[DO NOT COMMIT] Don't keep pointers to table sections when told to recalculate sections.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 1290 matching lines @@
 }
 
 bool LayoutObject::mapToVisualRectInAncestorSpace(
     const LayoutBoxModelObject* ancestor,
     LayoutRect& rect,
     VisualRectFlags visualRectFlags) const {
   // For any layout object that doesn't override this method (the main example
   // is LayoutText), the rect is assumed to be in the parent's coordinate space,
   // except for container flip.
 
+  DCHECK(!needsLayout());
   if (ancestor == this)
     return true;
 
   if (LayoutObject* parent = this->parent()) {
     if (parent->isBox()) {
       LayoutBox* parentBox = toLayoutBox(parent);
 
       // Never flip for SVG as it handles writing modes itself.
       if (!isSVG())
         parentBox->flipForWritingMode(rect);
@@ skipping 2187 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->parent())
       root = root->parent();
     root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif