Add projection touch HUD to keyboard overlay

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="pp_ifdef('chromeos')">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 3164 matching lines @@
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_TOGGLE_CAPS_LOCK" desc="The text in the keyboard overlay to explain the shortcut (enable or disable caps lock).">
     Toggle caps lock
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_TOGGLE_SPEECH_INPUT" desc="The text in the keyboard overlay to explain the shortcut (start or stop speech input).">
     Toggle speech input
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_TOGGLE_SPOKEN_FEEDBACK" desc="The text in the keyboard overlay to explain the shortcut (enable or disable spoken feedback).">
     Toggle spoken feedback
   </message>
+  <message name="IDS_KEYBOARD_OVERLAY_TOGGLE_TOUCH_HUD_PROJECTION" desc="The text in the keyboard overlay to explain the shortcut (enable or disable projection touch HUD).">
+    Toggle projection touch HUD
+  </message>
   <message name="IDS_KEYBOARD_OVERLAY_UNDO" desc="The text in the keyboard overlay to explain the shortcut.">
     Undo
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_VIEW_KEYBOARD_OVERLAY" desc="The text in the keyboard overlay to explain the shortcut.">
     View keyboard overlay
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_VIEW_SOURCE" desc="The text in the keyboard overlay to explain the shortcut.">
     View source
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_WORD_MOVE" desc="The text in the keyboard overlay to explain the shortcut.">
@@ skipping 548 matching lines @@
     You are currently connected to the <ph name="NETWORK_TYPE">$1<ex>cellular</ex></ph> network.
   </message>
   <message name="IDS_UPGRADE_NETWORK_LIST_CELLULAR_ALLOWED" desc="Status label: for updates you need to connect to an Ethernet or Wi-Fi">
     To check for updates, please use Ethernet or Wi-Fi.
   </message>
   <message name="IDS_UPGRADE_NETWORK_LIST_CELLULAR_DISALLOWED" desc="Status label: for updates you need to connect to an Ethernet, mobile data or Wi-Fi">
     To check for updates, please use Ethernet, Wi-Fi or mobile data.
   </message>
 
 </grit-part>