Add a message for Reading List Snackbar

ios/chrome/app/strings/ios_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains definition of resources that will be translated for each
 locale.  The strings in this file are specific to iOS.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
@@ skipping 1020 matching lines @@
       </message>
       <message name="IDS_IOS_QR_SCANNER_TORCH_OFF_ACCESSIBILITY_VALUE" desc="Accessiblity value of the button to turn torch on in the QR Scanner. The button communicates that the torch is current off. [Length: unlimited] [iOS only]">
         Off
       </message>
       <message name="IDS_IOS_QR_SCANNER_TORCH_ON_ACCESSIBILITY_VALUE" desc="Accessibility value of the button to turn torch off in the QR Scanner. The button communicates that the torch is currently on. [Length: unlimited] [iOS only]">
         On
       </message>
       <message name="IDS_IOS_QR_SCANNER_VIEWPORT_CAPTION" desc="Message displayed below the QR scanner viewport instructing the user to position the scanned QR or bar code inside the viewport. [Length: unlimited] [iOS only]">
         QR Code or barcode
       </message>
+      <message name="IDS_IOS_READING_LIST_SNACKBAR_MESSAGE" desc="Message briefly displayed at the bottom of the screen to the user to inform that the selected page has been added to the reading list. [Length: 35em]" meaning="The selected page has been added to your reading list. [Length: 35em]">
+        Added to Reading List
+      </message>
       <message name="IDS_IOS_READING_LIST_CANCEL_BUTTON" desc="Label of the button to stop editing the reading list entries (delete, mark as read/unread) [Length: 15em]" meaning="Stop editing. [Length: 15em]">
         Cancel
       </message>
       <message name="IDS_IOS_READING_LIST_DELETE_ALL_READ_BUTTON" desc="Label of the button to delete all the reading list entries read [Length: 15em]" meaning="Delete all the read entries. [Length: 15em]">
         Delete Read
       </message>
       <message name="IDS_IOS_READING_LIST_DELETE_BUTTON" desc="Label of the button to delete the reading list entries [Length: 15em]" meaning="Delete the selected entries. [Length: 15em]">
         Delete
       </message>
       <message name="IDS_IOS_READING_LIST_DONE_BUTTON" desc="Label of the button to dismiss reading list dialog">
@@ skipping 467 matching lines @@
       </message>
       <message name="IDS_IOS_VOICE_SEARCH_SETTING_TITLE" desc="The title for Voice Search setting [Length: 29em] [iOS only]">
         Voice Search
       </message>
       <message name="IDS_IOS_VOICE_SEARCH_SETTING_TTS" desc="The label for setting switch enabling text-to-speech response after voice search [Length: 29em] [iOS only]">
         Speak Answers Back
       </message>
     </messages>
   </release>
 </grit>