Add the ability to whitelist plugins

pkg/analysis_server/test/analysis_abstract.dart

Index: pkg/analysis_server/test/analysis_abstract.dart
diff --git a/pkg/analysis_server/test/analysis_abstract.dart b/pkg/analysis_server/test/analysis_abstract.dart
index 580dcf1b51f283d309326a9fa1dbf8f790750a52..53f04afd31955a4fabe8002e2e05828b7c1f5ed7 100644
--- a/pkg/analysis_server/test/analysis_abstract.dart
+++ b/pkg/analysis_server/test/analysis_abstract.dart
@@ -365,4 +365,9 @@ class TestPluginManager implements PluginManager {
     fail('Unexpected invocation of stopAll');
     return null;
   }
+
+  @override
+  void whitelistEverything() {
+    fail('Unexpected invocation of whitelistEverything');
+  }
 }