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

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 dad59a8555c06933c6fb76ae84ec546c98e8d15e..537434fa67a3bc324b040a6f053f768754645a83 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -432,7 +432,7 @@ 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);
@@ -1057,7 +1057,7 @@ Node *Node::previousNodeConsideringAtomicNodes() const
 
 Node *Node::nextNodeConsideringAtomicNodes() const
 {
-    if (!isAtomicNode(this) && firstChild())
+    if (!isAtomicNode(this) && hasChildren())
         return firstChild();
     if (nextSibling())
         return nextSibling();