Serialize NativeBehavior for elements

tests/compiler/dart2js/serialization/compilation_test.dart

 // Copyright (c) 2016, 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 dart2js.serialization_compilation_test;
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/compiler.dart';
 import 'package:compiler/src/filenames.dart';
@@ skipping 20 matching lines @@
   });
 }
 
 Future compile(
     Uri entryPoint,
     {Map<String, String> sourceFiles: const <String, String>{},
      List<Uri> resolutionInputs,
      int index,
      Test test,
      bool verbose: false}) async {
-  if (test != null && test.name == 'Disable tree shaking through reflection') {
-    // TODO(johnniwinther): Support serialization of native element data.
-    return;
-  }
   String testDescription = test != null ? test.name : '${entryPoint}';
   String id = index != null ? '$index: ' : '';
   print('------------------------------------------------------------------');
   print('compile ${id}${testDescription}');
   print('------------------------------------------------------------------');
   OutputCollector outputCollector = new OutputCollector();
   await runCompiler(
       entryPoint: entryPoint,
       memorySourceFiles: sourceFiles,
       resolutionInputs: resolutionInputs,
       options: [],
       outputProvider: outputCollector);
   if (verbose) {
     print(outputCollector.getOutput('', 'js'));
   }
 }