Remove Element.users support.

pkg/analyzer/test/generated/incremental_resolver_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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 2071 matching lines @@
   String code;
   LibraryElement library;
   CompilationUnit unit;
 
   void setUp() {
     super.setUp();
     test_resolveApiChanges = true;
     log.logger = log.NULL_LOGGER;
   }
 
-  void test_api_method_edit_returnType() {
-    _resolveUnit(r'''
-class A {
-  int m() {
-    return null;
-  }
-}
-main() {
-  A a = new A();
-  int v = a.m();
-  print(v);
-}
-''');
-    _resolve(_editString('int m', 'String m'), _isDeclaration);
-    // We don't add or fix an error, but we verify that type of "v"
-    // is updated from "int" to "String".
-  }
-
   void test_classMemberAccessor_body() {
     _resolveUnit(r'''
 class A {
   int get test {
     return 1 + 2;
   }
 }''');
     _resolve(_editString('+', '*'), _isFunctionBody);
   }
 
@@ skipping 1576 matching lines @@
   }
 }
 
 
 class _Edit {
   final int offset;
   final int length;
   final String replacement;
   _Edit(this.offset, this.length, this.replacement);
 }