Remove the non-driver versions of several tests

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

Index: pkg/analysis_server/test/services/completion/dart/combinator_contributor_test.dart
diff --git a/pkg/analysis_server/test/services/completion/dart/combinator_contributor_test.dart b/pkg/analysis_server/test/services/completion/dart/combinator_contributor_test.dart
index a0d113fee09d8042dbeef7c92fc8ebaf70e7319a..9801a311d9f56bea0c491aed26e99b3a3f3885dc 100644
--- a/pkg/analysis_server/test/services/completion/dart/combinator_contributor_test.dart
+++ b/pkg/analysis_server/test/services/completion/dart/combinator_contributor_test.dart
@@ -13,13 +13,15 @@ import 'completion_contributor_util.dart';
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(CombinatorContributorTest);
-    defineReflectiveTests(CombinatorContributorTest_Driver);
   });
 }
 
 @reflectiveTest
 class CombinatorContributorTest extends DartCompletionContributorTest {
   @override
+  bool get enableNewAnalysisDriver => true;
+
+  @override
   DartCompletionContributor createContributor() {
     return new CombinatorContributor();
   }
@@ -154,9 +156,3 @@ class CombinatorContributorTest extends DartCompletionContributorTest {
         kind: CompletionSuggestionKind.IDENTIFIER);
   }
 }
-
-@reflectiveTest
-class CombinatorContributorTest_Driver extends CombinatorContributorTest {
-  @override
-  bool get enableNewAnalysisDriver => true;
-}