[Sync] Trigger unapply + getupdates for persistence errors

chrome/browser/sync/glue/backend_data_type_configurer.h

Index: chrome/browser/sync/glue/backend_data_type_configurer.h
diff --git a/chrome/browser/sync/glue/backend_data_type_configurer.h b/chrome/browser/sync/glue/backend_data_type_configurer.h
index 308dee6f68768fb388d1d8f4be06d7daaf562793..eb4d93eccf340961f4a5f42543c1ea3e4a919d95 100644
--- a/chrome/browser/sync/glue/backend_data_type_configurer.h
+++ b/chrome/browser/sync/glue/backend_data_type_configurer.h
@@ -24,6 +24,8 @@ class BackendDataTypeConfigurer {
     CONFIGURE_INACTIVE,   // Already configured or to be configured in future.
                           // Data of such types is left as it is, no
                           // downloading or purging.
+    CONFIGURE_CLEAN,      // Actively being configured but requiring unapply
+                          // and GetUpdates first (e.g. for persistence errors).
     DISABLED,             // Not syncing. Disabled by user.
     FATAL,                // Not syncing due to unrecoverable error.
     CRYPTO,               // Not syncing due to a cryptographer error.