Use NodeList where possible.

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

Index: compiler/java/com/google/dart/compiler/ast/DartVariableStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartVariableStatement.java b/compiler/java/com/google/dart/compiler/ast/DartVariableStatement.java
index e3d18e2978054665f8c774527c9d3ee8b025cf4b..7f5a5612548ecd6d310029d84b9192d08e432094 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartVariableStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartVariableStatement.java
@@ -11,7 +11,7 @@ import java.util.List;
  */
 public class DartVariableStatement extends DartStatement {
 
-  private final List<DartVariable> vars;
+  private final NodeList<DartVariable> vars = NodeList.create(this);
   private DartTypeNode typeNode;
   private final Modifiers modifiers;
 
@@ -20,7 +20,7 @@ public class DartVariableStatement extends DartStatement {
   }
 
   public DartVariableStatement(List<DartVariable> vars, DartTypeNode type, Modifiers modifiers) {
-    this.vars = becomeParentOf(vars);
+    this.vars.addAll(vars);
     this.typeNode = becomeParentOf(type);
     this.modifiers = modifiers;
   }
@@ -42,7 +42,7 @@ public class DartVariableStatement extends DartStatement {
     if (typeNode != null) {
       typeNode.accept(visitor);
     }
-    visitor.visit(vars);
+    vars.accept(visitor);
   }
 
   @Override