Removed fixed dependencies

packages/analyzer/lib/src/task/model.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.task.model;
 
-import 'package:analyzer/src/generated/engine.dart' hide AnalysisTask;
+import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/task/inputs.dart';
 import 'package:analyzer/task/model.dart';
 
 /**
  * The default [ResultCachingPolicy], results are never flushed.
  */
-const ResultCachingPolicy DEFAULT_CACHING_POLICY =
+const ResultCachingPolicy<Object> DEFAULT_CACHING_POLICY =
     const SimpleResultCachingPolicy(-1, -1);
 
 /**
  * A concrete implementation of a [ListResultDescriptor].
  */
 class ListResultDescriptorImpl<E> extends ResultDescriptorImpl<List<E>>
     implements ListResultDescriptor<E> {
   /**
    * Initialize a newly created analysis result to have the given [name] and
    * [defaultValue]. If a [cachingPolicy] is provided, it will control how long
@@ skipping 94 matching lines @@
   @override
   final CreateTaskInputs createTaskInputs;
 
   /**
    * A list of the analysis results that will be computed by the described task.
    */
   @override
   final List<ResultDescriptor> results;
 
   /**
+   * The function used to determine whether the described task is suitable for
+   * a given target.
+   */
+  final SuitabilityFor _suitabilityFor;
+
+  /**
    * Initialize a newly created task descriptor to have the given [name] and to
-   * describe a task that takes the inputs built using the given [createTaskInputs],
-   * and produces the given [results]. The [buildTask] will be used to create
-   * the instance of [AnalysisTask] thusly described.
+   * describe a task that takes the inputs built using the given [inputBuilder],
+   * and produces the given [results]. The [buildTask] function will be used to
+   * create the instance of [AnalysisTask] being described. If provided, the
+   * [isAppropriateFor] function will be used to determine whether the task can
+   * be used on a specific target.
    */
   TaskDescriptorImpl(
-      this.name, this.buildTask, this.createTaskInputs, this.results);
+      this.name, this.buildTask, this.createTaskInputs, this.results,
+      {SuitabilityFor suitabilityFor})
+      : _suitabilityFor = suitabilityFor ?? _defaultSuitability;
 
   @override
   AnalysisTask createTask(AnalysisContext context, AnalysisTarget target,
       Map<String, dynamic> inputs) {
     AnalysisTask task = buildTask(context, target);
     task.inputs = inputs;
     return task;
   }
 
   @override
+  TaskSuitability suitabilityFor(AnalysisTarget target) =>
+      _suitabilityFor(target);
+
+  @override
   String toString() => name;
+
+  /**
+   * The function that will be used to determine the suitability of a task if no
+   * other function is provided.
+   */
+  static TaskSuitability _defaultSuitability(AnalysisTarget target) =>
+      TaskSuitability.LOWEST;
 }