Fix several element properties in serialization.

pkg/compiler/lib/src/elements/common.dart

 // Copyright (c) 2015, 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.
 
 /// Mixins that implement convenience methods on [Element] subclasses.
 
 library elements.common;
 
 import '../common/names.dart' show Names, Uris;
 import '../core_types.dart' show CoreClasses;
@@ skipping 576 matching lines @@
 
   @override
   void forEachLocalMember(void f(Element member)) {
     constructors.forEach(f);
     if (mixin != null)
       mixin.forEachLocalMember((Element mixedInElement) {
       if (mixedInElement.isInstanceMember) f(mixedInElement);
     });
   }
 }
+
+abstract class AbstractFieldElementCommon implements AbstractFieldElement {
+  @override
+  bool get isInstanceMember {
+    return isClassMember && !isStatic;
+  }
+
+  @override
+  bool get isAbstract {
+    return getter != null && getter.isAbstract ||
+        setter != null && setter.isAbstract;
+  }
+}