fix parsing of semantic template interation w/ shadowdom polyfill

tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate

Index: tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate b/tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate
index eb3eb5152169a2b27ea425b28f42d581d534b1e0..94ad7288761ed365ea6b65b1e9e8e35ab098de99 100644
--- a/tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate
+++ b/tools/dom/templates/html/impl/impl_HTMLTemplateElement.darttemplate
@@ -135,6 +135,7 @@ $!MEMBERS
     _injectStylesheet();
 
     var templateElement = template;
+    templateElement._templateIsDecorated = true;
     var isNative = templateElement is TemplateElement;
     var bootstrapContents = isNative;
     var liftContents = !isNative;
@@ -147,12 +148,11 @@ $!MEMBERS
             'attribute templates.');
       }
       templateElement = _extractTemplateFromAttributeTemplate(template);
+      templateElement._templateIsDecorated = true;
       isNative = templateElement is TemplateElement;
       liftRoot = true;
      }
 
-    templateElement._templateIsDecorated = true;
-
     if (!isNative) {
       var doc = _getTemplateContentsOwner(templateElement.document);
       templateElement._templateContent = doc.createDocumentFragment();