Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartFieldDefinition.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartFieldDefinition.java b/compiler/java/com/google/dart/compiler/ast/DartFieldDefinition.java
index 8e90cc0ef00f25ef8dd997078cbd6fa95ae3e405..da502141b22af430ccc332ae255d9f9edb619baa 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartFieldDefinition.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartFieldDefinition.java
@@ -32,18 +32,7 @@ public class DartFieldDefinition extends DartNode {
   }
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    if (v.visit(this, ctx)) {
-      if (getTypeNode() != null) {
-        setTypeNode(v.accept(getTypeNode()));
-      }
-      v.acceptWithInsertRemove(this, getFields());
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
+  public void visitChildren(ASTVisitor<?> visitor) {
     if (getTypeNode() != null) {
       getTypeNode().accept(visitor);
     }
@@ -51,7 +40,7 @@ public class DartFieldDefinition extends DartNode {
   }
 
   @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitFieldDefinition(this);
   }
 }