Remove more warnings.

lib/compiler/implementation/elements/elements.dart

 // 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.
 
 #library('elements');
 
 #import('dart:uri');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
@@ skipping 1607 matching lines @@
   /**
    * The compile-time constant which this annotation resolves to.
    * In the mirror system, this would be an object mirror.
    */
   abstract Constant get value;
   Element annotatedElement;
   int resolutionState;
 
   MetadataAnnotation([this.resolutionState = STATE_NOT_STARTED]);
 
-  abstract Node parseNode(DiagnosticListener listener);
-
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }