Fix crash with forcing variations when the trial exists.
This can happen, for example, when a user used the
--force-fieldtrials= command-line to set a different
group than what they have selected from chrome://flags.
Includes a test.
BUG=409976
Review URL: https://codereview.chromium.org/529183002
Cr-Commit-Position: refs/heads/master@{#293173}
diff --git a/components/variations/variations_seed_processor_unittest.cc b/components/variations/variations_seed_processor_unittest.cc
index 07eed692..fe58842 100644
--- a/components/variations/variations_seed_processor_unittest.cc
+++ b/components/variations/variations_seed_processor_unittest.cc
@@ -463,4 +463,28 @@
base::FieldTrialList::FindFullName(kFlagStudyName));
}
+TEST_F(VariationsSeedProcessorTest, ForcingFlagAlreadyForced) {
+ Study study = CreateStudyWithFlagGroups(100, 0, 0);
+ ASSERT_EQ(kNonFlagGroupName, study.experiment(0).name());
+ Study_Experiment_Param* param = study.mutable_experiment(0)->add_param();
+ param->set_name("x");
+ param->set_value("y");
+ study.mutable_experiment(0)->set_google_web_experiment_id(kExperimentId);
+
+ base::FieldTrialList field_trial_list(NULL);
+ base::FieldTrialList::CreateFieldTrial(kFlagStudyName, kNonFlagGroupName);
+
+ CommandLine::ForCurrentProcess()->AppendSwitch(kForcingFlag1);
+ EXPECT_TRUE(CreateTrialFromStudy(&study));
+ // The previously forced experiment should still hold.
+ EXPECT_EQ(kNonFlagGroupName,
+ base::FieldTrialList::FindFullName(study.name()));
+
+ // Check that params and experiment ids correspond.
+ EXPECT_EQ("y", GetVariationParamValue(study.name(), "x"));
+ VariationID id = GetGoogleVariationID(GOOGLE_WEB_PROPERTIES, kFlagStudyName,
+ kNonFlagGroupName);
+ EXPECT_EQ(kExperimentId, id);
+}
+
} // namespace variations
