Ensure that newly-constructed elements don't have parents.

client/html/src/SVGElementWrappingImplementation.dart

 // 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.
 
 class _SVGClassSet extends _CssClassSet {
   _SVGClassSet(element) : super(element);
 
   String _className() => _element.className.baseVal;
 
   void _write(Set s) {
@@ skipping 11 matching lines @@
   factory SVGElementWrappingImplementation.svg(String svg) {
     Element parentTag;
     final match = _START_TAG_REGEXP.firstMatch(svg);
     if (match != null && match.group(1).toLowerCase() == 'svg') {
       parentTag = new Element.tag('div');
     } else {
       parentTag = new SVGSVGElement();
     }
 
     parentTag.innerHTML = svg;
-    if (parentTag.elements.length == 1) return parentTag.elements[0];
+    if (parentTag.elements.length == 1) return parentTag.nodes.removeLast();
 
     throw new IllegalArgumentException('SVG had ${parentTag.elements.length} ' +
         'top-level elements but 1 expected');
   }
 
   Set<String> get classes() {
     if (_cssClassSet === null) {
       _cssClassSet = new _SVGClassSet(_ptr);
     }
     return _cssClassSet;
@@ skipping 40 matching lines @@
   void set innerHTML(String svg) {
     var container = new Element.tag("div");
     // Wrap the SVG string in <svg> so that SVGElements are created, rather than
     // HTMLElements.
     container.innerHTML = '<svg version="1.1">$svg</svg>';
     this.elements = container.elements.first.elements;
   }
 
   SVGElement clone(bool deep) => super.clone(deep);
 }