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

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc.
  *               All rights reserved.
  *
  * 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.
  *
@@ skipping 170 matching lines @@
 
 void LayoutView::updateLogicalWidth() {
   setLogicalWidth(LayoutUnit(viewLogicalWidthForBoxSizing()));
 }
 
 bool LayoutView::isChildAllowed(LayoutObject* child,
                                 const ComputedStyle&) const {
   return child->isBox();
 }
 
+bool LayoutView::canHaveChildren() const {
+  FrameOwner* owner = frame()->owner();
+  if (!owner)
+    return true;
+  return !owner->isDisplayNone();
+}
+
 void LayoutView::layoutContent() {
   ASSERT(needsLayout());
 
   LayoutBlockFlow::layout();
 
 #if ENABLE(ASSERT)
   checkLayoutState();
 #endif
 }
 
@@ skipping 839 matching lines @@
   if (block)
     block->adjustChildDebugRect(rect);
 
   rect.setWidth(LayoutUnit(viewWidth(IncludeScrollbars)));
   rect.setHeight(LayoutUnit(viewHeight(IncludeScrollbars)));
 
   return rect;
 }
 
 }  // namespace blink