content: Add RendererScheduler.

content/renderer/scheduler/single_thread_idle_task_runner.cc

+// Copyright 2014 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 "content/renderer/scheduler/single_thread_idle_task_runner.h"
+
+#include "base/location.h"
+
+namespace content {
+
+IdleTaskDeadlineSupplier::~IdleTaskDeadlineSupplier() {
+}
+
+SingleThreadIdleTaskRunner::SingleThreadIdleTaskRunner(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    base::WeakPtr<IdleTaskDeadlineSupplier> deadline_supplier)
+    : task_runner_(task_runner), deadline_supplier_(deadline_supplier) {

[alexclarke, 2014/10/27 17:35:29]

Maybe DCHECK that deadline_supplier is not null?

[rmcilroy, 2014/10/27 18:18:02]

Then it would fail with the NullRendererScheduler where I explicitly pass null
:).

+}
+
+SingleThreadIdleTaskRunner::~SingleThreadIdleTaskRunner() {
+}
+
+bool SingleThreadIdleTaskRunner::RunsTasksOnCurrentThread() const {
+  return task_runner_->RunsTasksOnCurrentThread();
+}
+
+void SingleThreadIdleTaskRunner::PostIdleTask(
+    const tracked_objects::Location& from_here,
+    const IdleTask& idle_task) {
+  task_runner_->PostTask(
+      from_here,
+      base::Bind(&SingleThreadIdleTaskRunner::RunTask, this, idle_task));
+}
+
+void SingleThreadIdleTaskRunner::RunTask(IdleTask idle_task) {
+  if (deadline_supplier_) {
+    idle_task.Run(deadline_supplier_->CurrentIdleTaskDeadline());
+  }
+}
+
+}  // namespace content