MD History: Add tooltip for history menu button

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 191 matching lines @@
     Choose font types and encoding
   </message>
 
   <!-- Common -->
   <message name="IDS_SETTINGS_ADVANCED" desc="Name of the settings page which displays advanced preferences.">
     Advanced
   </message>
   <message name="IDS_SETTINGS_BASIC" desc="Name of the settings page which displays advanced preferences.">
     Basic
   </message>
+  <message name="IDS_SETTINGS_MENU_BUTTON_LABEL" desc="Text used to identify the sidebar menu button for screen readers.">
+    Menu
+  </message>
   <message name="IDS_SETTINGS_SEARCH_PROMPT" desc="Label for input field to search within settings.">
     Search settings
   </message>
   <message name="IDS_SETTINGS_SEARCH_NO_RESULTS" desc="Text description of a search that has no results.">
     No matches were found.
   </message>
   <message name="IDS_SETTINGS_SEARCH_NO_RESULTS_HELP" desc="Help text for a search that has no results.">
     Go to <ph name="BEGIN_LINK_CHROMIUM">&lt;a target="_blank" href="$1"&gt;</ph>Google Chrome help<ph name="END_LINK_CHROMIUM">&lt;/a&gt;</ph> if you can't find what you're looking for.
   </message>
   <message name="IDS_SETTINGS_SETTINGS" desc="The settings page title.">
@@ skipping 1666 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>