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

components/scheduler/child/scheduler_tqm_delegate_impl.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/scheduler_tqm_delegate_impl.h"
+
+namespace scheduler {
+
+// static
+scoped_refptr<SchedulerTqmDelegateImpl> SchedulerTqmDelegateImpl::Create(
+    base::MessageLoop* message_loop,
+    scoped_ptr<base::TickClock> time_source) {
+  return make_scoped_refptr(
+      new SchedulerTqmDelegateImpl(message_loop, time_source.Pass()));
+}
+
+SchedulerTqmDelegateImpl::SchedulerTqmDelegateImpl(
+    base::MessageLoop* message_loop,
+    scoped_ptr<base::TickClock> time_source)
+    : message_loop_(message_loop),
+      message_loop_task_runner_(message_loop->task_runner()),
+      time_source_(time_source.Pass()) {}
+
+SchedulerTqmDelegateImpl::~SchedulerTqmDelegateImpl() {
+  RestoreDefaultTaskRunner();
+}
+
+void SchedulerTqmDelegateImpl::SetDefaultTaskRunner(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
+  message_loop_->SetTaskRunner(task_runner);
+}
+
+void SchedulerTqmDelegateImpl::RestoreDefaultTaskRunner() {
+  if (base::MessageLoop::current() == message_loop_)
+    message_loop_->SetTaskRunner(message_loop_task_runner_);
+}
+
+bool SchedulerTqmDelegateImpl::PostDelayedTask(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta delay) {
+  return message_loop_task_runner_->PostDelayedTask(from_here, task, delay);
+}
+
+bool SchedulerTqmDelegateImpl::PostNonNestableDelayedTask(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta delay) {
+  return message_loop_task_runner_->PostNonNestableDelayedTask(from_here, task,
+                                                               delay);
+}
+
+bool SchedulerTqmDelegateImpl::RunsTasksOnCurrentThread() const {
+  return message_loop_task_runner_->RunsTasksOnCurrentThread();
+}
+
+bool SchedulerTqmDelegateImpl::IsNested() const {
+  return message_loop_->IsNested();
+}
+
+base::TimeTicks SchedulerTqmDelegateImpl::NowTicks() {
+  return time_source_->NowTicks();
+}
+
+void SchedulerTqmDelegateImpl::OnNoMoreImmediateWork() {}
+
+}  // namespace scheduler