[scheduler] Implement time-based cpu throttling.

third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
index 71f4103a4b82445237f6de8c6352580d25c34611..016ea609f468449db0d039385b005a4298e7b0e2 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
@@ -149,6 +149,8 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   bool IsQueueEnabled() const override;
   bool IsEmpty() const override;
   bool HasPendingImmediateWork() const override;
+  base::Optional<base::TimeTicks> GetNextScheduledWakeUp() override;
+  base::Optional<base::TimeTicks> GetNextTaskRunTime() override;
   void SetQueuePriority(QueuePriority priority) override;
   QueuePriority GetQueuePriority() const override;
   void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer) override;
@@ -293,6 +295,9 @@ class BLINK_PLATFORM_EXPORT TaskQueueImpl final : public TaskQueue {
   static void TaskAsValueInto(const Task& task,
                               base::trace_event::TracedValue* state);
 
+  // Same as public version, but uses given LazyNow.
+  bool HasPendingImmediateWork(LazyNow* lazy_now) const;
+
   const base::PlatformThreadId thread_id_;
 
   mutable base::Lock any_thread_lock_;