Adds a flag to support "Virtual Time" to the blink scheduler

components/scheduler/child/worker_scheduler.h

 // 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.
 
 #ifndef COMPONENTS_SCHEDULER_CHILD_WORKER_SCHEDULER_H_
 #define COMPONENTS_SCHEDULER_CHILD_WORKER_SCHEDULER_H_
 
 #include "base/message_loop/message_loop.h"
 #include "components/scheduler/child/child_scheduler.h"
 #include "components/scheduler/child/single_thread_idle_task_runner.h"
 #include "components/scheduler/scheduler_export.h"
 
 namespace base {
 class MessageLoop;
 }
 
 namespace scheduler {
-class SchedulerTaskRunnerDelegate;
+class SchedulerTqmDelegate;
 
 class SCHEDULER_EXPORT WorkerScheduler : public ChildScheduler {
  public:
   ~WorkerScheduler() override;
   static scoped_ptr<WorkerScheduler> Create(
-      scoped_refptr<SchedulerTaskRunnerDelegate> main_task_runner);
+      scoped_refptr<SchedulerTqmDelegate> main_task_runner);
 
   // Must be called before the scheduler can be used. Does any post construction
   // initialization needed such as initializing idle period detection.
   virtual void Init() = 0;
 
  protected:
   WorkerScheduler();
   DISALLOW_COPY_AND_ASSIGN(WorkerScheduler);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_CHILD_WORKER_SCHEDULER_H_