Clean up chrome://version page.

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 975 matching lines @@
       </message>
       <message name="IDS_IOS_PAYMENT_REQUEST_TOTAL_HEADER" desc="Label of the header of the section which displays the total charge for a payment request [iOS only].">
         Total
       </message>
       <message name="IDS_IOS_PHOTO_LIBRARY_USAGE_DESCRIPTION" desc="Specifies the reason for accessing the user's photo library while the app is in use [Length: unlimited] [iOS only].">
         This lets you save and upload photos.
       </message>
       <message name="IDS_IOS_PLACEHOLDER_FIND_IN_PAGE" desc="The iOS placeholder for searching in the current page [Length: 30em] [iOS only]">
         Find in page...
       </message>
-      <message name="IDS_IOS_PLATFORM_LABEL" desc="Label for Platform. [Length: unlimited] [iOS only]">
-        Platform
-      </message>
       <message name="IDS_IOS_POPUPS_ALLOWED" desc="Label for the list of sites that the user has allowed to show pop-ups. [Length: 20em] [iOS only]">
         Pop-ups Allowed
       </message>
       <message name="IDS_IOS_POPUPS_ALWAYS_SHOW_MOBILE" desc="Label of the button in the block popups infobar that let the user allowing the popups for the current site.">
         Always show
       </message>
       <message name="IDS_IOS_POPUPS_BLOCKED_MOBILE" desc="Message shown in the infobar when a popup is blocked [length: 20em]">
         Pop-ups blocked (<ph name="NUMBER_OF_BLOCKED_POPUPS">$1<ex>1</ex></ph>)
       </message>
       <message name="IDS_IOS_PRINT_PDF_ERROR_SUBTITLE" desc="Message of a popup window indicating that the printing operation did not succeed. [Length: 100em] [iOS only]">
@@ skipping 551 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>