Run dartfmt on all files under runtime.

runtime/observatory/tests/service/instance_field_order_rpc_test.dart

 // Copyright (c) 2016, 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.
 // VMOptions=--error_on_bad_type --error_on_bad_override
 
 library get_object_rpc_test;
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
 
 class Super {
   var z = 1;
   var y = 2;
 }
+
 class Sub extends Super {
   var y = 3;
   var x = 4;
 }
 
 eval(Isolate isolate, String expression) async {
   Map params = {
     'targetId': isolate.rootLibrary.id,
     'expression': expression,
   };
@@ skipping 18 matching lines @@
     expect(result['fields'][1]['decl']['name'], 'y');
     expect(result['fields'][1]['value']['valueAsString'], '2');
     expect(result['fields'][2]['decl']['name'], 'y');
     expect(result['fields'][2]['value']['valueAsString'], '3');
     expect(result['fields'][3]['decl']['name'], 'x');
     expect(result['fields'][3]['value']['valueAsString'], '4');
   },
 ];
 
 main(args) async => runIsolateTests(args, tests);