Change to <- for types.

pkg/compiler/lib/src/kernel/kernel.dart

Index: pkg/compiler/lib/src/kernel/kernel.dart
diff --git a/pkg/compiler/lib/src/kernel/kernel.dart b/pkg/compiler/lib/src/kernel/kernel.dart
index 35ff9ea49490cf6ea642f34166ab4706265ddc42..d82486f0619505d43f9be37b0d4381ae3a9225ac 100644
--- a/pkg/compiler/lib/src/kernel/kernel.dart
+++ b/pkg/compiler/lib/src/kernel/kernel.dart
@@ -33,11 +33,9 @@ import '../elements/modelx.dart' show ErroneousFieldElementX;
 import '../tree/tree.dart' show FunctionExpression, Node;
 import 'kernel_visitor.dart' show IrFunction, KernelVisitor;
 
-typedef void WorkAction();
-
 class WorkItem {
   final Element element;
-  final WorkAction action;
+  final void <- () action;
 
   WorkItem(this.element, this.action);
 }
@@ -78,7 +76,7 @@ class Kernel {
 
   Kernel(this.compiler);
 
-  void addWork(Element element, WorkAction action) {
+  void addWork(Element element, void <- () action) {
     workQueue.addLast(new WorkItem(element, action));
   }