Move diagnostics to `diagnostics` domain (#24931).

pkg/analysis_server/test/domain_diagnostic_test.dart

Index: pkg/analysis_server/test/domain_diagnostic_test.dart
diff --git a/pkg/analysis_server/test/domain_experimental_test.dart b/pkg/analysis_server/test/domain_diagnostic_test.dart
similarity index 85%
rename from pkg/analysis_server/test/domain_experimental_test.dart
rename to pkg/analysis_server/test/domain_diagnostic_test.dart
index 22dcc7dbe877d410f9f31d4fd3cddfb98d96e912..fdb336ea8cda92f3a1cdc905e73a8d2ad390bd33 100644
--- a/pkg/analysis_server/test/domain_experimental_test.dart
+++ b/pkg/analysis_server/test/domain_diagnostic_test.dart
@@ -2,11 +2,11 @@
 // 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 test.domain.experimental;
+library test.domain.diagnostic;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/analysis_server.dart';
-import 'package:analysis_server/src/domain_experimental.dart';
+import 'package:analysis_server/src/domain_diagnostic.dart';
 import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
@@ -19,7 +19,7 @@ import 'utils.dart';
 
 main() {
   AnalysisServer server;
-  ExperimentalDomainHandler handler;
+  DiagnosticDomainHandler handler;
   MemoryResourceProvider resourceProvider;
 
   initializeTestEnvironment();
@@ -39,10 +39,10 @@ main() {
         new AnalysisServerOptions(),
         new MockSdk(),
         InstrumentationService.NULL_SERVICE);
-    handler = new ExperimentalDomainHandler(server);
+    handler = new DiagnosticDomainHandler(server);
   });
 
-  group('ExperimentalDomainHandler', () {
+  group('DiagnosticDomainHandler', () {
     test('getDiagnostics', () async {
       String file = '/project/bin/test.dart';
       resourceProvider.newFile('/project/pubspec.yaml', 'name: project');
@@ -52,7 +52,7 @@ main() {
 
       await server.onAnalysisComplete;
 
-      var request = new ExperimentalGetDiagnosticsParams().toRequest('0');
+      var request = new DiagnosticGetDiagnosticsParams().toRequest('0');
       var response = handler.handleRequest(request);
 
       int fileCount = MockSdk.LIBRARIES.length + 1 /* test.dart */;
@@ -67,7 +67,7 @@ main() {
     });
 
     test('getDiagnostics - (no root)', () async {
-      var request = new ExperimentalGetDiagnosticsParams().toRequest('0');
+      var request = new DiagnosticGetDiagnosticsParams().toRequest('0');
       var response = handler.handleRequest(request);
       var json = response.toJson()[Response.RESULT];
       expect(json['contexts'], hasLength(0));