Make RenderFrame(Host) own a RenderWidget(Host).

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index c2b22ad51862120ddaf9b8d912bf0e0cffbb5c4e..f8c7b3602ef01c84ef27db2c06484c14df61b07a 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -96,6 +96,12 @@ class CONTENT_EXPORT RenderWidget
                               blink::WebPopupType popup_type,
                               const blink::WebScreenInfo& screen_info);
 
+  // Creates a new RenderWidget that will be attached to a RenderFrame.
+  static RenderWidget* CreateForFrame(int routing_id,
+                                      int surface_id,
+                                      bool hidden,
+                                      const blink::WebScreenInfo& screen_info);
+
   // Creates a WebWidget based on the popup type.
   static blink::WebWidget* CreateWebWidget(RenderWidget* render_widget);
 
@@ -120,6 +126,9 @@ class CONTENT_EXPORT RenderWidget
     return host_context_menu_location_;
   }
 
+  // ScreenInfo exposed so it can be passed to subframe RenderWidgets.
+  blink::WebScreenInfo screen_info() const { return screen_info_; }
+
   // Functions to track out-of-process frames for special notifications.
   void RegisterRenderFrameProxy(RenderFrameProxy* proxy);
   void UnregisterRenderFrameProxy(RenderFrameProxy* proxy);