chrome/renderer/prerender/prerender_helper.h

   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
  13 namespace 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.
  17 class PrerenderHelper
  18     : public content::RenderFrameObserver,
  19       public content::RenderFrameObserverTracker<PrerenderHelper> {
  20  public:
  21   explicit PrerenderHelper(content::RenderFrame* render_frame);
  22   ~PrerenderHelper() override;
  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   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_