Add PeripheralBatteryObserver

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 439 matching lines @@
       </message>
       <message name="IDS_ASH_DISPLAY_FAILURE_ON_MIRRORING" desc="An error message to show that the system failed to enter the mirroring mode.">
         Could not mirror displays since no supported resolutions found. Entered extended desktop instead.
       </message>
       <message name="IDS_ASH_DISPLAY_FAILURE_ON_NON_MIRRORING" desc="An error message to show that the system failed to enter the extended desktop mode or unknown status. Please translate the parentized text.">
         Dear Monitor, it's not working out between us. (That monitor is not supported)
       </message>
       <message name="IDS_ASH_INTERNAL_DISPLAY_NAME" desc="The name of the internal display which is shown in the display settings.">
         Internal Display
       </message>
+      <message name="IDS_ASH_LOW_PERIPHERAL_BATTERY_NOTIFICATION_TEXT" desc="The text of the notification when a peripheral device is in low battery condition.">
+        Battery Low (<ph name="percentage">$1<ex>56</ex></ph>%)

[Daniel Erat, 2013/04/09 02:06:18]

"Battery low" (with a lowercase L) instead?  the screenshot notification text
seems to not have each word capitalized, for instance

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+      </message>
       <message name="IDS_ASH_SCREENSHOT_NOTIFICATION_TITLE_SUCCESS" desc="The title of the notification when a screenshot was taken.">
         Screenshot taken
       </message>
       <message name="IDS_ASH_SCREENSHOT_NOTIFICATION_TITLE_FAIL" desc="The title of the notification when taking a screenshot failed.">
         An error occurred
       </message>
       <message name="IDS_ASH_SCREENSHOT_NOTIFICATION_TEXT_SUCCESS" desc="The text of the notification when a screenshot was taken.">
         Click to view
       </message>
       <message name="IDS_ASH_SCREENSHOT_NOTIFICATION_TEXT_FAIL" desc="The text of the notification when taking a screenshot failed.">
         Failed to save screenshot
       </message>
 
       <!-- ChromeOS-specific strings -->
       <if expr="pp_ifdef('chromeos')">
         <part file="ash_chromeos_strings.grdp" />
       </if>
 
     </messages>
   </release>
 </grit>