Clean up unload-related state after the ack is received.

content/browser/renderer_host/render_view_host.h

Index: content/browser/renderer_host/render_view_host.h
diff --git a/content/browser/renderer_host/render_view_host.h b/content/browser/renderer_host/render_view_host.h
index 114ad411f3a39fb8254195d2ca9f51c8ae2b1ac1..2e1e564a74053393a69fcd7a0fd193af376bec0c 100644
--- a/content/browser/renderer_host/render_view_host.h
+++ b/content/browser/renderer_host/render_view_host.h
@@ -179,6 +179,9 @@ class RenderViewHost : public RenderWidgetHost {
                  int new_render_process_host_id,
                  int new_request_id);
 
+  // Called by ResourceDispatcherHost after the ClosePageACK is received.
+  void OnClosePageACK(bool for_cross_site_transition);
+
   // Close the page ignoring whether it has unload events registers.
   // This is called after the beforeunload and unload events have fired
   // and the user has agreed to continue with closing the page.