Elements. Migrate lib/src/handler/legacy/legacy_handler.dart

Change-Id: Ie28f56623633c3774ee2b9a8fb9273e532b0216e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/399033
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>

Author: scheglov

pkg/analysis_server/analyzer_use_new_elements.txt

@@ -5,7 +5,6 @@ lib/src/computer/computer_call_hierarchy.dart
 lib/src/computer/computer_documentation.dart
 lib/src/domains/analysis/occurrences_dart.dart
 lib/src/handler/legacy/edit_get_available_refactorings.dart
-lib/src/handler/legacy/legacy_handler.dart
 lib/src/handler/legacy/search_find_element_references.dart
 lib/src/handler/legacy/search_get_type_hierarchy.dart
 lib/src/lsp/completion_utils.dart

pkg/analysis_server/lib/src/handler/legacy/legacy_handler.dart

@@ -10,7 +10,6 @@ import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/legacy_analysis_server.dart';
 import 'package:analysis_server/src/protocol/protocol_internal.dart';
 import 'package:analyzer/dart/analysis/results.dart';
-import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/error/syntactic_errors.g.dart';
 import 'package:analyzer/src/util/performance/operation_performance.dart';
@@ -113,19 +112,11 @@ abstract class LegacyHandler {
   }
 }
 
-extension LibraryElement2Extension on LibraryElement2 {
-  // TODO(dantup): Remove this once we can use `languageVersion.effective`
-  //  in element-model-migrated files without triggering the lint.
-  Version get effectiveLanguageVersion {
-    return languageVersion.effective;
-  }
-}
-
 extension SomeResolvedLibraryResultExtension on SomeResolvedLibraryResult? {
   Version get effectiveLanguageVersion {
     var self = this;
     if (self is ResolvedLibraryResult) {
-      return self.element.languageVersion.effective;
+      return self.element2.languageVersion.effective;
     }
     return DartFormatter.latestLanguageVersion;
   }