Extract ScopedTestNSSDB from nss_util.

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();
+}
+
+}  // namespace crypto