Add device policy to disallow shutdown - ash UI modifications

ash/ash_strings.grd

Index: ash/ash_strings.grd
diff --git a/ash/ash_strings.grd b/ash/ash_strings.grd
index 26b6ed4969a5f50b08ff4788a3a0908e459cae37..c6c3e937ea800e76e79ccee97b5ec19ecda53a7a 100644
--- a/ash/ash_strings.grd
+++ b/ash/ash_strings.grd
@@ -352,6 +352,9 @@ Press Ctrl+Alt+Z to disable.
       <message name="IDS_ASH_STATUS_TRAY_DATE" desc="The date displayed on ash system bubble, Depending on launguage, please choose the best separator(eg ',') between abbreviated weekday and date">
         <ph name="short_weekday">$1<ex>Fri</ex></ph>, <ph name="date">$2<ex>Aug 31, 2012</ex></ph>
       </message>
+      <message name="IDS_ASH_STATUS_TRAY_REBOOT" desc="The accessible text for the reboot button.">

[Daniel Erat, 2015/01/07 16:18:40]

nit: "the restart button"?

i think it's a bit weird that we call it rebooting in the code and restarting in
the ui, but i don't know if it's worth changing. "restarting" is a bit vague
when reading the code but i can understand if we don't want to show users the
word "reboot".

[cschuet (SLOW), 2015/01/13 10:38:28]

Indeed, the rationale was that all user-facing strings mention "restart" rather
than "reboot".

+        Restart
+      </message>
       <message name="IDS_ASH_STATUS_TRAY_SHUTDOWN" desc="The accessible text for the shutdown button.">
         Shut down
       </message>