Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartWhileStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartWhileStatement.java b/compiler/java/com/google/dart/compiler/ast/DartWhileStatement.java
index 136fd6379557d0e5d12c23a12cff70b5bbea2284..f171fbbe9bd5510b5e1e72170acc88d53856fd7a 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartWhileStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartWhileStatement.java
@@ -26,22 +26,13 @@ public class DartWhileStatement extends DartStatement {
   }
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    if (v.visit(this, ctx)) {
-      condition = becomeParentOf(v.accept(condition));
-      body = becomeParentOf(v.accept(body));
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
+  public void visitChildren(ASTVisitor<?> visitor) {
     condition.accept(visitor);
     body.accept(visitor);
   }
 
   @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitWhileStatement(this);
   }
 }