[MD settings] inform users that the spelling service sends data to google

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- About Page -->
   <if expr="chromeos">
     <message name="IDS_SETTINGS_ABOUT_PAGE_DETAILED_BUILD_INFO" desc="Label describing the section that shows detailed information about the current Chrome build.">
       Detailed build information
     </message>
     <message name="IDS_SETTINGS_ABOUT_PAGE_ARC_VERSION" desc="Label for ARC version">
       ARC Version
@@ skipping 1451 matching lines @@
   </message>
   <message name="IDS_SETTINGS_SAFEBROWSING_ENABLEPROTECTION" desc="The label of the 'Protect you and your device from dangerous sites' checkbox">
     Protect you and your device from dangerous sites
   </message>
   <message name="IDS_SETTINGS_SAFEBROWSING_ENABLE_EXTENDED_REPORTING" desc="Checkbox label: should Chrome upload information about suspicious downloads and websites to Safe Browsing">
     Automatically report details of possible security incidents to Google
   </message>
   <message name="IDS_SETTINGS_SPELLING_PREF" desc="The documentation string of the 'Use Spelling' preference">
     Use a web service to help resolve spelling errors
   </message>
+  <message name="IDS_SETTINGS_SPELLING_DESCRIPTION" desc="Description of using a web serviced to help resolve spelling errors. It is important to convey that what the user types will be sent to Google.">
+    Smarter spell-checking by sending what you type in the browser to Google
+  </message>
   <message name="IDS_SETTINGS_ENABLE_LOGGING" desc="The label of the checkbox to enable/disable crash and user metrics logging">
     Automatically send usage statistics and crash reports to Google
   </message>
   <message name="IDS_SETTINGS_ENABLE_LOGGING_DIAGNOSTIC_AND_USAGE_DATA" desc="The label of the checkbox to enable/disable diagnostic and user metrics logging">
     Automatically send diagnostic and usage data to Google
   </message>
   <message name="IDS_SETTINGS_ENABLE_DO_NOT_TRACK" desc="The label of the checkbox to enable/disable sending the 'Do Not track' header">
     Send a "Do Not Track" request with your browsing traffic
   </message>
   <message name="IDS_SETTINGS_ENABLE_CONTENT_PROTECTION_ATTESTATION" desc="description label for verified access about premium contents">
@@ skipping 982 matching lines @@
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_BUTTON" desc="Text for the button that changes a user's network proxy settings.">
       Change proxy settings
     </message>
   </if>
 </grit-part>