performance measurement improvements and README update

pkg/analysis_server/benchmark/integration/operation.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 server.operation;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:logging/logging.dart';
@@ skipping 93 matching lines @@
   void processResult(
       String id, Map<String, dynamic> result, Stopwatch stopwatch) {
     converter.processResponseResult(id, result);
   }
 }
 
 /**
  * A [ResponseOperation] waits for a [JSON] response from the server.
  */
 class ResponseOperation extends Operation {
-  static final Duration responseTimeout = new Duration(seconds: 5);
+  static final Duration responseTimeout = new Duration(seconds: 60);
   final CommonInputConverter converter;
   final Map<String, dynamic> requestJson;
   final Map<String, dynamic> responseJson;
   final Completer completer = new Completer();
   Driver driver;
 
   ResponseOperation(this.converter, this.requestJson, this.responseJson) {
     completer.future.then(_processResult).timeout(responseTimeout);
   }
 
@@ skipping 101 matching lines @@
         subscription.cancel();
         timer.cancel();
         String message = 'gave up waiting for analysis to complete';
         driver.logger.log(Level.WARNING, message);
         completer.completeError(message);
       }
     });
     return completer.future;
   }
 }