content: Add RendererScheduler.

content/renderer/scheduler/null_renderer_scheduler.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/null_renderer_scheduler.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop_proxy.h"
+
+namespace content {
+
+namespace {
+
+class NullIdleTaskRunner : public SingleThreadIdleTaskRunner {
+ public:
+  NullIdleTaskRunner(scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  void PostIdleTask(const tracked_objects::Location& from_here,
+                    const IdleTask& idle_task) override;
+
+ protected:
+  virtual ~NullIdleTaskRunner();
+};
+
+}  // namespace
+
+NullIdleTaskRunner::NullIdleTaskRunner(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    : SingleThreadIdleTaskRunner(task_runner,
+                                 base::WeakPtr<IdleTaskDeadlineSupplier>()) {
+}
+
+NullIdleTaskRunner::~NullIdleTaskRunner() {
+}
+
+void NullIdleTaskRunner::PostIdleTask(
+    const tracked_objects::Location& from_here,
+    const IdleTask& idle_task) {
+}
+
+NullRendererScheduler::NullRendererScheduler()
+    : task_runner_(base::MessageLoopProxy::current()),
+      idle_task_runner_(new NullIdleTaskRunner(task_runner_)) {
+}
+
+NullRendererScheduler::~NullRendererScheduler() {
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+NullRendererScheduler::DefaultTaskRunner() {
+  return task_runner_;
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+NullRendererScheduler::CompositorTaskRunner() {
+  return task_runner_;
+}
+
+scoped_refptr<SingleThreadIdleTaskRunner>
+NullRendererScheduler::IdleTaskRunner() {
+  return idle_task_runner_;
+}
+
+void NullRendererScheduler::WillBeginFrame(const cc::BeginFrameArgs& args) {

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

Do you get any compile warnings here?  I wonder if you need to remove args.

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

Nope, no warnings.  Unused arguments aren't don't get warnings like unused
locals AFAIK.

+}
+
+void NullRendererScheduler::DidCommitFrameToCompositor() {
+}
+
+void NullRendererScheduler::DidReceiveInputEvent() {
+}
+
+bool NullRendererScheduler::ShouldYieldForHighPriorityWork() {
+  return false;
+}
+
+void NullRendererScheduler::Shutdown() {
+}
+
+}  // namespace content