Use ASTVisitor as in new AST.

compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java

Index: compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java b/compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java
index 1c59e328ecb3bdf537f836dc98764216483485a4..0adb02f10515f8b48a63286ee8171fc0d861b619 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartEmptyStatement.java
@@ -10,17 +10,11 @@ package com.google.dart.compiler.ast;
 public class DartEmptyStatement extends DartStatement {
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    v.visit(this, ctx);
-    v.endVisit(this, ctx);
+  public void visitChildren(ASTVisitor<?> visitor) {
   }
 
   @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
-  }
-
-  @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitEmptyStatement(this);
   }
 }