tests/html: removed usage of deprecated unittest features

tests/html/websql_test.dart

 library WebDBTest;
 import 'dart:async';
 import 'dart:html';
 import 'dart:web_sql';
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 
-void fail(message) {
-  guardAsync(() {
-      expect(false, isTrue, reason: message);
-    });
-}
-
 Future<SqlTransaction> transaction(SqlDatabase db) {
   final completer = new Completer<SqlTransaction>.sync();
 
   db.transaction((SqlTransaction transaction) {
     completer.complete(transaction);
   }, (SqlError error) {
     completer.completeError(error);
   });
 
   return completer.future;
@@ skipping 114 matching lines @@
         var row = resultSet.rows.item(0);
         expect(row.containsKey(columnName), isTrue);
         expect(row[columnName], 'Some text data');
         expect(resultSet.rows[0], row);
       }).then((_) {
         return dropTable(tx, tableName);
       });
     });
   });
 }