Fix Try Dart newline handling on IE11.

tools/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.
 
 part of $LIBRARYNAME;
 
 class _ChildrenElementList extends ListBase<Element>
     implements NodeListWrapper {
   // Raw Element.
   final Element _element;
@@ skipping 696 matching lines @@
   /**
    * Gets the offset of this element relative to its offsetParent.
    */
   Rectangle get offset => new Rectangle(offsetLeft, offsetTop, offsetWidth,
       offsetHeight);
 
   /**
    * Adds the specified text after the last child of this element.
    */
   void appendText(String text) {
-    this.insertAdjacentText('beforeend', text);
+    this.append(new Text(text));
   }
 
   /**
    * Parses the specified text as HTML and adds the resulting node after the
    * last child of this element.
    */
   void appendHtml(String text) {
     this.insertAdjacentHtml('beforeend', text);
   }
 
@@ skipping 754 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }