sync: Make nudge + config jobs reliable in SyncerThread2

chrome/browser/sync/glue/sync_backend_host.h

Index: chrome/browser/sync/glue/sync_backend_host.h
diff --git a/chrome/browser/sync/glue/sync_backend_host.h b/chrome/browser/sync/glue/sync_backend_host.h
index 1e65dd9dec898ffa5e8c27bcff08d2674b2b969b..086b2e056b10991ed665183b1506335426bd46cd 100644
--- a/chrome/browser/sync/glue/sync_backend_host.h
+++ b/chrome/browser/sync/glue/sync_backend_host.h
@@ -326,7 +326,6 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
     void CreateSyncNotifier(const scoped_refptr<net::URLRequestContextGetter>&
         request_context_getter);
 
-
     // Note:
     //
     // The Do* methods are the various entry points from our SyncBackendHost.
@@ -402,6 +401,8 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
         const std::string& name, const JsArgList& args,
         const JsEventHandler* sender);
 
+    void DoStartConfigurationMode();
+
     // A callback from the SyncerThread when it is safe to continue config.
     void FinishConfigureDataTypes();