Remove setFixedBackendName method from Element.

pkg/compiler/lib/src/elements/modelx.dart

 // Copyright (c) 2013, 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 elements.modelx;
 
 import 'elements.dart';
 import '../constants/expressions.dart';
 import '../helpers/helpers.dart';  // Included for debug helpers.
 import '../tree/tree.dart';
@@ skipping 226 matching lines @@
   String _fixedBackendName = null;
   bool _isNative = false;
   bool get isNative => _isNative;
   bool get hasFixedBackendName => _fixedBackendName != null;
   String get fixedBackendName => _fixedBackendName;
   // Marks this element as a native element.
   void setNative(String name) {
     _isNative = true;
     _fixedBackendName = name;
   }
-  void setFixedBackendName(String name) {
-    _fixedBackendName = name;
-  }
 
   FunctionElement asFunctionElement() => null;
 
   bool get isAbstract => modifiers.isAbstract;
   bool isForeign(Backend backend) => backend.isForeign(this);
 
   void diagnose(Element context, DiagnosticListener listener) {}
 
   bool get hasTreeElements => analyzableElement.hasTreeElements;
 
@@ skipping 2803 matching lines @@
   AstElement get definingElement;
 
   bool get hasResolvedAst => definingElement.hasTreeElements;
 
   ResolvedAst get resolvedAst {
     return new ResolvedAst(declaration,
         definingElement.node, definingElement.treeElements);
   }
 
 }