Ensure RenderViewHost is not shut down until a screenshot of the page is taken.

content/browser/renderer_host/render_view_host_impl.h

 // Copyright (c) 2012 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_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 212 matching lines @@
   virtual void SetWebUIProperty(const std::string& name,
                                 const std::string& value) OVERRIDE;
   virtual void Zoom(PageZoom zoom) OVERRIDE;
   virtual void SyncRendererPrefs() OVERRIDE;
   virtual void ToggleSpeechInput() OVERRIDE;
   virtual WebPreferences GetWebkitPreferences() OVERRIDE;
   virtual void UpdateWebkitPreferences(
       const WebPreferences& prefs) OVERRIDE;
   virtual void GetAudioOutputControllers(
       const GetAudioOutputControllersCallback& callback) const OVERRIDE;
+  virtual void CopyFromBackingStore(
+      const gfx::Rect& src_rect,
+      const gfx::Size& accelerated_dst_size,
+      const base::Callback<void(bool, const SkBitmap&)>& callback,
+      const SkBitmap::Config& bitmap_config) OVERRIDE;
 
 #if defined(OS_ANDROID)
   virtual void ActivateNearestFindResult(int request_id,
                                          float x,
                                          float y) OVERRIDE;
   virtual void RequestFindMatchRects(int current_version) OVERRIDE;
   virtual void DisableFullscreenEncryptedMediaPlayback() OVERRIDE;
 #endif
 
 #if defined(USE_MOJO)
   virtual void SetWebUIHandle(mojo::ScopedMessagePipeHandle handle) OVERRIDE;
 #endif
 
+  void CopyFromBackingStoreCallback(
+      const base::Callback<void(bool, const SkBitmap&)>& callback,
+      bool success,
+      const SkBitmap& bitmap);
+
   void set_delegate(RenderViewHostDelegate* d) {
     CHECK(d);  // http://crbug.com/82827
     delegate_ = d;
   }
 
   // Set up the RenderView child process. Virtual because it is overridden by
   // TestRenderViewHost. If the |frame_name| parameter is non-empty, it is used
   // as the name of the new top-level frame.
   // The |opener_route_id| parameter indicates which RenderView created this
   // (MSG_ROUTING_NONE if none). If |max_page_id| is larger than -1, the
@@ skipping 457 matching lines @@
   // Manages all the android mediaplayer objects and handling IPCs for video.
   scoped_ptr<BrowserMediaPlayerManager> media_player_manager_;
 #endif
 
   // Used to swap out or shutdown this RVH when the unload event is taking too
   // long to execute, depending on the number of active views in the
   // SiteInstance.
   // TODO(nasko): Move to RenderFrameHost, as this is per-frame state.
   scoped_ptr<TimeoutMonitor> unload_event_monitor_timeout_;
 
-  // Called after receiving the SwapOutACK when the RVH is in state pending
-  // shutdown. Also called if the unload timer times out.
+  // Called after receiving the SwapOutACK and completing outstanding copy
+  // requests when the RVH is in state pending shutdown. Also called if the
+  // unload timer times out.
   // TODO(nasko): Move to RenderFrameHost, as this is per-frame state.
   base::Closure pending_shutdown_on_swap_out_;
 
+  // Set to true if pending_shutdown_on_swap_out_ is not invoked upon receiving
+  // the SwapOutACK because of outstanding copy requests. In this case
+  // pending_shutdown_on_swap_out_ gets called when the copy requests complete.
+  bool pending_shutdown_on_copy_requests_done_;
+
+  // Stores the number of the outstanding copy requests (see
+  // CopyFromBackingStore()). If the host gets swapped out with outstanding copy
+  // requests, we delay its shutdown until the copy requests complete.
+  int copy_requests_;
+
   base::WeakPtrFactory<RenderViewHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_