[iOS] Add accessibility labels to Keyboard Accessory View buttons.

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 680 matching lines @@
       </message>
       <message name="IDS_IOS_ICON_INFO" desc="Accessibility label for the info icon [iOS only].">
         Info
       </message>
       <message name="IDS_IOS_ICON_SEARCH" desc="Accessibility label for the search icon [iOS only].">
         Search
       </message>
       <message name="IDS_IOS_JAVA_SCRIPT_DIALOG_BLOCKING_BUTTON_TEXT" desc="The text used for the button added to JavaScript dialogs to prevent a page from spamming the user with endless alerts. [Length:27em]">
         Suppress Dialogs
       </message>
+      <message name="IDS_IOS_KEYBOARD_ACCESSORY_VIEW_QR_CODE_SEARCH" desc="Accessibility label for a button that starts scanning QR Codes [iOS only].">
+        QR code Search
+      </message>
+      <message name="IDS_IOS_KEYBOARD_ACCESSORY_VIEW_VOICE_SEARCH" desc="Accessibility label for a button that starts a Voice Search [iOS only]">
+        Voice Search
+      </message>
       <message name="IDS_IOS_KEYBOARD_BOOKMARK_THIS_PAGE" desc="In Title Case: Title of the keyboard shortcut that bookmarks the current page. [Length: 20 em] [iOS only]">
         Bookmark This Page...
       </message>
       <message name="IDS_IOS_KEYBOARD_HISTORY_BACK" desc="Title of the keyboard shortcut to go back in the history menu. [Length: 20 em] [iOS only]">
         Back
       </message>
       <message name="IDS_IOS_KEYBOARD_HISTORY_FORWARD" desc="Title of the keyboard shortcut to go forward in the history menu. [Length: 20 em] [iOS only]">
         Forward
       </message>
       <message name="IDS_IOS_KEYBOARD_OPEN_LOCATION" desc="Title of the keyboard shortcut to open a location (puts cursor in the URL bar). [Length: 20 em] [iOS only]">
@@ skipping 810 matching lines @@
       </message>
       <message name="IDS_IOS_SYSTEM_MAIL_APP" desc="Name of iOS system-provided Mail app. Note that this is not consistently translated for all locales, e.g. it is still 'Mail' (in English) for French locale, but is translated to '邮件' for Chinese locale. [Length: 10em]">
         Mail
       </message>
       <message name="IDS_IOS_COMPOSE_EMAIL_SETTING" desc="Title for the view and option to select a handler for mailto: URLs. [Length: 20em]">
         Compose Email
       </message>
     </messages>
   </release>
 </grit>