Run dartfmt on all files under runtime.

runtime/observatory/tests/observatory_ui/mocks/repositories/flag.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
 
 part of mocks;
 
 class FlagsRepositoryMock implements M.FlagsRepository {
   final Iterable<M.Flag> _list;
   bool isListInvoked = false;
 
   Future<Iterable<M.Flag>> list() async {
     isListInvoked = true;
     return _list;
   }
 
   FlagsRepositoryMock({Iterable<M.Flag> list: const []})
-    : _list = new List.unmodifiable(list);
+      : _list = new List.unmodifiable(list);
 }