Adding Element.AddHTML and Element.addText methods.

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

Index: lib/dom/templates/html/impl/impl_Element.darttemplate
diff --git a/lib/dom/templates/html/impl/impl_Element.darttemplate b/lib/dom/templates/html/impl/impl_Element.darttemplate
index fc2842d02aec158e2ee99ab902f5c8115768eec6..5979e4b80c0fd585b396205afcc38be7a643b884 100644
--- a/lib/dom/templates/html/impl/impl_Element.darttemplate
+++ b/lib/dom/templates/html/impl/impl_Element.darttemplate
@@ -624,14 +624,14 @@ class _ElementRectImpl implements ElementRect {
 
   // 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,
@@ -720,6 +720,14 @@ class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
         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;