Implement PostDelayedTaskAt for guaranteed timer ordering

components/scheduler/renderer/renderer_scheduler_impl.cc

 // 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.
 
 #include "components/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/output/begin_frame_args.h"
 #include "components/scheduler/child/nestable_single_thread_task_runner.h"
 #include "components/scheduler/child/prioritizing_task_queue_selector.h"
+#include "components/scheduler/child/task_queue.h"
 
 namespace scheduler {
 
 RendererSchedulerImpl::RendererSchedulerImpl(
     scoped_refptr<NestableSingleThreadTaskRunner> main_task_runner)
     : helper_(main_task_runner,
               "renderer.scheduler",
               TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
               TRACE_DISABLED_BY_DEFAULT("renderer.scheduler.debug"),
               TASK_QUEUE_COUNT),
@@ skipping 58 matching lines @@
 }
 
 RendererSchedulerImpl::CompositorThreadOnly::~CompositorThreadOnly() {
 }
 
 void RendererSchedulerImpl::Shutdown() {
   helper_.Shutdown();
   MainThreadOnly().was_shutdown_ = true;
 }
 
-scoped_refptr<base::SingleThreadTaskRunner>
-RendererSchedulerImpl::DefaultTaskRunner() {
+scoped_refptr<TaskQueue> RendererSchedulerImpl::DefaultTaskRunner() {
   return helper_.DefaultTaskRunner();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 RendererSchedulerImpl::CompositorTaskRunner() {
   helper_.CheckOnValidThread();
   return compositor_task_runner_;
 }
 
 scoped_refptr<SingleThreadIdleTaskRunner>
 RendererSchedulerImpl::IdleTaskRunner() {
   return idle_helper_.IdleTaskRunner();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 RendererSchedulerImpl::LoadingTaskRunner() {
   helper_.CheckOnValidThread();
   return loading_task_runner_;
 }
 
-scoped_refptr<base::SingleThreadTaskRunner>
-RendererSchedulerImpl::TimerTaskRunner() {
+scoped_refptr<TaskQueue> RendererSchedulerImpl::TimerTaskRunner() {
   helper_.CheckOnValidThread();
   return timer_task_runner_;
 }
 
 bool RendererSchedulerImpl::CanExceedIdleDeadlineIfRequired() const {
   return idle_helper_.CanExceedIdleDeadlineIfRequired();
 }
 
 void RendererSchedulerImpl::AddTaskObserver(
     base::MessageLoop::TaskObserver* task_observer) {
@@ skipping 573 matching lines @@
   UpdatePolicyLocked(UpdateType::MAY_EARLY_OUT_IF_POLICY_UNCHANGED);
 }
 
 bool RendererSchedulerImpl::HadAnIdlePeriodRecently(base::TimeTicks now) const {
   return (now - AnyThread().last_idle_period_end_time_) <=
          base::TimeDelta::FromMilliseconds(
              kIdlePeriodStarvationThresholdMillis);
 }
 
 }  // namespace scheduler