Remove uses of the old plugin model from the analysis server

pkg/analysis_server/test/socket_server_test.dart

Index: pkg/analysis_server/test/socket_server_test.dart
diff --git a/pkg/analysis_server/test/socket_server_test.dart b/pkg/analysis_server/test/socket_server_test.dart
index f25ef4499594d24e248c46f4c0c6af391d0fee5b..244e7c86f083ad79b8203042d011bb14d86b3abb 100644
--- a/pkg/analysis_server/test/socket_server_test.dart
+++ b/pkg/analysis_server/test/socket_server_test.dart
@@ -8,13 +8,11 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_constants.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/analysis_server.dart';
-import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analysis_server/src/socket_server.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/generated/sdk.dart';
-import 'package:plugin/manager.dart';
 import 'package:test/test.dart';
 
 import 'mocks.dart';
@@ -112,9 +110,6 @@ class SocketServerTest {
   static SocketServer _createSocketServer() {
     PhysicalResourceProvider resourceProvider =
         PhysicalResourceProvider.INSTANCE;
-    ServerPlugin serverPlugin = new ServerPlugin();
-    ExtensionManager manager = new ExtensionManager();
-    manager.processPlugins([serverPlugin]);
     return new SocketServer(
         new AnalysisServerOptions(),
         new DartSdkManager('', false),
@@ -122,7 +117,6 @@ class SocketServerTest {
             FolderBasedDartSdk.defaultSdkDirectory(resourceProvider)),
         InstrumentationService.NULL_SERVICE,
         null,
-        serverPlugin,
         null,
         null);
   }