Don't demote top match for certain match types.

chrome/browser/omnibox/omnibox_field_trial_unittest.cc

Index: chrome/browser/omnibox/omnibox_field_trial_unittest.cc
diff --git a/chrome/browser/omnibox/omnibox_field_trial_unittest.cc b/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
index 82522b6dc6973d3761ab570cf83051e084e18a08..ef17cb5f1954c0b062e017321c69788d5676fca4 100644
--- a/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
+++ b/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
@@ -188,6 +188,34 @@ TEST_F(OmniboxFieldTrialTest, GetDemotionsByTypeWithFallback) {
   VerifyDemotion(demotions_by_type, AutocompleteMatchType::HISTORY_URL, 0.25);
 }
 
+TEST_F(OmniboxFieldTrialTest, GetUndemotableTopTypes) {
+  {
+    std::map<std::string, std::string> params;
+    const std::string rule(OmniboxFieldTrial::kUndemotableTopTypeRule);
+    params[rule + ":1:*"] = "1,3";
+    params[rule + ":3:*"] = "5";
+    params[rule + ":*:*"] = "2";
+    ASSERT_TRUE(chrome_variations::AssociateVariationParams(
+        OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A", params));
+  }
+  base::FieldTrialList::CreateFieldTrial(
+      OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A");
+  OmniboxFieldTrial::UndemotableTopMatchTypes undemotable_types;
+  OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::NEW_TAB_PAGE, &undemotable_types);
+  ASSERT_EQ(2u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_URL));
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_BODY));
+  OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::HOME_PAGE, &undemotable_types);
+  ASSERT_EQ(1u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::NAVSUGGEST));
+  OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::BLANK, &undemotable_types);
+  ASSERT_EQ(1u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_TITLE));
+}
+
 TEST_F(OmniboxFieldTrialTest, GetValueForRuleInContext) {
   // This test starts with Instant Extended off (the default state), then
   // enables Instant Extended and tests again on the same rules.