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

test/codegen/lib/html/selectelement_test.dart

+// Copyright (c) 2012, 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 selectelement_test;
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+import 'dart:html';
+
+main() {
+  useHtmlConfiguration();
+
+  test('selectedOptions', () {
+    var element = new SelectElement();
+    element.multiple = false;
+    var options = [
+      new OptionElement(),
+      new DivElement(),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new DivElement(),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new OptionElement(),
+    ];
+    element.children.addAll(options);
+    expect(element.selectedOptions.length, 1);
+    expect(element.selectedOptions[0], equals(options[4]));
+  });
+
+  test('multiple selectedOptions', () {
+    var element = new SelectElement();
+    element.multiple = true;
+    var options = [
+      new OptionElement(),
+      new DivElement(),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new DivElement(),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new OptionElement(),
+      new OptionElement(data: 'data', value: 'two', selected: false),
+    ];
+    element.children.addAll(options);
+    expect(element.selectedOptions.length, 2);
+    expect(element.selectedOptions[0], equals(options[2]));
+    expect(element.selectedOptions[1], equals(options[4]));
+  });
+
+  test('options', () {
+    var element = new SelectElement();
+    var options = [
+      new OptionElement(),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new OptionElement(data: 'data', value: 'two', selected: true),
+      new OptionElement(),
+    ];
+    element.children.addAll(options);
+    // Use last to make sure that the list was correctly wrapped.
+    expect(element.options.last, equals(options[3]));
+  });
+
+  test('optgroup', () {
+    var element = new Element.html(
+      '<select>'
+        '<option>1</option>'
+        '<optgroup>'
+          '<option>2</option>'
+        '</optgroup>'
+      '</select>');
+
+    expect(element.options.length, 2);
+    element.selectedIndex = 1;
+
+    var optGroup = element.children[1];
+    expect(optGroup is OptGroupElement, isTrue);
+    expect(optGroup.children.single.selected, isTrue);
+    expect(element.selectedOptions, optGroup.children);
+  });
+}