| // Copyright 2017 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/metrics/field_trial_params.h" | 
 |  | 
 | #include "base/feature_list.h" | 
 | #include "base/macros.h" | 
 | #include "base/metrics/field_trial.h" | 
 | #include "base/metrics/field_trial_param_associator.h" | 
 | #include "base/test/scoped_feature_list.h" | 
 | #include "testing/gtest/include/gtest/gtest.h" | 
 |  | 
 | namespace base { | 
 |  | 
 | namespace { | 
 |  | 
 | // Call FieldTrialList::FactoryGetFieldTrial() with a future expiry date. | 
 | scoped_refptr<FieldTrial> CreateFieldTrial( | 
 |     const std::string& trial_name, | 
 |     int total_probability, | 
 |     const std::string& default_group_name, | 
 |     int* default_group_number) { | 
 |   return FieldTrialList::FactoryGetFieldTrial( | 
 |       trial_name, total_probability, default_group_name, | 
 |       FieldTrialList::kNoExpirationYear, 1, 1, FieldTrial::SESSION_RANDOMIZED, | 
 |       default_group_number); | 
 | } | 
 |  | 
 | }  // namespace | 
 |  | 
 | class FieldTrialParamsTest : public ::testing::Test { | 
 |  public: | 
 |   FieldTrialParamsTest() : field_trial_list_(nullptr) {} | 
 |  | 
 |   ~FieldTrialParamsTest() override { | 
 |     // Ensure that the maps are cleared between tests, since they are stored as | 
 |     // process singletons. | 
 |     FieldTrialParamAssociator::GetInstance()->ClearAllParamsForTesting(); | 
 |   } | 
 |  | 
 |   void CreateFeatureWithTrial(const Feature& feature, | 
 |                               FeatureList::OverrideState override_state, | 
 |                               FieldTrial* trial) { | 
 |     std::unique_ptr<FeatureList> feature_list(new FeatureList); | 
 |     feature_list->RegisterFieldTrialOverride(feature.name, override_state, | 
 |                                              trial); | 
 |     scoped_feature_list_.InitWithFeatureList(std::move(feature_list)); | 
 |   } | 
 |  | 
 |  private: | 
 |   FieldTrialList field_trial_list_; | 
 |   test::ScopedFeatureList scoped_feature_list_; | 
 |  | 
 |   DISALLOW_COPY_AND_ASSIGN(FieldTrialParamsTest); | 
 | }; | 
 |  | 
 | TEST_F(FieldTrialParamsTest, AssociateFieldTrialParams) { | 
 |   const std::string kTrialName = "AssociateFieldTrialParams"; | 
 |  | 
 |   { | 
 |     std::map<std::string, std::string> params; | 
 |     params["a"] = "10"; | 
 |     params["b"] = "test"; | 
 |     ASSERT_TRUE(AssociateFieldTrialParams(kTrialName, "A", params)); | 
 |   } | 
 |   { | 
 |     std::map<std::string, std::string> params; | 
 |     params["a"] = "5"; | 
 |     ASSERT_TRUE(AssociateFieldTrialParams(kTrialName, "B", params)); | 
 |   } | 
 |  | 
 |   FieldTrialList::CreateFieldTrial(kTrialName, "B"); | 
 |   EXPECT_EQ("5", GetFieldTrialParamValue(kTrialName, "a")); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "b")); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "x")); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   EXPECT_TRUE(GetFieldTrialParams(kTrialName, ¶ms)); | 
 |   EXPECT_EQ(1U, params.size()); | 
 |   EXPECT_EQ("5", params["a"]); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, AssociateFieldTrialParams_Fail) { | 
 |   const std::string kTrialName = "AssociateFieldTrialParams_Fail"; | 
 |   const std::string kGroupName = "A"; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "10"; | 
 |   ASSERT_TRUE(AssociateFieldTrialParams(kTrialName, kGroupName, params)); | 
 |   params["a"] = "1"; | 
 |   params["b"] = "2"; | 
 |   ASSERT_FALSE(AssociateFieldTrialParams(kTrialName, kGroupName, params)); | 
 |  | 
 |   FieldTrialList::CreateFieldTrial(kTrialName, kGroupName); | 
 |   EXPECT_EQ("10", GetFieldTrialParamValue(kTrialName, "a")); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "b")); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, AssociateFieldTrialParams_TrialActiveFail) { | 
 |   const std::string kTrialName = "AssociateFieldTrialParams_TrialActiveFail"; | 
 |   FieldTrialList::CreateFieldTrial(kTrialName, "A"); | 
 |   ASSERT_EQ("A", FieldTrialList::FindFullName(kTrialName)); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "10"; | 
 |   EXPECT_FALSE(AssociateFieldTrialParams(kTrialName, "B", params)); | 
 |   EXPECT_FALSE(AssociateFieldTrialParams(kTrialName, "A", params)); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, AssociateFieldTrialParams_DoesntActivateTrial) { | 
 |   const std::string kTrialName = | 
 |       "AssociateFieldTrialParams_DoesntActivateTrial"; | 
 |  | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "10"; | 
 |   EXPECT_TRUE(AssociateFieldTrialParams(kTrialName, "A", params)); | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParams_NoTrial) { | 
 |   const std::string kTrialName = "GetFieldTrialParams_NoParams"; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   EXPECT_FALSE(GetFieldTrialParams(kTrialName, ¶ms)); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "x")); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "y")); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParams_NoParams) { | 
 |   const std::string kTrialName = "GetFieldTrialParams_NoParams"; | 
 |  | 
 |   FieldTrialList::CreateFieldTrial(kTrialName, "A"); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   EXPECT_FALSE(GetFieldTrialParams(kTrialName, ¶ms)); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "x")); | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "y")); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParams_ActivatesTrial) { | 
 |   const std::string kTrialName = "GetFieldTrialParams_ActivatesTrial"; | 
 |  | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   EXPECT_FALSE(GetFieldTrialParams(kTrialName, ¶ms)); | 
 |   ASSERT_TRUE(FieldTrialList::IsTrialActive(kTrialName)); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParamValue_ActivatesTrial) { | 
 |   const std::string kTrialName = "GetFieldTrialParamValue_ActivatesTrial"; | 
 |  | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |   ASSERT_FALSE(FieldTrialList::IsTrialActive(kTrialName)); | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValue(kTrialName, "x")); | 
 |   ASSERT_TRUE(FieldTrialList::IsTrialActive(kTrialName)); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParamsByFeature) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |   const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["x"] = "1"; | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   std::map<std::string, std::string> actualParams; | 
 |   EXPECT_TRUE(GetFieldTrialParamsByFeature(kFeature, &actualParams)); | 
 |   EXPECT_EQ(params, actualParams); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParamValueByFeature) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |   const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["x"] = "1"; | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   std::map<std::string, std::string> actualParams; | 
 |   EXPECT_EQ(params["x"], GetFieldTrialParamValueByFeature(kFeature, "x")); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParamsByFeature_Disable) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |   const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["x"] = "1"; | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_DISABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   std::map<std::string, std::string> actualParams; | 
 |   EXPECT_FALSE(GetFieldTrialParamsByFeature(kFeature, &actualParams)); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, GetFieldTrialParamValueByFeature_Disable) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |   const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["x"] = "1"; | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_DISABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   std::map<std::string, std::string> actualParams; | 
 |   EXPECT_EQ(std::string(), GetFieldTrialParamValueByFeature(kFeature, "x")); | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamString) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<std::string> a{&kFeature, "a", "default"}; | 
 |   static const FeatureParam<std::string> b{&kFeature, "b", ""}; | 
 |   static const FeatureParam<std::string> c{&kFeature, "c", "default"}; | 
 |   static const FeatureParam<std::string> d{&kFeature, "d", ""}; | 
 |   static const FeatureParam<std::string> e{&kFeature, "e", "default"}; | 
 |   static const FeatureParam<std::string> f{&kFeature, "f", ""}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = ""; | 
 |   params["b"] = "non-default"; | 
 |   params["c"] = "non-default"; | 
 |   params["d"] = ""; | 
 |   // "e" is not registered | 
 |   // "f" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_EQ("default", a.Get());  // empty | 
 |   EXPECT_EQ("non-default", b.Get()); | 
 |   EXPECT_EQ("non-default", c.Get()); | 
 |   EXPECT_EQ("", d.Get());         // empty | 
 |   EXPECT_EQ("default", e.Get());  // not registered | 
 |   EXPECT_EQ("", f.Get());         // not registered | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamInt) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<int> a{&kFeature, "a", 0}; | 
 |   static const FeatureParam<int> b{&kFeature, "b", 0}; | 
 |   static const FeatureParam<int> c{&kFeature, "c", 0}; | 
 |   static const FeatureParam<int> d{&kFeature, "d", 0}; | 
 |   static const FeatureParam<int> e{&kFeature, "e", 0}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "1"; | 
 |   params["b"] = "1.5"; | 
 |   params["c"] = "foo"; | 
 |   params["d"] = ""; | 
 |   // "e" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_EQ(1, GetFieldTrialParamByFeatureAsInt(kFeature, "a", 0)); | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsInt(kFeature, "b", 0));  // invalid | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsInt(kFeature, "c", 0));  // invalid | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsInt(kFeature, "d", 0));  // empty | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsInt(kFeature, "e", 0));  // empty | 
 |  | 
 |   EXPECT_EQ(1, a.Get()); | 
 |   EXPECT_EQ(0, b.Get());  // invalid | 
 |   EXPECT_EQ(0, c.Get());  // invalid | 
 |   EXPECT_EQ(0, d.Get());  // empty | 
 |   EXPECT_EQ(0, e.Get());  // empty | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamDouble) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<double> a{&kFeature, "a", 0.0}; | 
 |   static const FeatureParam<double> b{&kFeature, "b", 0.0}; | 
 |   static const FeatureParam<double> c{&kFeature, "c", 0.0}; | 
 |   static const FeatureParam<double> d{&kFeature, "d", 0.0}; | 
 |   static const FeatureParam<double> e{&kFeature, "e", 0.0}; | 
 |   static const FeatureParam<double> f{&kFeature, "f", 0.0}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "1"; | 
 |   params["b"] = "1.5"; | 
 |   params["c"] = "1.0e-10"; | 
 |   params["d"] = "foo"; | 
 |   params["e"] = ""; | 
 |   // "f" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_EQ(1, GetFieldTrialParamByFeatureAsDouble(kFeature, "a", 0)); | 
 |   EXPECT_EQ(1.5, GetFieldTrialParamByFeatureAsDouble(kFeature, "b", 0)); | 
 |   EXPECT_EQ(1.0e-10, GetFieldTrialParamByFeatureAsDouble(kFeature, "c", 0)); | 
 |   EXPECT_EQ(0, | 
 |             GetFieldTrialParamByFeatureAsDouble(kFeature, "d", 0));  // invalid | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsDouble(kFeature, "e", 0));  // empty | 
 |   EXPECT_EQ(0, GetFieldTrialParamByFeatureAsDouble(kFeature, "f", 0));  // empty | 
 |  | 
 |   EXPECT_EQ(1, a.Get()); | 
 |   EXPECT_EQ(1.5, b.Get()); | 
 |   EXPECT_EQ(1.0e-10, c.Get()); | 
 |   EXPECT_EQ(0, d.Get());  // invalid | 
 |   EXPECT_EQ(0, e.Get());  // empty | 
 |   EXPECT_EQ(0, f.Get());  // empty | 
 | } | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamBool) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<bool> a{&kFeature, "a", false}; | 
 |   static const FeatureParam<bool> b{&kFeature, "b", true}; | 
 |   static const FeatureParam<bool> c{&kFeature, "c", false}; | 
 |   static const FeatureParam<bool> d{&kFeature, "d", true}; | 
 |   static const FeatureParam<bool> e{&kFeature, "e", true}; | 
 |   static const FeatureParam<bool> f{&kFeature, "f", true}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "true"; | 
 |   params["b"] = "false"; | 
 |   params["c"] = "1"; | 
 |   params["d"] = "False"; | 
 |   params["e"] = ""; | 
 |   // "f" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_TRUE(a.Get()); | 
 |   EXPECT_FALSE(b.Get()); | 
 |   EXPECT_FALSE(c.Get());  // invalid | 
 |   EXPECT_TRUE(d.Get());   // invalid | 
 |   EXPECT_TRUE(e.Get());   // empty | 
 |   EXPECT_TRUE(f.Get());   // empty | 
 | } | 
 |  | 
 | enum Hand { ROCK, PAPER, SCISSORS }; | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamEnum) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const FeatureParam<Hand>::Option hands[] = { | 
 |       {ROCK, "rock"}, {PAPER, "paper"}, {SCISSORS, "scissors"}}; | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<Hand> a{&kFeature, "a", ROCK, &hands}; | 
 |   static const FeatureParam<Hand> b{&kFeature, "b", ROCK, &hands}; | 
 |   static const FeatureParam<Hand> c{&kFeature, "c", ROCK, &hands}; | 
 |   static const FeatureParam<Hand> d{&kFeature, "d", ROCK, &hands}; | 
 |   static const FeatureParam<Hand> e{&kFeature, "e", PAPER, &hands}; | 
 |   static const FeatureParam<Hand> f{&kFeature, "f", SCISSORS, &hands}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "rock"; | 
 |   params["b"] = "paper"; | 
 |   params["c"] = "scissors"; | 
 |   params["d"] = "lizard"; | 
 |   params["e"] = ""; | 
 |   // "f" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_EQ(ROCK, a.Get()); | 
 |   EXPECT_EQ(PAPER, b.Get()); | 
 |   EXPECT_EQ(SCISSORS, c.Get()); | 
 |   EXPECT_EQ(ROCK, d.Get());      // invalid | 
 |   EXPECT_EQ(PAPER, e.Get());     // invalid/empty | 
 |   EXPECT_EQ(SCISSORS, f.Get());  // not registered | 
 | } | 
 |  | 
 | enum class UI { ONE_D, TWO_D, THREE_D }; | 
 |  | 
 | TEST_F(FieldTrialParamsTest, FeatureParamEnumClass) { | 
 |   const std::string kTrialName = "GetFieldTrialParamsByFeature"; | 
 |  | 
 |   static const FeatureParam<UI>::Option uis[] = { | 
 |       {UI::ONE_D, "1d"}, {UI::TWO_D, "2d"}, {UI::THREE_D, "3d"}}; | 
 |   static const Feature kFeature{"TestFeature", FEATURE_DISABLED_BY_DEFAULT}; | 
 |   static const FeatureParam<UI> a{&kFeature, "a", UI::ONE_D, &uis}; | 
 |   static const FeatureParam<UI> b{&kFeature, "b", UI::ONE_D, &uis}; | 
 |   static const FeatureParam<UI> c{&kFeature, "c", UI::ONE_D, &uis}; | 
 |   static const FeatureParam<UI> d{&kFeature, "d", UI::ONE_D, &uis}; | 
 |   static const FeatureParam<UI> e{&kFeature, "e", UI::TWO_D, &uis}; | 
 |   static const FeatureParam<UI> f{&kFeature, "f", UI::THREE_D, &uis}; | 
 |  | 
 |   std::map<std::string, std::string> params; | 
 |   params["a"] = "1d"; | 
 |   params["b"] = "2d"; | 
 |   params["c"] = "3d"; | 
 |   params["d"] = "4d"; | 
 |   params["e"] = ""; | 
 |   // "f" is not registered | 
 |   AssociateFieldTrialParams(kTrialName, "A", params); | 
 |   scoped_refptr<FieldTrial> trial( | 
 |       CreateFieldTrial(kTrialName, 100, "A", nullptr)); | 
 |  | 
 |   CreateFeatureWithTrial(kFeature, FeatureList::OVERRIDE_ENABLE_FEATURE, | 
 |                          trial.get()); | 
 |  | 
 |   EXPECT_EQ(UI::ONE_D, a.Get()); | 
 |   EXPECT_EQ(UI::TWO_D, b.Get()); | 
 |   EXPECT_EQ(UI::THREE_D, c.Get()); | 
 |   EXPECT_EQ(UI::ONE_D, d.Get());    // invalid | 
 |   EXPECT_EQ(UI::TWO_D, e.Get());    // invalid/empty | 
 |   EXPECT_EQ(UI::THREE_D, f.Get());  // not registered | 
 | } | 
 |  | 
 | }  // namespace base |