Adds a flag to support "Virtual Time" to the blink 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 15 matching lines @@
 
 namespace scheduler {
 class RenderWidgetSchedulingState;
 
 class SCHEDULER_EXPORT RendererSchedulerImpl
     : public RendererScheduler,
       public IdleHelper::Delegate,
       public SchedulerHelper::Observer,
       public RenderWidgetSignals::Observer {
  public:
+  enum class TimeSource { NORMAL, VIRTUAL };
+
   RendererSchedulerImpl(
-      scoped_refptr<SchedulerTaskRunnerDelegate> main_task_runner);
+      scoped_refptr<SchedulerTaskRunnerDelegate> main_task_runner,
+      TimeSource time_source);
   ~RendererSchedulerImpl() override;
 
   // RendererScheduler implementation:
   scoped_refptr<TaskQueue> DefaultTaskRunner() override;
   scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner() override;
   scoped_refptr<base::SingleThreadTaskRunner> CompositorTaskRunner() override;
   scoped_refptr<base::SingleThreadTaskRunner> LoadingTaskRunner() override;
   scoped_refptr<TaskQueue> TimerTaskRunner() override;
   scoped_refptr<TaskQueue> NewLoadingTaskRunner(const char* name) override;
   scoped_refptr<TaskQueue> NewTimerTaskRunner(const char* name) override;
@@ skipping 16 matching lines @@
   bool IsHighPriorityWorkAnticipated() override;
   bool ShouldYieldForHighPriorityWork() override;
   bool CanExceedIdleDeadlineIfRequired() const override;
   void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer) override;
   void RemoveTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) override;
   void Shutdown() override;
   void SuspendTimerQueue() override;
   void ResumeTimerQueue() override;
   void SetTimerQueueSuspensionWhenBackgroundedEnabled(bool enabled) override;
+  double currentTime() const override;
+  double monotonicallyIncreasingTime() 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;
 
   // Test helpers.
@@ skipping 150 matching lines @@
   std::set<scoped_refptr<TaskQueue>> loading_task_runners_;
   std::set<scoped_refptr<TaskQueue>> timer_task_runners_;
   scoped_refptr<TaskQueue> default_loading_task_runner_;
   scoped_refptr<TaskQueue> default_timer_task_runner_;
 
   base::Closure update_policy_closure_;
   DeadlineTaskRunner delayed_update_policy_runner_;
   CancelableClosureHolder end_renderer_hidden_idle_period_closure_;
   CancelableClosureHolder suspend_timers_when_backgrounded_closure_;
 
+  const TimeSource time_source_;
+
   // We have decided to improve thread safety at the cost of some boilerplate
   // (the accessors) for the following data members.
 
   struct MainThreadOnly {
-    explicit MainThreadOnly(
-        const scoped_refptr<TaskQueue>& compositor_task_runner);
+    MainThreadOnly(const scoped_refptr<TaskQueue>& compositor_task_runner,
+                   base::TickClock* time_source);
     ~MainThreadOnly();
 
     TaskCostEstimator loading_task_cost_estimator;
     TaskCostEstimator timer_task_cost_estimator;
     IdleTimeEstimator idle_time_estimator;
     UseCase current_use_case;
     Policy current_policy;
     base::TimeTicks current_policy_expiration_time;
     base::TimeTicks estimated_next_frame_begin;
     base::TimeDelta compositor_frame_interval;
@@ skipping 73 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_