Make more use of generated code in analysis server.

pkg/analysis_server/test/search/element_references_test.dart

Index: pkg/analysis_server/test/search/element_references_test.dart
diff --git a/pkg/analysis_server/test/search/element_references_test.dart b/pkg/analysis_server/test/search/element_references_test.dart
index 4997f2d018599a29da9a6a83b0da8a35cb0c1012..546709cc0d95f9e90754c2430b57db3348223b03 100644
--- a/pkg/analysis_server/test/search/element_references_test.dart
+++ b/pkg/analysis_server/test/search/element_references_test.dart
@@ -7,10 +7,7 @@ library test.search.element_references;
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
-import 'package:analysis_server/src/protocol2.dart' show
-    SearchFindElementReferencesParams, ElementKind,
-    SearchFindElementReferencesResult, Element;
-import 'package:analysis_server/src/search/search_result.dart';
+import 'package:analysis_server/src/protocol2.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:unittest/unittest.dart';