Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartBooleanLiteral.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartBooleanLiteral.java b/compiler/java/com/google/dart/compiler/ast/DartBooleanLiteral.java
index f1da6cb7af6b24c4f96d310ad2436a79c6005a58..cdf51600daced020b1af55cddca5e41ec544c50e 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartBooleanLiteral.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartBooleanLiteral.java
@@ -24,17 +24,11 @@ public class DartBooleanLiteral extends DartLiteral {
   }
 
   @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.visitBooleanLiteral(this);
   }
 }