Implement support for monitor suspend.

chrome/browser/chromeos/power/suspend_observer.cc

+// Copyright (c) 2013 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 "chrome/browser/chromeos/power/suspend_observer.h"
+#include "chrome/browser/extensions/system/system_api.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/display/output_configurator.h"
+
+namespace chromeos {
+
+SuspendObserver::SuspendObserver() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
+}
+
+SuspendObserver::~SuspendObserver() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
+}
+
+void SuspendObserver::SuspendImminent() {
+  ash::Shell::GetInstance()->output_configurator()->SuspendDisplays();
+}
+
+}  // namespace chromeos