Add contentDescription to offline badges on the NTP

chrome/android/java/strings/android_chrome_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- android_chrome_strings.grd contains strings for Chrome for Android.
 
 FAQ:
   - How do I add, change, or remove a string?
       Just update this file.
   - Translations will happen automatically??
       Yes, indeed. Just add your string before the branch point and
       make the description good.
@@ skipping 1929 matching lines @@
       </message>
       <message name="IDS_REMOVE_ALL" desc="Context menu option to clear the list of recently closed tabs">
         Remove all
       </message>
       <message name="IDS_NTP_STATUS_CARD_TITLE_EMPTY" desc="Title of the card explaining the status of the ntp suggested content, when we don't have anything to show.">
         All Read
       </message>
       <message name="IDS_NTP_STATUS_CARD_BODY_EMPTY" desc="Body of the card explaining the status of the ntp suggested content, when we don't have anything to show.">
         More cards will appear when the time is right.
       </message>
+      <message name="IDS_ACCESSIBILITY_NTP_OFFLINE_BADGE" desc="Content description for the badge that indicates offline availability of a most visited item on the new tab page.">
+        Available offline
+      </message>
 
       <!-- Toolbar button strings -->
       <message name="IDS_OPEN_TABS" desc="Text for button to enter the tab switcher and show tabs that are open on this device">
         Open tabs
       </message>
       <message name="IDS_BUTTON_NEW_TAB" desc="Button name for opening a new tab.">
         New tab
       </message>
 
       <!-- Main menu items -->
@@ skipping 595 matching lines @@
         Tap this button for quick access to your tabs.
       </message>
 
       <!-- Item Chooser UI strings -->
       <message name="IDS_ITEM_CHOOSER_ITEM_NAME_WITH_ID" desc="To distinguish items with the same name, the item chooser shows the item name with id.">
         <ph name="ITEM_NAME">%1$s<ex>item_name</ex></ph> (<ph name="ITEM_ID">%2$s<ex>item id</ex></ph>)
       </message>
     </messages>
   </release>
 </grit>