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

pkg/analysis_server/lib/plugin/edit/fix/fix_dart.dart

 // Copyright (c) 2015, 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 analysis_server.plugin.edit.fix.fix_dart;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/src/services/correction/fix_internal.dart'
     show DartFixContextImpl;
 import 'package:analysis_server/src/services/correction/namespace.dart'
     show getExportedElement;
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/src/dart/analysis/ast_provider_context.dart';
 import 'package:analyzer/src/dart/analysis/top_level_declaration.dart';
+import 'package:analyzer/src/dart/element/ast_provider.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/dart.dart' show LIBRARY_ELEMENT4;
 
 /**
  * Complete with top-level declarations with the given [name].
  */
 typedef Future<List<TopLevelDeclarationInSource>> GetTopLevelDeclarations(
     String name);
 
 /**
  * An object used to provide context information for [DartFixContributor]s.
  *
  * Clients may not extend, implement or mix-in this class.
  */
 abstract class DartFixContext implements FixContext {
   /**
+   * The provider for parsed or resolved ASTs.
+   */
+  AstProvider get astProvider;
+
+  /**
    * The function to get top-level declarations from.
    */
   GetTopLevelDeclarations get getTopLevelDeclarations;
 
   /**
    * The [CompilationUnit] to compute fixes in.
    */
   CompilationUnit get unit;
 }
 
@@ skipping 14 matching lines @@
     List<Source> libraries = analysisContext.getLibrariesContaining(source);
     if (libraries.isEmpty) {
       return Fix.EMPTY_LIST;
     }
     CompilationUnit unit =
         analysisContext.getResolvedCompilationUnit2(source, libraries[0]);
     if (unit == null) {
       return Fix.EMPTY_LIST;
     }
     DartFixContext dartContext = new DartFixContextImpl(
-        context, _getTopLevelDeclarations(analysisContext), unit);
+        context,
+        _getTopLevelDeclarations(analysisContext),
+        new AstProviderForContext(analysisContext),
+        unit);
     return internalComputeFixes(dartContext);
   }
 
   /**
    * Return a list of fixes for the given [context].
    */
   Future<List<Fix>> internalComputeFixes(DartFixContext context);
 
   GetTopLevelDeclarations _getTopLevelDeclarations(AnalysisContext context) {
     return (String name) async {
@@ skipping 27 matching lines @@
         if (topLevelKind != null) {
           bool isExported = element.librarySource != librarySource;
           declarations.add(new TopLevelDeclarationInSource(librarySource,
               new TopLevelDeclaration(topLevelKind, element.name), isExported));
         }
       }
       return declarations;
     };
   }
 }