scheduler: Throttle timers in out-of-view frames

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/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 212 matching lines @@
       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());
   }
   timer_task_queue->AddTaskObserver(
       &MainThreadOnly().timer_task_cost_estimator);
   return timer_task_queue;
 }
 
+scoped_refptr<TaskQueue> RendererSchedulerImpl::NewDefaultTaskRunner(
+    const char* name) {
+  helper_.CheckOnValidThread();
+  scoped_refptr<TaskQueue> default_task_queue(helper_.NewTaskQueue(
+      TaskQueue::Spec(name).SetShouldMonitorQuiescence(true)));
+  return default_task_queue;
+}
+
 std::unique_ptr<RenderWidgetSchedulingState>
 RendererSchedulerImpl::NewRenderWidgetSchedulingState() {
   return render_widget_scheduler_signals_.NewRenderWidgetSchedulingState();
 }
 
 void RendererSchedulerImpl::OnUnregisterTaskQueue(
     const scoped_refptr<TaskQueue>& task_queue) {
   if (throttling_helper_.get())
     throttling_helper_->UnregisterTaskQueue(task_queue.get());
 
@@ skipping 1099 matching lines @@
     BroadcastConsoleWarning(
         "Blink deferred a task in order to make scrolling smoother. "
         "Your timer and network tasks should take less than 50ms to run "
         "to avoid this. Please see "
         "https://developers.google.com/web/tools/chrome-devtools/profile/evaluate-performance/rail"
         " and https://crbug.com/574343#c40 for more information.");
   }
 }
 
 }  // namespace scheduler