sync: Retry soon when server returns conflict

sync/internal_api/public/util/syncer_error.cc

Index: sync/internal_api/public/util/syncer_error.cc
diff --git a/sync/internal_api/public/util/syncer_error.cc b/sync/internal_api/public/util/syncer_error.cc
index b2d25aa6427b18399c5a4f9272ffcedaea17e32e..ef45d819f821c3eff0454b857c8f99f108c8651a 100644
--- a/sync/internal_api/public/util/syncer_error.cc
+++ b/sync/internal_api/public/util/syncer_error.cc
@@ -12,7 +12,6 @@ namespace syncer {
 const char* GetSyncerErrorString(SyncerError value) {
   switch (value) {
     ENUM_CASE(UNSET);
-    ENUM_CASE(DIRECTORY_LOOKUP_FAILED);
     ENUM_CASE(CANNOT_DO_WORK);
     ENUM_CASE(NETWORK_CONNECTION_UNAVAILABLE);
     ENUM_CASE(NETWORK_IO_ERROR);
@@ -25,6 +24,7 @@ const char* GetSyncerErrorString(SyncerError value) {
     ENUM_CASE(SERVER_RETURN_MIGRATION_DONE);
     ENUM_CASE(SERVER_RETURN_CLEAR_PENDING);
     ENUM_CASE(SERVER_RETURN_NOT_MY_BIRTHDAY);
+    ENUM_CASE(SERVER_RETURN_CONFLICT);
     ENUM_CASE(SERVER_RESPONSE_VALIDATION_FAILED);
     ENUM_CASE(SYNCER_OK);
   }