RenderWidgetHostViewChildFrame's called a virtual in its ctor.

content/browser/frame_host/render_widget_host_view_child_frame.h

Index: content/browser/frame_host/render_widget_host_view_child_frame.h
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.h b/content/browser/frame_host/render_widget_host_view_child_frame.h
index 8993a5a63c4c9418f75d5a6b297664b7de3d9cde..96b886a275a3b3dfb32bbfa700a7cc77377cd8c7 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.h
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.h
@@ -53,7 +53,7 @@ class CONTENT_EXPORT RenderWidgetHostViewChildFrame
       public cc::SurfaceFactoryClient,
       public cc::BeginFrameObserver {
  public:
-  explicit RenderWidgetHostViewChildFrame(RenderWidgetHost* widget);
+  static RenderWidgetHostViewChildFrame* Create(RenderWidgetHost* widget);
   ~RenderWidgetHostViewChildFrame() override;
 
   void SetCrossProcessFrameConnector(
@@ -196,6 +196,9 @@ class CONTENT_EXPORT RenderWidgetHostViewChildFrame
   friend class RenderWidgetHostViewChildFrameTest;
   friend class RenderWidgetHostViewGuestSurfaceTest;
 
+  explicit RenderWidgetHostViewChildFrame(RenderWidgetHost* widget);
+  void Init();
+
   // Clears current compositor surface, if one is in use.
   void ClearCompositorSurfaceIfNecessary();