Add a string for Chrome branding

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 778 matching lines @@
       </message>
       <message name="IDS_ACCOUNT_MANAGEMENT_CHILD_CONTENT_APPROVED" desc="Setting that permits child accounts to visit only sites approved by their parents.">
         Only approved sites
       </message>
       <message name="IDS_ACCOUNT_MANAGEMENT_CHILD_CONTENT_ALL" desc="Setting that permits child accounts to visit any websites.">
         Uncontrolled
       </message>
       <message name="IDS_ACCOUNT_MANAGEMENT_CHILD_SAFE_SEARCH_TITLE" desc="Title of Google SafeSearch, which blocks inappropriate or explicit search results.">
         SafeSearch
       </message>
+      <message name="IDS_CHROME_BRANDING_MESSAGE" desc="The branding message for prompting user with context.">

[newt (away), 2015/07/09 18:55:59]

How about: "A message indicating that the current page is running in Chrome"

[Yusuf, 2015/07/09 18:57:33]

Done.

+        Powered by Chrome
+      </message>
 
       <!-- Sync strings in account management dialog -->
       <message name="IDS_SYNC_ANDROID_MASTER_SYNC_DISABLED" desc="Message to show when Android master sync flag is disabled">
         Android system sync disabled. Please re-enable and try again.
       </message>
       <message name="IDS_SYNC_IS_ENABLED" desc="Message to show when Chrome sync is enabled">
         Sync is on
       </message>
       <message name="IDS_SYNC_IS_DISABLED" desc="Message to show when Chrome sync is disabled">
         Sync is off
@@ skipping 1391 matching lines @@
       </message>
       <message name="IDS_HELP_CONTEXT_USAGE_REPORTS" translateable="false">
         send_crash_report
       </message>
       <message name="IDS_HELP_CONTEXT_SAD_TAB" translateable="false">
         mobile_awsnap
       </message>
     </messages>
   </release>
 </grit>