Revert "Fix test failures on the bots"

pkg/analysis_server/test/abstract_context.dart

Index: pkg/analysis_server/test/abstract_context.dart
diff --git a/pkg/analysis_server/test/abstract_context.dart b/pkg/analysis_server/test/abstract_context.dart
index ca6e57f8885d73779999d632df6414f3f37d847e..80498906924e085d80ebbe5ba320627935ba336d 100644
--- a/pkg/analysis_server/test/abstract_context.dart
+++ b/pkg/analysis_server/test/abstract_context.dart
@@ -13,7 +13,6 @@ import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source_io.dart';
-import 'package:plugin/manager.dart';
 
 import 'mock_sdk.dart';
 
@@ -85,8 +84,6 @@ class AbstractContextTest {
   }
 
   void setUp() {
-    ExtensionManager extensionManager = new ExtensionManager();
-    extensionManager.processPlugins(AnalysisEngine.instance.supportedPlugins);
     setupResourceProvider();
     resourceResolver = new ResourceUriResolver(provider);
     packageMap = new Map<String, List<Folder>>();