Switch dart2js 'typedef name = mixinApplication' to 'class name = mixinApplication'.

sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart

 // Copyright (c) 2012, 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.
 
 part of dart_backend;
 
 class CloningVisitor implements Visitor<Node> {
   final TreeElements originalTreeElements;
   final TreeElementMapping cloneTreeElements;
 
@@ skipping 108 matching lines @@
 
   visitMixinApplication(MixinApplication node) => new MixinApplication(
       visit(node.superclass), visit(node.mixins));
 
   visitNamedMixinApplication(NamedMixinApplication node) =>
       new NamedMixinApplication(visit(node.name),
                                 visit(node.typeParameters),
                                 visit(node.modifiers),
                                 visit(node.mixinApplication),
                                 visit(node.interfaces),
-                                node.typedefKeyword,
+                                node.classKeyword,
                                 node.endToken);
 
   visitModifiers(Modifiers node) => new Modifiers(visit(node.nodes));
 
   visitNamedArgument(NamedArgument node) => new NamedArgument(
       visit(node.name), node.colonToken, visit(node.expression));
 
   visitNewExpression(NewExpression node) => new NewExpression(
       node.newToken, visit(node.send));
 
@@ skipping 144 matching lines @@
   }
 
   Node visitStringNode(StringNode node) {
     unimplemented('visitNode', node: node);
   }
 
   unimplemented(String message, {Node node}) {
     throw message;
   }
 }