Move throttling of background timers into the renderer scheduler

components/scheduler/renderer/renderer_scheduler_impl.h

 // Copyright 2014 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 COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 #define COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 
 #include "base/atomicops.h"
 #include "base/synchronization/lock.h"
 #include "components/scheduler/base/pollable_thread_safe_flag.h"
@@ skipping 64 matching lines @@
   double MonotonicallyIncreasingTimeSeconds() const override;
 
   // RenderWidgetSignals::Observer implementation:
   void SetAllRenderWidgetsHidden(bool hidden) override;
   void SetHasVisibleRenderWidgetWithTouchHandler(
       bool has_visible_render_widget_with_touch_handler) override;
 
   // 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();
+
   // Test helpers.
   SchedulerHelper* GetSchedulerHelperForTesting();
   TaskCostEstimator* GetLoadingTaskCostEstimatorForTesting();
   TaskCostEstimator* GetTimerTaskCostEstimatorForTesting();
   IdleTimeEstimator* GetIdleTimeEstimatorForTesting();
   base::TimeTicks CurrentIdleTaskDeadlineForTesting() const;
 
  private:
   friend class RendererSchedulerImplTest;
   friend class RendererSchedulerImplForTest;
@@ skipping 247 matching lines @@
 
   PollableThreadSafeFlag policy_may_need_update_;
   base::WeakPtrFactory<RendererSchedulerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererSchedulerImpl);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_