Make domains plugable

pkg/analysis_server/lib/src/plugin/plugin_impl.dart

 // Copyright (c) 2015, 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 analysis_server.src.plugin.plugin_impl;
 
 import 'dart:collection';
 
 import 'package:analysis_server/plugin/plugin.dart';
 
@@ skipping 12 matching lines @@
   /**
    * Process each of the given [plugins] by allowing them to register extension
    * points and extensions.
    *
    * An [ExtensionError] will be thrown if any of the plugins throws such an
    * exception while registering with this manager.
    */
   void processPlugins(List<Plugin> plugins) {
     for (Plugin plugin in plugins) {
       plugin.registerExtensionPoints(
-          (String identifier, [ExtensionValidator validator]) {
-        registerExtensionPoint(plugin, identifier, validator);
-      });
+          (String identifier, [ExtensionValidator validator]) =>
+              registerExtensionPoint(plugin, identifier, validator));
     }
     for (Plugin plugin in plugins) {
       plugin.registerExtensions(registerExtension);
     }
   }
 
   /**
    * Register an [extension] to the extension point with the given unique
    * [identifier].
    */
@@ skipping 69 matching lines @@
    * Validate that the given [extension] is appropriate for this extension
    * point, and if it is then add it to the list of registered exceptions.
    */
   void add(Object extension) {
     if (validator != null) {
       validator(extension);
     }
     _extensions.add(extension);
   }
 }