Remove unused method and field from DartSdkManager

pkg/analysis_server/test/single_context_manager_test.dart

 // Copyright (c) 2016, 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.analysis_server.src.single_context_manager;
 
 import 'dart:core';
 
 import 'package:analysis_server/src/single_context_manager.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/util/glob.dart';
 import 'package:linter/src/plugin/linter_plugin.dart';
 import 'package:path/path.dart';
 import 'package:plugin/manager.dart';
 import 'package:plugin/plugin.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'context_manager_test.dart' show TestContextManagerCallbacks;
-import 'mock_sdk.dart';
 import 'mocks.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(SingleContextManagerTest);
   });
 }
 
 @reflectiveTest
 class SingleContextManagerTest {
@@ skipping 22 matching lines @@
   String newFolder(List<String> pathComponents) {
     String folderPath = posix.joinAll(pathComponents);
     resourceProvider.newFolder(folderPath);
     return folderPath;
   }
 
   void setUp() {
     packageResolver = new TestUriResolver();
 
     _processRequiredPlugins();
-    DartSdkManager sdkManager =
-        new DartSdkManager('', false, (_) => new MockSdk());
+    DartSdkManager sdkManager = new DartSdkManager('', false);
     manager = new SingleContextManager(resourceProvider, sdkManager,
         (_) => packageResolver, analysisFilesGlobs, new AnalysisOptionsImpl());
     callbacks = new TestContextManagerCallbacks(resourceProvider);
     manager.callbacks = callbacks;
   }
 
   void test_isIgnored_false() {
     String project = '/project';
     resourceProvider.newFolder(project);
     manager.setRoots(<String>[project], <String>[], <String, String>{});
@@ skipping 462 matching lines @@
     manager.processPlugins(plugins);
   }
 }
 
 class TestUriResolver extends UriResolver {
   @override
   Source resolveAbsolute(Uri uri, [Uri actualUri]) {
     return null;
   }
 }