Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java b/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
index ee2cb9ee00ec20fcf259c38eb5e42fcaf3db0a24..2ab304ee85b80b09264fe9f0f0a4ae4b59f30974 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
@@ -25,24 +25,14 @@ public class DartReturnStatement extends DartStatement {
   }
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    if (v.visit(this, ctx)) {
-      if (value != null) {
-        value = becomeParentOf(v.accept(value));
-      }
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
+  public void visitChildren(ASTVisitor<?> visitor) {
     if (value != null) {
       value.accept(visitor);
     }
   }
 
   @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitReturnStatement(this);
   }
 }