Revert of Move throttling of background timers into the renderer scheduler

components/scheduler/renderer/renderer_scheduler_impl.h

Index: components/scheduler/renderer/renderer_scheduler_impl.h
diff --git a/components/scheduler/renderer/renderer_scheduler_impl.h b/components/scheduler/renderer/renderer_scheduler_impl.h
index d4025da53be109e0fba4a6a9580f27c1ec52751b..6fb097a19a77ede866d0145e0fc64b9b43b0d558 100644
--- a/components/scheduler/renderer/renderer_scheduler_impl.h
+++ b/components/scheduler/renderer/renderer_scheduler_impl.h
@@ -15,7 +15,6 @@
 #include "components/scheduler/renderer/render_widget_signals.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
 #include "components/scheduler/renderer/task_cost_estimator.h"
-#include "components/scheduler/renderer/throttling_helper.h"
 #include "components/scheduler/renderer/user_model.h"
 #include "components/scheduler/scheduler_export.h"
 
@@ -27,7 +26,6 @@
 
 namespace scheduler {
 class RenderWidgetSchedulingState;
-class ThrottlingHelper;
 
 class SCHEDULER_EXPORT RendererSchedulerImpl
     : public RendererScheduler,
@@ -84,26 +82,12 @@
   // TaskQueueManager::Observer implementation:
   void OnUnregisterTaskQueue(const scoped_refptr<TaskQueue>& queue) override;
 
-  // Returns a task runner where tasks run at the highest possible priority.
-  scoped_refptr<TaskQueue> ControlTaskRunner();
-
-  void RegisterTimeDomain(TimeDomain* time_domain);
-  void UnregisterTimeDomain(TimeDomain* time_domain);
-
   // Test helpers.
   SchedulerHelper* GetSchedulerHelperForTesting();
   TaskCostEstimator* GetLoadingTaskCostEstimatorForTesting();
   TaskCostEstimator* GetTimerTaskCostEstimatorForTesting();
   IdleTimeEstimator* GetIdleTimeEstimatorForTesting();
   base::TimeTicks CurrentIdleTaskDeadlineForTesting() const;
-
-  base::TickClock* tick_clock() const;
-
-  RealTimeDomain* real_time_domain() const {
-    return helper_.real_time_domain();
-  }
-
-  ThrottlingHelper* throttling_helper() { return &throttling_helper_; }
 
  private:
   friend class RendererSchedulerImplTest;
@@ -249,7 +233,6 @@
 
   SchedulerHelper helper_;
   IdleHelper idle_helper_;
-  ThrottlingHelper throttling_helper_;
   RenderWidgetSignals render_widget_scheduler_signals_;
 
   const scoped_refptr<TaskQueue> control_task_runner_;