Add an idle task to periodically sweep canceled delayed tasks

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

 // Copyright 2015 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.
 
 #include "platform/scheduler/child/scheduler_helper.h"
 
 #include "base/time/default_tick_clock.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "platform/scheduler/base/task_queue_impl.h"
@@ skipping 111 matching lines @@
     task_queue_manager_->RemoveTaskTimeObserver(task_time_observer);
 }
 
 void SchedulerHelper::SetObserver(Observer* observer) {
   CheckOnValidThread();
   observer_ = observer;
   DCHECK(task_queue_manager_);
   task_queue_manager_->SetObserver(this);
 }
 
+void SchedulerHelper::SweepCanceledDelayedTasks() {
+  CheckOnValidThread();
+  DCHECK(task_queue_manager_);
+  task_queue_manager_->SweepCanceledDelayedTasks();
+}
+
 RealTimeDomain* SchedulerHelper::real_time_domain() const {
   CheckOnValidThread();
   DCHECK(task_queue_manager_);
   return task_queue_manager_->real_time_domain();
 }
 
 void SchedulerHelper::RegisterTimeDomain(TimeDomain* time_domain) {
   CheckOnValidThread();
   DCHECK(task_queue_manager_);
   task_queue_manager_->RegisterTimeDomain(time_domain);
@@ skipping 19 matching lines @@
 }
 
 TaskQueue* SchedulerHelper::CurrentlyExecutingTaskQueue() const {
   if (!task_queue_manager_)
     return nullptr;
   return task_queue_manager_->currently_executing_task_queue();
 }
 
 }  // namespace scheduler
 }  // namespace blink