1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_RENDERER_PRERENDER_PRERENDER_HELPER_H_
6#define CHROME_RENDERER_PRERENDER_PRERENDER_HELPER_H_
7
8#include "base/compiler_specific.h"
9#include "base/time/time.h"
10#include "content/public/renderer/render_frame_observer.h"
11#include "content/public/renderer/render_frame_observer_tracker.h"
12
13namespace prerender {
14
15// Helper class to track whether its RenderFrame is currently being prerendered.
16// Created when prerendering starts and deleted as soon as it stops.
17class PrerenderHelper
18    : public content::RenderFrameObserver,
19      public content::RenderFrameObserverTracker<PrerenderHelper> {
20 public:
21  explicit PrerenderHelper(content::RenderFrame* render_frame);
22  virtual ~PrerenderHelper();
23
24  // Returns true if |render_view| is currently prerendering.
25  static bool IsPrerendering(const content::RenderFrame* render_frame);
26
27 private:
28  // RenderViewObserver implementation
29  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
30
31  void OnSetIsPrerendering(bool is_prerendering);
32
33  DISALLOW_COPY_AND_ASSIGN(PrerenderHelper);
34};
35
36}  // namespace prerender
37
38#endif  // CHROME_RENDERER_PRERENDER_PRERENDER_HELPER_H_
39