Don't schedule invalidations when attributes changed if not needed or incorrect.

Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1004 matching lines @@
                 doc.activeChainNodeDetached(this);
             doc.userActionElements().didDetach(this);
         }
     }
 
     setStyleChange(NeedsReattachStyleChange);
     setChildNeedsStyleRecalc();
 
     if (StyleResolver* resolver = document().styleResolver())
         resolver->ruleFeatureSet().styleInvalidator().clearInvalidation(*this);
+    clearChildNeedsStyleInvalidation();
+    clearNeedsStyleInvalidation();
 
 #ifndef NDEBUG
     detachingNode = 0;
 #endif
 }
 
 void Node::reattachWhitespaceSiblings(Text* start)
 {
     for (Node* sibling = start; sibling; sibling = sibling->nextSibling()) {
         if (sibling->isTextNode() && toText(sibling)->containsOnlyWhitespace()) {
@@ skipping 1549 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif