Fix unresponsive tab closure when a navigation is in progress.

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 e22df0e989a6e5f428b81c5bd5aac65565ed585d..2e1d81f4c495980afaba938cd04338fefef9d83d 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -221,6 +221,9 @@ class CONTENT_EXPORT RenderViewHostImpl
     is_swapped_out_ = is_swapped_out;
   }
 
+  // TODO(creis): Remove as part of http://crbug.com/418265.
+  bool is_waiting_for_close_ack() const { return is_waiting_for_close_ack_; }
+
   // Tells the renderer that this RenderView will soon be swapped out, and thus
   // not to create any new modal dialogs until it happens.  This must be done
   // separately so that the PageGroupLoadDeferrers of any current dialogs are no