Re-enabled UserCloudPolicyManagerChromeOS unit tests

chrome/browser/policy/cloud/cloud_policy_test_utils.cc

+// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/policy/cloud/cloud_policy_test_utils.h"
+#include "components/policy/core/common/policy_map.h"
+#include "components/policy/policy_constants.h"
+
+namespace policy {
+
+void GetExpectedDefaultPolicy(PolicyMap* policy_map) {
+  policy_map->Set(key::kNTPContentSuggestionsEnabled, POLICY_LEVEL_MANDATORY,

[emaxx, 2016/11/29 16:21:15]

nit: include "components/policy/core/common/policy_types.h"

[Andrew T Wilson (Slow), 2016/11/30 10:02:34]

Done.

+                  POLICY_SCOPE_USER, POLICY_SOURCE_ENTERPRISE_DEFAULT,
+                  base::WrapUnique(new base::FundamentalValue(false)), nullptr);

[emaxx, 2016/11/29 16:21:15]

nit: include "base/values.h"

[Andrew T Wilson (Slow), 2016/11/30 10:02:34]

Done.

+#if defined(OS_CHROMEOS)
+  SetEnterpriseUsersDefaults(policy_map);

[pmarko, 2016/11/29 14:03:34]

Two small questions:
- Is this not defeating the purpose of testing the defaults, or was re-stating
them in the test just found to be redundant?
- There is a small behavior change to the old version: This puts the default
policy values into policy_map only if the keys are missing. I'd suggest we
either document that this method is not guaranteed to replace existing keys or
actually clear policy_map at the beginning of the method (and document *that*).
Current callers seem to be passing empty PolicyMap instances only, so it should
not be a real problem at the moment.

[Andrew T Wilson (Slow), 2016/11/30 10:02:34]

This was turning out to be a maintenance problem, because when someone wanted to
add the |default_for_enterprise_users| attribute to a policy, they had to update
multiple files (policy_templates.json, cloud_policy_browsertests.cc,
user_cloud_policy_manager_chromeos_unittest.cc). I just want people to be able
to add the attribute to policy_templates.json and be done with it.

That said, there was some value in the old approach as it ensured that the code
that injected the defaults continued to work. I've added a new test to
selectively check that one well-known default policy is getting injected - that
should be enough test coverage for that code path without increasing the
maintenance burden.
I'm going to keep the current behavior in the CL, and I've documented it.

+#endif
+}
+
+
+}  // namespace policy