Make CUPS USB printing play better with the settings page. This change does several things:

chrome/browser/chromeos/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//extensions/features/features.gni")
 import("//media/media_options.gni")
 import("//printing/features/features.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 1210 matching lines @@
     "printing/cups_print_job.cc",
     "printing/cups_print_job.h",
     "printing/cups_print_job_manager.cc",
     "printing/cups_print_job_manager.h",
     "printing/cups_print_job_manager_factory.cc",
     "printing/cups_print_job_manager_factory.h",
     "printing/cups_print_job_notification.cc",
     "printing/cups_print_job_notification.h",
     "printing/cups_print_job_notification_manager.cc",
     "printing/cups_print_job_notification_manager.h",
-    "printing/fake_printer_discoverer.cc",
-    "printing/fake_printer_discoverer.h",
     "printing/ppd_provider_factory.cc",
     "printing/ppd_provider_factory.h",
     "printing/printer_configurer.cc",
     "printing/printer_configurer.h",
+    "printing/printer_discoverer.cc",
     "printing/printer_discoverer.h",
     "printing/printers_manager.cc",
     "printing/printers_manager.h",
     "printing/printers_manager_factory.cc",
     "printing/printers_manager_factory.h",
     "printing/printers_sync_bridge.cc",
     "printing/printers_sync_bridge.h",
     "printing/specifics_translation.cc",
     "printing/specifics_translation.h",
     "printing/usb_printer_util.cc",
@@ skipping 568 matching lines @@
     "policy/proto/chrome_device_policy.proto",
     "policy/proto/install_attributes.proto",
   ]
 }
 
 proto_library("attestation_proto") {
   sources = [
     "attestation/attestation_key_payload.proto",
   ]
 }