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

components/scheduler/child/scheduler_task_runner_delegate_for_test.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 CONTENT_RENDERER_SCHEDULER_TASK_RUNNER_DELEGATE_FOR_TEST_H_
-#define CONTENT_RENDERER_SCHEDULER_TASK_RUNNER_DELEGATE_FOR_TEST_H_
-
-#include "components/scheduler/child/scheduler_task_runner_delegate.h"
-
-namespace scheduler {
-
-class NestableTaskRunnerForTest;
-
-class SchedulerTaskRunnerDelegateForTest : public SchedulerTaskRunnerDelegate {
- public:
-  static scoped_refptr<SchedulerTaskRunnerDelegateForTest> Create(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-
-  // SchedulerTaskRunnerDelegate implementation
-  void SetDefaultTaskRunner(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner) override;
-  void RestoreDefaultTaskRunner() override;
-  bool PostDelayedTask(const tracked_objects::Location& from_here,
-                       const base::Closure& task,
-                       base::TimeDelta delay) override;
-  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
-                                  const base::Closure& task,
-                                  base::TimeDelta delay) override;
-  bool RunsTasksOnCurrentThread() const override;
-  bool IsNested() const override;
-
-  base::SingleThreadTaskRunner* default_task_runner() const {
-    return default_task_runner_.get();
-  }
-
- protected:
-  ~SchedulerTaskRunnerDelegateForTest() override;
-
- private:
-  explicit SchedulerTaskRunnerDelegateForTest(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-
-  scoped_refptr<base::SingleThreadTaskRunner> default_task_runner_;
-
-  scoped_refptr<NestableTaskRunnerForTest> task_runner_;
-
-  DISALLOW_COPY_AND_ASSIGN(SchedulerTaskRunnerDelegateForTest);
-};
-
-}  // namespace scheduler
-
-#endif  // CONTENT_RENDERER_SCHEDULER_SCHEDULER_TASK_RUNNER_DELEGATE_FOR_TEST_H_