[Sync] Refactor non-frontend DTC to handle new API properly.

chrome/browser/sync/glue/extension_data_type_controller.cc

Index: chrome/browser/sync/glue/extension_data_type_controller.cc
diff --git a/chrome/browser/sync/glue/extension_data_type_controller.cc b/chrome/browser/sync/glue/extension_data_type_controller.cc
index 11f4a72c6f6c1a644b52e3585944f0af238f840a..ad977e8bebb3adf3513b41416e9a4f5dc6a11aae 100644
--- a/chrome/browser/sync/glue/extension_data_type_controller.cc
+++ b/chrome/browser/sync/glue/extension_data_type_controller.cc
@@ -36,7 +36,12 @@ void ExtensionDataTypeController::CreateSyncComponents() {
       profile_sync_factory_->CreateExtensionSyncComponents(sync_service_,
                                                      this);
   set_model_associator(sync_components.model_associator);
-  set_change_processor(sync_components.change_processor);
+  generic_change_processor_.reset(static_cast<GenericChangeProcessor*>(
+      sync_components.change_processor));
+}
+
+GenericChangeProcessor* ExtensionDataTypeController::change_processor() const {
+  return generic_change_processor_.get();
 }
 
 void ExtensionDataTypeController::RecordUnrecoverableError(