Fix XML tests on Safari and IE.

client/html/src/XMLElementWrappingImplementation.dart

 // 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.
 
 class _XMLClassSet extends _CssClassSet {
   _XMLClassSet(element) : super(element);
 
   String _className() {
     final classStr = _element.getAttribute('class');
     return classStr == null ? '' : classStr;
@@ skipping 34 matching lines @@
 
   // TODO: The type of value should be Collection<Element>. See http://b/5392897
   void set elements(value) {
     final elements = this.elements;
     elements.clear();
     elements.addAll(value);
   }
 
   String get outerHTML() {
     final container = new Element.tag("div");
-    container.elements.add(this.clone(true));
+    // Safari requires that the clone be removed from its owner document before
+    // being inserted into the HTML document.
+    container.elements.add(this.clone(true).remove());
     return container.innerHTML;
   }
 
   String get innerHTML() {
     final container = new Element.tag("div");
-    container.nodes.addAll(this.clone(true).nodes);
+    // Safari requires that the clone be removed from its owner document before
+    // being inserted into the HTML document.
+    container.nodes.addAll(this.clone(true).remove().nodes);
     return container.innerHTML;
   }
 
   void set innerHTML(String xml) {
     final xmlDoc = new XMLDocument.xml('<xml>$xml</xml>');
-    this.nodes = xmlDoc.nodes;
+    // Safari requires that the root node be removed from the document before
+    // being inserted into the HTML document.
+    this.nodes = xmlDoc.remove().nodes;
   }
 
   Node _insertAdjacentNode(String where, Node node) {
     switch (where.toLowerCase()) {
       case "beforebegin":
         if (parent == null) return null;
         parent.insertBefore(node, this);
         return node;
       case "afterend":
         if (parent == null) return null;
@@ skipping 99 matching lines @@
 
   void set lang(String value) { attributes['lang'] = value; }
 
   String get dir() => _attr('dir');
 
   void set dir(String value) { attributes['dir'] = value; }
 
   String _attr(String name, [String def = '']) =>
     attributes.containsKey(name) ? attributes[name] : def;
 }