !defined(OS_NACL)
 // static
-void TaskScheduler::CreateAndSetSimpleTaskScheduler(int max_threads) {
+void TaskScheduler::CreateAndSetSimpleTaskScheduler(const std::string& name) {
+  constexpr int kMinNumThreads = 1;
   std::vector<SchedulerWorkerPoolParams> worker_pool_params_vector;
   worker_pool_params_vector.emplace_back(
-      "Simple", ThreadPriority::NORMAL,
-      SchedulerWorkerPoolParams::StandbyThreadPolicy::LAZY, max_threads,
+      name, ThreadPriority::NORMAL,
+      SchedulerWorkerPoolParams::StandbyThreadPolicy::LAZY,
+      std::max(kMinNumThreads, base::SysInfo::NumberOfProcessors()),
       TimeDelta::FromSeconds(30));
   CreateAndSetDefaultTaskScheduler(
       worker_pool_params_vector,
       Bind([](const TaskTraits&) -> size_t { return 0; }));
 }
+#endif  // !defined(OS_NACL)
 
 // static
 void TaskScheduler::CreateAndSetDefaultTaskScheduler(