datastore: Update AllocateIDs to take keys.

filter/featureBreaker/rds.go

Index: filter/featureBreaker/rds.go
diff --git a/filter/featureBreaker/rds.go b/filter/featureBreaker/rds.go
index ee7829e4cdfde230b3f0d306d4feae2893dc4a27..4f5fb3ecac4e56799cc7649e27bce7d6709bf549 100644
--- a/filter/featureBreaker/rds.go
+++ b/filter/featureBreaker/rds.go
@@ -16,13 +16,10 @@ type dsState struct {
 	rds ds.RawInterface
 }
 
-func (r *dsState) AllocateIDs(incomplete *ds.Key, n int) (int64, error) {
-	start := int64(0)
-	err := r.run(func() (err error) {
-		start, err = r.rds.AllocateIDs(incomplete, n)
-		return
+func (r *dsState) AllocateIDs(keys []*ds.Key, cb ds.PutMultiCB) error {
+	return r.run(func() error {
+		return r.rds.AllocateIDs(keys, cb)
 	})
-	return start, err
 }
 
 func (r *dsState) DecodeCursor(s string) (ds.Cursor, error) {