Rename childNodeCount() / childNode() methods for clarity

Source/web/WebPageSerializerImpl.cpp

Index: Source/web/WebPageSerializerImpl.cpp
diff --git a/Source/web/WebPageSerializerImpl.cpp b/Source/web/WebPageSerializerImpl.cpp
index a2b7705831973b07453dac353a514cc0ede8cf3b..bf1895acbcfe6200863938448f984d07d4bb96a3 100644
--- a/Source/web/WebPageSerializerImpl.cpp
+++ b/Source/web/WebPageSerializerImpl.cpp
@@ -352,7 +352,7 @@ void WebPageSerializerImpl::openTagToString(Element* element,
     // Do post action for open tag.
     String addedContents = postActionAfterSerializeOpenTag(element, param);
     // Complete the open tag for element when it has child/children.
-    if (element->hasChildNodes() || param->haveAddedContentsBeforeEnd)
+    if (element->hasChildren() || param->haveAddedContentsBeforeEnd)
         result.append('>');
     // Append the added contents generate in  post action of open tag.
     result.append(addedContents);
@@ -371,7 +371,7 @@ void WebPageSerializerImpl::endTagToString(Element* element,
     if (needSkip)
         return;
     // Write end tag when element has child/children.
-    if (element->hasChildNodes() || param->haveAddedContentsBeforeEnd) {
+    if (element->hasChildren() || param->haveAddedContentsBeforeEnd) {
         result.appendLiteral("</");
         result.append(element->nodeName().lower());
         result.append('>');