Remove unused field

pkg/analysis_server/lib/src/context_manager.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 context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:core' hide Resource;
@@ skipping 28 matching lines @@
 import 'package:package_config/src/packages_impl.dart' show MapPackages;
 import 'package:path/path.dart' as pathos;
 import 'package:watcher/watcher.dart';
 import 'package:yaml/yaml.dart';
 
 /**
  * Information tracked by the [ContextManager] for each context.
  */
 class ContextInfo {
   /**
-   * The [ContextManager] which is tracking this information.
-   */
-  final ContextManagerImpl contextManager;
-
-  /**
    * The [Folder] for which this information object is created.
    */
   final Folder folder;
 
   /// The [PathFilter] used to filter sources from being analyzed.
   final PathFilter pathFilter;
 
   /**
    * The enclosed pubspec-based contexts.
    */
@@ skipping 31 matching lines @@
   AnalysisContext context;
 
   /**
    * Map from full path to the [Source] object, for each source that has been
    * added to the context.
    */
   Map<String, Source> sources = new HashMap<String, Source>();
 
   ContextInfo(ContextManagerImpl contextManager, this.parent, Folder folder,
       File packagespecFile, this.packageRoot)
-      : contextManager = contextManager,
-        folder = folder,
+      : folder = folder,
         pathFilter = new PathFilter(
             folder.path, null, contextManager.resourceProvider.pathContext) {
     packageDescriptionPath = packagespecFile.path;
     parent.children.add(this);
   }
 
   /**
    * Create the virtual [ContextInfo] which acts as an ancestor to all other
    * [ContextInfo]s.
    */
   ContextInfo._root()
-      : contextManager = null,
-        folder = null,
+      : folder = null,
         pathFilter = null;
 
   /**
    * Iterate through all [children] and their children, recursively.
    */
   Iterable<ContextInfo> get descendants sync* {
     for (ContextInfo child in children) {
       yield child;
       yield* child.descendants;
     }
@@ skipping 1665 matching lines @@
       ResourceProvider resourceProvider) {
     if (packages != null) {
       // Construct package map for the SdkExtUriResolver.
       Map<String, List<Folder>> packageMap = buildPackageMap(resourceProvider);
       return <UriResolver>[new SdkExtUriResolver(packageMap)];
     } else {
       return const <UriResolver>[];
     }
   }
 }