[CUPS] Implement the Webui handler for the printers auto discovery.

chrome/app/settings_strings.grdp

Index: chrome/app/settings_strings.grdp
diff --git a/chrome/app/settings_strings.grdp b/chrome/app/settings_strings.grdp
index f799281f3e5b9d3950135e2fe2d269f7eb1af3d2..2c0cd3672c611f85a62e534ef969f4a9fc98c79e 100644
--- a/chrome/app/settings_strings.grdp
+++ b/chrome/app/settings_strings.grdp
@@ -855,9 +855,21 @@
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_BUTTON_SELECT_DRIVER" desc="Text for the button which allows user to select a PPD file from the file system.">
       Browse
     </message>
-    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADDED_PRINTER_MESSAGE" desc="The message shown when a new printer is set up successfully.">
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADDED_PRINTER_DONE_MESSAGE" desc="The message shown when a new printer is set up successfully.">
       Added <ph name="PRINTER_NAME">$1<ex>printer</ex></ph>
     </message>
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_NO_PRINTER_NEARBY" desc="The no-printer-found message shown in the auto discovery dialog.">
+      No printers nearby
+    </message>
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_SEARCHING_NEARBY_PRINTER" desc="The searching-in-progress message shown in the auto discovery dialog.">
+      Searching...
+    </message>
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADDED_PRINTER_ERROR_MESSAGE" desc="The message shown when a new printer is not set up successfully.">
+      Error adding printer
+    </message>
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADDED_PRINTER_TRY_AGAIN_MESSAGE" desc="The try-again message shown when a new printer is not set up successfully.">
+      Try again
+    </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