Fix test failures on the bots

pkg/analysis_server/test/domain_diagnostic_test.dart

Index: pkg/analysis_server/test/domain_diagnostic_test.dart
diff --git a/pkg/analysis_server/test/domain_diagnostic_test.dart b/pkg/analysis_server/test/domain_diagnostic_test.dart
index fdb336ea8cda92f3a1cdc905e73a8d2ad390bd33..d13f2af1077ef37b75af3cceb581f9a39516d855 100644
--- a/pkg/analysis_server/test/domain_diagnostic_test.dart
+++ b/pkg/analysis_server/test/domain_diagnostic_test.dart
@@ -10,7 +10,9 @@ import 'package:analysis_server/src/domain_diagnostic.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/engine.dart';
 import 'package:plugin/manager.dart';
+import 'package:plugin/plugin.dart';
 import 'package:unittest/unittest.dart';
 
 import 'mock_sdk.dart';
@@ -29,7 +31,9 @@ main() {
     resourceProvider = new MemoryResourceProvider();
     ExtensionManager manager = new ExtensionManager();
     ServerPlugin serverPlugin = new ServerPlugin();
-    manager.processPlugins([serverPlugin]);
+    List<Plugin> plugins = [serverPlugin];
+    plugins.addAll(AnalysisEngine.instance.supportedPlugins);
+    manager.processPlugins(plugins);
     server = new AnalysisServer(
         serverChannel,
         resourceProvider,