Refactor preference syncing.

chrome/browser/sync/glue/non_frontend_data_type_controller.h

Index: chrome/browser/sync/glue/non_frontend_data_type_controller.h
diff --git a/chrome/browser/sync/glue/non_frontend_data_type_controller.h b/chrome/browser/sync/glue/non_frontend_data_type_controller.h
index c2f2ee07be85033e0f7bf880b4f097ade8a28325..f6fe8cda031ca3048591e431b06315f436697c94 100644
--- a/chrome/browser/sync/glue/non_frontend_data_type_controller.h
+++ b/chrome/browser/sync/glue/non_frontend_data_type_controller.h
@@ -20,6 +20,7 @@ class ProfileSyncFactory;
 namespace base { class TimeDelta; }
 namespace browser_sync {
 
+class NewAssociatorInterface;
 class AssociatorInterface;
 class ChangeProcessor;
 
@@ -55,6 +56,11 @@ class NonFrontendDataTypeController : public DataTypeController {
   // Note: this is performed on the datatype's thread.
   virtual void OnUnrecoverableError(const tracked_objects::Location& from_here,
                                     const std::string& message);
+
+  // TODO(zea): ensure this plays nicely with threads once non-UI datatypes
+  // use the new associator interface.
+  virtual NewAssociatorInterface* model_associator() const;
+  virtual void set_model_associator(AssociatorInterface* associator);
  protected:
   // For testing only.
   NonFrontendDataTypeController();
@@ -134,7 +140,6 @@ class NonFrontendDataTypeController : public DataTypeController {
   Profile* profile() const;
   ProfileSyncService* profile_sync_service() const;
   void set_state(State state);
-  void set_model_associator(AssociatorInterface* associator);
   void set_change_processor(ChangeProcessor* change_processor);
 
  private:
@@ -145,6 +150,8 @@ class NonFrontendDataTypeController : public DataTypeController {
   State state_;
 
   scoped_ptr<StartCallback> start_callback_;
+  // TODO(zea): make |model_associator_| RefCountedThreadSafe and remove
+  // |change_processor_| once we're using the new associator interface.
   scoped_ptr<AssociatorInterface> model_associator_;
   scoped_ptr<ChangeProcessor> change_processor_;