Avoid calling markAncestorsWithChildNeedsStyleRecalc() constantly in childrenChanged

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 d99a120dacc3f38b6960ce0594e8d816009a3f46..0f334c0fc4326a2618128a989490559bfdebf361 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -744,6 +744,9 @@ void Node::markAncestorsWithChildNeedsStyleRecalc()
     for (ContainerNode* p = parentOrShadowHostNode(); p && !p->childNeedsStyleRecalc(); p = p->parentOrShadowHostNode())
         p->setChildNeedsStyleRecalc();
 
+    if (document().hasPendingStyleRecalc())

[eseidel, 2014/03/31 21:01:34]

Why this additional check?  Does document().scheduleRenderTreeUpdate not already
check this?

+        return;
+
     if (document().needsStyleRecalc() || document().childNeedsStyleRecalc())
         document().scheduleRenderTreeUpdate();
 }