[content]: Add CanExceedIdleDeadlineIfRequired function to RendererScheduler.

content/renderer/scheduler/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 "content/renderer/scheduler/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 482 matching lines @@
   control_task_runner_->PostTask(
       FROM_HERE,
       initiate_next_long_idle_period_closure_.callback());
 }
 
 void RendererSchedulerImpl::StartIdlePeriod(IdlePeriodState new_state) {
   TRACE_EVENT_ASYNC_BEGIN0("renderer.scheduler",
                            "RendererSchedulerIdlePeriod", this);
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK(IsInIdlePeriod(new_state));
+
   renderer_task_queue_selector_->EnableQueue(
       IDLE_TASK_QUEUE, RendererTaskQueueSelector::BEST_EFFORT_PRIORITY);
   task_queue_manager_->PumpQueue(IDLE_TASK_QUEUE);
   idle_period_state_ = new_state;
 }
 
 void RendererSchedulerImpl::EndIdlePeriod() {
   DCHECK(main_thread_checker_.CalledOnValidThread());
 
   end_idle_period_closure_.Cancel();
@@ skipping 24 matching lines @@
 
   renderer_task_queue_selector_->DisableQueue(IDLE_TASK_QUEUE);
   idle_period_state_ = IdlePeriodState::NOT_IN_IDLE_PERIOD;
 }
 
 // static
 bool RendererSchedulerImpl::IsInIdlePeriod(IdlePeriodState state) {
   return state != IdlePeriodState::NOT_IN_IDLE_PERIOD;
 }
 
+bool RendererSchedulerImpl::CanExceedIdleDeadlineIfRequired() const {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  return idle_period_state_ ==

[Sami, 2015/03/05 19:18:07]

Could you add a trace event here so we can see if we should make this also look
at the current time as a follow-up to avoid overruns?

[rmcilroy, 2015/03/16 22:08:04]

Done.

+         IdlePeriodState::IN_LONG_IDLE_PERIOD_WITH_MAX_DEADLINE;
+}
+
 void RendererSchedulerImpl::SetTimeSourceForTesting(
     scoped_refptr<cc::TestNowSource> time_source) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   time_source_ = time_source;
   task_queue_manager_->SetTimeSourceForTesting(time_source);
 }
 
 void RendererSchedulerImpl::SetWorkBatchSizeForTesting(size_t work_batch_size) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   task_queue_manager_->SetWorkBatchSize(work_batch_size);
@@ skipping 164 matching lines @@
 }
 
 void RendererSchedulerImpl::RemoveTaskObserver(
     base::MessageLoop::TaskObserver* task_observer) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   if (task_queue_manager_)
     task_queue_manager_->RemoveTaskObserver(task_observer);
 }
 
 }  // namespace content