Use dartfmt on Observatory code

runtime/observatory/lib/src/models/objects/code.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 models;
 
-enum CodeKind {
-  dart,
-  native,
-  stub,
-  tag,
-  collected
-}
+enum CodeKind { dart, native, stub, tag, collected }
 
 bool isSyntheticCode(CodeKind kind) {
   switch (kind) {
     case CodeKind.collected:
     case CodeKind.native:
     case CodeKind.tag:
       return true;
     default:
       return false;
   }
 }
 
 bool isDartCode(CodeKind kind) => !isSyntheticCode(kind);
 
 abstract class CodeRef extends ObjectRef {
   /// The name of this class.
   String get name;
 
   // What kind of code object is this?
   CodeKind get kind;
 
   bool get isOptimized;
 }
 
 abstract class Code extends Object implements CodeRef {
   FunctionRef get function;
   ObjectPoolRef get objectPool;
   Iterable<FunctionRef> get inlinedFunctions;
 }