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

content/browser/renderer_host/render_view_host_impl.h

Index: content/browser/renderer_host/render_view_host_impl.h
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 8aef8e532a81e989d0f32093bc8d7f709e020e8a..62e362045dfcb8cfd4a5273f98d4658ed98947e6 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -231,6 +231,16 @@ class CONTENT_EXPORT RenderViewHostImpl
       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;
+
+  void CopyFromBackingStoreCallback(

[nasko, 2014/03/26 22:48:27]

This isn't a RenderViewHost method override, so it shouldn't be mixed with the
rest of the overrides. 

[mfomitchev, 2014/03/27 21:51:34]

Done.

+      const base::Callback<void(bool, const SkBitmap&)>& callback,
+      bool success,
+      const SkBitmap& bitmap);
 
 #if defined(OS_ANDROID)
   virtual void ActivateNearestFindResult(int request_id,
@@ -726,6 +736,8 @@ class CONTENT_EXPORT RenderViewHostImpl
   // TODO(nasko): Move to RenderFrameHost, as this is per-frame state.
   base::Closure pending_shutdown_on_swap_out_;
 
+  int copy_requests_;

[nasko, 2014/03/26 22:48:27]

Please add a comment on what this is used for and why.

[mfomitchev, 2014/03/27 21:51:34]

Done.

+
   base::WeakPtrFactory<RenderViewHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);