Add API to allow you to get the non-transactional datastore or taskqueue.

impl/prod/raw_datastore.go

Index: impl/prod/raw_datastore.go
diff --git a/impl/prod/raw_datastore.go b/impl/prod/raw_datastore.go
index bc835c03bcca53d58e87991bbe4e8056804a983a..e70b31adb06670de9cbcdab4a238626571dbcb8b 100644
--- a/impl/prod/raw_datastore.go
+++ b/impl/prod/raw_datastore.go
@@ -15,8 +15,18 @@ import (
 // useRDS adds a gae.RawDatastore implementation to context, accessible
 // by gae.GetDS(c)
 func useRDS(c context.Context) context.Context {
-	return ds.SetRawFactory(c, func(ci context.Context) ds.RawInterface {
-		return rdsImpl{ci, AEContext(ci), info.Get(ci).GetNamespace()}
+	return ds.SetRawFactory(c, func(ci context.Context, wantTxn bool) ds.RawInterface {
+		ns := info.Get(ci).GetNamespace()
+		maybeTxnCtx := AEContext(ci)
+
+		if wantTxn {
+			return rdsImpl{ci, maybeTxnCtx, ns}
+		}
+		aeCtx := AEContextNoTxn(ci)
+		if maybeTxnCtx != aeCtx {
+			ci = context.WithValue(ci, prodContextKey, aeCtx)
+		}
+		return rdsImpl{ci, aeCtx, ns}
 	})
 }
 
@@ -223,8 +233,8 @@ func (d rdsImpl) Count(fq *ds.FinalizedQuery) (int64, error) {
 
 func (d rdsImpl) RunInTransaction(f func(c context.Context) error, opts *ds.TransactionOptions) error {
 	ropts := (*datastore.TransactionOptions)(opts)
-	return datastore.RunInTransaction(d.aeCtx, func(aeCtx context.Context) error {
-		return f(context.WithValue(d.userCtx, prodContextKey, aeCtx))
+	return datastore.RunInTransaction(d.aeCtx, func(c context.Context) error {
+		return f(context.WithValue(d.userCtx, prodContextKey, c))
 	}, ropts)
 }