Make the analysis server integration tests driver only.

pkg/analysis_server/test/integration/execution/delete_context_test.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../integration_tests.dart';
 
@@ skipping 22 matching lines @@
 
     // After the delete, expect this to fail.
     try {
       result =
           await sendExecutionMapUri(contextId, uri: 'package:foo/main.dart');
       fail('expected exception after context delete');
     } on ServerErrorMessage catch (message) {
       expect(message.error['code'], 'INVALID_PARAMETER');
     }
   }
-
-  @override
-  bool get enableNewAnalysisDriver => true;
 }