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

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

Index: sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart b/sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart
index 57ee07ace938c2c531a4275e4dcdbe82fff5c858..6b885d6f48baa2deca30b866c82e7c76962b03e5 100644
--- a/sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart_backend/utils.dart
@@ -126,7 +126,7 @@ class CloningVisitor implements Visitor<Node> {
                                 visit(node.modifiers),
                                 visit(node.mixinApplication),
                                 visit(node.interfaces),
-                                node.typedefKeyword,
+                                node.classKeyword,
                                 node.endToken);
 
   visitModifiers(Modifiers node) => new Modifiers(visit(node.nodes));