Add onGetUsbPrinterInfoRequested event to printerProvider API.

chrome/browser/ui/webui/print_preview/extension_printer_handler.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/print_preview/extension_printer_handler.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 132 matching lines @@
     return;
   }
 
   print_job->content_type = kContentTypePWGRaster;
   ConvertToPWGRaster(print_data, printer_description, ticket, page_size,
                      print_job.Pass(),
                      base::Bind(&ExtensionPrinterHandler::DispatchPrintJob,
                                 weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
+void ExtensionPrinterHandler::StartGrantUsbPrinterAccess(
+    const std::string& extension_id,
+    int device_id,
+    const GrantUsbPrinterAccessCallback& callback) {
+  extensions::PrinterProviderAPIFactory::GetInstance()
+      ->GetForBrowserContext(browser_context_)
+      ->DispatchGrantUsbPrinterAccess(
+          extension_id, device_id,
+          base::Bind(
+              &ExtensionPrinterHandler::WrapGrantUsbPrinterAccessCallback,
+              weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
 void ExtensionPrinterHandler::SetPwgRasterConverterForTesting(
     scoped_ptr<local_discovery::PWGRasterConverter> pwg_raster_converter) {
   pwg_raster_converter_ = pwg_raster_converter.Pass();
 }
 
 void ExtensionPrinterHandler::ConvertToPWGRaster(
     const scoped_refptr<base::RefCountedMemory>& data,
     const cloud_devices::CloudDeviceDescription& printer_description,
     const cloud_devices::CloudDeviceDescription& ticket,
     const gfx::Size& page_size,
@@ skipping 38 matching lines @@
     const base::DictionaryValue& capability) {
   callback.Run(destination_id, capability);
 }
 
 void ExtensionPrinterHandler::WrapPrintCallback(
     const PrinterHandler::PrintCallback& callback,
     bool success,
     const std::string& status) {
   callback.Run(success, status);
 }
+
+void ExtensionPrinterHandler::WrapGrantUsbPrinterAccessCallback(
+    const GrantUsbPrinterAccessCallback& callback,
+    const base::DictionaryValue& printer_info) {
+  callback.Run(printer_info);
+}