Revert of Redirect the MessageLoop's task runner to the renderer scheduler

components/scheduler/child/nestable_task_runner_for_test.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 "components/scheduler/child/nestable_task_runner_for_test.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 
 namespace scheduler {
@@ skipping 45 matching lines @@
       base::Bind(&NestableTaskRunnerForTest::WrapTask,
                  weak_nestable_task_runner_ptr_, base::Owned(wrapped_task)),
       delay);
 }
 
 bool NestableTaskRunnerForTest::RunsTasksOnCurrentThread() const {
   return task_runner_->RunsTasksOnCurrentThread();
 }
 
 bool NestableTaskRunnerForTest::IsNested() const {
-  return false;
+  return is_nested_;
+}
+
+void NestableTaskRunnerForTest::SetNested(bool is_nested) {
+  is_nested_ = is_nested;
 }
 
 void NestableTaskRunnerForTest::AddTaskObserver(
     base::MessageLoop::TaskObserver* task_observer) {
   task_observers_.AddObserver(task_observer);
 }
 
 void NestableTaskRunnerForTest::RemoveTaskObserver(
     base::MessageLoop::TaskObserver* task_observer) {
   task_observers_.RemoveObserver(task_observer);
 }
 
 }  // namespace scheduler