Add a first pass of a class descendant invalidator, and a containing RuleSetAnalyzer

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 2c1dc4c1baf841dd990e8fe7c0838f2d70b72a92..a64525517455bd864871c2485a407edec4b20bec 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -646,6 +646,25 @@ void Node::setIsLink(bool isLink)
     setFlag(isLink && !SVGImage::isInSVGImage(toElement(this)), IsLinkFlag);
 }
 
+void Node::markAncestorsWithChildNeedsInvalidation()
+{
+    for (Node* node = this; node && !node->childNeedsDistributionRecalc(); node = node->parentOrShadowHostNode())
+        node->setChildNeedsInvalidation();
+    if (document().childNeedsInvalidation())
+        document().scheduleStyleRecalc();
+}
+
+// get rid of this method!
+void Node::setNeedsInvalidation()
+{
+    markAncestorsWithChildNeedsInvalidation();
+}
+
+bool Node::needsInvalidation() const
+{
+    return false;
+}
+
 void Node::markAncestorsWithChildNeedsDistributionRecalc()
 {
     for (Node* node = this; node && !node->childNeedsDistributionRecalc(); node = node->parentOrShadowHostNode())