Add a string resource for set wallpaper from context menu.

ash/ash_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains the strings for ash.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/ash_strings.h" type="rc_header">
@@ skipping 156 matching lines @@
       <message name="IDS_AURA_APP_LIST_TITLE" desc="The title used for the Aura app list in the launcher">
         Applications
       </message>
       <message name="IDS_AURA_CYCLER_TITLE" desc="The title used for the Aura window cycler in the launcher">
         Window Cycler
       </message>
       <message name="IDS_AURA_LAUNCHER_OVERFLOW_NAME" desc="The title used for the Aura overflow button in the launcher">
         Overflow Button
       </message>
 
+      <message name="IDS_AURA_SET_DESKTOP_WALLPAPER" desc="The label used for change wallpaper in context menu">
+        Set Wallpaper...
+      </message>
+
       <message name="IDS_FRAME_MAXIMIZE_BUTTON_TOOLTIP" desc="Tooltip for the maximize/restore button in window frames in aura">
         Pull down to minimize, left or right to tile
       </message>
 
       <!-- Status tray items -->
       <message name="IDS_ASH_STATUS_TRAY_ACCESSIBLE_NAME" desc="The accessible name of the status tray.">
         Status tray
       </message>
       <message name="IDS_ASH_STATUS_TRAY_SETTINGS_AND_HELP" desc="The label used for the help-and-settings item in the status tray.">
         Settings and Help
@@ skipping 71 matching lines @@
         Battery full
       </message>
       <message name="IDS_ASH_STATUS_TRAY_BATTERY_STATUS" desc="The label in the tray dialog to show the status of the battery power.">
 Battery: <ph name="percentage">$1<ex>56</ex></ph>%
 <ph name="hour">$2</ph>h <ph name="minute">$3</ph>m
       </message>
     </messages>
   </release>
 </grit>