Add another unittest for configuring sign-in dependency.

components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc

Index: components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc
diff --git a/components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc b/components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc
index a8c6baaf8f44587c09de836e92fbd5b93a019b7c..1a320278d6628ba68883d82cbc8e15853a6b9f17 100644
--- a/components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc
+++ b/components/ntp_snippets/remote/remote_suggestions_status_service_unittest.cc
@@ -6,6 +6,8 @@
 
 #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"
@@ -14,6 +16,7 @@
 #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"
 
@@ -33,11 +36,40 @@ class RemoteSuggestionsStatusServiceTest : public ::testing::Test {
 
  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();
 
@@ -50,7 +82,7 @@ TEST_F(RemoteSuggestionsStatusServiceTest, DisabledViaPref) {
   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());