Revert "Converting Polymer and TemplateElement to use deprecated Node.document"

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 9ceaa5bfb8e4c12321459bca2bf97a6d1cecae88..dec8d31cfa4a78be2888e0b4a785225a6a517ef3 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -23608,7 +23608,7 @@ class TemplateElement extends HtmlElement native "HTMLTemplateElement" {
      }
 
     if (!isNative) {
-      var doc = _getTemplateContentsOwner(templateElement.document);
+      var doc = _getTemplateContentsOwner(templateElement.ownerDocument);
       templateElement._templateContent = doc.createDocumentFragment();
     }
 
@@ -23657,7 +23657,7 @@ class TemplateElement extends HtmlElement native "HTMLTemplateElement" {
   //       + <td>Bar</td>
   //
   static Element _extractTemplateFromAttributeTemplate(Element el) {
-    var template = el.document.createElement('template');
+    var template = el.ownerDocument.createElement('template');
     el.parentNode.insertBefore(template, el);
 
     for (var name in el.attributes.keys.toList()) {