(TBR) fix the build

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 40 matching lines @@
   /**
    * A list of code completion peformance measurements for the latest
    * completion operation up to [performanceListMaxLength] measurements.
    */
   final List<CompletionPerformance> performanceList =
       new List<CompletionPerformance>();
 
   /**
    * The maximum number of performance measurements to keep.
    */
-  static const int performanceListMaxLength = 50;
+  static const int performanceListMaxLength = 0;
 
   /**
    * Performance for the last priority change event.
    */
   CompletionPerformance priorityChangedPerformance;
 
   /**
    * Initialize a new request handler for the given [server].
    */
   CompletionDomainHandler(this.server) {
@@ skipping 195 matching lines @@
     if (_sourcesChangedSubscription != null) {
       _sourcesChangedSubscription.cancel();
       _sourcesChangedSubscription = null;
     }
     if (_manager != null) {
       _manager.dispose();
       _manager = null;
     }
   }
 }