Unify the server and plugin versions of the generators

pkg/analysis_server/benchmark/perf/analysis_timing_tests.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.performance.analysis.timing;
 
 import 'dart:async';
 import 'dart:io';
 
-import 'package:analysis_server/plugin/protocol/protocol.dart';
+import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:args/args.dart';
 import 'package:test/test.dart';
 
 import 'performance_tests.dart';
 
 /**
  * Pass in the directory of the source to be analyzed as option `--source`,
  * optionally specify a priority file with `--priority` and the specific
  * test to run with `--metric`.  If no test is specified, the default is
  * `analysis`.
@@ skipping 133 matching lines @@
 
     sendAnalysisSetPriorityFiles([priorityFile]);
 
     await analysisFinished;
     print('analysis completed in ${stopwatch.elapsed}');
     metrics.forEach((Metric m) => print('${m.name} timings: ${m.timings}'));
 
     await shutdown();
   }
 }