[package:mdv] port createInstance change

pkg/mdv/test/template_element_test.dart

Index: pkg/mdv/test/template_element_test.dart
diff --git a/pkg/mdv/test/template_element_test.dart b/pkg/mdv/test/template_element_test.dart
index 10b39e1618e7f0c5d9fdddae740324384e78b684..d645a425d3659d76723977311ca30ebaf2f70a68 100644
--- a/pkg/mdv/test/template_element_test.dart
+++ b/pkg/mdv/test/template_element_test.dart
@@ -1542,19 +1542,28 @@ templateElementTests() {
   });
 
   test('CreateInstance', () {
-    var div = createTestHtml(
-      '<template bind="{{a}}">'
-        '<template bind="{{b}}">'
-          '{{text}}'
-        '</template>'
-      '</template>');
-    var outer = div.nodes.first;
+    TemplateElement.syntax['Test'] = new TestBindingSyntax();
+    try {
+      var div = createTestHtml(
+        '<template bind="{{a}}">'
+          '<template bind="{{b}}">'
+            '{{ foo }}:{{ replaceme }}'
+          '</template>'
+        '</template>');
+      var outer = div.nodes.first;
+      var model = toSymbolMap({'b': {'foo': 'bar'}});
 
-    var instance = outer.createInstance();
-    expect(outer.content.nodes.first, instance.nodes.first.ref);
+      var host = new DivElement();
+      var instance = outer.createInstance(model, 'Test');
+      expect(outer.content.nodes.first, instance.nodes.first.ref);
+      expect(instance.firstChild.attributes['syntax'], 'Test');
 
-    var instance2 =  outer.createInstance();
-    expect(instance2.nodes.first.ref, instance.nodes.first.ref);
+      host.append(instance);
+      deliverChangeRecords();
+      expect(host.firstChild.nextNode.text, 'bar:replaced');
+    } finally {
+      TemplateElement.syntax.remove('Test');
+    }
   });
 
   test('Bootstrap', () {
@@ -1609,6 +1618,13 @@ templateElementTests() {
   });
 }
 
+class TestBindingSyntax extends CustomBindingSyntax {
+  getBinding(model, String path, name, node) {
+    if (path.trim() == 'replaceme') return new ObservableBox('replaced');
+    return null;
+  }
+}
+
 class UnbindingInNestedBindSyntax extends CustomBindingSyntax {
   int expectedAge = 42;
   int count = 0;
@@ -1666,4 +1682,3 @@ _deepToSymbol(value) {
   }
   return value;
 }
-