Generalize DartSdkManager to support embedder SDKs

pkg/analysis_server/test/domain_server_test.dart

Index: pkg/analysis_server/test/domain_server_test.dart
diff --git a/pkg/analysis_server/test/domain_server_test.dart b/pkg/analysis_server/test/domain_server_test.dart
index 5c3d75e6bc4afd17d35c9d27d45f2de8c91eba75..5ffd328f80bfab328e8090f166ff7f4daefcb9ae 100644
--- a/pkg/analysis_server/test/domain_server_test.dart
+++ b/pkg/analysis_server/test/domain_server_test.dart
@@ -11,6 +11,7 @@ import 'package:analysis_server/src/domain_server.dart';
 import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
+import 'package:analyzer/src/generated/sdk.dart';
 import 'package:plugin/manager.dart';
 import 'package:unittest/unittest.dart';
 
@@ -37,7 +38,7 @@ main() {
         null,
         serverPlugin,
         new AnalysisServerOptions(),
-        (_) => new MockSdk(),
+        new DartSdkManager('', false, (_) => new MockSdk()),
         InstrumentationService.NULL_SERVICE);
     handler = new ServerDomainHandler(server);
   });