Add another unittest for configuring sign-in dependency.

components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc

 // Copyright 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 "components/ntp_snippets/remote/remote_suggestions_status_service.h"
 
 #include <memory>
 
+#include "components/ntp_snippets/features.h"
+#include "components/ntp_snippets/ntp_snippets_constants.h"
 #include "components/ntp_snippets/pref_names.h"
 #include "components/ntp_snippets/remote/test_utils.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/testing_pref_service.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "components/signin/core/browser/fake_signin_manager.h"
 #include "components/signin/core/browser/test_signin_client.h"
 #include "components/signin/core/common/signin_pref_names.h"
+#include "components/variations/variations_params_manager.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace ntp_snippets {
 
 class RemoteSuggestionsStatusServiceTest : public ::testing::Test {
  public:
   RemoteSuggestionsStatusServiceTest() {
     RemoteSuggestionsStatusService::RegisterProfilePrefs(
         utils_.pref_service()->registry());
   }
 
   std::unique_ptr<RemoteSuggestionsStatusService> MakeService() {
     return base::MakeUnique<RemoteSuggestionsStatusService>(
         utils_.fake_signin_manager(), utils_.pref_service());
   }
 
  protected:
   test::RemoteSuggestionsTestUtils utils_;
+  variations::testing::VariationParamsManager params_manager_;
 };
 
-// TODO(jkrcal): Extend the ways to override variation parameters in unit-test
-// (bug 645447), and recover the SigninStateCompatibility test that sign-in is
-// required when the parameter is overriden.
+TEST_F(RemoteSuggestionsStatusServiceTest, SigninNeededIfSpecifiedByParam) {
+  // Specify by the parameter that no signin is required.

[Marc Treib, 2016/12/06 10:21:09]

I think the "no" shouldn't be here?

[jkrcal, 2016/12/06 10:32:44]

Done.

+  params_manager_.SetVariationParamsWithFeatureAssociations(
+      ntp_snippets::kStudyName, {{"fetching_requires_signin", "true"}},
+      {ntp_snippets::kArticleSuggestionsFeature.name});
+
+  auto service = MakeService();
+
+  // The default test setup is signed out.
+  EXPECT_EQ(RemoteSuggestionsStatus::SIGNED_OUT_AND_DISABLED,
+            service->GetStatusFromDeps());
+
+  // Once signed in, we should be in a compatible state.
+  utils_.fake_signin_manager()->SignIn("foo@bar.com");
+  EXPECT_EQ(RemoteSuggestionsStatus::ENABLED_AND_SIGNED_IN,
+            service->GetStatusFromDeps());

[Marc Treib, 2016/12/06 10:21:09]

Would be nice to rewrite this tests in terms of the public interface and remove
the FRIEND_TESTs.
Not for this CL, but maybe add a TODO somewhere here?

[jkrcal, 2016/12/06 10:32:44]

Done.

+}
+
+TEST_F(RemoteSuggestionsStatusServiceTest, NoSigninNeeded) {
+  auto service = MakeService();
+
+  // Indeed, no signin is required.

[Marc Treib, 2016/12/06 10:21:09]

s/Indeed/By default/
?

[jkrcal, 2016/12/06 10:32:44]

Done.

+  EXPECT_EQ(RemoteSuggestionsStatus::ENABLED_AND_SIGNED_OUT,
+            service->GetStatusFromDeps());
+
+  // Once can still sign in.

[Marc Treib, 2016/12/06 10:21:09]

s/Once/One/
?

[jkrcal, 2016/12/06 10:32:44]

Done.

+  utils_.fake_signin_manager()->SignIn("foo@bar.com");
+  EXPECT_EQ(RemoteSuggestionsStatus::ENABLED_AND_SIGNED_IN,
+            service->GetStatusFromDeps());
+}
+
 TEST_F(RemoteSuggestionsStatusServiceTest, DisabledViaPref) {
   auto service = MakeService();
 
   // The default test setup is signed out. The service is enabled.
   ASSERT_EQ(RemoteSuggestionsStatus::ENABLED_AND_SIGNED_OUT,
             service->GetStatusFromDeps());
 
   // Once the enabled pref is set to false, we should be disabled.
   utils_.pref_service()->SetBoolean(prefs::kEnableSnippets, false);
   EXPECT_EQ(RemoteSuggestionsStatus::EXPLICITLY_DISABLED,
             service->GetStatusFromDeps());
 
-  // Signing-in shouldn't matter anymore.
+  // The other dependencies shouldn't matter anymore.
   utils_.fake_signin_manager()->SignIn("foo@bar.com");
   EXPECT_EQ(RemoteSuggestionsStatus::EXPLICITLY_DISABLED,
             service->GetStatusFromDeps());
 }
 
 }  // namespace ntp_snippets