[CUPS] Implement the UI handler for adding a new printer.

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 813 matching lines @@
     </message>
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_FOUND_PRINTER" desc="The printer-found message shown in the manually add printer dialog.">
       Printer found
     </message>
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_SELECT_MANUFACTURER_MODEL" desc="The message shown in the select manufacturer and model dialog.">
       Could not detect your printer model. Select a manufacturer and model from the list.
     </message>
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_MANUFACTURER" desc="Label for the dropdown menu to select a manufacturer for the printer.">
       Manufacturer
     </message>
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADDED_PRINTER_MESSAGE" desc="The message shown when a new printer is setup successfully.">

[michaelpg, 2016/09/20 20:58:42]

nit: "set up" (2 words)

[xdai1, 2016/09/21 17:40:19]

Done.

+      Added <ph name="PRINTER_NAME">$1<ex>printer</ex></ph>
+    </message>
   </if>
   <message name="IDS_SETTINGS_PRINTING_CLOUD_PRINTERS" desc="In Printing Settings, the title of the google cloud printers setting section.">
     Google Cloud Print
   </message>
 
   <!-- Downloads Page -->
   <message name="IDS_SETTINGS_DOWNLOADS" desc="Name of the settings page which displays download preferences.">
     Downloads
   </message>
   <message name="IDS_SETTINGS_DOWNLOAD_LOCATION" desc="Label for the input which allows the user to specify the default download directory.">
@@ skipping 1461 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>