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());
+    bool elementHasTwoChildren = (element->firstChild() && element->firstChild()->nextSibling() && !element->firstChild()->nextSibling()->nextSibling());

[eseidel, 2014/02/19 05:39:54]

I wonder if a generic hasChildCount(unsigned) is useful.

[Inactive, 2014/02/19 14:28:15]

This is likely the only place where we would need it but why not. At least,
people would be less prone to using childNodeCount() for such use cases. I'll
look into this now.

+    return (elementHasTwoChildren && isTabSpanTextNode(element->firstChild()->firstChild()) && element->firstChild()->nextSibling()->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);
 }
 
 }