Change UsbDeviceFilter to use const references instead of

chrome/browser/chromeos/printer_detector/cups_printer_detector.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 <stdint.h>
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 84 matching lines @@
 
   // UsbService::observer override.
   void OnDeviceAdded(scoped_refptr<device::UsbDevice> device) override {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
     MaybeSetUpDevice(device, true);
   }
 
   // UsbService::observer override.
   void OnDeviceRemoved(scoped_refptr<device::UsbDevice> device) override {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-    if (!UsbDeviceIsPrinter(device)) {
+    if (!UsbDeviceIsPrinter(*device)) {
       return;
     }
     known_printers_.erase(device->guid());
     // TODO(justincarlson):  Update failed printers.
   }
 
   // Returns the existing printer using this URI, if one exists, or
   // null otherwise.
   std::unique_ptr<Printer> FindExistingPrinter(const std::string& uri) {
     // TODO(justincarlson): add a GetPrinterByURI to PrintersManager.
     // https://crbug.com/700602
     auto existing_printers =
         PrintersManagerFactory::GetForBrowserContext(profile_)->GetPrinters();
     for (std::unique_ptr<Printer>& printer : existing_printers) {
       if (printer->uri() == uri) {
         // Found a match, so use the existing configuration.
         return std::move(printer);
       }
     }
     return nullptr;
   }
 
   // If this device is a printer and we haven't already tried to set it up,
   // starts the process of setting the printer up.  |hotplugged|
   // should be true if this was plugged in during the session.
   void MaybeSetUpDevice(scoped_refptr<device::UsbDevice> device,
                         bool hotplugged) {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-    if (!UsbDeviceIsPrinter(device) ||
+    if (!UsbDeviceIsPrinter(*device) ||
         base::ContainsKey(known_printers_, device->guid())) {
       return;
     }
     known_printers_.insert(device->guid());
 
     auto data = base::MakeUnique<SetUpPrinterData>();
     data->configurer = PrinterConfigurer::Create(profile_);
     data->device = device;
     data->hotplugged = hotplugged;
 
@@ skipping 99 matching lines @@
 };
 
 }  // namespace
 
 // static
 std::unique_ptr<PrinterDetector> PrinterDetector::CreateCups(Profile* profile) {
   return base::MakeUnique<CupsPrinterDetectorImpl>(profile);
 }
 
 }  // namespace chromeos