MetadataAnnotation should be spannable.

dart/sdk/lib/_internal/compiler/implementation/scanner/class_element_parser.dart

 // Copyright (c) 2011, 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.
 
 part of scanner;
 
 class ClassElementParser extends PartialParser {
   ClassElementParser(Listener listener) : super(listener);
 
   Token parseClassBody(Token token) => fullParseClassBody(token);
@@ skipping 174 matching lines @@
     metadata = const Link<MetadataAnnotation>();
     enclosingElement.addMember(memberElement, listener);
   }
 
   void endMetadata(Token beginToken, Token periodBeforeName, Token endToken) {
     popNode(); // Discard arguments.
     if (periodBeforeName != null) {
       popNode(); // Discard name.
     }
     popNode(); // Discard node (Send or Identifier).
-    pushMetadata(new PartialMetadataAnnotation(beginToken));
+    pushMetadata(new PartialMetadataAnnotation(beginToken, endToken));
   }
 }