[omnibox] Raise max suggestions default and enable limit URLs by default

But allow flag override. Uses max of 8 and URL limit of 7.
Desktop only. Will be managed by a Finch roll-out.

Bug: 964049
Change-Id: I29db26586dda34c2eaeda2744feb5718010c2648
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1891458
Commit-Queue: Kevin Bailey <krb@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711483}

chrome/browser/autocomplete/search_provider_unittest.cc

@@ -1339,6 +1339,14 @@ TEST_F(SearchProviderTest, DefaultProviderNoSuggestRelevanceInKeywordMode) {
 // case to this test, please consider adding it to the tests in
 // KeywordFetcherSuggestRelevance below.
 TEST_F(SearchProviderTest, DefaultFetcherSuggestRelevance) {
+  // This test was written assuming a different default.
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeaturesAndParameters(
+      {
+          {omnibox::kUIExperimentMaxAutocompleteMatches,
+           {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+      },
+      {/* nothing disabled */});
   struct {
     const std::string json;
     const ExpectedMatch matches[6];
@@ -1577,6 +1585,14 @@ TEST_F(SearchProviderTest, DefaultFetcherSuggestRelevance) {
 // test is added to this TEST_F, please consider if it would be
 // appropriate to add to DefaultFetcherSuggestRelevance as well.
 TEST_F(SearchProviderTest, KeywordFetcherSuggestRelevance) {
+  // This test was written assuming a different default.
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeaturesAndParameters(
+      {
+          {omnibox::kUIExperimentMaxAutocompleteMatches,
+           {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+      },
+      {/* nothing disabled */});
   struct KeywordFetcherMatch {
     std::string contents;
     bool from_keyword;
@@ -2315,6 +2331,14 @@ TEST_F(SearchProviderTest, DontCacheCalculatorSuggestions) {
 }
 
 TEST_F(SearchProviderTest, LocalAndRemoteRelevances) {
+  // This test was written assuming a different default.
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeaturesAndParameters(
+      {
+          {omnibox::kUIExperimentMaxAutocompleteMatches,
+           {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+      },
+      {/* nothing disabled */});
   // We hardcode the string "term1" below, so ensure that the search term that
   // got added to history already is that string.
   ASSERT_EQ(ASCIIToUTF16("term1"), term1_);

components/omnibox/browser/autocomplete_result.cc

@@ -78,9 +78,11 @@ size_t AutocompleteResult::GetMaxMatches(bool is_zero_suggest) {
   constexpr size_t kDefaultMaxAutocompleteMatches = 5;
   if (is_zero_suggest)
     return kDefaultMaxAutocompleteMatches;
-#else
+#elif defined(OS_IOS)  // !defined(OS_ANDROID)
   constexpr size_t kDefaultMaxAutocompleteMatches = 6;
-#endif  // defined(OS_ANDROID)
+#else                  // !defined(OS_ANDROID) && !defined(OS_IOS)
+  constexpr size_t kDefaultMaxAutocompleteMatches = 8;
+#endif
   static_assert(kMaxAutocompletePositionValue > kDefaultMaxAutocompleteMatches,
                 "kMaxAutocompletePositionValue must be larger than the largest "
                 "possible autocomplete result size.");

components/omnibox/browser/autocomplete_result_unittest.cc

@@ -1458,6 +1458,14 @@ TEST_F(AutocompleteResultTest, SortAndCullPromoteDuplicateSearchURLs) {
 }
 
 TEST_F(AutocompleteResultTest, SortAndCullGroupSuggestionsByType) {
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeaturesAndParameters(
+      {
+          {omnibox::kUIExperimentMaxAutocompleteMatches,
+           {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+          {omnibox::kOmniboxGroupSuggestionsBySearchVsUrl, {/* no params */}},
+      },
+      {/* nothing disabled */});
   TestData data[] = {
     { 0, 1,  500, false },
     { 1, 2,  600, false },
@@ -1480,10 +1488,6 @@ TEST_F(AutocompleteResultTest, SortAndCullGroupSuggestionsByType) {
   for (size_t i = 0; i < base::size(data); ++i)
     matches[i].type = match_types[i];
 
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(
-      omnibox::kOmniboxGroupSuggestionsBySearchVsUrl);
-
   AutocompleteInput input(base::ASCIIToUTF16("a"),
                           metrics::OmniboxEventProto::OTHER,
                           TestSchemeClassifier());
@@ -1505,7 +1509,9 @@ TEST_F(AutocompleteResultTest, SortAndCullGroupSuggestionsByType) {
 TEST_F(AutocompleteResultTest, SortAndCullMaxURLMatches) {
   base::test::ScopedFeatureList feature_list;
   feature_list.InitWithFeaturesAndParameters(
-      {{omnibox::kOmniboxMaxURLMatches,
+      {{omnibox::kUIExperimentMaxAutocompleteMatches,
+        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+       {omnibox::kOmniboxMaxURLMatches,
         {{OmniboxFieldTrial::kOmniboxMaxURLMatchesParam, "3"}}}},
       {omnibox::kOmniboxGroupSuggestionsBySearchVsUrl,
        omnibox::kOmniboxPreserveDefaultMatchScore});
@@ -1591,7 +1597,9 @@ TEST_F(
     MOBILE_DISABLED(SortAndCullMaxURLMatchesWithPreserveAndGroupingFeatures)) {
   base::test::ScopedFeatureList feature_list;
   feature_list.InitWithFeaturesAndParameters(
-      {{omnibox::kOmniboxMaxURLMatches,
+      {{omnibox::kUIExperimentMaxAutocompleteMatches,
+        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
+       {omnibox::kOmniboxMaxURLMatches,
         {{OmniboxFieldTrial::kOmniboxMaxURLMatchesParam, "3"}}},
        {omnibox::kOmniboxGroupSuggestionsBySearchVsUrl, {}},
        {omnibox::kOmniboxPreserveDefaultMatchScore, {}}},

components/omnibox/browser/omnibox_field_trial.cc

@@ -624,10 +624,10 @@ OmniboxFieldTrial::GetEmphasizeTitlesConditionForInput(
 }
 
 size_t OmniboxFieldTrial::GetMaxURLMatches() {
+  constexpr size_t kDefaultMaxURLMatches = 7;
   return base::GetFieldTrialParamByFeatureAsInt(
       omnibox::kOmniboxMaxURLMatches,
-      OmniboxFieldTrial::kOmniboxMaxURLMatchesParam,
-      0);  // default
+      OmniboxFieldTrial::kOmniboxMaxURLMatchesParam, kDefaultMaxURLMatches);
 }
 
 bool OmniboxFieldTrial::IsPreserveDefaultMatchScoreEnabled() {

components/omnibox/common/omnibox_features.cc

@@ -78,8 +78,14 @@ const base::Feature kOmniboxLocalEntitySuggestions{
 // there are no more non-URL matches available.) If enabled, there is a
 // companion parameter - OmniboxMaxURLMatches - which specifies the maximum
 // desired number of URL-type matches.
-const base::Feature kOmniboxMaxURLMatches{"OmniboxMaxURLMatches",
-                                          base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kOmniboxMaxURLMatches {
+  "OmniboxMaxURLMatches",
+#if defined(OS_IOS) || defined(OS_ANDROID)
+      base::FEATURE_DISABLED_BY_DEFAULT
+#else
+      base::FEATURE_ENABLED_BY_DEFAULT
+#endif
+};
 
 // Feature used to enable entity suggestion images and enhanced presentation
 // showing more context and descriptive text about the entity.