[scheduler] Implement time-based cpu throttling.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
index babb10cae27e56de7bba049a0950a5a8d0b504da..c367d8f9c2f5f94db3be6ec57301c65627ea2326 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
@@ -86,7 +86,8 @@ RendererSchedulerImpl::RendererSchedulerImpl(
                         helper_.scheduler_tqm_delegate()->NowTicks()),
       policy_may_need_update_(&any_thread_lock_),
       weak_factory_(this) {
-  throttling_helper_.reset(new ThrottlingHelper(this, "renderer.scheduler"));
+  task_queue_throttler_.reset(
+      new TaskQueueThrottler(this, "renderer.scheduler"));
   update_policy_closure_ = base::Bind(&RendererSchedulerImpl::UpdatePolicy,
                                       weak_factory_.GetWeakPtr());
   end_renderer_hidden_idle_period_closure_.Reset(base::Bind(
@@ -199,7 +200,7 @@ void RendererSchedulerImpl::Shutdown() {
   MainThreadOnly().background_main_thread_load_tracker.RecordIdle(now);
   MainThreadOnly().foreground_main_thread_load_tracker.RecordIdle(now);
 
-  throttling_helper_.reset();
+  task_queue_throttler_.reset();
   helper_.Shutdown();
   MainThreadOnly().was_shutdown = true;
   MainThreadOnly().rail_mode_observer = nullptr;
@@ -252,7 +253,7 @@ scoped_refptr<TaskQueue> RendererSchedulerImpl::NewLoadingTaskRunner(
       MainThreadOnly().current_policy.loading_queue_policy.priority);
   if (MainThreadOnly().current_policy.loading_queue_policy.time_domain_type ==
       TimeDomainType::THROTTLED) {
-    throttling_helper_->IncreaseThrottleRefCount(loading_task_queue.get());
+    task_queue_throttler_->IncreaseThrottleRefCount(loading_task_queue.get());
   }
   loading_task_queue->AddTaskObserver(
       &MainThreadOnly().loading_task_cost_estimator);
@@ -277,7 +278,7 @@ scoped_refptr<TaskQueue> RendererSchedulerImpl::NewTimerTaskRunner(
       MainThreadOnly().current_policy.timer_queue_policy.priority);
   if (MainThreadOnly().current_policy.timer_queue_policy.time_domain_type ==
       TimeDomainType::THROTTLED) {
-    throttling_helper_->IncreaseThrottleRefCount(timer_task_queue.get());
+    task_queue_throttler_->IncreaseThrottleRefCount(timer_task_queue.get());
   }
   timer_task_queue->AddTaskObserver(
       &MainThreadOnly().timer_task_cost_estimator);
@@ -302,8 +303,8 @@ RendererSchedulerImpl::NewRenderWidgetSchedulingState() {
 
 void RendererSchedulerImpl::OnUnregisterTaskQueue(
     const scoped_refptr<TaskQueue>& task_queue) {
-  if (throttling_helper_.get())
-    throttling_helper_->UnregisterTaskQueue(task_queue.get());
+  if (task_queue_throttler_.get())
+    task_queue_throttler_->UnregisterTaskQueue(task_queue.get());
 
   if (loading_task_runners_.find(task_queue) != loading_task_runners_.end()) {
     task_queue->RemoveTaskObserver(
@@ -1027,8 +1028,8 @@ void RendererSchedulerImpl::ApplyTaskQueuePolicy(
     const TaskQueuePolicy& old_task_queue_policy,
     const TaskQueuePolicy& new_task_queue_policy) const {
   if (old_task_queue_policy.is_enabled != new_task_queue_policy.is_enabled) {
-    throttling_helper_->SetQueueEnabled(task_queue,
-                                        new_task_queue_policy.is_enabled);
+    task_queue_throttler_->SetQueueEnabled(task_queue,
+                                           new_task_queue_policy.is_enabled);
   }
 
   if (old_task_queue_policy.priority != new_task_queue_policy.priority)
@@ -1037,10 +1038,10 @@ void RendererSchedulerImpl::ApplyTaskQueuePolicy(
   if (old_task_queue_policy.time_domain_type !=
       new_task_queue_policy.time_domain_type) {
     if (old_task_queue_policy.time_domain_type == TimeDomainType::THROTTLED) {
-      throttling_helper_->DecreaseThrottleRefCount(task_queue);
+      task_queue_throttler_->DecreaseThrottleRefCount(task_queue);
     } else if (new_task_queue_policy.time_domain_type ==
                TimeDomainType::THROTTLED) {
-      throttling_helper_->IncreaseThrottleRefCount(task_queue);
+      task_queue_throttler_->IncreaseThrottleRefCount(task_queue);
     } else if (new_task_queue_policy.time_domain_type ==
                TimeDomainType::VIRTUAL) {
       DCHECK(virtual_time_domain_);
@@ -1461,22 +1462,25 @@ void RendererSchedulerImpl::OnTriedToExecuteBlockedTask(
   }
 }
 
-void RendererSchedulerImpl::ReportTaskTime(double start_time, double end_time) {
-  base::TimeTicks start_time_ticks =
-      MonotonicTimeInSecondsToTimeTicks(start_time);
-  base::TimeTicks end_time_ticks = MonotonicTimeInSecondsToTimeTicks(end_time);
+void RendererSchedulerImpl::ReportTaskTime(TaskQueue* task_queue,
+                                           base::TimeTicks start_time,
+                                           base::TimeTicks end_time) {
+  MainThreadOnly().queueing_time_estimator.OnToplevelTaskCompleted(start_time,
+                                                                   end_time);
+
+  task_queue_throttler()->OnTaskRunTimeReported(task_queue, start_time,
+                                                end_time);
 
-  MainThreadOnly().queueing_time_estimator.OnToplevelTaskCompleted(
-      start_time_ticks, end_time_ticks);
   // We want to measure thread time here, but for efficiency reasons
   // we stick with wall time.
   MainThreadOnly().foreground_main_thread_load_tracker.RecordTaskTime(
-      start_time_ticks, end_time_ticks);
+      start_time, end_time);
   MainThreadOnly().background_main_thread_load_tracker.RecordTaskTime(
-      start_time_ticks, end_time_ticks);
+      start_time, end_time);
   // TODO(altimin): Per-page metrics should also be considered.
+
   UMA_HISTOGRAM_CUSTOM_COUNTS("RendererScheduler.TaskTime",
-                              (end_time_ticks - start_time_ticks).InMicroseconds(), 1,
+                              (end_time - start_time).InMicroseconds(), 1,
                               1000000, 50);
 }
 
@@ -1516,7 +1520,7 @@ void RendererSchedulerImpl::EnableVirtualTime() {
   for (const scoped_refptr<TaskQueue>& task_queue : unthrottled_task_runners_)
     task_queue->SetTimeDomain(time_domain);
 
-  throttling_helper_->EnableVirtualTime();
+  task_queue_throttler_->EnableVirtualTime();
 
   ForceUpdatePolicy();
 }