One extension manager (to bind them all).

pkg/analysis_server/lib/src/server/driver.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library driver;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:math';
 
@@ skipping 384 matching lines @@
     AnalysisEngine.instance.instrumentationService = service;
     //
     // Enable the new task model, if appropriate.
     //
     AnalysisEngine.instance.useTaskModel = !results[DISABLE_NEW_TASK_MODEL];
     //
     // Process all of the plugins so that extensions are registered.
     //
     ServerPlugin serverPlugin = new ServerPlugin();
     List<Plugin> plugins = <Plugin>[];
-    plugins.addAll(AnalysisEngine.instance.supportedPlugins);
     plugins.add(serverPlugin);
     plugins.addAll(_userDefinedPlugins);
     plugins.add(linterPlugin);
-    ExtensionManager manager = new ExtensionManager();
-    manager.processPlugins(plugins);
+
+    // Defer to the extension manager in AE for plugin registration.
+    AnalysisEngine.instance.userDefinedPlugins = plugins;
+    // Force registration.
+    AnalysisEngine.instance.taskManager;
+
     //
     // Create the sockets and start listening for requests.
     //
     socketServer = new SocketServer(analysisServerOptions, defaultSdk, service,
         serverPlugin, packageResolverProvider);
     httpServer = new HttpAnalysisServer(socketServer);
     stdioServer = new StdioAnalysisServer(socketServer);
     socketServer.userDefinedPlugins = _userDefinedPlugins;
 
     if (serve_http) {
@@ skipping 144 matching lines @@
       uuidFile.parent.createSync(recursive: true);
       uuidFile.writeAsStringSync(uuid);
     } catch (exception, stackTrace) {
       service.logPriorityException(exception, stackTrace);
       // Slightly alter the uuid to indicate it was not persisted
       uuid = 'temp-$uuid';
     }
     return uuid;
   }
 }