Implement search engine auto switch when entering or leaving some locale

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 2585 matching lines @@
       <!-- Special locale UI strings -->
       <message name="IDS_SEARCH_WITH_SOGOU" desc="Text telling the user that the search engine will be switched to Sogou.">
         Search with Sogou
       </message>
       <message name="IDS_SOGOU_EXPLANATION" desc="Text explaining why Sogou should be used as default search engine.">
         Chrome can use Sogou for search in China. You can change this in <ph name="BEGIN_LINK">&lt;link&gt;</ph>Settings<ph name="END_LINK">&lt;/link&gt;</ph>.
       </message>
       <message name="IDS_KEEP_GOOGLE" desc="Text representing the option that the user wants to keep Google as the default search engine.">
         Keep Google
       </message>
+      <message name="IDS_USING_SOGOU" desc="Text notifying users that the default search engine has been set to Sogou.">
+        Using Sogou for search
+      </message>
+      <message name="IDS_USING_GOOGLE" desc="Text notifying users that the default search engine has been set to Google.">
+        Using Google for search
+      </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>
 
       <message name="IDS_INSTANT_APPS_OPEN_IN_APP" desc="Button label for the user action that will open an Instant App.">
         Open app
       </message>
     </messages>
   </release>
 </grit>