Implement style invalidation tree walk for targeted style recalc upon class change.

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 621 matching lines @@
     }
 
     clearChildNeedsDistributionRecalc();
 }
 
 void Node::setIsLink(bool isLink)
 {
     setFlag(isLink && !SVGImage::isInSVGImage(toElement(this)), IsLinkFlag);
 }
 
+void Node::setNeedsStyleInvalidation()
+{
+    setFlag(NeedsStyleInvalidation);
+    markAncestorsWithChildNeedsStyleInvalidation();
+}
+
+
+void Node::markAncestorsWithChildNeedsStyleInvalidation()
+{
+    for (Node* node = this; node && !node->childNeedsStyleInvalidation(); node = node->parentOrShadowHostNode())
+        node->setChildNeedsStyleInvalidation();
+    if (document().childNeedsStyleInvalidation())
+        document().scheduleStyleRecalc();
+}
+
 void Node::markAncestorsWithChildNeedsDistributionRecalc()
 {
     for (Node* node = this; node && !node->childNeedsDistributionRecalc(); node = node->parentOrShadowHostNode())
         node->setChildNeedsDistributionRecalc();
     if (document().childNeedsDistributionRecalc())
         document().scheduleStyleRecalc();
 }
 
 namespace {
 
@@ skipping 1909 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif