Change UsbDeviceFilter to use const references instead of

chrome/browser/chromeos/printing/usb_printer_util.cc

 // Copyright 2017 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/chromeos/printing/usb_printer_util.h"
 
 #include <ctype.h>
 #include <stdint.h>
 #include <vector>
 
@@ skipping 32 matching lines @@
       buf.push_back(kHexDigits[c & 0xf]);
     } else {
       buf.push_back(c);
     }
   }
   return std::string(buf.data(), buf.size());
 }
 
 }  // namespace
 
-bool UsbDeviceIsPrinter(scoped_refptr<device::UsbDevice> usb_device) {
+bool UsbDeviceIsPrinter(const device::UsbDevice& usb_device) {
   device::UsbDeviceFilter printer_filter;
   printer_filter.interface_class = kPrinterInterfaceClass;
   return printer_filter.Matches(usb_device);
 }
 
 std::string UsbPrinterDeviceDetailsAsString(const device::UsbDevice& device) {
   return base::StringPrintf(
       " guid:                %s\n"
       " usb version:         %d\n"
       " device class:        %d\n"
@@ skipping 47 matching lines @@
   // There doesn't seem to be a robust solution to this problem; if printers
   // don't supply a serial number, we don't have any reliable way to do that
   // differentiation.
   std::string serial = base::UTF16ToUTF8(device.serial_number());
   return CupsURIEscape(base::StringPrintf("usb://%04x/%04x?serial=%s",
                                           device.vendor_id(),
                                           device.product_id(), serial.c_str()));
 }
 
 }  // namespace chromeos