Remove the old task model

pkg/analysis_server/test/mock_sdk.dart

Index: pkg/analysis_server/test/mock_sdk.dart
diff --git a/pkg/analysis_server/test/mock_sdk.dart b/pkg/analysis_server/test/mock_sdk.dart
index 99be8fc7549870445e8bb3fe4e33ead7b90e27d7..5aaec99e3f7419c3644921415f014e3c8981f57e 100644
--- a/pkg/analysis_server/test/mock_sdk.dart
+++ b/pkg/analysis_server/test/mock_sdk.dart
@@ -6,7 +6,7 @@ library testing.mock_sdk;
 
 import 'package:analyzer/file_system/file_system.dart' as resource;
 import 'package:analyzer/file_system/memory_file_system.dart' as resource;
-import 'package:analyzer/src/context/context.dart' as newContext;
+import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
@@ -219,11 +219,7 @@ external void printToConsole(String line);
   @override
   AnalysisContext get context {
     if (_analysisContext == null) {
-      if (AnalysisEngine.instance.useTaskModel) {
-        _analysisContext = new newContext.SdkAnalysisContext();
-      } else {
-        _analysisContext = new SdkAnalysisContext();
-      }
+      _analysisContext = new SdkAnalysisContext();
       SourceFactory factory = new SourceFactory([new DartUriResolver(this)]);
       _analysisContext.sourceFactory = factory;
       ChangeSet changeSet = new ChangeSet();