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