Format all tests.

tests/lib_strong/html/async_periodictimer.dart

 library async_periodictimer;
 
 import 'dart:async';
 import 'package:unittest/unittest.dart';
 
 main(message, replyTo) {
   var command = message.first;
   expect(command, 'START');
   int counter = 0;
   new Timer.periodic(const Duration(milliseconds: 10), (timer) {
     if (counter == 3) {
       counter = 1024;
       timer.cancel();
       // Wait some more time to be sure callback won't be invoked any
       // more.
       new Timer(const Duration(milliseconds: 30), () {
         replyTo.send('DONE');
       });
       return;
     }
     assert(counter < 3);
     counter++;
   });
-}
+}