Get rid of loops looking for the first Element ancestor

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2259 matching lines @@
     }
 
     exceptionState.throwDOMException(SyntaxError, "The value provided ('" + where + "') is not one of 'beforeBegin', 'afterBegin', 'beforeEnd', or 'afterEnd'.");
     return 0;
 }
 
 // Step 1 of http://domparsing.spec.whatwg.org/#insertadjacenthtml()
 static Element* contextElementForInsertion(const String& where, Element* element, ExceptionState& exceptionState)
 {
     if (equalIgnoringCase(where, "beforeBegin") || equalIgnoringCase(where, "afterEnd")) {
-        ContainerNode* parent = element->parentNode();
-        if (!parent || !parent->isElementNode()) {
+        Element* parent = element->parentElement();
+        if (!parent) {
             exceptionState.throwDOMException(NoModificationAllowedError, "The element has no parent.");
             return 0;
         }
-        return toElement(parent);
+        return parent;
     }
     if (equalIgnoringCase(where, "afterBegin") || equalIgnoringCase(where, "beforeEnd"))
         return element;
     exceptionState.throwDOMException(SyntaxError, "The value provided ('" + where + "') is not one of 'beforeBegin', 'afterBegin', 'beforeEnd', or 'afterEnd'.");
     return 0;
 }
 
 Element* Element::insertAdjacentElement(const String& where, Element* newChild, ExceptionState& exceptionState)
 {
     if (!newChild) {
@@ skipping 952 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink