Add all dart:html tests from the sdk to test/codegen.

test/codegen/lib/html/custom_tags_test.dart

Index: test/codegen/lib/html/custom_tags_test.dart
diff --git a/test/codegen/lib/html/custom_tags_test.dart b/test/codegen/lib/html/custom_tags_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..5f5457b5f27d20b41e1ab4fac95e6dbe51155b30
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+++ b/test/codegen/lib/html/custom_tags_test.dart
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+// Copyright (c) 2013, 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.
+
+library custom_tags_test;
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+import 'dart:html';
+import 'utils.dart';
+
+main() {
+  useHtmlConfiguration();
+
+  test('create via custom tag', () {
+    var element = new Element.tag('x-basic1')..id = 'basic1';
+    document.body.nodes.add(element);
+
+    var queryById = query('#basic1');
+    expect(queryById, equals(element));
+
+    var queryByTag = queryAll('x-basic1');
+    expect(queryByTag.length, equals(1));
+    expect(queryByTag[0], equals(element));
+  });
+
+  test('custom inner html', () {
+    var element = new DivElement();
+    element.setInnerHtml("<x-basic2 id='basic2'></x-basic2>",
+        treeSanitizer: new NullTreeSanitizer());
+    document.body.nodes.add(element);
+
+    var queryById = query('#basic2');
+    expect(queryById is Element, isTrue);
+
+    var queryByTag = queryAll('x-basic2');
+    expect(queryByTag.length, equals(1));
+    expect(queryByTag[0], equals(queryById));
+  });
+
+  test('type extension inner html', () {
+    var element = new DivElement();
+    element.setInnerHtml("<div is='x-basic3' id='basic3'></div>",
+        treeSanitizer: new NullTreeSanitizer());
+    document.body.nodes.add(element);
+
+    var queryById = query('#basic3');
+    expect(queryById is DivElement, isTrue);
+  });
+}