Add support for metadata annotation syntax (issue 4056)

compiler/java/com/google/dart/compiler/ast/DartDeclaration.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;
 
 /**
  * Common supertype for most declarations. A declaration introduces a new name in a scope. Certain
  * tools, such as the IDE, need to know the location of this name, but the name should otherwise be
  * considered a part of the declaration, not an independent node. So the name is not visited when
  * traversing the AST.
  */
-public abstract class DartDeclaration<N extends DartExpression> extends DartNode {
+public abstract class DartDeclaration<N extends DartExpression> extends DartNodeWithMetadata {
 
   private N name; // Not visited.
   private DartComment dartDoc;
-  private DartObsoleteMetadata metadata = DartObsoleteMetadata.EMPTY;
+  private DartObsoleteMetadata obsoleteMetadata = DartObsoleteMetadata.EMPTY;
 
   protected DartDeclaration(N name) {
     this.name = becomeParentOf(name);
   }
 
   public final N getName() {
     return name;
   }
 
   public final void setName(N newName) {
     name = becomeParentOf(newName);
   }
 
   public DartComment getDartDoc() {
     return dartDoc;
   }
 
   public void setDartDoc(DartComment dartDoc) {
     // dartDoc is still parented by the containing DartUnit.
     this.dartDoc = dartDoc;
   }
 
-  public DartObsoleteMetadata getMetadata() {
-    return metadata;
+  public DartObsoleteMetadata getObsoleteMetadata() {
+    return obsoleteMetadata;
   }
 
-  public void setMetadata(DartObsoleteMetadata metadata) {
-    this.metadata = metadata;
+  public void setObsoleteMetadata(DartObsoleteMetadata metadata) {
+    this.obsoleteMetadata = metadata;
   }
 
   @Override
   public void visitChildren(ASTVisitor<?> visitor) {
+    super.visitChildren(visitor);
     safelyVisitChild(name, visitor);
   }
 }