Reusing names of policy keys from policy_constants.h

Before this change, Chromoting-specific code under
src/remoting/host/policy_hack was introducing its own constants for
names of Chromoting policies, rather than reusing the constants already
generated into policy_constants.h from
src/components/policy/resources/policy_templates.json.  This change
fixes this (as asked for by crbug.com/368321).

Removing names of policy keys from policy_watcher.cc is good because:
- It enourages keeping policy_templates.json in-sync with remoting code
  (i.e. RemoteAccessHostTokenUrl was introduced to policy_watcher.cc but
  not to policy_templates.json;  after this changes this should be less
  likely).
- Code removal is good.

Updating and keeping in-sync policy_templates.json is good because:
- This is where rest of Chromium infrastructure looks for policy
  descriptions, examples, supported-since, etc.
- Up-to-date policy_templates.json is a pre-requisite for removing
  src/remoting/host/policy_hack and instead reusing PolicyService and/or
  ConfigurationPolicyProvider(s) for Win/Linux/Mac.

While working on the change, I've noticed that 5 out of 15 Chromoting
policies are not covered in policy_templates.json (i.e.
src/components/policy and src/remoting/host/policy_hack got out of
sync).  This change fixes this as well.  Notes:
- Making src/components/policy and src/remoting/host/policy_hack in-sync
  again is good for the short-term.
- In the long-term we might want to somehow separate Chromoting-specific
  policies out of policy_templates.json (separate
  chromoting_policy_templates.json?  separate supported_on?). This
  should be done in a separate changelist because
    1) the separation concerns should not block current changelist and
       more importantly crrev.com/830193002 which gets rid of most code
       under policy_hack and
    2) the separation is quite involved in itself (i.e. need to account
       for it2me/chromeos differences and make sure that tools for
       enterprise admins continue to support chromoting policies).

BUG=368321
R=asvitkine@chromium.org, bartfab@chromium.org, mnissler@chromium.org, sergeyu@chromium.org

Review URL: https://codereview.chromium.org/820133002

Patch from Lukasz Anforowicz <lukasza@chromium.org>.

Cr-Commit-Position: refs/heads/master@{#311968}

1 files changed, 2 insertions, 0 deletions

diff --git a/remoting/DEPS b/remoting/DEPS
index 5d7065f..f2616fe 100644
--- a/remoting/DEPS
+++ b/remoting/DEPS
@@ -9,6 +9,8 @@ include_rules = [
   "+net/socket",
   "+net/url_request",
 
+  "+policy/policy_constants.h",
+
   "-remoting",
   "+remoting/base",
   "+remoting/proto",