improve completion performance status page

pkg/analysis_server/lib/src/domain_completion.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.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
@@ skipping 157 matching lines @@
     String completionId = (_nextCompletionId++).toString();
     AnalysisContext context = server.getAnalysisContext(params.file);
     Source source = server.getSource(params.file);
     recordRequest(performance, context, source, params.offset);
     CompletionManager manager = completionManagerFor(context, source);
     CompletionRequest completionRequest =
         new CompletionRequest(params.offset, performance);
     int notificationCount = 0;
     manager.results(completionRequest).listen((CompletionResult result) {
       ++notificationCount;
-      performance.logElapseTime("notification $notificationCount", () {
+      performance.logElapseTime("notification $notificationCount send", () {
         sendCompletionNotification(
             completionId,
             result.replacementOffset,
             result.replacementLength,
             result.suggestions,
             result.last);
       });
+      if (notificationCount == 1) {
+        performance.logFirstNotificationComplete('notification 1 complete');
+      }
       if (result.last) {
         performance.notificationCount = notificationCount;
         performance.suggestionCount = result.suggestions.length;
         performance.complete();
       }
     });
     // initial response without results
     return new CompletionGetSuggestionsResult(
         completionId).toResponse(request.id);
   }
@@ skipping 68 matching lines @@
     if (_sourcesChangedSubscription != null) {
       _sourcesChangedSubscription.cancel();
       _sourcesChangedSubscription = null;
     }
     if (_manager != null) {
       _manager.dispose();
       _manager = null;
     }
   }
 }