[content] Add support for Non nestable idle tasks the the RendererScheduler

content/renderer/scheduler/renderer_scheduler_message_loop_delegate.h

+// 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.
+
+#ifndef CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_MESSAGE_LOOP_DELEGATE_H_
+#define CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_MESSAGE_LOOP_DELEGATE_H_
+
+#include "base/message_loop/message_loop.h"
+#include "content/common/content_export.h"
+#include "content/renderer/scheduler/nestable_single_thread_task_runner.h"
+
+namespace content {
+
+class CONTENT_EXPORT RendererSchedulerMessageLoopDelegate
+    : public NestableSingleThreadTaskRunner {
+ public:
+  // |message_loop| is not owned and must outlive the lifetime of this object.
+  static scoped_refptr<RendererSchedulerMessageLoopDelegate> Create(
+      base::MessageLoop* message_loop);
+
+  // NestableSingleThreadTaskRunner implementation
+  bool PostDelayedTask(const tracked_objects::Location& from_here,
+                       const base::Closure& task,
+                       base::TimeDelta delay) override;
+  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
+                                  const base::Closure& task,
+                                  base::TimeDelta delay) override;
+  bool RunsTasksOnCurrentThread() const override;
+  bool IsNested() const override;
+
+ protected:
+  ~RendererSchedulerMessageLoopDelegate() override;
+
+ private:
+  RendererSchedulerMessageLoopDelegate(base::MessageLoop* message_loop);
+
+  // Not owned.
+  base::MessageLoop* message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererSchedulerMessageLoopDelegate);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_MESSAGE_LOOP_DELEGATE_H_