Add AnalysisSession to analyzer

pkg/analysis_server/test/src/plugin/plugin_watcher_test.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 import 'dart:typed_data';
 
 import 'package:analysis_server/src/plugin/plugin_locator.dart';
 import 'package:analysis_server/src/plugin/plugin_manager.dart';
 import 'package:analysis_server/src/plugin/plugin_watcher.dart';
 import 'package:analyzer/context/context_root.dart';
+import 'package:analyzer/dart/analysis/session.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/dart/analysis/file_state.dart';
+import 'package:analyzer/src/dart/analysis/session.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisOptionsImpl;
 import 'package:analyzer/src/generated/source.dart';
 import 'package:front_end/src/base/performace_logger.dart';
 import 'package:front_end/src/incremental/byte_store.dart';
 import 'package:path/path.dart' as path;
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../mock_sdk.dart';
 
@@ skipping 64 matching lines @@
     watcher.removedDriver(driver);
     expect(manager.removedContextRoots, equals([contextRoot]));
   }
 }
 
 class TestDriver implements AnalysisDriver {
   final MemoryResourceProvider resourceProvider;
 
   SourceFactory sourceFactory;
   FileSystemState fsState;
+  AnalysisSession currentSession;
 
   final _resultController = new StreamController<AnalysisResult>();
 
   TestDriver(this.resourceProvider, ContextRoot contextRoot) {
     path.Context pathContext = resourceProvider.pathContext;
     MockSdk sdk = new MockSdk(resourceProvider: resourceProvider);
     String packageName = pathContext.basename(contextRoot.root);
     String libPath = pathContext.join(contextRoot.root, 'lib');
     sourceFactory = new SourceFactory([
       new DartUriResolver(sdk),
       new PackageMapUriResolver(resourceProvider, {
         packageName: [resourceProvider.getFolder(libPath)],
         'pkg2': [
           resourceProvider.getFolder(resourceProvider.convertPath('/pkg2/lib'))
         ]
       })
     ]);
     fsState = new FileSystemState(
         new PerformanceLog(null),
         new MemoryByteStore(),
         null,
         resourceProvider,
         sourceFactory,
         new AnalysisOptionsImpl(),
         new Uint32List(0));
+    currentSession = new DriverBasedAnalysisSession(this);
   }
 
   Stream<AnalysisResult> get results => _resultController.stream;
 
   Future<Null> computeResult(String uri) {
     FileState file = fsState.getFileForUri(Uri.parse(uri));
     AnalysisResult result = new AnalysisResult(
         this, null, file.path, null, true, null, null, null, null, null, null);
     _resultController.add(result);
     return new Future.delayed(new Duration(milliseconds: 1));
@@ skipping 14 matching lines @@
     return null;
   }
 
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 
   @override
   void removedContextRoot(ContextRoot contextRoot) {
     removedContextRoots.add(contextRoot);
   }
 }