Add debug output for getNavigation().

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/src/analysis_server.dart';
@@ skipping 102 matching lines @@
     var params = new AnalysisGetNavigationParams.fromRequest(request);
     String file = params.file;
     Future<AnalysisDoneReason> analysisFuture =
         server.onFileAnalysisComplete(file);
     if (analysisFuture == null) {
       return new Response.getNavigationInvalidFile(request);
     }
     analysisFuture.then((AnalysisDoneReason reason) {
       switch (reason) {
         case AnalysisDoneReason.COMPLETE:
+          print('AnalysisDoneReason.COMPLETE');
           List<CompilationUnit> units =
               server.getResolvedCompilationUnits(file);
+          print('units: $units');
           if (units.isEmpty) {
             server.sendResponse(new Response.getNavigationInvalidFile(request));
           } else {
             DartUnitNavigationComputer computer =
                 new DartUnitNavigationComputer();
             _GetNavigationAstVisitor visitor = new _GetNavigationAstVisitor(
                 params.offset, params.offset + params.length, computer);
             for (CompilationUnit unit in units) {
               unit.accept(visitor);
             }
             server.sendResponse(new AnalysisGetNavigationResult(
                     computer.files, computer.targets, computer.regions)
                 .toResponse(request.id));
           }
           break;
         case AnalysisDoneReason.CONTEXT_REMOVED:
+          print('AnalysisDoneReason.CONTEXT_REMOVED');
           // The active contexts have changed, so try again.
           Response response = getNavigation(request);
           if (response != Response.DELAYED_RESPONSE) {
             server.sendResponse(response);
           }
           break;
       }
+    }).catchError((e, st) {
+      print('Exception in AnalysisDomainHandler.getNavigation()');
+      print(e);
+      print(st);
     });
     // delay response
     return Response.DELAYED_RESPONSE;
   }
 
   @override
   Response handleRequest(Request request) {
     try {
       String requestName = request.method;
       if (requestName == ANALYSIS_GET_ERRORS) {
@@ skipping 153 matching lines @@
       return;
     }
     // The node starts or ends in the range.
     if (isInRange(node.offset) || isInRange(node.end)) {
       computer.compute(node);
       return;
     }
     super.visitNode(node);
   }
 }