(blink) Propagate scrolling/marginwidth/marginheight property values to child frame.

Source/core/html/HTMLFrameOwnerElement.h

Index: Source/core/html/HTMLFrameOwnerElement.h
diff --git a/Source/core/html/HTMLFrameOwnerElement.h b/Source/core/html/HTMLFrameOwnerElement.h
index 87ad3856ec50b56c797c85a6dd4ef71339d38373..07bb8655a568b5b2323cf4a40e42dad3d3d00381 100644
--- a/Source/core/html/HTMLFrameOwnerElement.h
+++ b/Source/core/html/HTMLFrameOwnerElement.h
@@ -58,8 +58,6 @@ public:
 
     Document* getSVGDocument(ExceptionState&) const;
 
-    virtual ScrollbarMode scrollingMode() const { return ScrollbarAuto; }
-
     virtual bool loadedNonEmptyDocument() const { return false; }
     virtual void didLoadNonEmptyDocument() { }
 
@@ -81,12 +79,18 @@ public:
     void dispatchLoad() override;
     SandboxFlags sandboxFlags() const override { return m_sandboxFlags; }
     void renderFallbackContent() override { }
+    ScrollbarMode scrollingMode() const override { return m_scrollingMode; }
+    int marginWidth() const { return m_marginWidth; }
+    int marginHeight() const { return m_marginHeight; }
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     HTMLFrameOwnerElement(const QualifiedName& tagName, Document&);
     void setSandboxFlags(SandboxFlags);
+    void setScrollingMode(ScrollbarMode);
+    void setMarginWidth(int);
+    void setMarginHeight(int);
 
     bool loadOrRedirectSubframe(const KURL&, const AtomicString& frameName, bool replaceCurrentItem);
 
@@ -97,6 +101,9 @@ private:
     RawPtrWillBeMember<Frame> m_contentFrame;
     RefPtrWillBeMember<Widget> m_widget;
     SandboxFlags m_sandboxFlags;
+    ScrollbarMode m_scrollingMode;
+    int m_marginWidth;
+    int m_marginHeight;
 };
 
 DEFINE_ELEMENT_TYPE_CASTS(HTMLFrameOwnerElement, isFrameOwnerElement());