The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/892645a2b31bac84e21d3dcd327aef105ef65bac

commit 892645a2b31bac84e21d3dcd327aef105ef65bac
Author: Justin Carlson <justincarlson@chromium.org>
Date: Thu Jan 25 18:32:32 2018

Remove unused callback from PpdCache::Store.

Bug:  803953 
Change-Id: I9a8f880d9dabef462b25dbc5876b0dd678cb9c60
Reviewed-on: https://chromium-review.googlesource.com/883977
Reviewed-by: Sean Kau <skau@chromium.org>
Commit-Queue: Justin Carlson <justincarlson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531955}
[modify] https://crrev.com/892645a2b31bac84e21d3dcd327aef105ef65bac/chromeos/printing/ppd_cache.cc
[modify] https://crrev.com/892645a2b31bac84e21d3dcd327aef105ef65bac/chromeos/printing/ppd_cache.h
[modify] https://crrev.com/892645a2b31bac84e21d3dcd327aef105ef65bac/chromeos/printing/ppd_cache_unittest.cc
[modify] https://crrev.com/892645a2b31bac84e21d3dcd327aef105ef65bac/chromeos/printing/ppd_provider.cc