Remove unused method and field from DartSdkManager

pkg/analysis_server/test/context_manager_test.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 test.context.directory.manager;
 
 import 'dart:collection';
 
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analyzer/error/error.dart';
@@ skipping 1773 matching lines @@
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins(plugins);
   }
 
   UriResolver providePackageResolver(Folder folder) => packageResolver;
 
   void setUp() {
     processRequiredPlugins();
     resourceProvider = new MemoryResourceProvider();
     packageMapProvider = new MockPackageMapProvider();
-    DartSdk sdk = new MockSdk(resourceProvider: resourceProvider);
-    DartSdkManager sdkManager = new DartSdkManager('/', false, (_) => sdk);
+    // Create an SDK in the mock file system.
+    new MockSdk(resourceProvider: resourceProvider);
+    DartSdkManager sdkManager = new DartSdkManager('/', false);
     manager = new ContextManagerImpl(
         resourceProvider,
         sdkManager,
         providePackageResolver,
         packageMapProvider,
         analysisFilesGlobs,
         InstrumentationService.NULL_SERVICE,
         new AnalysisOptionsImpl());
     callbacks = new TestContextManagerCallbacks(resourceProvider);
     manager.callbacks = callbacks;
@@ skipping 892 matching lines @@
     expect(currentContextPaths, unorderedEquals(expected));
   }
 
   @override
   void computingPackageMap(bool computing) {
     // Do nothing.
   }
 
   @override
   ContextBuilder createContextBuilder(Folder folder, AnalysisOptions options) {
-    DartSdkManager sdkManager = new DartSdkManager('/', false, null);
+    DartSdkManager sdkManager = new DartSdkManager('/', false);
     ContextBuilder builder =
         new ContextBuilder(resourceProvider, sdkManager, new ContentCache());
     builder.defaultOptions = options;
     return builder;
   }
 
   @override
   void moveContext(Folder from, Folder to) {
     String path = from.path;
     String path2 = to.path;
@@ skipping 37 matching lines @@
 class TestUriResolver extends UriResolver {
   Map<Uri, Source> uriMap;
 
   TestUriResolver(this.uriMap);
 
   @override
   Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     return uriMap[uri];
   }
 }