Minor clean-ups and rename

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, [ValidateExtension validateExtension]) =>
+              registerExtensionPoint(plugin, identifier, validateExtension));
     }
     for (Plugin plugin in plugins) {
       plugin.registerExtensions(registerExtension);
     }
   }
 
   /**
    * Register an [extension] to the extension point with the given unique
    * [identifier].
    */
   void registerExtension(String identifier, Object extension) {
     ExtensionPointImpl extensionPoint = extensionPoints[identifier];
     if (extensionPoint == null) {
       throw new ExtensionError(
           'There is no extension point with the id "$identifier"');
     }
     extensionPoint.add(extension);
   }
 
   /**
    * Register an extension point being defined by the given [plugin] with the
-   * given simple [identifier] and [validator].
+   * given simple [identifier] and [validateExtension].
    */
   ExtensionPoint registerExtensionPoint(Plugin plugin, String identifier,
-      ExtensionValidator validator) {
+      ValidateExtension validateExtension) {
     String uniqueIdentifier = Plugin.buildUniqueIdentifier(plugin, identifier);
     if (extensionPoints.containsKey(uniqueIdentifier)) {
       throw new ExtensionError(
           'There is already an extension point with the id "$identifier"');
     }
     ExtensionPointImpl extensionPoint =
-        new ExtensionPointImpl(plugin, identifier, validator);
+        new ExtensionPointImpl(plugin, identifier, validateExtension);
     extensionPoints[uniqueIdentifier] = extensionPoint;
     return extensionPoint;
   }
 }
 
 /**
  * A concrete representation of an extension point.
  */
 class ExtensionPointImpl implements ExtensionPoint {
   @override
   final Plugin plugin;
 
   @override
   final String simpleIdentifier;
 
   /**
-   * The validator used to validate extensions to this extension point.
+   * The function used to validate extensions to this extension point.
    */
-  final ExtensionValidator validator;
+  final ValidateExtension validateExtension;
 
   /**
    * The list of extensions to this extension point.
    */
   final List<Object> _extensions = <Object>[];
 
   /**
    * Initialize a newly create extension point to belong to the given [plugin]
-   * and have the given [simpleIdentifier]. If the [validator] is non-`null` it
-   * will be used to validate extensions associated with this extension point.
+   * and have the given [simpleIdentifier]. If [validateExtension] is non-`null`
+   * it will be used to validate extensions associated with this extension
+   * point.
    */
-  ExtensionPointImpl(this.plugin, this.simpleIdentifier, this.validator);
+  ExtensionPointImpl(this.plugin, this.simpleIdentifier,
+      this.validateExtension);
 
   /**
    * Return a list containing all of the extensions that have been registered
    * for this extension point.
    */
   List<Object> get extensions => new UnmodifiableListView(_extensions);
 
   /**
    * Return the identifier used to uniquely identify this extension point. The
    * unique identifier is the identifier for the plugin, followed by a period
    * (`.`), followed by the [simpleIdentifier] for the extension point.
    */
   String get uniqueIdentifier =>
       Plugin.buildUniqueIdentifier(plugin, simpleIdentifier);
 
   /**
    * 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);
+    if (validateExtension != null) {
+      validateExtension(extension);
     }
     _extensions.add(extension);
   }
 }