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

test/codegen/lib/html/dom_constructors_test.dart

Index: test/codegen/lib/html/dom_constructors_test.dart
diff --git a/test/codegen/lib/html/dom_constructors_test.dart b/test/codegen/lib/html/dom_constructors_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..a2bcf55e73625446357634964abb3f04f2bcd470
--- /dev/null
+++ b/test/codegen/lib/html/dom_constructors_test.dart
@@ -0,0 +1,12 @@
+library DOMConstructorsTest;
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
+import 'dart:html';
+
+main() {
+  useHtmlConfiguration();
+  test('FileReader', () {
+    FileReader fileReader = new FileReader();
+    expect(fileReader.readyState, equals(FileReader.EMPTY));
+  });
+}