Support metadata on patches.

pkg/compiler/lib/src/resolution/signatures.dart

 // Copyright (c) 2014, 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 dart2js.resolution.signatures;
 
 import '../compiler.dart' show
     Compiler;
 import '../dart_types.dart';
 import '../diagnostics/invariant.dart' show
@@ skipping 84 matching lines @@
     if (node.modifiers.isStatic) {
       compiler.reportError(node, MessageKind.FORMAL_DECLARED_STATIC);
     }
 
     if (currentDefinitions != null) {
       internalError(node, 'function type parameters not supported');
     }
     currentDefinitions = node;
     FormalElementX element = definition.accept(this);
     if (currentDefinitions.metadata != null) {
-      element.metadata = compiler.resolver.resolveMetadata(element, node);
+      element.metadataInternal =
+          compiler.resolver.resolveMetadata(element, node);
     }
     currentDefinitions = null;
     return element;
   }
 
   void validateName(Identifier node) {
     if (isOptionalParameter &&
         optionalParametersAreNamed &&
         Name.isPrivateName(node.source)) {
       compiler.reportError(node, MessageKind.PRIVATE_NAMED_PARAMETER);
@@ skipping 316 matching lines @@
 
   DartType resolveReturnType(TypeAnnotation annotation) {
     if (annotation == null) return const DynamicType();
     DartType result = resolver.resolveTypeAnnotation(annotation);
     if (result == null) {
       return const DynamicType();
     }
     return result;
   }
 }