[Sync] Add support for dynamically enabling/disabling types

chrome/browser/sync/glue/sync_backend_host_impl.cc

Index: chrome/browser/sync/glue/sync_backend_host_impl.cc
diff --git a/chrome/browser/sync/glue/sync_backend_host_impl.cc b/chrome/browser/sync/glue/sync_backend_host_impl.cc
index 253db617d6b24f2920171bbe8d5af70e20289204..0bf20f7a70933988d24d764bfac3e5112cf7e8ad 100644
--- a/chrome/browser/sync/glue/sync_backend_host_impl.cc
+++ b/chrome/browser/sync/glue/sync_backend_host_impl.cc
@@ -347,8 +347,11 @@ void SyncBackendHostImpl::ConfigureDataTypes(
       GetDataTypesInState(FATAL, config_state_map);
   syncer::ModelTypeSet crypto_types =
       GetDataTypesInState(CRYPTO, config_state_map);
+  syncer::ModelTypeSet unready_types =
+      GetDataTypesInState(UNREADY, config_state_map);
   disabled_types.PutAll(fatal_types);
   disabled_types.PutAll(crypto_types);
+  disabled_types.PutAll(unready_types);

[haitaol1, 2014/06/19 18:14:35]

This will remove routing info of unready types in registar. If unready type is
disabled later, it seems the the type won't be added to types_to_purge below
because types_to_purge is calculated by differing previous and current types in
routing info. Actually I wonder if there's a bug with crypto_types because of
this.

[Nicolas Zea, 2014/06/19 21:13:02]

Hmm, I suspect you're right. They'll both be purged on the next restart though,
as part of the first configuration, so it's not too problematic. That said, I'll
file a bug to fix that separately, since it's an existing issue and would
probably require some further logic.

Added todo.

   syncer::ModelTypeSet active_types =
       GetDataTypesInState(CONFIGURE_ACTIVE, config_state_map);
   syncer::ModelTypeSet clean_first_types =
@@ -392,6 +395,7 @@ void SyncBackendHostImpl::ConfigureDataTypes(
   syncer::ModelTypeSet inactive_types =
       GetDataTypesInState(CONFIGURE_INACTIVE, config_state_map);
   types_to_purge.RemoveAll(inactive_types);
+  types_to_purge.RemoveAll(unready_types);
 
   // If a type has already been disabled and unapplied or journaled, it will
   // not be part of the |types_to_purge| set, and therefore does not need