Move observing notify helper into AMo

activemodel/lib/active_model/observing.rb

@@ -58,6 +58,12 @@ module ActiveModel
           notify_observers :observed_class_inherited, subclass
         end
     end
+
+    private
+      def notify(method) #:nodoc:
+        self.class.changed
+        self.class.notify_observers(method, self)
+      end
   end
 
   class Observer

activerecord/lib/active_record/callbacks.rb

@@ -353,10 +353,5 @@ module ActiveRecord
 
         return result
       end
-
-      def notify(method) #:nodoc:
-        self.class.changed
-        self.class.notify_observers(method, self)
-      end
   end
 end