Revert "Implementing polyfills for insertAdjacent* to get them working on FF."

lib/dom/templates/html/interface/interface_Element.darttemplate

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // WARNING: Do not edit - generated code.
 
 // TODO(vsm): Eliminate this type.
 
 // Note, ElementList implements List (instead of List<Element>) so
 // that its implementing classes may be cast to Lists of more specific
@@ skipping 54 matching lines @@
 
   /** @domName className, classList */
   Set<String> get classes();
 
   void set classes(Collection<String> value);
 
   AttributeMap get dataAttributes();
   void set dataAttributes(Map<String, String> value);
 
   /**
-   * Adds the specified text as a text node after the last child of this.
-   */
-  void addText(String text);
-
-  /**
-   * Parses the specified text as HTML and adds the resulting node after the
-   * last child of this.
-   */
-  void addHTML(String html);
-
-  /**
    * @domName getClientRects, getBoundingClientRect, clientHeight, clientWidth,
    * clientTop, clientLeft, offsetHeight, offsetWidth, offsetTop, offsetLeft,
    * scrollHeight, scrollWidth, scrollTop, scrollLeft
    */
   Future<ElementRect> get rect();
 
   /** @domName Window.getComputedStyle */
   Future<CSSStyleDeclaration> get computedStyle();
 
   /** @domName Window.getComputedStyle */
   Future<CSSStyleDeclaration> getComputedStyle(String pseudoElement);
 
   Element clone(bool deep);
 
   Element get parent();
 
 $!MEMBERS
 }