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

components/scheduler/base/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/base/nestable_task_runner_for_test.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 
 namespace scheduler {
 
 // static
 scoped_refptr<NestableTaskRunnerForTest> NestableTaskRunnerForTest::Create(
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
-  return make_scoped_refptr(new NestableTaskRunnerForTest(task_runner));
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    scoped_ptr<base::TickClock> time_source) {
+  return make_scoped_refptr(
+      new NestableTaskRunnerForTest(task_runner, time_source.Pass()));
 }
 
 NestableTaskRunnerForTest::NestableTaskRunnerForTest(
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
-    : task_runner_(task_runner) {}
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    scoped_ptr<base::TickClock> time_source)
+    : task_runner_(task_runner), time_source_(time_source.Pass()) {}
 
 NestableTaskRunnerForTest::~NestableTaskRunnerForTest() {}
 
 bool NestableTaskRunnerForTest::PostDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
   return task_runner_->PostDelayedTask(from_here, task, delay);
 }
 
 bool NestableTaskRunnerForTest::PostNonNestableDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
   return task_runner_->PostNonNestableDelayedTask(from_here, task, delay);
 }
 
 bool NestableTaskRunnerForTest::RunsTasksOnCurrentThread() const {
   return task_runner_->RunsTasksOnCurrentThread();
 }
 
 bool NestableTaskRunnerForTest::IsNested() const {
   return false;
 }
 
+base::TimeTicks NestableTaskRunnerForTest::NowTicks() {
+  return time_source_->NowTicks();
+}
+
+void NestableTaskRunnerForTest::OnNoMoreWork() {}
+
 }  // namespace scheduler