Enable system NSS key slot.

crypto/scoped_test_system_nss_key_slot.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "crypto/scoped_test_system_nss_key_slot.h"
 
 #include "crypto/nss_util_internal.h"
 #include "crypto/scoped_test_nss_db.h"
 
 namespace crypto {
 
 ScopedTestSystemNSSKeySlot::ScopedTestSystemNSSKeySlot()
     : test_db_(new ScopedTestNSSDB) {
   if (!test_db_->is_open())
     return;
   SetSystemKeySlotForTesting(
       ScopedPK11Slot(PK11_ReferenceSlot(test_db_->slot())));
 }
 
 ScopedTestSystemNSSKeySlot::~ScopedTestSystemNSSKeySlot() {
   SetSystemKeySlotForTesting(ScopedPK11Slot());
 }
 
 bool ScopedTestSystemNSSKeySlot::ConstructedSuccessfully() const {
   return test_db_->is_open();
 }
 
+PK11SlotInfo* ScopedTestSystemNSSKeySlot::slot() const {
+  return test_db_->slot();
+}
+
 }  // namespace crypto