Start cleaning up the HTML tests.

pkg/dev_compiler/test/codegen/lib/html/input_element_test.dart

-library input_element_test;
-import 'package:unittest/unittest.dart';
-import 'package:unittest/html_individual_config.dart';
 import 'dart:html';
 
+import 'package:minitest/minitest.dart';
+
 void check(InputElement element, String type, [bool supported = true]) {
   expect(element is InputElement, true);
   if (supported) {
     expect(element.type, type);
   } else {
     expect(element.type, 'text');
   }
 }
 
 main() {
-  useHtmlIndividualConfiguration();
-
   group('supported_search', () {
     test('supported', () {
       expect(SearchInputElement.supported, true);
     });
   });
 
   group('supported_url', () {
     test('supported', () {
       expect(UrlInputElement.supported, true);
     });
@@ skipping 158 matching lines @@
     });
     test('valueSetNullProxy', () {
       final e = new TextInputElement();
       e.value = _undefined;
       expect(e.value, '');
     });
   });
 }
 
 var _undefined = (() => new List(5)[0])();