Fix for making variable initializer synthetic.

pkg/analyzer/test/src/summary/resynthesize_test.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.
 
 library test.src.serialization.elements_test;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 876 matching lines @@
   }
 
   void compareVariableInitializers(
       FunctionElement resynthesized, FunctionElement original, String desc) {
     if (original == null && resynthesized == null) {
       return;
     }
     expect(resynthesized, isNotNull, reason: desc);
     expect(resynthesized.nameOffset, original.nameOffset, reason: desc);
     expect(resynthesized.name, original.name, reason: desc);
+    expect(resynthesized.isSynthetic, original.isSynthetic, reason: desc);
     // TODO(scheglov) replace this method with compareFunctionElements()
     // once we resynthesize initializers return types.
   }
 
   /**
    * Serialize the given [library] into a summary.  Then create a
    * [_TestSummaryResynthesizer] which can deserialize it, along with any
    * references it makes to `dart:core`.
    *
    * Errors will lead to a test failure unless [allowErrors] is `true`.
@@ skipping 2788 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }