suggest this keyword in constructor param list

pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // 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 services.completion.contributor.dart.keyword;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
@@ skipping 100 matching lines @@
         Keyword.DYNAMIC,
         Keyword.FINAL,
         Keyword.TYPEDEF,
         Keyword.VAR,
         Keyword.VOID
       ], DART_RELEVANCE_HIGH);
     }
   }
 
   @override
+  visitFormalParameterList(FormalParameterList node) {
+    AstNode constructorDecl =
+        node.getAncestor((p) => p is ConstructorDeclaration);
+    if (constructorDecl != null) {
+      _addSuggestions([Keyword.THIS]);
+    }
+  }
+
+  @override
   visitIfStatement(IfStatement node) {
     if (entity == node.thenStatement) {
       _addStatementKeywords(node);
     }
   }
 
   @override
   visitImportDirective(ImportDirective node) {
     if (entity == node.asKeyword) {
       if (node.deferredKeyword == null) {
@@ skipping 73 matching lines @@
         return false;
       }
       AstNode parent = body.parent;
       if (parent is ConstructorDeclaration || parent is MethodDeclaration) {
         return true;
       }
       node = parent;
     }
   }
 }