Lock screen for Chrome-Athena

athena/screen_lock/screen_lock_manager_base.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 "athena/screen_lock/screen_lock_manager_base.h"
+
+#include "base/logging.h"
+
+namespace athena {
+namespace {
+
+ScreenLockManager* instance = NULL;
+
+}  // namespace
+
+ScreenLockManagerBase::ScreenLockManagerBase() {
+  DCHECK(!instance);
+  instance = this;
+}
+
+ScreenLockManagerBase::~ScreenLockManagerBase() {
+  DCHECK_EQ(instance, this);
+  instance = NULL;
+}
+
+// static
+ScreenLockManager* ScreenLockManager::Get() {
+  return instance;
+}
+
+// static
+void ScreenLockManager::Shutdown() {
+  if (instance) {
+    delete instance;
+    DCHECK(!instance);
+  }
+}
+
+}  // namespace athena