Implement support for monitor suspend.

chrome/browser/chromeos/power/suspend_observer.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_POWER_SUSPEND_OBSERVER_H_
+#define CHROME_BROWSER_CHROMEOS_POWER_SUSPEND_OBSERVER_H_
+
+#include "ash/shell.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chromeos/dbus/power_manager_client.h"
+
+namespace chromeos {
+
+// A class to observe suspend events.
+class SuspendObserver : public PowerManagerClient::Observer {
+ public:
+  // This class registers/unregisters itself as an observer in ctor/dtor.
+  SuspendObserver();
+  virtual ~SuspendObserver();
+
+  // PowerManagerClient::Observer override.
+  virtual void SuspendImminent() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SuspendObserver);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_POWER_SUSPEND_OBSERVER_H_