Use ContainerNode::hasChildren() instead of firstChild() in conditionals

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 414 matching lines @@
         if (!isBeforePseudoElement())
             return parent->pseudoElement(BEFORE);
     }
     return previousSibling();
 }
 
 Node* Node::pseudoAwareNextSibling() const
 {
     if (parentElement() && !nextSibling()) {
         Element* parent = parentElement();
-        if (isBeforePseudoElement() && parent->firstChild())
+        if (isBeforePseudoElement() && parent->hasChildren())
             return parent->firstChild();
         if (!isAfterPseudoElement())
             return parent->pseudoElement(AFTER);
     }
     return nextSibling();
 }
 
 Node* Node::pseudoAwareFirstChild() const
 {
     if (isElementNode()) {
@@ skipping 604 matching lines @@
     else if (parentNode()) {
         return parentNode();
     }
     else {
         return 0;
     }
 }
 
 Node *Node::nextNodeConsideringAtomicNodes() const
 {
-    if (!isAtomicNode(this) && firstChild())
+    if (!isAtomicNode(this) && hasChildren())
         return firstChild();
     if (nextSibling())
         return nextSibling();
     const Node *n = this;
     while (n && !n->nextSibling())
         n = n->parentNode();
     if (n)
         return n->nextSibling();
     return 0;
 }
@@ skipping 1479 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif