Get rid of loops looking for the first Element ancestor

Source/core/rendering/TextAutosizer.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 103 matching lines @@
 #endif
 
 static const RenderObject* parentElementRenderer(const RenderObject* renderer)
 {
     // At style recalc, the renderer's parent may not be attached,
     // so we need to obtain this from the DOM tree.
     const Node* node = renderer->node();
     if (!node)
         return 0;
 
-    for (node = node->parentNode(); node; node = node->parentNode()) {
-        if (node->isElementNode())
-            return node->renderer();
-    }
+    // FIXME: This should be using NodeRenderingTraversal::parent().
+    if (Element* parent = node->parentElement())
+        return parent->renderer();
     return 0;
 }
 
 static bool isNonTextAreaFormControl(const RenderObject* renderer)
 {
     const Node* node = renderer ? renderer->node() : 0;
     if (!node || !node->isElementNode())
         return false;
     const Element* element = toElement(node);
 
@@ skipping 1014 matching lines @@
     }
     return computedSize;
 }
 
 void TextAutosizer::trace(Visitor* visitor)
 {
     visitor->trace(m_document);
 }
 
 } // namespace blink