Switch analysis_server to use 'package:test'.

pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart

Index: pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart
diff --git a/pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart b/pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart
index 731bec5586afd38beb53a241462b24bc2b60efc0..8447c5db3bbdf084fa1ffc1c8a2ac78f03b972aa 100644
--- a/pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart
+++ b/pkg/analysis_server/benchmark/perf/analysis_timing_tests.dart
@@ -9,7 +9,7 @@ import 'dart:io';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:args/args.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import '../../test/utils.dart';
 import 'performance_tests.dart';
@@ -34,7 +34,6 @@ main(List<String> arguments) {
   for (var name in names) {
     metricNames.add(name as String);
   }
-  unittestConfiguration.timeout = new Duration(minutes: 20);
 
   var test;