Implement `.instanceMembers`.

reflectable/lib/src/reflectable_implementation.dart

 // Copyright (c) 2015, the Dart Team. All rights reserved. Use of this
 // source code is governed by a BSD-style license that can be found in
 // the LICENSE file.
 
 /// Implementation of the reflectable interface using dart mirrors.
 library reflectable.src.reflectable_implementation;
 
 import 'dart:mirrors' as dm;
 import '../capability.dart';
 import '../reflectable.dart' as r;
@@ skipping 474 matching lines @@
 
   @override
   Map<String, r.DeclarationMirror> get declarations {
     // TODO(sigurdm): Possibly cache this.
     Map<String, r.DeclarationMirror> result =
         new Map<String, r.DeclarationMirror>();
     _classMirror.declarations.forEach(
         (Symbol nameSymbol, dm.DeclarationMirror declarationMirror) {
       String name = dm.MirrorSystem.getName(nameSymbol);
       if (declarationMirror is dm.MethodMirror) {
+        if (declarationMirror.isAbstract) {
+          // Dart2js implementation of dart:mirrors does not include abstract
+          // members in declarations. We choose to go the same route.
+          return;
+        }
         if ((declarationMirror.isStatic &&
                 reflectableSupportsStaticInvoke(_reflectable, name)) ||
             reflectableSupportsInstanceInvoke(
                 _reflectable, name, _classMirror)) {
           result[name] = wrapDeclarationMirror(declarationMirror, _reflectable);
         }
       } else if (declarationMirror is dm.VariableMirror) {
         // For variableMirrors we test both for support of the name and the
         // derived setter name.
         if ((declarationMirror.isStatic &&
@@ skipping 481 matching lines @@
   }
 
   @override
   int get hashCode => _sourceLocation.hashCode;
 
   @override
   String toString() {
     return "_SourceLocationImpl('${_sourceLocation}')";
   }
 }