[polymer] add a new API to create an element without polymer-element in HTML

pkg/polymer/test/register_test.dart

Index: pkg/polymer/test/register_test.dart
diff --git a/pkg/polymer/test/register_test.dart b/pkg/polymer/test/register_test.dart
index f5f2bda89014da5bbc924db49ced9881340a1569..c0ab7d3967e67371e4a82904e4ee56ea1379722a 100644
--- a/pkg/polymer/test/register_test.dart
+++ b/pkg/polymer/test/register_test.dart
@@ -3,9 +3,9 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:html';
+import 'package:polymer/polymer.dart';
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
-import 'package:polymer/polymer.dart';
 
 @CustomTag('x-html')
 class XHtmlElement extends PolymerElement {
@@ -27,6 +27,19 @@ class XDiv2Element extends XDivElement {
   XDiv2Element.created() : super.created();
 }
 
+/// Dart-specific test:
+/// This element is registered from code without an associated polymer-element.
+class XPolymerElement extends PolymerElement {
+  XPolymerElement.created() : super.created();
+}
+
+/// Dart-specific test:
+/// This element is registered from code without an associated polymer-element.
+class XButtonElement extends ButtonElement with Polymer, Observable {
+  XButtonElement.created() : super.created();
+}
+
+
 @initMethod
 main() {
   useHtmlConfiguration();
@@ -39,4 +52,30 @@ main() {
     expect(querySelector('#x-div') is XDivElement, isTrue);
     expect(querySelector('#x-div-two') is XDiv2Element, isTrue);
   });
+
+  group('register without polymer-element', () {
+    test('custom element', () {
+      Polymer.registerSync('x-polymer', XPolymerElement,
+          template: new Element.html('<template>FOOBAR'));
+
+      expect(document.createElement('x-polymer') is XPolymerElement, isTrue,
+          reason: 'should have been registered');
+
+      var e = document.querySelector('x-polymer');
+      expect(e is XPolymerElement, isTrue,
+          reason: 'elements on page should be upgraded');
+      expect(e.shadowRoot, isNotNull,
+          reason: 'shadowRoot was created from template');
+      expect(e.shadowRoot.nodes[0].text, 'FOOBAR');
+    });
+
+    test('type extension', () {
+      Polymer.registerSync('x-button', XButtonElement, extendsTag: 'button');
+
+      expect(document.createElement('button', 'x-button') is XButtonElement,
+          isTrue, reason: 'should have been registered');
+      expect(document.querySelector('[is=x-button]') is XButtonElement, isTrue,
+          reason: 'elements on page should be upgraded');
+    });
+  });
 }