Oops - I meant to say UserPolicyDiskCache, not UserCloudPolicyStoreChromeos

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fabbe1317d8d93fad920da7291912b6f74e96175

commit fabbe1317d8d93fad920da7291912b6f74e96175
Author: jdufault <jdufault@chromium.org>
Date: Fri Feb 10 02:17:05 2017

Remove UserPolicyDiskCache; it is not used.

BUG= 690665 

Review-Url: https://codereview.chromium.org/2681093005
Cr-Commit-Position: refs/heads/master@{#449516}

[modify] https://crrev.com/fabbe1317d8d93fad920da7291912b6f74e96175/chrome/browser/chromeos/BUILD.gn
[modify] https://crrev.com/fabbe1317d8d93fad920da7291912b6f74e96175/chrome/browser/chromeos/policy/user_cloud_policy_store_chromeos.cc
[delete] https://crrev.com/b029ab9d45570a58d161c96f97185b2b0e6cebea/chrome/browser/chromeos/policy/user_policy_disk_cache.cc
[delete] https://crrev.com/b029ab9d45570a58d161c96f97185b2b0e6cebea/chrome/browser/chromeos/policy/user_policy_disk_cache.h