Switch the default from non-driver to driver in several tests

pkg/analysis_server/test/services/completion/statement/statement_completion_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.
 
 library test.services.completion.statement;
 
 import 'package:analysis_server/src/protocol_server.dart';
 import 'package:analysis_server/src/services/completion/statement/statement_completion.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:test/test.dart';
@@ skipping 12 matching lines @@
     defineReflectiveTests(_SimpleCompletionTest);
     defineReflectiveTests(_SwitchCompletionTest);
     defineReflectiveTests(_TryCompletionTest);
     defineReflectiveTests(_WhileCompletionTest);
   });
 }
 
 class StatementCompletionTest extends AbstractSingleUnitTest {
   SourceChange change;
 
-  bool get enableNewAnalysisDriver => true;
-
   int _after(String source, String match) =>
       source.indexOf(match) + match.length;
 
   int _afterLast(String source, String match) =>
       source.lastIndexOf(match) + match.length;
 
   void _assertHasChange(String message, String expectedCode, [Function cmp]) {
     if (change.message == message) {
       if (!change.edits.isEmpty) {
         String resultCode =
@@ skipping 1422 matching lines @@
         '''
 main() {
   while () {
     ////
   }
 }
 ''',
         (s) => _after(s, 'while ('));
   }
 }