Replicate sandbox flags for OOPIF (Blink part 2)

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 b30e04fbc37703316ad581209d7bd88411178b47..090a605fac0fbca83d948fddd105f393146166e8 100644
--- a/Source/core/html/HTMLFrameOwnerElement.h
+++ b/Source/core/html/HTMLFrameOwnerElement.h
@@ -77,6 +77,11 @@ public:
         void performDeferredWidgetTreeOperations();
     };
 
+    // FrameOwner overrides:
+    virtual bool isLocal() const { return true; }
+    virtual void dispatchLoad() override;
+    virtual SandboxFlags sandboxFlags() const override { return m_sandboxFlags; }
+
     virtual void trace(Visitor*) override;
 
 protected:
@@ -89,11 +94,6 @@ private:
     virtual bool isKeyboardFocusable() const override;
     virtual bool isFrameOwnerElement() const override final { return true; }
 
-    // FrameOwner overrides:
-    virtual bool isLocal() const { return true; }
-    virtual SandboxFlags sandboxFlags() const override;
-    virtual void dispatchLoad() override;
-
     RawPtrWillBeMember<Frame> m_contentFrame;
     RefPtrWillBeMember<Widget> m_widget;
     SandboxFlags m_sandboxFlags;