datastore: Add DecodeCursor to [Raw]Interface.

filter/count/rds.go

Index: filter/count/rds.go
diff --git a/filter/count/rds.go b/filter/count/rds.go
index f3ce9f8736cfbc22ecc544e62ad6db1d5bf4b4b7..22e8c9bfd816e66c2afeab818ba4801d80a31666 100644
--- a/filter/count/rds.go
+++ b/filter/count/rds.go
@@ -13,6 +13,7 @@ import (
 // DSCounter is the counter object for the datastore service.
 type DSCounter struct {
 	NewKey           Entry
+	DecodeCursor     Entry
 	DecodeKey        Entry
 	NewQuery         Entry
 	RunInTransaction Entry
@@ -45,6 +46,11 @@ func (r *dsCounter) NewQuery(kind string) ds.Query {
 	return r.ds.NewQuery(kind)
 }
 
+func (r *dsCounter) DecodeCursor(s string) (ds.Cursor, error) {
+	r.c.DecodeCursor.up()
+	return r.ds.DecodeCursor(s)

[iannucci, 2015/08/21 23:30:03]

I think you want

ret, err := r.ds.DecodeCursor(s)
return ret, r.c.DecodeCursor.up(err)

+}
+
 func (r *dsCounter) Run(q ds.Query, cb ds.RawRunCB) error {
 	return r.c.Run.up(r.ds.Run(q, cb))
 }