Implement a JavaScript API for document scanning

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 156 matching lines @@
     <file path="strings/extensions_strings_th.xtb" lang="th" />
     <file path="strings/extensions_strings_tr.xtb" lang="tr" />
     <file path="strings/extensions_strings_uk.xtb" lang="uk" />
     <file path="strings/extensions_strings_vi.xtb" lang="vi" />
     <file path="strings/extensions_strings_zh-CN.xtb" lang="zh-CN" />
     <file path="strings/extensions_strings_zh-TW.xtb" lang="zh-TW" />
   </translations>
   <release seq="1" allow_pseudo="false">
     <messages fallback_to_english="true">
 
+      <!-- Document Scan API strings. Please keep alphabetized. -->
+      <message name="IDS_EXTENSION_PROMPT_WARNING_DOCUMENT_SCAN" desc="Permission string for access to document scanning.">
+        Access document scanners attached via USB or on the local network
+      </message>
+
       <!-- General extensions strings. Please keep alphabetized. -->
       <message name="IDS_EXTENSION_CONTAINS_PRIVATE_KEY" desc="Error message when an extension includes a file containing a private key.">
         This extension includes the key file '<ph name="KEY_PATH">$1<ex>relative/path/to/file.pem</ex></ph>'. You probably don't want to do that.
       </message>
       <message name="IDS_EXTENSION_LOAD_BACKGROUND_SCRIPT_FAILED" desc="">
         Could not load background script '<ph name="BACKGROUND_SCRIPT">$1<ex>script.js</ex></ph>'.
       </message>
       <message name="IDS_EXTENSION_LOAD_BACKGROUND_PAGE_FAILED" desc="">
         Could not load background page '<ph name="BACKGROUND_PAGE">$1<ex>page.html</ex></ph>'.
       </message>
@@ skipping 136 matching lines @@
       <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>