sync: Introduce control data types

sync/internal_api/public/sync_encryption_handler.cc

Index: sync/internal_api/public/sync_encryption_handler.cc
diff --git a/sync/internal_api/public/sync_encryption_handler.cc b/sync/internal_api/public/sync_encryption_handler.cc
index d2b1ca2aae40c59f894bed5a7b2b15862f3e3b7c..e967600d65de997554b39608d28716fc4e4a417c 100644
--- a/sync/internal_api/public/sync_encryption_handler.cc
+++ b/sync/internal_api/public/sync_encryption_handler.cc
@@ -14,11 +14,9 @@ SyncEncryptionHandler::~SyncEncryptionHandler() {}
 
 // Static.
 ModelTypeSet SyncEncryptionHandler::SensitiveTypes() {
-  // Both of these have their own encryption schemes, but we include them
-  // anyways.
+  // It has its own encryption scheme, but we include it anyway.
   ModelTypeSet types;
   types.Put(PASSWORDS);
-  types.Put(NIGORI);
   return types;
 }