Stop using Element.unit directly.

pkg/analysis_server/test/services/refactoring/abstract_refactoring.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.refactoring;
 
 import 'dart:async';
 
-import 'package:analysis_server/plugin/protocol/protocol.dart';
+import 'package:analysis_server/plugin/protocol/protocol.dart'
+    show
+        RefactoringProblem,
+        RefactoringProblemSeverity,
+        SourceChange,
+        SourceEdit,
+        SourceFileEdit;
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/services/search/search_engine_internal.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/element/element.dart' show Element;
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test/test.dart';
 
 import '../../abstract_single_unit.dart';
 
 int findIdentifierLength(String search) {
   int length = 0;
   while (length < search.length) {
     int c = search.codeUnitAt(length);
@@ skipping 113 matching lines @@
    */
   void assertTestChangeResult(String expectedCode) {
     // prepare FileEdit
     SourceFileEdit fileEdit = refactoringChange.getFileEdit(testFile);
     expect(fileEdit, isNotNull);
     // validate resulting code
     String actualCode = SourceEdit.applySequence(testCode, fileEdit.edits);
     expect(actualCode, expectedCode);
   }
 
+  /**
+   * Completes with a fully resolved unit that contains the [element].
+   */
+  Future<CompilationUnit> getResolvedUnitWithElement(Element element) async {
+    return element.context
+        .resolveCompilationUnit(element.source, element.library);
+  }
+
   void indexTestUnit(String code) {
     resolveTestUnit(code);
     index.indexUnit(testUnit);
   }
 
   void indexUnit(String file, String code) {
     Source source = addSource(file, code);
     CompilationUnit unit = resolveLibraryUnit(source);
     index.indexUnit(unit);
   }
 
   void setUp() {
     super.setUp();
     index = createMemoryIndex();
     searchEngine = new SearchEngineImpl(index);
   }
 }