Worker: Introduce per-global-scope task scheduler

third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.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/worker_scheduler.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "platform/scheduler/child/scheduler_tqm_delegate.h"
 #include "platform/scheduler/child/worker_scheduler_impl.h"
 
 namespace blink {
 namespace scheduler {
 
-WorkerScheduler::WorkerScheduler() {}
+WorkerScheduler::WorkerScheduler(std::unique_ptr<SchedulerHelper> helper)
+    : helper_(std::move(helper)) {}
 
 WorkerScheduler::~WorkerScheduler() {}
 
 // static
 std::unique_ptr<WorkerScheduler> WorkerScheduler::Create(
     scoped_refptr<SchedulerTqmDelegate> main_task_runner) {
   return base::WrapUnique(new WorkerSchedulerImpl(std::move(main_task_runner)));
 }
 
+scoped_refptr<TaskQueue> WorkerScheduler::CreateUnthrottledTaskRunner(
+    TaskQueue::QueueType queue_type) {
+  helper_->CheckOnValidThread();
+  scoped_refptr<TaskQueue> unthrottled_task_queue(
+      helper_->NewTaskQueue(TaskQueue::Spec(queue_type)
+                                .SetShouldMonitorQuiescence(true)
+                                .SetTimeDomain(nullptr)));
+  return unthrottled_task_queue;
+}
+
 }  // namespace scheduler
 }  // namespace blink