[Sync] Use ModelTypeProcessor instead of ModelTypeProcessorImpl.

sync/sessions/model_type_registry.h

Index: sync/sessions/model_type_registry.h
diff --git a/sync/sessions/model_type_registry.h b/sync/sessions/model_type_registry.h
index a27468eee1e0b050c6bd3bde38a7b649793897b5..9e097cfb988a6e5c7424772d078d93d474318813 100644
--- a/sync/sessions/model_type_registry.h
+++ b/sync/sessions/model_type_registry.h
@@ -22,7 +22,7 @@
 
 namespace syncer_v2 {
 struct DataTypeState;
-class ModelTypeProcessorImpl;
+class ModelTypeProcessor;
 class ModelTypeWorker;
 }
 
@@ -66,7 +66,8 @@ class SYNC_EXPORT_PRIVATE ModelTypeRegistry
       const syncer_v2::DataTypeState& data_type_state,
       const syncer_v2::UpdateResponseDataList& saved_pending_updates,
       const scoped_refptr<base::SequencedTaskRunner>& type_task_runner,
-      const base::WeakPtr<syncer_v2::ModelTypeProcessorImpl>& proxy) override;
+      const base::WeakPtr<syncer_v2::ModelTypeProcessor>& type_processor)
+      override;
 
   // Disables the syncing of an off-thread type.
   //