Do not resolve the selector to find the getter, but the receiver instead.

frog/leg/resolver.dart

Index: frog/leg/resolver.dart
===================================================================
--- frog/leg/resolver.dart	(revision 3128)
+++ frog/leg/resolver.dart	(working copy)
@@ -374,7 +374,7 @@
         getter = target;
       } else {
         // TODO(ngeoffray): Find the getter from the setter.
-        getter = context.lookup(node.selector.asIdentifier().source);
+        getter = target;
       }
       useElement(node.selector, getter);
     }