Add ArcEnabled policy implementation

chrome/browser/policy/policy_browsertest.cc

 // Copyright (c) 2012 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 <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 3924 matching lines @@
   EXPECT_TRUE(display_manager->unified_desktop_enabled());
   policies.Set(key::kUnifiedDesktopEnabledByDefault,
                POLICY_LEVEL_MANDATORY,
                POLICY_SCOPE_USER,
                POLICY_SOURCE_CLOUD,
                new base::FundamentalValue(false),
                NULL);
   UpdateProviderPolicy(policies);
   EXPECT_FALSE(display_manager->unified_desktop_enabled());
 }
+
+// Test ArcEnabled policy mapping.
+IN_PROC_BROWSER_TEST_F(PolicyTest, ArcEnabled) {

[bartfab (slow), 2016/02/16 15:23:00]

This test duplicates what policy_test_cases.json does already. Browser tests
should not just check that a policy maps to a pref correctly. They should verify
that the intended subsystems honor the policy/pref.

[Polina Bondarenko, 2016/02/16 15:41:13]

There are some tests that verify ArcEnabled pref impact on ArcAuthService. And
if we already have ArcEnabled policy->pref tests in policy_test_cases.json,
should I add new policy_browsertest that verifies ArcEnabled policy ->
ArcAuthService ?

[bartfab (slow), 2016/02/16 15:44:22]

Yes. ArcEnabled policy->pref is one unit test, ArcEnabled pref->ArcAuthService
is another. The missing piece is an integration test that verifies everything
end-to-end in one go.

+  PrefService* pref = browser()->profile()->GetPrefs();

[bartfab (slow), 2016/02/16 15:23:00]

Nit: const pointer.

[Polina Bondarenko, 2016/02/25 15:28:30]

Done.

+  EXPECT_FALSE(pref->GetBoolean(prefs::kArcEnabled));
+
+  // Enable ARC.
+  PolicyMap policies;
+  policies.Set(key::kArcEnabled,
+               POLICY_LEVEL_MANDATORY,
+               POLICY_SCOPE_USER,
+               POLICY_SOURCE_CLOUD,
+               new base::FundamentalValue(true),
+               NULL);
+  UpdateProviderPolicy(policies);
+  EXPECT_TRUE(pref->GetBoolean(prefs::kArcEnabled));
+
+  // Disable ARC.
+  policies.Set(key::kArcEnabled,
+               POLICY_LEVEL_MANDATORY,
+               POLICY_SCOPE_USER,
+               POLICY_SOURCE_CLOUD,
+               new base::FundamentalValue(false),
+               NULL);
+  UpdateProviderPolicy(policies);
+  EXPECT_FALSE(pref->GetBoolean(prefs::kArcEnabled));
+}
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace policy