Don't create layout objects for children of display-none iframes.

third_party/WebKit/Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 810 matching lines @@
   ResizeObserverController& ensureResizeObserverController();
 
   void updateViewportDescription();
 
   // Returns the owning element in the parent document. Returns nullptr if
   // this is the top level document or the owner is remote.
   HTMLFrameOwnerElement* localOwner() const;
 
   void willChangeFrameOwnerProperties(int marginWidth,
                                       int marginHeight,
-                                      ScrollbarMode);
+                                      ScrollbarMode,
+                                      bool isDisplayNone);
 
   // Returns true if this document belongs to a frame that the parent document
   // made invisible (for instance by setting as style display:none).
   bool isInInvisibleSubframe() const;
 
   String title() const { return m_title; }
   void setTitle(const String&);
 
   Element* titleElement() const { return m_titleElement.get(); }
   void setTitleElement(Element*);
@@ skipping 875 matching lines @@
 DEFINE_TYPE_CASTS(TreeScope, Document, document, true, true);
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLiveDocumentInstances();
 #endif
 
 #endif  // Document_h