Issue 25686. Add 'var' for untyped unimplemented fields.

pkg/analysis_server/test/services/correction/fix_test.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 test.services.correction.fix;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/edit/fix/fix_dart.dart';
@@ skipping 2109 matching lines @@
     await assertHasFix(
         DartFixKind.CREATE_LOCAL_VARIABLE,
         '''
 main() {
   int test;
   test += 42;
 }
 ''');
   }
 
+  test_createMissingOverrides_field_untyped() async {
+    resolveTestUnit('''
+class A {
+  var f;
+}
+
+class B implements A {
+}
+''');
+    await assertHasFix(
+        DartFixKind.CREATE_MISSING_OVERRIDES,
+        '''
+class A {
+  var f;
+}
+
+class B implements A {
+  var f;
+}
+''');
+  }
+
   test_createMissingOverrides_functionTypeAlias() async {
     resolveTestUnit('''
 typedef int Binary(int left, int right);
 
 abstract class Emulator {
   void performBinary(Binary binary);
 }
 
 class MyEmulator extends Emulator {
 }
@@ skipping 2792 matching lines @@
       int offset = resultCode.indexOf(search);
       positions.add(new Position(testFile, offset));
     }
     return positions;
   }
 
   void _performAnalysis() {
     while (context.performAnalysisTask().hasMoreWork);
   }
 }