Use new is*Element() helper functions more in rendering code

Source/core/rendering/RenderTreeAsText.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 96 matching lines @@
 {
     if (n->isDocumentNode())
         return "";
     if (n->nodeType() == Node::COMMENT_NODE)
         return "COMMENT";
     return n->nodeName();
 }
 
 static bool isEmptyOrUnstyledAppleStyleSpan(const Node* node)
 {
-    if (!node || !node->isHTMLElement() || !node->hasTagName(spanTag))
+    if (!isHTMLSpanElement(node))
         return false;
 
-    const HTMLElement* elem = toHTMLElement(node);
-    if (elem->getAttribute(classAttr) != "Apple-style-span")
+    const HTMLElement& elem = toHTMLElement(*node);
+    if (elem.getAttribute(classAttr) != "Apple-style-span")
         return false;
 
-    if (!node->hasChildren())
+    if (!elem.hasChildren())
         return true;
 
-    const StylePropertySet* inlineStyleDecl = elem->inlineStyle();
+    const StylePropertySet* inlineStyleDecl = elem.inlineStyle();
     return (!inlineStyleDecl || inlineStyleDecl->isEmpty());
 }
 
 String quoteAndEscapeNonPrintables(const String& s)
 {
     StringBuilder result;
     result.append('"');
     for (unsigned i = 0; i != s.length(); ++i) {
         UChar c = s[i];
         if (c == '\\') {
@@ skipping 625 matching lines @@
     element->document().updateLayout();
 
     RenderObject* renderer = element->renderer();
     if (!renderer || !renderer->isListItem())
         return String();
 
     return toRenderListItem(renderer)->markerText();
 }
 
 } // namespace WebCore