Add Search-. as a shortcut for the Insert key when Search is acting as a Function key.

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>
   <!-- Idle Logout Dialog Strings -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog">
     Are you still there?
   </message>
   <message name="IDS_IDLE_LOGOUT_WARNING_RESTART" desc="Restart label for the idle logout dialog">
     This computer will reset in <ph name="LOGOUT_TIME_LEFT">$1<ex>20</ex></ph> seconds.
@@ skipping 2660 matching lines @@
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_F10" desc="The text in the keyboard overlay to explain the shortcut.">
     F10
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_F11" desc="The text in the keyboard overlay to explain the shortcut.">
     F11
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_F12" desc="The text in the keyboard overlay to explain the shortcut.">
     F12
   </message>
+  <message name="IDS_KEYBOARD_OVERLAY_INSERT" desc="The text in the keyboard overlay to explain the shortcut.">
+    Insert
+  </message>
   <!-- BEGIN GENERATED KEYBOARD OVERLAY STRINGS -->
   <message name="IDS_KEYBOARD_OVERLAY_ACTIVATE_LAST_LAUNCHER_ITEM" desc="The text in the keyboard overlay to explain the shortcut (Open the last launcher item).">
     Activate last launcher item
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_ACTIVATE_LAST_TAB" desc="The text in the keyboard overlay to explain the shortcut.">
     Activate last tab
   </message>
   <message name="IDS_KEYBOARD_OVERLAY_ACTIVATE_LAUNCHER_ITEM_1" desc="The text in the keyboard overlay to explain the shortcut (Open the launcher item at the specified position).">
     Activate launcher item 1
   </message>
@@ skipping 803 matching lines @@
   <message name="IDS_LOGIN_MANAGED_BY_STATUS_NETWORK_ERROR" desc="Text for the network error status in 'Managed by DOMAIN' label on login screen.">
     Network error while communicating with the device management service.
   </message>
   <message name="IDS_LOGIN_MANAGED_BY_NOTICE" desc="Text for the notification bar on the login screen showing that this is a managed device.">
     This device is managed by <ph name="DOMAIN">$1<ex>yourdomain.com</ex></ph>.
   </message>
   <message name="IDS_LOGIN_MANAGED_REPORTING_HINT" desc="Text for the hint on reporting features displayed in the enterprise notification bar on the login screen.">
     Device usage may be tracked.
   </message>
 </grit-part>