Make server forward getNavigation requests to plugins

pkg/analysis_server/test/analysis/get_navigation_test.dart

Index: pkg/analysis_server/test/analysis/get_navigation_test.dart
diff --git a/pkg/analysis_server/test/analysis/get_navigation_test.dart b/pkg/analysis_server/test/analysis/get_navigation_test.dart
index b8463f78e6ce831a45f024fd26e149948154b844..6df117964a31686571e8b4c7839c6efcc6c16d20 100644
--- a/pkg/analysis_server/test/analysis/get_navigation_test.dart
+++ b/pkg/analysis_server/test/analysis/get_navigation_test.dart
@@ -44,9 +44,14 @@ main() {
     assertHasTarget('test = 0');
   }
 
-  test_fileDoesNotExist() {
+  test_fileDoesNotExist() async {
     String file = '$projectPath/doesNotExist.dart';
-    return _checkInvalid(file, -1, -1);
+    Request request = _createGetNavigationRequest(file, 0, 100);
+    Response response = await serverChannel.sendRequest(request);
+    expect(response.error, isNull);
+    expect(response.result['files'], isEmpty);
+    expect(response.result['targets'], isEmpty);
+    expect(response.result['regions'], isEmpty);
   }
 
   test_fileOutsideOfRoot() async {
@@ -228,13 +233,6 @@ main() {
     assertHasTarget('test = 0');
   }
 
-  _checkInvalid(String file, int offset, int length) async {
-    Request request = _createGetNavigationRequest(file, offset, length);
-    Response response = await serverChannel.sendRequest(request);
-    expect(response.error, isNotNull);
-    expect(response.error.code, RequestErrorCode.GET_NAVIGATION_INVALID_FILE);
-  }
-
   Request _createGetNavigationRequest(String file, int offset, int length) {
     return new AnalysisGetNavigationParams(file, offset, length)
         .toRequest(requestId);