Fix rolling averages in diagnostic status.

pkg/analysis_server/lib/src/domain_diagnostic.dart

 // Copyright (c) 2015, 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 src.domain_diagnostic;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core' hide Resource;
 
@@ skipping 120 matching lines @@
   /// TOOD(pq): consider adding GC to remove mappings for deleted folders
   Map<Folder, Average> averages = new HashMap<Folder, Average>();
 
   final AnalysisServer server;
   Sampler(this.server) {
     start();
     _sample();
   }
 
   /// Get the average for the context associated with the given [folder].
-  int getAverage(Folder folder) {
+  num getAverage(Folder folder) {
     resetTimerCountdown();
     return averages[folder].value;
   }
 
   /// Check if we're currently sampling.
   bool isSampling() => timer?.isActive ?? false;
 
   /// Reset counter.
   void resetTimerCountdown() {
     sampleCount = 0;
@@ skipping 29 matching lines @@
             averages[folder] = average;
           }
           average.addSample(_workItemCount(context));
         }
       });
     } on Exception {
       stop();
     }
   }
 }