Revert of Add ScopedTaskEnvironment::ExecutionControlMode.

base/task_scheduler/task_scheduler_impl.h

 // 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.
 
 #ifndef BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_
 #define BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string_piece.h"
 #include "base/synchronization/atomic_flag.h"
 #include "base/task_scheduler/delayed_task_manager.h"
 #include "base/task_scheduler/scheduler_single_thread_task_runner_manager.h"
 #include "base/task_scheduler/scheduler_worker_pool_impl.h"
 #include "base/task_scheduler/single_thread_task_runner_thread_mode.h"
 #include "base/task_scheduler/task_scheduler.h"
 #include "base/task_scheduler/task_tracker.h"
 #include "base/task_scheduler/task_traits.h"
 #include "base/threading/thread.h"
 #include "build/build_config.h"
 
 #if defined(OS_POSIX) && !defined(OS_NACL_SFI)
 #include "base/task_scheduler/task_tracker_posix.h"
 #endif
 
 namespace base {
 
 class HistogramBase;
 
 namespace internal {
 
 // Default TaskScheduler implementation. This class is thread-safe.
 class BASE_EXPORT TaskSchedulerImpl : public TaskScheduler {
  public:
-  using TaskTrackerType =
-#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
-      TaskTrackerPosix;
-#else
-      TaskTracker;
-#endif
-
-  // |name| is used to label threads and histograms. |task_tracker| can be used
-  // for tests that need more execution control. By default, you get the
-  // production TaskTracker.
-  explicit TaskSchedulerImpl(StringPiece name,
-                             std::unique_ptr<TaskTrackerType> task_tracker =
-                                 MakeUnique<TaskTrackerType>());
+  // |name| is used to label threads and histograms.
+  explicit TaskSchedulerImpl(StringPiece name);
   ~TaskSchedulerImpl() override;
 
   // TaskScheduler:
   void Start(const TaskScheduler::InitParams& init_params) override;
   void PostDelayedTaskWithTraits(const tracked_objects::Location& from_here,
                                  const TaskTraits& traits,
                                  OnceClosure task,
                                  TimeDelta delay) override;
   scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits(
       const TaskTraits& traits) override;
@@ skipping 14 matching lines @@
   void FlushForTesting() override;
   void JoinForTesting() override;
 
  private:
   // Returns the worker pool that runs Tasks with |traits|.
   SchedulerWorkerPoolImpl* GetWorkerPoolForTraits(
       const TaskTraits& traits) const;
 
   const std::string name_;
   Thread service_thread_;
-  const std::unique_ptr<TaskTrackerType> task_tracker_;
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
+  TaskTrackerPosix task_tracker_;
+#else
+  TaskTracker task_tracker_;
+#endif
   DelayedTaskManager delayed_task_manager_;
   SchedulerSingleThreadTaskRunnerManager single_thread_task_runner_manager_;
 
   // There are 4 SchedulerWorkerPoolImpl in this array to match the 4
   // SchedulerWorkerPoolParams in TaskScheduler::InitParams.
   std::unique_ptr<SchedulerWorkerPoolImpl> worker_pools_[4];
 
 #if DCHECK_IS_ON()
   // Set once JoinForTesting() has returned.
   AtomicFlag join_for_testing_returned_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(TaskSchedulerImpl);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_