Remove the non-driver versions of several tests

pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart

Index: pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart
diff --git a/pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart b/pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart
index c791de8be70b1bf3ed84c56e17385473ca04bc32..75c5ac58e588c18a43166d800261f849c6322d84 100644
--- a/pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart
+++ b/pkg/analysis_server/test/services/completion/dart/completion_manager_test.dart
@@ -22,13 +22,15 @@ import 'completion_contributor_util.dart';
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(CompletionManagerTest);
-    defineReflectiveTests(CompletionManagerTest_Driver);
   });
 }
 
 @reflectiveTest
 class CompletionManagerTest extends DartCompletionContributorTest {
   @override
+  bool get enableNewAnalysisDriver => true;
+
+  @override
   DartCompletionContributor createContributor() {
     return new ImportedReferenceContributor();
   }
@@ -111,9 +113,3 @@ part '$testFile';
     assertImportedLib('/libA.dart');
   }
 }
-
-@reflectiveTest
-class CompletionManagerTest_Driver extends CompletionManagerTest {
-  @override
-  bool get enableNewAnalysisDriver => true;
-}