Add missing components/policy build dependencies

Generated files in components/policy used header files that
they didn't depend on. This oversight caused errors when running
gn check --check-generated (brand new gn feature!)

For instance:
ERROR at //out/Default/gen/components/policy/policy_constants.h:14:11: Include not allowed.
#include "components/policy/core/common/policy_details.h"
          ^---------------------------------------------
It is not in any dependency of
  //components/policy:generated
The include file is in the target(s):
  //components/policy/core/common:internal
which should somehow be reachable.

This CL fixes those errors by listing/allowing necessary dependencies.

An alternative would be to extract policy_details.h and policy_map.h
into a new build target, including everything they depend on.
I didn't investigate how much work that is because of time
constraints.

Bug: 938893
Change-Id: I69775047ae70f15138ad0754f4c4d51bd02c7530
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1527534
Commit-Queue: Daniel Bratell <bratell@opera.com>
Reviewed-by: Lutz Justen <ljusten@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644380}
2 files changed