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

components/scheduler/base/task_queue_manager_perftest.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/base/task_queue_manager.h"
 
 #include "base/bind.h"
 #include "base/threading/thread.h"
-#include "components/scheduler/base/nestable_task_runner_for_test.h"
+#include "base/time/default_tick_clock.h"
 #include "components/scheduler/base/task_queue_impl.h"
+#include "components/scheduler/base/task_queue_manager_delegate_for_test.h"
 #include "components/scheduler/base/task_queue_selector.h"
 #include "components/scheduler/base/task_queue_sets.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/perf/perf_test.h"
 
 namespace scheduler {
 
 class TaskQueueManagerPerfTest : public testing::Test {
  public:
   TaskQueueManagerPerfTest()
       : num_queues_(0),
         max_tasks_in_flight_(0),
         num_tasks_in_flight_(0),
         num_tasks_to_post_(0),
         num_tasks_to_run_(0) {}
 
   void SetUp() override {
     if (base::ThreadTicks::IsSupported())
       base::ThreadTicks::WaitUntilInitialized();
   }
 
   void Initialize(size_t num_queues) {
     num_queues_ = num_queues;
     message_loop_.reset(new base::MessageLoop());
     manager_ = make_scoped_ptr(new TaskQueueManager(
-        NestableTaskRunnerForTest::Create(message_loop_->task_runner()),
+        TaskQueueManagerDelegateForTest::Create(
+            message_loop_->task_runner(),
+            make_scoped_ptr(new base::DefaultTickClock())),
         "fake.category", "fake.category", "fake.category.debug"));
     for (size_t i = 0; i < num_queues; i++)
       queues_.push_back(manager_->NewTaskQueue(TaskQueue::Spec("test")));
   }
 
   void TestDelayedTask() {
     if (--num_tasks_to_run_ == 0) {
       message_loop_->QuitWhenIdle();
     }
 
@@ skipping 90 matching lines @@
   max_tasks_in_flight_ = 200;
   Benchmark("run 10000 delayed tasks with eight queues",
             base::Bind(&TaskQueueManagerPerfTest::ResetAndCallTestDelayedTask,
                        base::Unretained(this), 10000));
 }
 
 // TODO(alexclarke): Add additional tests with different mixes of non-delayed vs
 // delayed tasks.
 
 }  // namespace scheduler