[Reland #1] Don't create layout objects for children of display-none iframes.

third_party/WebKit/Source/core/layout/LayoutView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 251 matching lines @@
 
   const LayoutObject* pushMappingToContainer(
       const LayoutBoxModelObject* ancestorToStopAt,
       LayoutGeometryMap&) const override;
   void mapAncestorToLocal(const LayoutBoxModelObject*,
                           TransformState&,
                           MapCoordinatesFlags) const override;
   void computeSelfHitTestRects(Vector<LayoutRect>&,
                                const LayoutPoint& layerOffset) const override;
 
+  bool canHaveChildren() const override;
+
   void layoutContent();
 #if DCHECK_IS_ON()
   void checkLayoutState();
 #endif
 
   void updateFromStyle() override;
   bool allowsOverflowClip() const override;
 
   bool shouldUsePrintingLayout() const;
 
@@ skipping 44 matching lines @@
   unsigned m_hitTestCount;
   unsigned m_hitTestCacheHits;
   Persistent<HitTestCache> m_hitTestCache;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutView, isLayoutView());
 
 }  // namespace blink
 
 #endif  // LayoutView_h