Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartUnqualifiedInvocation.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartUnqualifiedInvocation.java b/compiler/java/com/google/dart/compiler/ast/DartUnqualifiedInvocation.java
index 681052efef3df6a5536739ea678449b8f67e930d..67df500f264d0824383afe3748673891484a02e6 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartUnqualifiedInvocation.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartUnqualifiedInvocation.java
@@ -25,22 +25,13 @@ public class DartUnqualifiedInvocation extends DartInvocation {
   }
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    if (v.visit(this, ctx)) {
-      target = becomeParentOf(v.accept(target));
-      v.acceptWithInsertRemove(this, getArgs());
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
+  public void visitChildren(ASTVisitor<?> visitor) {
     target.accept(visitor);
     visitor.visit(getArgs());
   }
 
   @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitUnqualifiedInvocation(this);
   }
 }