Create new c/b/c/policy/core directory

chrome/browser/chromeos/policy contains too many files.
Move all files inside chrome/browser/chromeos/policy that
make up the core policy infrastructure (retrieving, storing,
validating, managing, servicing policy).

Steps that created this change:
* Make a list of all files that should be moved.
* Move them with tools/git/move_source_file.py.
* Fix chrome/test/BUILD.gn (i.e. add the new core/ dir to the browser test
  paths).
* Fix chrome/browser/chromeos/policy/tools/generate_device_policy_remover.py,
  which has a path hard-coded.
* Run `git cl format`.
* In chrome/browser/chromeos/policy/core/device_policy_decoder_chromeos.cc,
  replace instances of local variables "whitelist" and "blacklist" with
  "list" to avoid presubmit errors, and added "// nocheck" to lines where
  replacement is not possible for backwards compatibility reasons.

`git cl format` changed a lot of formatting issues.

I'm overriding a bunch of presubmit warnings, since fixing all of the issues
would be out of scope for this change. The tests are passing.

Bug: 1209781
Test: unit_tests --gtest_filter=*Policy*
Test: browser_tests --gtest_filter=*Policy*
Change-Id: I98c0123b1eb0830941f02ef48a9de2baee1d4b56
AX-Relnotes: n/a.
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2933878
Reviewed-by: Roland Bock <[email protected]>
Reviewed-by: Kentaro Hara <[email protected]>
Commit-Queue: Philipp Weiß <[email protected]>
Auto-Submit: Philipp Weiß <[email protected]>
Owners-Override: Kentaro Hara <[email protected]>
Cr-Commit-Position: refs/heads/master@{#891238}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index efc1e36..558d8cd 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -323,10 +323,10 @@
 #include "chrome/browser/chromeos/first_run/first_run.h"
 #include "chrome/browser/chromeos/full_restore/full_restore_prefs.h"
 #include "chrome/browser/chromeos/net/network_throttling_observer.h"
-#include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
-#include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
+#include "chrome/browser/chromeos/policy/core/browser_policy_connector_chromeos.h"
+#include "chrome/browser/chromeos/policy/core/device_cloud_policy_manager_chromeos.h"
+#include "chrome/browser/chromeos/policy/core/dm_token_storage.h"
 #include "chrome/browser/chromeos/policy/dlp/dlp_rules_manager_impl.h"
-#include "chrome/browser/chromeos/policy/dm_token_storage.h"
 #include "chrome/browser/chromeos/policy/enrollment/auto_enrollment_client_impl.h"
 #include "chrome/browser/chromeos/policy/enrollment/enrollment_requisition_manager.h"
 #include "chrome/browser/chromeos/policy/external_data/handlers/device_wallpaper_image_external_data_handler.h"