Use ASTVisitor as in new AST.

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

Index: compiler/java/com/google/dart/compiler/ast/DartParameter.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartParameter.java b/compiler/java/com/google/dart/compiler/ast/DartParameter.java
index 9c82f8c06fbbf04fe02e35c298ec8b24d6464f9c..e2ddb2559f99b81a5d7b3fd7bef5f7a7b6ca3270 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartParameter.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartParameter.java
@@ -93,23 +93,7 @@ public class DartParameter extends DartDeclaration<DartExpression> implements Ha
   }
 
   @Override
-  public void traverse(DartVisitor v, DartContext ctx) {
-    if (v.visit(this, ctx)) {
-      if (typeNode != null) {
-        typeNode = becomeParentOf(v.accept(typeNode));
-      }
-      if (defaultExpr != null) {
-        defaultExpr = becomeParentOf(v.accept(defaultExpr));
-      }
-      if (functionParameters != null) {
-        v.acceptWithInsertRemove(this, functionParameters);
-      }
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public void visitChildren(DartPlainVisitor<?> visitor) {
+  public void visitChildren(ASTVisitor<?> visitor) {
     if (typeNode != null) {
       typeNode.accept(visitor);
     }
@@ -120,7 +104,7 @@ public class DartParameter extends DartDeclaration<DartExpression> implements Ha
   }
 
   @Override
-  public <R> R accept(DartPlainVisitor<R> visitor) {
+  public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitParameter(this);
   }
 }