dart2js: run dartfmt on tests

tests/compiler/dart2js/number_output_test.dart

 // Copyright (c) 2015, 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.
 
 import 'dart:async';
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
 import 'memory_compiler.dart';
 
 const MEMORY_SOURCE_FILES = const {
-    'main.dart': '''
+  'main.dart': '''
         main() {
           print(12300000);
           print(1234567890123456789012345);
           print(double.MAX_FINITE);
           print(-22230000);
-        }'''};
+        }'''
+};
 
 Future test({bool minify}) async {
   OutputCollector collector = new OutputCollector();
   await runCompiler(
       memorySourceFiles: MEMORY_SOURCE_FILES,
       outputProvider: collector,
       options: minify ? ['--minify'] : []);
 
   // Check that we use the shorter exponential representations.
   String jsOutput = collector.getOutput('', 'js');
@@ skipping 15 matching lines @@
   // for its prefix.
   Expect.isFalse(jsOutput.contains('179769313486231570814527423731'));
 }
 
 main() {
   asyncTest(() async {
     await test(minify: true);
     await test(minify: false);
   });
 }