Stop using Element.unit directly.

pkg/analysis_server/lib/src/services/refactoring/convert_method_to_getter.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.src.refactoring.convert_method_to_getter;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/source_range.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring_internal.dart';
 import 'package:analysis_server/src/services/search/hierarchy.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/ast/utilities.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
  * [ConvertMethodToGetterRefactoring] implementation.
  */
 class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
     implements ConvertMethodToGetterRefactoring {
   final SearchEngine searchEngine;
+  final GetResolvedUnit getResolvedUnit;
   final ExecutableElement element;
 
   SourceChange change;
 
-  ConvertMethodToGetterRefactoringImpl(this.searchEngine, this.element);
+  ConvertMethodToGetterRefactoringImpl(
+      this.searchEngine, this.getResolvedUnit, this.element);
 
   @override
   String get refactoringName => 'Convert Method To Getter';
 
   @override
   Future<RefactoringStatus> checkFinalConditions() {
     RefactoringStatus result = new RefactoringStatus();
     return new Future.value(result);
   }
 
@@ skipping 65 matching lines @@
       SourceEdit edit = new SourceEdit(element.nameOffset, 0, 'get ');
       doSourceChange_addElementEdit(change, element, edit);
     }
     // remove parameters
     {
       SourceEdit edit = newSourceEdit_range(rangeNode(parameters), '');
       doSourceChange_addElementEdit(change, element, edit);
     }
   }
 
-  Future _updateElementReferences(Element element) async {
+  Future<Null> _updateElementReferences(Element element) async {
     List<SearchMatch> matches = await searchEngine.searchReferences(element);
     List<SourceReference> references = getSourceReferences(matches);
     for (SourceReference reference in references) {
       Element refElement = reference.element;
       SourceRange refRange = reference.range;
       // prepare invocation
       MethodInvocation invocation;
       {
-        CompilationUnit refUnit = refElement.unit;
+        CompilationUnit refUnit = await getResolvedUnit(refElement);
         AstNode refNode =
             new NodeLocator(refRange.offset).searchWithin(refUnit);
         invocation = refNode.getAncestor((node) => node is MethodInvocation);
       }
       // we need invocation
       if (invocation != null) {
         SourceRange range = rangeEndEnd(refRange, invocation);
         SourceEdit edit = newSourceEdit_range(range, '');
         doSourceChange_addElementEdit(change, refElement, edit);
       }
     }
   }
 }