Run dartfmt on all files under runtime.

runtime/observatory/tests/observatory_ui/mocks/objects/guarded.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 GuardedMock<T> implements M.Guarded {
   bool get isSentinel => asSentinel != null;
   bool get isValue => asValue != null;
   final T asValue;
   final M.Sentinel asSentinel;
 
-  const GuardedMock.fromValue(this.asValue)
-    : asSentinel = null;
+  const GuardedMock.fromValue(this.asValue) : asSentinel = null;
 
-  const GuardedMock.fromSentinel(this.asSentinel)
-    : asValue = null;
+  const GuardedMock.fromSentinel(this.asSentinel) : asValue = null;
 }