Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/analysis/set_priority_files_test.dart

Index: pkg/analysis_server/test/analysis/set_priority_files_test.dart
diff --git a/pkg/analysis_server/test/analysis/set_priority_files_test.dart b/pkg/analysis_server/test/analysis/set_priority_files_test.dart
index 9a1b5c9055ed3ee482b89831b1c545e60f87ebfb..19a17a013b46849a19aa355480f0c42ac7b252b3 100644
--- a/pkg/analysis_server/test/analysis/set_priority_files_test.dart
+++ b/pkg/analysis_server/test/analysis/set_priority_files_test.dart
@@ -9,8 +9,8 @@ import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analyzer/src/generated/engine.dart'
     show InternalAnalysisContext;
 import 'package:analyzer/src/generated/source.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../analysis_abstract.dart';
 import '../mocks.dart';
@@ -18,7 +18,9 @@ import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(SetPriorityFilesTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(SetPriorityFilesTest);
+  });
 }
 
 @reflectiveTest
@@ -26,7 +28,9 @@ class SetPriorityFilesTest extends AbstractAnalysisTest {
   @override
   void setUp() {
     super.setUp();
-    server.handlers = [new AnalysisDomainHandler(server),];
+    server.handlers = [
+      new AnalysisDomainHandler(server),
+    ];
     createProject();
   }