RenderWidgetHostViewChildFrame's called a virtual in its ctor.

content/browser/web_contents/web_contents_view_guest.cc

Index: content/browser/web_contents/web_contents_view_guest.cc
diff --git a/content/browser/web_contents/web_contents_view_guest.cc b/content/browser/web_contents/web_contents_view_guest.cc
index 3f73a26259439d9412804dcb6a0d78175dc371ba..f7e452de43e1c33b13fc85cb6f0b3829464019e0 100644
--- a/content/browser/web_contents/web_contents_view_guest.cc
+++ b/content/browser/web_contents/web_contents_view_guest.cc
@@ -148,9 +148,8 @@ RenderWidgetHostViewBase* WebContentsViewGuest::CreateViewForWidget(
   RenderWidgetHostViewBase* platform_widget =
       platform_view_->CreateViewForWidget(render_widget_host, true);
 
-  return new RenderWidgetHostViewGuest(render_widget_host,
-                                       guest_,
-                                       platform_widget->GetWeakPtr());
+  return RenderWidgetHostViewGuest::Create(render_widget_host, guest_,
+                                           platform_widget->GetWeakPtr());
 }
 
 RenderWidgetHostViewBase* WebContentsViewGuest::CreateViewForPopupWidget(