[Sync] Make BackendMigrator not wait for full sync cycles

chrome/browser/sync/glue/data_type_manager_impl.h

Index: chrome/browser/sync/glue/data_type_manager_impl.h
diff --git a/chrome/browser/sync/glue/data_type_manager_impl.h b/chrome/browser/sync/glue/data_type_manager_impl.h
index 01af332f8afc1098d910ce680ade83b74cf5c59a..f7d63ff43d141f7c2f85c771335944ce547b156e 100644
--- a/chrome/browser/sync/glue/data_type_manager_impl.h
+++ b/chrome/browser/sync/glue/data_type_manager_impl.h
@@ -59,6 +59,10 @@ class DataTypeManagerImpl : public DataTypeManager {
   bool GetControllersNeedingStart(
       std::vector<DataTypeController*>* needs_start);
 
+  // If there's a pending reconfigure, processes it and returns true.
+  // Otherwise, returns false.
+  bool ProcessReconfigure();
+
   void Restart(sync_api::ConfigureReason reason, bool enable_nigori);
   void DownloadReady(bool success);
   void NotifyStart();
@@ -88,8 +92,12 @@ class DataTypeManagerImpl : public DataTypeManager {
   bool needs_reconfigure_;
 
   // The reason for the last reconfigure attempt. Not this will be set to a
-  // valid value only if needs_reconfigure_ is set.
+  // valid value only when |needs_reconfigure_| is set.
   sync_api::ConfigureReason last_configure_reason_;
+  // Whether enable_nigori was set on the last reconfigure attempt.
+  // Like |last_configure_reason_|, set to a valid value only when
+  // |needs_reconfigure_| is set.
+  bool last_enable_nigori_;

[Nicolas Zea, 2011/08/31 17:34:27]

Is it possible to determine this based on the last_configure_reason_? We don't
currently include nigori in the requested_types, but I wonder if that would be
cleaner. This would also get rid of the need for the separate
ConfigureWithoutNigori method.

[akalin, 2011/08/31 21:15:50]

I don't think so.  A false enable_nigori flag implies last_configure_reason_ ==
migration, but not vice versa.

I tried removing the ConfigureWithoutNigori function before, but the problem is
that you'd have to change all the calls of Configure() to inject nigori, and
really only SyncBackendHost and lower layers should care about nigori. 
Migration is really the only thing that may need to Configure without nigori,
which is why that method was added. :(

 
   base::WeakPtrFactory<DataTypeManagerImpl> weak_ptr_factory_;