Make navigation notification operation Source based, without Dart knowledge.

pkg/analysis_server/lib/src/domain_analysis.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 domain.analysis;
 
 import 'dart:async';
 import 'dart:core' hide Resource;
 
 import 'package:analysis_server/analysis/analysis_domain.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/computer/computer_hover.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analysis_server/src/domains/analysis/navigation.dart';
 import 'package:analysis_server/src/operation/operation_analysis.dart'
-    show sendAnalysisNotificationNavigation;
+    show NavigationOperation, sendAnalysisNotificationNavigation;
 import 'package:analysis_server/src/protocol_server.dart';
 import 'package:analysis_server/src/services/dependencies/library_dependencies.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart' as engine;
 import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/task/model.dart' show ResultDescriptor;
 
@@ skipping 312 matching lines @@
         .putIfAbsent(descriptor,
             () => new StreamController<engine.ComputedResult>.broadcast())
         .stream;
     server.getAnalysisContexts().forEach(_subscribeForContext);
     return stream;
   }
 
   @override
   void scheduleNotification(
       engine.AnalysisContext context, Source source, AnalysisService service) {
-    // TODO(scheglov) schedule, don't do it right now
     String file = source.fullName;
     if (server.hasAnalysisSubscription(service, file)) {
       if (service == AnalysisService.NAVIGATION) {
-        sendAnalysisNotificationNavigation(server, context, source);
+        server.scheduleOperation(new NavigationOperation(context, source));
       }
     }
   }
 
   void _subscribeForContext(engine.AnalysisContext context) {
     for (ResultDescriptor descriptor in controllers.keys) {
       context.onResultComputed(descriptor).listen((result) {
         StreamController<engine.ComputedResult> controller =
             controllers[result.descriptor];
         if (controller != null) {
           controller.add(result);
         }
       });
     }
   }
 }