Add support for metadata annotation syntax (issue 4056)

compiler/java/com/google/dart/compiler/ast/DartNodeWithMetadata.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;
+
+/**
+ * The abstract class {@code DartNodeWithMetadata} defines the behavior of nodes that can have
+ * metadata associated with them.
+ */
+public abstract class DartNodeWithMetadata extends DartNode {
+  private NodeList<DartMetadata> metadata = NodeList.create(this);

[scheglov, 2012/08/17 17:37:03]

Spec: "Metadata consists of  series of annotations".
So, may be DartMetadata should  be named DartAnnotation?

[Brian Wilkerson, 2012/08/17 18:28:02]

Done

+
+  protected DartNodeWithMetadata() {
+    super();
+  }
+
+  public NodeList<DartMetadata> getMetadata() {
+    return metadata;
+  }
+
+  public void setMetadata(List<DartMetadata> metadata) {
+    this.metadata.addAll(metadata);
+  }
+
+  @Override
+  public void visitChildren(ASTVisitor<?> visitor) {
+    metadata.accept(visitor);
+  }
+}