Forbid entering recalcStyle or attach from inside detach.

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1583 matching lines @@
 
 PassRefPtr<ComputedStyle> Element::originalStyleForLayoutObject()
 {
     ASSERT(document().inStyleRecalc());
     return document().ensureStyleResolver().styleForElement(this);
 }
 
 void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling)
 {
     ASSERT(document().inStyleRecalc());
+    ASSERT(!document().lifecycle().inDetach());
     ASSERT(!parentOrShadowHostNode()->needsStyleRecalc());
     ASSERT(inActiveDocument());
 
     if (hasCustomStyleCallbacks())
         willRecalcStyle(change);
 
     if (change >= Inherit || needsStyleRecalc()) {
         if (hasRareData()) {
             ElementRareData* data = elementRareData();
             data->clearComputedStyle();
@@ skipping 1803 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink