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

lib/dom/templates/html/impl/impl_Element.darttemplate

 // Copyright (c) 2012, 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.
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList implements ElementList {
   // Raw Element.
   final _ElementImpl _element;
   final _HTMLCollectionImpl _childElements;
@@ skipping 606 matching lines @@
  * All your element measurement needs in one place
  * @domName none
  */
 class _ElementRectImpl implements ElementRect {
   final ClientRect client;
   final ClientRect offset;
   final ClientRect scroll;
 
   // TODO(jacobr): should we move these outside of ElementRect to avoid the
   // overhead of computing them every time even though they are rarely used.
-  final _ClientRectImpl _boundingClientRect; 
+  final _ClientRectImpl _boundingClientRect;
   final _ClientRectListImpl _clientRects;
 
   _ElementRectImpl(_ElementImpl element) :
     client = new _SimpleClientRect(element.$dom_clientLeft,
                                   element.$dom_clientTop,
-                                  element.$dom_clientWidth, 
-                                  element.$dom_clientHeight), 
+                                  element.$dom_clientWidth,
+                                  element.$dom_clientHeight),
     offset = new _SimpleClientRect(element.$dom_offsetLeft,
                                   element.$dom_offsetTop,
                                   element.$dom_offsetWidth,
                                   element.$dom_offsetHeight),
     scroll = new _SimpleClientRect(element.$dom_scrollLeft,
                                   element.$dom_scrollTop,
                                   element.$dom_scrollWidth,
                                   element.$dom_scrollHeight),
     _boundingClientRect = element.$dom_getBoundingClientRect(),
     _clientRects = element.$dom_getClientRects();
@@ skipping 68 matching lines @@
      // TODO(jacobr): last param should be null, see b/5045788
      return getComputedStyle('');
   }
 
   Future<CSSStyleDeclaration> getComputedStyle(String pseudoElement) {
     return _createMeasurementFuture(
         () => _window.$dom_getComputedStyle(this, pseudoElement),
         new Completer<CSSStyleDeclaration>());
   }
 
+  void addText(String text) {
+    this.insertAdjacentText('beforeend', text);
+  }
+
+  void addHTML(String text) {
+    this.insertAdjacentHTML('beforeend', text);
+  }
+
   // Hooks to support custom WebComponents.
   var xtag;
 
 $if DARTIUM
   noSuchMethod(String name, List args) {
     if (dynamicUnknownElementDispatcher == null) {
       throw new NoSuchMethodException(this, name, args);
     } else {
       return dynamicUnknownElementDispatcher(this, name, args);
     }
   }
 $else
   // TODO(vsm): Implement noSuchMethod or similar for dart2js.
 $endif
 
+$if DART2JS
+  /** @domName Element.insertAdjacentText */
+  void insertAdjacentText(String where, String text) {
+    if (JS('bool', '!!this.insertAdjacentText')) {
+      _insertAdjacentText(where, text);
+    } else {
+      _insertAdjacentNode(where, new Text(text));
+    }
+  }
+
+  void _insertAdjacentText(String where, String text)
+      native 'insertAdjacentText';
+
+  /** @domName Element.insertAdjacentHTML */
+  void insertAdjacentHTML(String where, String text) {
+    if (JS('bool', '!!this.insertAdjacentHTML')) {
+      _insertAdjacentHTML(where, text);
+    } else {
+      _insertAdjacentNode(where, new DocumentFragment.html(text));
+    }
+  }
+
+  void _insertAdjacentHTML(String where, String text)
+      native 'insertAdjacentHTML';
+
+  /** @domName Element.insertAdjacentHTML */
+  Element insertAdjacentElement(String where, Element element) {
+    if (JS('bool', '!!this.insertAdjacentElement')) {
+      _insertAdjacentElement(where, element);
+    } else {
+      _insertAdjacentNode(where, element);
+    }
+    return element;
+  }
+
+  void _insertAdjacentElement(String where, Element element)
+      native 'insertAdjacentElement';
+
+  void _insertAdjacentNode(String where, Node node) {
+    switch (where.toLowerCase()) {
+      case 'beforebegin':
+        this.parent.insertBefore(node, this);
+        break;
+      case 'afterbegin':
+        this.insertBefore(node, this.nodes.first);
+        break;
+      case 'beforeend':
+        this.nodes.add(node);
+        break;
+      case 'afterend':
+        this.parent.insertBefore(node, this.nextNode);
+        break;
+      default:
+        throw new IllegalArgumentException("Invalid position ${where}");
+    }
+  }
+$else
+$endif
+
 $!MEMBERS
 }
 
 // Temporary dispatch hook to support WebComponents.
 Function dynamicUnknownElementDispatcher;
 
 final _START_TAG_REGEXP = const RegExp('<(\\w+)');
 class _ElementFactoryProvider {
   static final _CUSTOM_PARENT_TAG_MAP = const {
     'body' : 'html',
@@ skipping 47 matching lines @@
 
   /** @domName Document.createElement */
 $if DART2JS
   // Optimization to improve performance until the dart2js compiler inlines this
   // method.
   factory Element.tag(String tag) native "return document.createElement(tag)";
 $else
   factory Element.tag(String tag) => _document.$dom_createElement(tag);
 $endif
 }