Remove uses of the old plugin model from the analysis server

pkg/analysis_server/test/edit/format_test.dart

Index: pkg/analysis_server/test/edit/format_test.dart
diff --git a/pkg/analysis_server/test/edit/format_test.dart b/pkg/analysis_server/test/edit/format_test.dart
index d7c59917589eb1ca5bb0e2b8ab3bdfa07ae3eb2f..ced5eabf4b83c4f05abcef118e2585b794eade6b 100644
--- a/pkg/analysis_server/test/edit/format_test.dart
+++ b/pkg/analysis_server/test/edit/format_test.dart
@@ -8,7 +8,6 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/edit/edit_domain.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
-import 'package:plugin/manager.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -27,8 +26,6 @@ class FormatTest extends AbstractAnalysisTest {
   void setUp() {
     super.setUp();
     createProject();
-    ExtensionManager manager = new ExtensionManager();
-    manager.processPlugins([server.serverPlugin]);
     handler = new EditDomainHandler(server);
   }