Remove unused method and field from DartSdkManager

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 43938dd7a0efb8234257dfb999f73b268b2b7e98..a6ea8b176244caf7aaf9c62b996604c7827bd6b3 100644
--- a/pkg/analysis_server/test/socket_server_test.dart
+++ b/pkg/analysis_server/test/socket_server_test.dart
@@ -113,12 +113,11 @@ class SocketServerTest {
     ServerPlugin serverPlugin = new ServerPlugin();
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins([serverPlugin]);
-    SdkCreator sdkCreator = (_) => new FolderBasedDartSdk(resourceProvider,
-        FolderBasedDartSdk.defaultSdkDirectory(resourceProvider));
     return new SocketServer(
         new AnalysisServerOptions(),
-        new DartSdkManager('', false, sdkCreator),
-        sdkCreator(null),
+        new DartSdkManager('', false),
+        new FolderBasedDartSdk(resourceProvider,
+            FolderBasedDartSdk.defaultSdkDirectory(resourceProvider)),
         InstrumentationService.NULL_SERVICE,
         serverPlugin,
         null,