dart2js: Implement frequency based naming.

pkg/js_ast/lib/src/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_ast;
 
 abstract class NodeVisitor<T> {
   T visitProgram(Program node);
 
   T visitBlock(Block node);
@@ skipping 579 matching lines @@
 
   bool get allowRename => false;
 }
 
 class LiteralStringFromName extends LiteralString {
   Name name;
 
   LiteralStringFromName(this.name) : super(null);
 
   String get value => '"${name.name}"';
+
+  void visitChildren(NodeVisitor visitor) {
+    name.accept(visitor);
+  }
 }
 
 class LiteralExpression extends Expression {
   final String template;
   final List<Expression> inputs;
 
   LiteralExpression(this.template) : inputs = const [];
   LiteralExpression.withData(this.template, this.inputs);
 
   accept(NodeVisitor visitor) => visitor.visitLiteralExpression(this);
@@ skipping 663 matching lines @@
 class Comment extends Statement {
   final String comment;
 
   Comment(this.comment);
 
   accept(NodeVisitor visitor) => visitor.visitComment(this);
   Comment _clone() => new Comment(comment);
 
   void visitChildren(NodeVisitor visitor) {}
 }