Remove a couple of unnecessary is checks

pkg/analyzer/lib/instrumentation/instrumentation.dart

Index: pkg/analyzer/lib/instrumentation/instrumentation.dart
diff --git a/pkg/analyzer/lib/instrumentation/instrumentation.dart b/pkg/analyzer/lib/instrumentation/instrumentation.dart
index fe58cdb5abd73e306b6d995ded4f97ba78430238..92638f7531dab72c95ee86ed2361f6f80ad455cf 100644
--- a/pkg/analyzer/lib/instrumentation/instrumentation.dart
+++ b/pkg/analyzer/lib/instrumentation/instrumentation.dart
@@ -106,10 +106,8 @@ class InstrumentationService {
    */
   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]));
     }
   }