Nicer pretty printing of jsAst object literals.

sdk/lib/_internal/compiler/implementation/js_emitter/class_builder.dart

 // Copyright (c) 2013, 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 dart2js.js_emitter;
 
 /**
  * A data structure for collecting fragments of a class definition.
  */
 class ClassBuilder {
   // TODO (sigurdm) this is just a bag of properties, rename this class
 
   final List<jsAst.Property> properties = <jsAst.Property>[];
 
   /// Set to true by user if class is indistinguishable from its superclass.
   bool isTrivial = false;
 
   // Has the same signature as [DefineStubFunction].
   void addProperty(String name, jsAst.Expression value) {
     properties.add(new jsAst.Property(js.string(name), value));
   }
 
   jsAst.Expression toObjectInitializer() {
-    return new jsAst.ObjectInitializer(properties);
+    return new jsAst.ObjectInitializer(properties, isOneLiner: false);
   }
 
 }