Add experiment to exercise AffiliationService with dummy data, plus add related UMA histograms.

components/password_manager/core/browser/affiliation_utils_unittest.cc

Index: components/password_manager/core/browser/affiliation_utils_unittest.cc
diff --git a/components/password_manager/core/browser/affiliation_utils_unittest.cc b/components/password_manager/core/browser/affiliation_utils_unittest.cc
index f4147844e2682efbbe8f84822a4dc9256931a6ee..73240bc3560c67c78f19fdfe419e9610cd1e3a1a 100644
--- a/components/password_manager/core/browser/affiliation_utils_unittest.cc
+++ b/components/password_manager/core/browser/affiliation_utils_unittest.cc
@@ -280,4 +280,47 @@ TEST(AffiliationUtilsTest,
   }
 }
 
+TEST(AffiliationUtilsTest, IsAffiliationRequestsForDummyFacetsEnabled) {
+  const char kExperimentName[] = "DoesNotMatter";
+
+  struct {
+    const char* variation_param;
+    const char* command_line_switch;
+    bool expected_enabled;
+  } kTestCases[] = {
+      {"", "", false},
+      {"", switches::kEnableAffiliationBasedMatching, true},
+      {"", switches::kDisableAffiliationBasedMatching, false},
+      {"garbage value", "", false},
+      {"disabled", "", false},
+      {"Disabled", "", false},
+      {"Disabled", switches::kDisableAffiliationBasedMatching, false},
+      {"Disabled", switches::kEnableAffiliationBasedMatching, true},
+      {"enabled", "", true},
+      {"Enabled", "", true},
+      {"Enabled", switches::kDisableAffiliationBasedMatching, false},
+      {"Enabled", switches::kEnableAffiliationBasedMatching, true}};
+
+  for (const auto& test_case : kTestCases) {
+    SCOPED_TRACE(testing::Message("Command line = ")
+                 << test_case.command_line_switch);
+    SCOPED_TRACE(testing::Message("Variation param = ")
+                 << test_case.variation_param);
+
+    variations::testing::ClearAllVariationParams();
+    base::FieldTrialList field_trials(nullptr);
+    base::FieldTrialList::CreateFieldTrial(kFieldTrialName, kExperimentName);
+    std::map<std::string, std::string> variation_params;
+    variation_params["affiliation_requests_for_dummy_facets"] =
+        test_case.variation_param;
+    ASSERT_TRUE(variations::AssociateVariationParams(
+        kFieldTrialName, kExperimentName, variation_params));
+
+    base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+    command_line.AppendSwitch(test_case.command_line_switch);
+    EXPECT_EQ(test_case.expected_enabled,
+              IsAffiliationRequestsForDummyFacetsEnabled(command_line));
+  }
+}
+
 }  // namespace password_manager