Reinsert return.

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

 // Copyright (c) 2013, 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 elements.modelx;
 
 import 'dart:uri';
 import 'dart:collection' show LinkedHashMap;
 
 import 'elements.dart';
@@ skipping 1210 matching lines @@
       return 'origin ${super.toString()}';
     } else {
       return super.toString();
     }
   }
 
   bool isAbstract(Compiler compiler) {
     if (super.isAbstract(compiler)) return true;
     if (modifiers.isExternal()) return false;
     if (isFunction() || isAccessor()) {
-      compiler.withCurrentElement(this, () => !parseNode(compiler).hasBody());
+      return compiler.withCurrentElement(this,
+          () => !parseNode(compiler).hasBody());
     }
     return false;
   }
 }
 
 class ConstructorBodyElementX extends FunctionElementX
     implements ConstructorBodyElement {
   FunctionElement constructor;
 
   ConstructorBodyElementX(FunctionElement constructor)
@@ skipping 776 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }