Removed fixed dependencies

packages/analyzer/lib/src/plugin/options_plugin.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 analyzer.src.plugin.options;
+library analyzer.src.plugin.options_plugin;
 
 import 'package:analyzer/plugin/options.dart';
+import 'package:analyzer/plugin/task.dart';
+import 'package:analyzer/src/task/options.dart';
 import 'package:plugin/plugin.dart';
 
 /// A plugin that defines the extension points and extensions that are defined
 /// by applications that want to consume options defined in the analysis
 /// options file.
 class OptionsPlugin implements Plugin {
   /// The simple identifier of the extension point that allows plugins to
   /// register new options processors.
   static const String OPTIONS_PROCESSOR_EXTENSION_POINT = 'optionsProcessor';
 
+  /// The simple identifier of the extension point that allows plugins to
+  /// register new options validators.
+  static const String OPTIONS_VALIDATOR_EXTENSION_POINT = 'optionsValidator';
+
   /// The unique identifier of this plugin.
   static const String UNIQUE_IDENTIFIER = 'options.core';
 
-  /// The extension point that allows plugins to register new options processors.
-  ExtensionPoint optionsProcessorExtensionPoint;
+  /// The extension point that allows plugins to register new options
+  /// processors.
+  ExtensionPoint<OptionsProcessor> optionsProcessorExtensionPoint;
+
+  /// The extension point that allows plugins to register new options
+  /// validators.
+  ExtensionPoint<OptionsValidator> optionsValidatorExtensionPoint;
 
   /// All contributed options processors.
   List<OptionsProcessor> get optionsProcessors =>
-      optionsProcessorExtensionPoint == null
-          ? const []
-          : optionsProcessorExtensionPoint.extensions;
+      optionsProcessorExtensionPoint?.extensions ?? const <OptionsProcessor>[];
+
+  /// All contributed options validators.
+  List<OptionsValidator> get optionsValidators =>
+      optionsValidatorExtensionPoint?.extensions ?? const <OptionsValidator>[];
 
   @override
   String get uniqueIdentifier => UNIQUE_IDENTIFIER;
 
   @override
   void registerExtensionPoints(RegisterExtensionPoint registerExtensionPoint) {
-    optionsProcessorExtensionPoint = registerExtensionPoint(
-        OPTIONS_PROCESSOR_EXTENSION_POINT, _validateOptionsProcessorExtension);
+    optionsProcessorExtensionPoint = new ExtensionPoint<OptionsProcessor>(
+        this, OPTIONS_PROCESSOR_EXTENSION_POINT, null);
+    registerExtensionPoint(optionsProcessorExtensionPoint);
+    optionsValidatorExtensionPoint = new ExtensionPoint<OptionsValidator>(
+        this, OPTIONS_VALIDATOR_EXTENSION_POINT, null);
+    registerExtensionPoint(optionsValidatorExtensionPoint);
   }
 
   @override
   void registerExtensions(RegisterExtension registerExtension) {
-    // There are no default extensions.
-  }
-
-  /// Validate the given extension by throwing an [ExtensionError] if it is not a
-  /// valid options processor.
-  void _validateOptionsProcessorExtension(Object extension) {
-    if (extension is! OptionsProcessor) {
-      String id = optionsProcessorExtensionPoint.uniqueIdentifier;
-      throw new ExtensionError('Extensions to $id must be an OptionsProcessor');
-    }
+    // Analyze options files.
+    registerExtension(
+        TASK_EXTENSION_POINT_ID, GenerateOptionsErrorsTask.DESCRIPTOR);
+    // Validate analyzer analysis options.
+    registerExtension(
+        OPTIONS_VALIDATOR_EXTENSION_POINT_ID, new AnalyzerOptionsValidator());
   }
 }