Avoid calling markAncestorsWithChildNeedsStyleRecalc() constantly in childrenChanged

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 726 matching lines @@
 inline void Node::setStyleChange(StyleChangeType changeType)
 {
     m_nodeFlags = (m_nodeFlags & ~StyleChangeMask) | changeType;
 }
 
 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();
 }
 
 void Node::setNeedsStyleRecalc(StyleChangeType changeType)
 {
     ASSERT(changeType != NoStyleChange);
     if (!inActiveDocument())
         return;
 
@@ skipping 1767 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif