Clean-up the registration of plugins

pkg/analyzer/test/src/context/abstract_context.dart

Index: pkg/analyzer/test/src/context/abstract_context.dart
diff --git a/pkg/analyzer/test/src/context/abstract_context.dart b/pkg/analyzer/test/src/context/abstract_context.dart
index 135fd426a8a7e4681de402efe8ec2d0261c7b5f4..92c39ea2b266fa2b1162f97120b1f9e63f547c9a 100644
--- a/pkg/analyzer/test/src/context/abstract_context.dart
+++ b/pkg/analyzer/test/src/context/abstract_context.dart
@@ -15,6 +15,8 @@ import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/driver.dart';
 import 'package:analyzer/task/model.dart';
+import 'package:plugin/manager.dart';
+import 'package:plugin/plugin.dart';
 import 'package:unittest/unittest.dart';
 
 import 'mock_sdk.dart';
@@ -124,6 +126,14 @@ class AbstractContextTest {
   }
 
   void setUp() {
+    List<Plugin> plugins = <Plugin>[];
+    plugins.addAll(AnalysisEngine.instance.requiredPlugins);
+    plugins.add(AnalysisEngine.instance.commandLinePlugin);
+    plugins.add(AnalysisEngine.instance.optionsPlugin);
+
+    ExtensionManager manager = new ExtensionManager();
+    manager.processPlugins(plugins);
+
     prepareAnalysisContext();
   }