Add support for metadata annotation syntax (issue 4056)

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 package com.google.dart.compiler.ast;
 
 import java.util.List;
 
 /**
  * Represents a Dart field definition.
  */
-public class DartFieldDefinition extends DartNode {
+public class DartFieldDefinition extends DartNodeWithMetadata {
 
   private DartTypeNode typeNode;
   private final NodeList<DartField> fields = NodeList.create(this);
 
   public DartFieldDefinition(DartTypeNode typeNode, List<DartField> fields) {
     this.setTypeNode(typeNode);
     this.fields.addAll(fields);
   }
 
   public DartTypeNode getTypeNode() {
@@ skipping 12 matching lines @@
   public void visitChildren(ASTVisitor<?> visitor) {
     safelyVisitChild(typeNode, visitor);
     fields.accept(visitor);
   }
 
   @Override
   public <R> R accept(ASTVisitor<R> visitor) {
     return visitor.visitFieldDefinition(this);
   }
 }