Support SystemTrayDelegate::ShowPowerSettings() in mustash

ash/common/system/chromeos/power/dual_role_notification.cc

Index: ash/common/system/chromeos/power/dual_role_notification.cc
diff --git a/ash/common/system/chromeos/power/dual_role_notification.cc b/ash/common/system/chromeos/power/dual_role_notification.cc
index 1b902784442302a8fe4deebe00e2ebc59723f1ca..400403b811fcc1de3e3c647f936c7ccfb1c32e84 100644
--- a/ash/common/system/chromeos/power/dual_role_notification.cc
+++ b/ash/common/system/chromeos/power/dual_role_notification.cc
@@ -37,7 +37,8 @@ class DualRoleNotificationDelegate
 
   // Overridden from message_center::NotificationDelegate.
   void Click() override {
-    WmShell::Get()->system_tray_delegate()->ShowPowerSettings();
+    if (PowerStatus::Get()->IsBatteryPresent())

[James Cook, 2016/09/27 23:23:13]

I'm unsure if we still need this check (I moved it here from
SystemTrayDelegateChromeos). It wasn't clear to me if it made sense to show the
settings if you didn't have a battery.

[michaelpg, 2016/09/28 23:09:15]

We shouldn't show the *notification* if there isn't a battery. I believe that's
already the case from the power settings proto. So this check isn't needed in
the notification itself.

[James Cook, 2016/09/29 15:28:29]

Removed the if().

+      WmShell::Get()->system_tray_delegate()->ShowPowerSettings();
   }
 
  private: