Worker: Introduce per-global-scope task scheduler

third_party/WebKit/Source/platform/scheduler/child/worker_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 "platform/scheduler/child/worker_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 74 matching lines @@
 
   // The lifetime could be radically different for different workers,
   // some workers could be short-lived (but last at least 1 sec in
   // Service Workers case) or could be around as long as the tab is open.
   UMA_HISTOGRAM_CUSTOM_TIMES(
       "WorkerThread.Runtime", delta, base::TimeDelta::FromSeconds(1),
       base::TimeDelta::FromDays(1), 50 /* bucket count */);
   helper_.Shutdown();
 }
 
+scoped_refptr<TaskQueue> WorkerSchedulerImpl::NewUnthrottledTaskRunner(
+    TaskQueue::QueueType queue_type) {
+  helper_.CheckOnValidThread();
+  // TODO: TimeDomain??

[Sami, 2017/04/10 16:58:10]

A real time time domain (i.e., nullptr) is fine for now. We'll probably look at
supporting virtual time on worker threads at some point.

[nhiroki, 2017/04/11 10:47:54]

Thank you for the information. Removed this comment.

+  scoped_refptr<TaskQueue> unthrottled_task_queue(
+      helper_.NewTaskQueue(TaskQueue::Spec(queue_type)
+                               .SetShouldMonitorQuiescence(true)
+                               .SetTimeDomain(nullptr)));
+  return unthrottled_task_queue;
+}
+
 SchedulerHelper* WorkerSchedulerImpl::GetSchedulerHelperForTesting() {
   return &helper_;
 }
 
 bool WorkerSchedulerImpl::CanEnterLongIdlePeriod(base::TimeTicks,
                                                  base::TimeDelta*) {
   return true;
 }
 
 base::TimeTicks WorkerSchedulerImpl::CurrentIdleTaskDeadlineForTesting() const {
   return idle_helper_.CurrentIdleTaskDeadline();
 }
 
 }  // namespace scheduler
 }  // namespace blink