Add an idle task to periodically sweep canceled delayed tasks

third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc

Index: third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc b/third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc
index e0935523d170340b5279f2e31a4e2b4443398b96..07a8e08a6356fde50b184800dfe5079245c6b572 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc
+++ b/third_party/WebKit/Source/platform/scheduler/child/idle_helper.cc
@@ -174,6 +174,9 @@ void IdleHelper::StartIdlePeriod(IdlePeriodState new_state,
   helper_->CheckOnValidThread();
   DCHECK(IsInIdlePeriod(new_state));
 
+  // Allow any ready delayed idle tasks to run.
+  idle_task_runner_->EnqueueReadyDelayedIdleTasks();
+
   base::TimeDelta idle_period_duration(idle_period_deadline - now);
   if (idle_period_duration <
       base::TimeDelta::FromMilliseconds(kMinimumIdlePeriodDurationMillis)) {
@@ -321,6 +324,10 @@ void IdleHelper::DidProcessIdleTask() {
   }
 }
 
+base::TimeTicks IdleHelper::NowTicks() {
+  return helper_->scheduler_tqm_delegate()->NowTicks();
+}
+
 // static
 bool IdleHelper::IsInIdlePeriod(IdlePeriodState state) {
   return state != IdlePeriodState::NOT_IN_IDLE_PERIOD;