Stop using Element.computeNode() in refactorings and fixes.

pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart

Index: pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart
diff --git a/pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart b/pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart
index 4d9d93f8d70e0e1d3242eb0640c88a3e32c0dd39..5dd94166383e472e0a3c327aa5c3185b5f2e1b0c 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart
@@ -16,6 +16,7 @@ import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/src/dart/element/ast_provider.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
@@ -24,11 +25,13 @@ import 'package:analyzer/src/generated/source.dart';
 class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
     implements ConvertGetterToMethodRefactoring {
   final SearchEngine searchEngine;
+  final AstProvider astProvider;
   final PropertyAccessorElement element;
 
   SourceChange change;
 
-  ConvertGetterToMethodRefactoringImpl(this.searchEngine, this.element);
+  ConvertGetterToMethodRefactoringImpl(
+      this.searchEngine, this.astProvider, this.element);
 
   @override
   String get refactoringName => 'Convert Getter To Method';
@@ -50,7 +53,7 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
     change = new SourceChange(refactoringName);
     // function
     if (element.enclosingElement is CompilationUnitElement) {
-      _updateElementDeclaration(element);
+      await _updateElementDeclaration(element);
       await _updateElementReferences(element);
     }
     // method
@@ -58,11 +61,11 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
       FieldElement field = element.variable;
       Set<ClassMemberElement> elements =
           await getHierarchyMembers(searchEngine, field);
-      await Future.forEach(elements, (ClassMemberElement member) {
+      await Future.forEach(elements, (ClassMemberElement member) async {
         if (member is FieldElement) {
           PropertyAccessorElement getter = member.getter;
           if (!getter.isSynthetic) {
-            _updateElementDeclaration(getter);
+            await _updateElementDeclaration(getter);
             return _updateElementReferences(getter);
           }
         }
@@ -83,11 +86,12 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
     return new RefactoringStatus();
   }
 
-  void _updateElementDeclaration(PropertyAccessorElement element) {
+  Future<Null> _updateElementDeclaration(
+      PropertyAccessorElement element) async {
     // prepare "get" keyword
     Token getKeyword = null;
     {
-      AstNode node = element.computeNode();
+      AstNode node = await astProvider.getParsedNodeForElement(element);
       if (node is MethodDeclaration) {
         getKeyword = node.propertyKeyword;
       } else if (node is FunctionDeclaration) {