Redo our benchmarks; add a benchmark/benchmarks.dart tool.

pkg/analysis_server/benchmark/perf/completion_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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:test/test.dart';
 
 import 'performance_tests.dart';
 
+const COMPLETION_OFFSET = 'offset';
+const PRIORITY_FILE_OPTION = 'priority';
+const SOURCE_OPTION = 'source';
+
 /**
  * Pass in the directory of the source to be analyzed as option `--source`,
  * specify a priority file with `--priority` and an offset for completions
  * with a `--offset`.
  */
-main(List<String> arguments) {
+main(List<String> arguments) async {
   ArgParser parser = _createArgParser();
   var args = parser.parse(arguments);
   if (args[SOURCE_OPTION] == null) {
     print('path to source directory must be specified');
     exit(1);
   }
-  source = args[SOURCE_OPTION];
-  priorityFile = args[PRIORITY_FILE_OPTION];
-  offset = int.parse(args[COMPLETION_OFFSET]);
 
-  Future.wait([new CompletionTimingTest().test_timing()]);
+  int offset = int.parse(args[COMPLETION_OFFSET]);
+  String priorityFile = args[PRIORITY_FILE_OPTION];
+  String source = args[SOURCE_OPTION];
+
+  CompletionTimingTest test =
+      new CompletionTimingTest(offset, priorityFile, source);
+  await test.test_timing();
 }
 
-const COMPLETION_OFFSET = 'offset';
-const PRIORITY_FILE_OPTION = 'priority';
-const SOURCE_OPTION = 'source';
-
-int offset;
-String priorityFile;
-String source;
-
 ArgParser _createArgParser() => new ArgParser()
   ..addOption(SOURCE_OPTION, help: 'full path to source directory for analysis')
   ..addOption(PRIORITY_FILE_OPTION, help: 'full path to a priority file')
   ..addOption(COMPLETION_OFFSET, help: 'offset in file for code completions');
 
 /**
  * CompletionTimingTest measures the time taken for the analysis server to respond with
  * completion suggestions for a given file and offset. The time measured starts when
  * the analysis root is set and is done when the completion suggestions are received
  * from the server. The test does not wait for analysis to be complete before asking for
  * completions.
  */
 class CompletionTimingTest extends AbstractTimingTest {
+  final int offset;
+  final String priorityFile;
+  final String source;
+
   List<Duration> timings = <Duration>[];
 
+  CompletionTimingTest(this.offset, this.priorityFile, this.source);
+
   Future test_timing() async {
 //    debugStdio();
 
     expect(priorityFile, isNotNull,
         reason: 'A priority file must be specified for completion testing.');
     expect(offset, isNotNull,
         reason: 'An offset must be specified for completion testing.');
 
     await init(source);
     stopwatch.start();
 
     onCompletionResults.listen((_) {
       timings.add(new Duration(milliseconds: stopwatch.elapsed.inMilliseconds));
     });
 
     setAnalysisRoot();
     sendAnalysisSetPriorityFiles([priorityFile]);
     sendCompletionGetSuggestions(priorityFile, offset);
 
     await analysisFinished;
 
     print('analysis completed in ${stopwatch.elapsed}');
     print('completion received at : $timings');
     await shutdown();
   }
 }