Fix for events not firing on sanitized elements

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> {
   // Raw Element.
   final Element _element;
   final HtmlCollection _childElements;
@@ skipping 566 matching lines @@
    * group of selectors.
    *
    * [selectors] should be a string using CSS selector syntax.
    *
    *     var items = element.querySelectorAll('.itemClassName');
    */
   @DomName('Element.querySelectorAll')
   ElementList querySelectorAll(String selectors) =>
     new _FrozenElementList._wrap(_querySelectorAll(selectors));
 
-  /** 
+  /**
    * Alias for [querySelector]. Note this function is deprecated because its
    * semantics will be changing in the future.
    */
   @deprecated
   @DomName('Element.querySelector')
   @Experimental()
   Element query(String relativeSelectors) => querySelector(relativeSelectors);
 
-  /** 
+  /**
    * Alias for [querySelectorAll]. Note this function is deprecated because its
    * semantics will be changing in the future.
    */
   @deprecated
   @DomName('Element.querySelectorAll')
   @Experimental()
   ElementList queryAll(String relativeSelectors) =>
       querySelectorAll(relativeSelectors);
 
   /**
@@ skipping 715 matching lines @@
       fragment = _parseDocument.createDocumentFragment();
       while (contextElement.firstChild != null) {
         fragment.append(contextElement.firstChild);
       }
     }
     if (contextElement != _parseDocument.body) {
       contextElement.remove();
     }
 
     treeSanitizer.sanitizeTree(fragment);
+    // Copy the fragment over to the main document (fix for 14184)
+    document.adoptNode(fragment);
+
     return fragment;
   }
 
   /**
    * Parses the HTML fragment and sets it as the contents of this element.
    *
    * This uses the default sanitization behavior to sanitize the HTML fragment,
    * use [setInnerHtml] to override the default behavior.
    */
   void set innerHtml(String html) {
@@ skipping 76 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');
 }