Split "_Driver" tests to separate test files.

pkg/analysis_server/test/integration/analysis/update_content_test.dart

 // Copyright (c) 2014, 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';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(UpdateContentTest);
-    defineReflectiveTests(UpdateContentTest_Driver);
   });
 }
 
 class AbstractUpdateContentTest extends AbstractAnalysisServerIntegrationTest {
   test_updateContent() async {
     String path = sourcePath('test.dart');
     String goodText = r'''
 main() {
   print("Hello, world!");
 }''';
@@ skipping 78 matching lines @@
     await analysisFinished;
     expect(currentAnalysisErrors[pathname], isList);
     List<AnalysisError> errors2 = currentAnalysisErrors[pathname];
     expect(errors2, hasLength(1));
     expect(errors2[0].location.file, equals(pathname));
   }
 }
 
 @reflectiveTest
 class UpdateContentTest extends AbstractUpdateContentTest {}
-
-@reflectiveTest
-class UpdateContentTest_Driver extends AbstractUpdateContentTest {
-  @override
-  bool get enableNewAnalysisDriver => true;
-}