Fix comments in benchmark

pkg/analysis_server/benchmark/perf/benchmark_local.dart

 // Copyright (c) 2016, 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 server.performance.local;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 
@@ skipping 213 matching lines @@
           refactoringAtStr: 'getSourcesWithFullName(String path)',
           refactoringKind: RefactoringKind.RENAME,
           refactoringOptions: new RenameOptions('getSourcesWithFullName2'),
           numOfRepeats: 5);
   printBenchmarkResults(id, description, times);
 }
 
 Future run_memory_initialAnalysis_1() async {
   String id = 'memory-initialAnalysis-1';
   String description = r'''
-1. Start server, set 'analyzer' and 'analysis_server' analysis roots.
+1. Start server, set 'analyzer' as the analysis root.
 2. Measure the memory usage after finishing initial analysis.
 3. Shutdown the server.
 4. Go to (1).
 ''';
   List<int> sizes = await AnalysisServerMemoryUsageTest
       .start_waitInitialAnalysis_shutdown(
           roots: <String>[paths.analyzer], numOfRepeats: 3);
   printMemoryResults(id, description, sizes);
 }
 
@@ skipping 18 matching lines @@
   String flutterHelloWorld;
   String flutterStocks;
 
   PathHolder({String sdkPath, String flutterPath}) {
     analysisServer = '$sdkPath/pkg/analysis_server';
     analyzer = '$sdkPath/pkg/analyzer';
     flutterHelloWorld = '$flutterPath/examples/hello_world';
     flutterStocks = '$flutterPath/examples/stocks';
   }
 }