Nicer pretty printing of jsAst object literals.

sdk/lib/_internal/compiler/implementation/js/nodes.dart

 // Copyright (c) 2012, 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 js;
 
 abstract class NodeVisitor<T> {
   T visitProgram(Program node);
 
   T visitBlock(Block node);
@@ skipping 907 matching lines @@
 
   accept(NodeVisitor visitor) => visitor.visitArrayElement(this);
 
   void visitChildren(NodeVisitor visitor) {
     value.accept(visitor);
   }
 }
 
 class ObjectInitializer extends Expression {
   List<Property> properties;
+  bool isOneLiner;
 
-  ObjectInitializer(this.properties);
+  /**
+   * Constructs a new object-initializer containing the given [properties].
+   *
+   * [isOneLiner] describes the behaviour when pretty-printing (non-minified).
+   * If true print all properties on the same line.
+   * If false print each property on a seperate line.
+   */
+  ObjectInitializer(this.properties, {this.isOneLiner: true});
 
   accept(NodeVisitor visitor) => visitor.visitObjectInitializer(this);
 
   void visitChildren(NodeVisitor visitor) {
     for (Property init in properties) init.accept(visitor);
   }
 
   int get precedenceLevel => PRIMARY;
 }
 
@@ skipping 68 matching lines @@
  */
 class Comment extends Statement {
   final String comment;
 
   Comment(this.comment);
 
   accept(NodeVisitor visitor) => visitor.visitComment(this);
 
   void visitChildren(NodeVisitor visitor) {}
 }