[Athena] Make a quick power button tap suspend the device

chromeos/dbus/power_manager_client.h

Index: chromeos/dbus/power_manager_client.h
diff --git a/chromeos/dbus/power_manager_client.h b/chromeos/dbus/power_manager_client.h
index b490e98207ef37c3aecc3960a51a28a1f0b0272a..be598d5468e5a0b955a954ddcfb98eb246cb3011 100644
--- a/chromeos/dbus/power_manager_client.h
+++ b/chromeos/dbus/power_manager_client.h
@@ -128,6 +128,9 @@ class CHROMEOS_EXPORT PowerManagerClient : public DBusClient {
   // will be called asynchronously.
   virtual void RequestStatusUpdate() = 0;
 
+  // Requests suspend of the system.
+  virtual void RequestSuspend() = 0;
+
   // Requests restart of the system.
   virtual void RequestRestart() = 0;