Run dartfmt on all files under runtime.

runtime/observatory/tests/observatory_ui/mocks/objects/objectstore.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 ObjectStoreMock implements M.ObjectStore {
   final Iterable<M.NamedField> fields;
 
   const ObjectStoreMock({this.fields: const []});
 }
 
 class NamedFieldMock implements M.NamedField {
   final String name;
   final M.ObjectRef value;
 
-  const NamedFieldMock({this.name: 'field-name',
-                        this.value: const InstanceRefMock()});
+  const NamedFieldMock(
+      {this.name: 'field-name', this.value: const InstanceRefMock()});
 }