Get rid of inefficient uses of childNodeCount()

Source/core/editing/markup.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 351 matching lines @@
             next = NodeTraversal::nextSkippingChildren(*n);
             // Don't skip over pastEnd.
             if (pastEnd && pastEnd->isDescendantOf(n))
                 next = pastEnd;
         } else {
             // Add the node to the markup if we're not skipping the descendants
             if (shouldEmit)
                 appendStartTag(*n);
 
             // If node has no children, close the tag now.
-            if (!n->childNodeCount()) {
+            if (!n->hasChildNodes()) {
                 if (shouldEmit)
                     appendEndTag(*n);
                 lastClosed = n;
             } else {
                 openedTag = true;
                 ancestorsToClose.append(n);
             }
         }
 
         // If we didn't insert open tag and there's no more siblings or we're at the end of the traversal, take care of ancestors.
@@ skipping 392 matching lines @@
         // (if the last character is a tab, the list gets an extra empty entry)
         if (i + 1 != numEntries)
             tabText.append('\t');
         else if (!tabText.isEmpty())
             paragraph->appendChild(createTabSpanElement(document, tabText.toString()));
 
         first = false;
     }
 }
 
-bool isPlainTextMarkup(Node *node)
+bool isPlainTextMarkup(Node* node)
 {
-    if (!node->isElementNode() || !node->hasTagName(divTag) || toElement(node)->hasAttributes())
+    if (!node->isElementNode())
         return false;
 
-    if (node->childNodeCount() == 1 && (node->firstChild()->isTextNode() || (node->firstChild()->firstChild())))
+    Element* element = toElement(node);
+    if (!element->hasTagName(divTag) || !element->hasAttributes())
+        return false;
+
+    if (element->hasOneChild() && (element->firstChild()->isTextNode() || (element->firstChild()->firstChild())))
         return true;
 
-    return (node->childNodeCount() == 2 && isTabSpanTextNode(node->firstChild()->firstChild()) && node->firstChild()->nextSibling()->isTextNode());
+    return element->hasChildCount(2) && isTabSpanTextNode(element->firstChild()->firstChild()) && element->lastChild()->isTextNode();
 }
 
 static bool shouldPreserveNewline(const Range& range)
 {
     if (Node* node = range.firstNode()) {
         if (RenderObject* renderer = node->renderer())
             return renderer->style()->preserveNewline();
     }
 
     if (Node* node = range.startPosition().anchorNode()) {
@@ skipping 240 matching lines @@
         return;
 
     RefPtr<Text> textNode = toText(node.get());
     RefPtr<Text> textNext = toText(next);
     textNode->appendData(textNext->data());
     if (textNext->parentNode()) // Might have been removed by mutation event.
         textNext->remove(exceptionState);
 }
 
 }