Move the serial api and permission features to extensions/.

extensions/extensions_strings.grd

 <?xml version="1.0" encoding="utf-8"?>
 
 <!--
   Strings for the extensions module. Used mostly for low-level error messages.
   Where possible new strings should be kept in Chrome and the extensions module
   should return an error code, message flag, etc.
 -->
 
 <grit latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
@@ skipping 250 matching lines @@
         Exchange data with the computer named <ph name="HOSTNAME">$1<ex>foo.example.com</ex></ph>
       </message>
       <message name="IDS_EXTENSION_PROMPT_WARNING_SOCKET_SPECIFIC_HOSTS" desc="Permission string for access to multiple specific computers on the local network or internet.">
         Exchange data with the computers named: <ph name="HOSTNAMES">$1<ex>foo.example.com bar.example.com</ex></ph>
       </message>
       
       <!-- Device API strings. Please keep alphabetized. -->
       <message name="IDS_EXTENSION_PROMPT_WARNING_HID" desc="Permission string for access to HID devices.">
         Access your input devices
       </message>
+      <message name="IDS_EXTENSION_PROMPT_WARNING_SERIAL" desc="Permission string for access to serial devices.">
+        Access your serial devices
+      </message>
       <message name="IDS_EXTENSION_PROMPT_WARNING_USB" desc="Permission string for access to USB devices.">
         Access your USB devices
       </message>
       <message name="IDS_EXTENSION_PROMPT_WARNING_USB_DEVICE" desc="Permission string for access to a specific USB device.">
         Access the USB device <ph name="PRODUCT_NAME">$1<ex>SoundKnob</ex></ph> from <ph name="VENDOR_NAME">$2<ex>Griffin Technology</ex></ph>
       </message>
       <message name="IDS_EXTENSION_PROMPT_WARNING_USB_DEVICE_MISSING_PRODUCT" desc="Permission string for access to a specific USB device when a product name cannot be established for a USB device.">
         Access the USB device from <ph name="VENDOR_NAME">$1<ex>Griffin Technology</ex></ph>
       </message>
       <message name="IDS_EXTENSION_PROMPT_WARNING_USB_DEVICE_MISSING_VENDOR" desc="Permission string for access to a specific USB device when a vendor name cannot be established for a USB device.">
         Access the USB device
       </message>
 
     </messages>
   </release>
 </grit>