Support parameter metadata.

sdk/lib/_internal/compiler/implementation/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.
 
 part of resolution;
 
 /**
  * [SignatureResolver] resolves function signatures.
  */
 class SignatureResolver extends CommonResolverVisitor<Element> {
@@ skipping 45 matching lines @@
     }
     if (node.modifiers.isStatic()) {
       error(node, MessageKind.FORMAL_DECLARED_STATIC);
     }
 
     if (currentDefinitions != null) {
       cancel(node, 'function type parameters not supported');
     }
     currentDefinitions = node;
     Element element = definition.accept(this);
+    if (currentDefinitions.metadata != null) {
+      // TODO(johnniwinther): Unify handling of metadata on locals/formals.
+      for (Link<Node> link = currentDefinitions.metadata.nodes;
+           !link.isEmpty;
+           link = link.tail) {
+        ParameterMetadataAnnotation metadata =
+            new ParameterMetadataAnnotation(link.head);
+        element.addMetadata(metadata);
+        addDeferredAction(element, () {
+          metadata.ensureResolved(compiler);
+        });
+      }
+    }
     currentDefinitions = null;
     return element;
   }
 
   void validateName(Identifier node) {
     String name = node.source;
     if (isOptionalParameter &&
         optionalParametersAreNamed &&
         isPrivateName(node.source)) {
       compiler.reportError(node, MessageKind.PRIVATE_NAMED_PARAMETER);
@@ skipping 185 matching lines @@
     node.accept(new ResolverVisitor(compiler, enclosingElement,
                                     new TreeElementMapping(enclosingElement)));
   }
 
   // TODO(ahe): This is temporary.
   ClassElement get currentClass {
     return enclosingElement.isMember()
       ? enclosingElement.getEnclosingClass() : null;
   }
 }