The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a

commit a70ae98c9c70c4843027433eaa8fbdfd85c1e89a
Author: Justin Carlson <justincarlson@chromium.org>
Date: Thu Sep 07 20:36:10 2017

Convert USBPrinterDetector away from being a KeyedService.

It can be instantiated on demand instead.

Bug:  744993 
Change-Id: I2e502f23ea5f7848a900267fa2eeb5ea0e7295b0
Reviewed-on: https://chromium-review.googlesource.com/648526
Commit-Queue: Justin Carlson <justincarlson@chromium.org>
Reviewed-by: Sean Kau <skau@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500371}
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/BUILD.gn
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/printing/cups_printers_manager.cc
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/printing/cups_printers_manager.h
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/printing/cups_printers_manager_unittest.cc
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/printing/usb_printer_detector.cc
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/chromeos/printing/usb_printer_detector.h
[delete] https://crrev.com/0bcee8aa1518ed243a43a078872f5ad4920dc1b4/chrome/browser/chromeos/printing/usb_printer_detector_factory.cc
[delete] https://crrev.com/0bcee8aa1518ed243a43a078872f5ad4920dc1b4/chrome/browser/chromeos/printing/usb_printer_detector_factory.h
[modify] https://crrev.com/a70ae98c9c70c4843027433eaa8fbdfd85c1e89a/chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc