Add onGetUsbPrinterInfoRequested event to printerProvider API.

chrome/browser/ui/webui/print_preview/print_preview_handler.h

Index: chrome/browser/ui/webui/print_preview/print_preview_handler.h
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_handler.h b/chrome/browser/ui/webui/print_preview/print_preview_handler.h
index 5240f9e88927ce09c67131438692af8e32ecf551..35129115409cfaa7066c976ce5d801992a45e51e 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_handler.h
+++ b/chrome/browser/ui/webui/print_preview/print_preview_handler.h
@@ -21,6 +21,7 @@
 #include "chrome/browser/local_discovery/service_discovery_shared_client.h"
 #endif  // ENABLE_SERVICE_DISCOVERY
 
+class ExtensionPrinterHandler;
 class PrinterHandler;
 class PrintPreviewUI;
 class PrintSystemTaskProxy;
@@ -122,12 +123,16 @@ class PrintPreviewHandler
   // Gets the list of printers. |args| is unused.
   void HandleGetPrinters(const base::ListValue* args);
 
-  // Starts getting all local privet printers. |arg| is unused.
+  // Starts getting all local privet printers. |args| is unused.
   void HandleGetPrivetPrinters(const base::ListValue* args);
 
-  // Starts getting all local extension managed printers. |arg| is unused.
+  // Starts getting all local extension managed printers. |args| is unused.
   void HandleGetExtensionPrinters(const base::ListValue* args);
 
+  // Grants an extension access to a USB printer.  First element of |args| is
+  // the extension ID and the second element is USB device ID.
+  void HandleGrantExtensionUsbPrinterAccess(const base::ListValue* args);
+
   // Stops getting all local privet printers. |arg| is unused.
   void HandleStopGetPrivetPrinters(const base::ListValue* args);
 
@@ -308,6 +313,15 @@ class PrintPreviewHandler
   //     they manage.
   void OnGotPrintersForExtension(const base::ListValue& printers, bool done);
 
+  // Called when an extension reports information for a USB printer it has just
+  // been granted access to.
+  // |extension_id|: The extension that was queried.
+  // |device_id|: The id of the USB device.
+  // |printer_info|: The data reported by the extension.
+  void OnGotExtensionUsbPrinterInfo(const std::string& extension_id,
+                                    int device_id,
+                                    const base::DictionaryValue& printer_info);
+
   // Called when an extension reports the set of print capabilites for a
   // printer.
   // |printer_id|: The id of the printer whose capabilities are reported.
@@ -372,7 +386,7 @@ class PrintPreviewHandler
 
   // Handles requests for extension printers. Created lazily by calling
   // |EnsureExtensionPrinterHandlerSet|.
-  scoped_ptr<PrinterHandler> extension_printer_handler_;
+  scoped_ptr<ExtensionPrinterHandler> extension_printer_handler_;
 
   // Notifies tests that want to know if the PDF has been saved. This doesn't
   // notify the test if it was a successful save, only that it was attempted.