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 6fb097a19a77ede866d0145e0fc64b9b43b0d558..e08a089cf950a9e500291467a80b543afdc9ed17 100644
--- a/components/scheduler/renderer/renderer_scheduler_impl.h
+++ b/components/scheduler/renderer/renderer_scheduler_impl.h
@@ -15,6 +15,7 @@
 #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"
 
@@ -26,6 +27,7 @@ class ConvertableToTraceFormat;
 
 namespace scheduler {
 class RenderWidgetSchedulingState;
+class ThrottlingHelper;
 
 class SCHEDULER_EXPORT RendererSchedulerImpl
     : public RendererScheduler,
@@ -82,6 +84,12 @@ class SCHEDULER_EXPORT RendererSchedulerImpl
   // 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(const scoped_refptr<TimeDomain>& time_domain);
+  void UnregisterTimeDomain(const scoped_refptr<TimeDomain>& time_domain);
+
   // Test helpers.
   SchedulerHelper* GetSchedulerHelperForTesting();
   TaskCostEstimator* GetLoadingTaskCostEstimatorForTesting();
@@ -89,6 +97,14 @@ class SCHEDULER_EXPORT RendererSchedulerImpl
   IdleTimeEstimator* GetIdleTimeEstimatorForTesting();
   base::TimeTicks CurrentIdleTaskDeadlineForTesting() const;
 
+  base::TickClock* tick_clock() const;
+
+  const scoped_refptr<RealTimeDomain>& real_time_domain() const {
+    return helper_.real_time_domain();
+  }
+
+  ThrottlingHelper* throttling_helper() { return &throttling_helper_; }
+
  private:
   friend class RendererSchedulerImplTest;
   friend class RendererSchedulerImplForTest;
@@ -233,6 +249,7 @@ class SCHEDULER_EXPORT RendererSchedulerImpl
 
   SchedulerHelper helper_;
   IdleHelper idle_helper_;
+  ThrottlingHelper throttling_helper_;
   RenderWidgetSignals render_widget_scheduler_signals_;
 
   const scoped_refptr<TaskQueue> control_task_runner_;