Issue 23640. Implement 'analysis.getNavigation' request.

pkg/analysis_server/lib/src/operation/operation_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 operation.analysis;
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/computer/computer_highlights.dart';
 import 'package:analysis_server/src/computer/computer_navigation.dart';
 import 'package:analysis_server/src/computer/computer_occurrences.dart';
@@ skipping 115 matching lines @@
   _sendNotification(server, () {
     var regions = new DartUnitHighlightsComputer(dartUnit).compute();
     var params = new protocol.AnalysisHighlightsParams(file, regions);
     server.sendNotification(params.toNotification());
   });
 }
 
 void sendAnalysisNotificationNavigation(
     AnalysisServer server, String file, CompilationUnit dartUnit) {
   _sendNotification(server, () {
-    var computer = new DartUnitNavigationComputer(dartUnit);
-    computer.compute();
+    var computer = new DartUnitNavigationComputer();
+    computer.compute(dartUnit);
     var params = new protocol.AnalysisNavigationParams(
         file, computer.regions, computer.targets, computer.files);
     server.sendNotification(params.toNotification());
   });
 }
 
 void sendAnalysisNotificationOccurrences(
     AnalysisServer server, String file, CompilationUnit dartUnit) {
   _sendNotification(server, () {
     var occurrences = new DartUnitOccurrencesComputer(dartUnit).compute();
@@ skipping 293 matching lines @@
 abstract class _SingleFileOperation extends SourceSensitiveOperation {
   final String file;
 
   _SingleFileOperation(AnalysisContext context, this.file) : super(context);
 
   @override
   bool shouldBeDiscardedOnSourceChange(Source source) {
     return source.fullName == file;
   }
 }