Remove a couple of unnecessary is checks

pkg/analyzer/lib/instrumentation/instrumentation.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 analyzer.instrumentation.instrumentation;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:analyzer/task/model.dart';
@@ skipping 88 matching lines @@
    * The current time, expressed as a decimal encoded number of milliseconds.
    */
   String get _timestamp => new DateTime.now().millisecondsSinceEpoch.toString();
 
   /**
    * Log that the given analysis [task] is being performed in the given
    * [context].
    */
   void logAnalysisTask(String context, AnalysisTask task) {
     if (_instrumentationServer != null) {
-      String description =
-          (task is AnalysisTask) ? task.description : task.toString();
       _instrumentationServer
-          .log(_join([TAG_ANALYSIS_TASK, context, description]));
+          .log(_join([TAG_ANALYSIS_TASK, context, task.description]));
     }
   }
 
   /**
    * Log the fact that an error, described by the given [message], has occurred.
    */
   void logError(String message) {
     _log(TAG_ERROR, message);
   }
 
@@ skipping 248 matching lines @@
     }
   }
 
   @override
   Future shutdown() async {
     for (InstrumentationServer server in _servers) {
       await server.shutdown();
     }
   }
 }