[omnibox] Make max-match type parameters subject to kNewSearchFeatures.

kNewSearchFeatures is a kill switch intended for a long-term holdback of
all search-related launches. See https://crrev.com/c/2132641 and
https://crrev.com/c/2161357 for earlier uses of this Feature.

Bug: 1073606
Change-Id: Ic9ea4394892496c43c6096b22d8236a031f4db6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2202119
Commit-Queue: Justin Donnelly <jdonnelly@chromium.org>
Reviewed-by: manuk hovanesian <manukh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#769040}

components/omnibox/browser/autocomplete_result.cc

@@ -86,6 +86,11 @@ size_t AutocompleteResult::GetMaxMatches(bool input_from_omnibox_focus) {
                 "kMaxAutocompletePositionValue must be larger than the largest "
                 "possible autocomplete result size.");
 
+  // If new search features are disabled, ignore the other parameters and use
+  // the default value.
+  if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))
+    return kDefaultMaxAutocompleteMatches;
+
   // If we're interested in the zero suggest match limit, and one has been
   // specified, return it.
   if (input_from_omnibox_focus) {

components/omnibox/browser/omnibox_field_trial.cc

@@ -363,6 +363,11 @@ size_t OmniboxFieldTrial::GetProviderMaxMatches(
     AutocompleteProvider::Type provider) {
   size_t default_max_matches_per_provider = 3;
 
+  // If new search features are disabled, ignore the parameter and use the
+  // default value.
+  if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))
+    return default_max_matches_per_provider;
+
   std::string param_value = base::GetFieldTrialParamValueByFeature(
       omnibox::kUIExperimentMaxAutocompleteMatches,
       OmniboxFieldTrial::kUIMaxAutocompleteMatchesByProviderParam);
@@ -658,6 +663,12 @@ OmniboxFieldTrial::GetEmphasizeTitlesConditionForInput(
 
 size_t OmniboxFieldTrial::GetMaxURLMatches() {
   constexpr size_t kDefaultMaxURLMatches = 7;
+
+  // If new search features are disabled, ignore the parameter and use the
+  // default value.
+  if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))
+    return kDefaultMaxURLMatches;
+
   return base::GetFieldTrialParamByFeatureAsInt(
       omnibox::kOmniboxMaxURLMatches,
       OmniboxFieldTrial::kOmniboxMaxURLMatchesParam, kDefaultMaxURLMatches);
@@ -710,6 +721,11 @@ bool OmniboxFieldTrial::IsExperimentalKeywordModeEnabled() {
 }
 
 bool OmniboxFieldTrial::IsMaxURLMatchesFeatureEnabled() {
+  // If new search features are disabled, return the default/launched value for
+  // the respective platforms, independent of the state of the Feature.
+  if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))
+    return omnibox::kOmniboxMaxURLMatchesEnabledByDefault;
+
   return base::FeatureList::IsEnabled(omnibox::kOmniboxMaxURLMatches);
 }
 

components/omnibox/common/omnibox_features.cc

@@ -217,25 +217,27 @@ const base::Feature kNewSearchFeatures{"OmniboxNewSearchFeatures",
 const base::Feature kMaxZeroSuggestMatches{"OmniboxMaxZeroSuggestMatches",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Feature used to cap max suggestions shown according to the params
+// UIMaxAutocompleteMatches and UIMaxAutocompleteMatchesByProvider.
+const base::Feature kUIExperimentMaxAutocompleteMatches{
+    "OmniboxUIExperimentMaxAutocompleteMatches",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Feature used to cap the number of URL-type matches shown within the
 // Omnibox. If enabled, the number of URL-type matches is limited (unless
 // 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",
+const bool kOmniboxMaxURLMatchesEnabledByDefault =
 #if defined(OS_IOS) || defined(OS_ANDROID)
-      base::FEATURE_DISABLED_BY_DEFAULT
+    false;
 #else
-      base::FEATURE_ENABLED_BY_DEFAULT
+    true;
 #endif
-};
-
-// Feature used to cap max suggestions shown according to the params
-// UIMaxAutocompleteMatches and UIMaxAutocompleteMatchesByProvider.
-const base::Feature kUIExperimentMaxAutocompleteMatches{
-    "OmniboxUIExperimentMaxAutocompleteMatches",
-    base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kOmniboxMaxURLMatches{
+    "OmniboxMaxURLMatches", kOmniboxMaxURLMatchesEnabledByDefault
+                                ? base::FEATURE_ENABLED_BY_DEFAULT
+                                : base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Feature that configures ZeroSuggestProvider using the "ZeroSuggestVariant"
 // per-page-classification parameter.

components/omnibox/common/omnibox_features.h

@@ -49,9 +49,14 @@ extern const base::Feature kNewSearchFeatures;
 
 // Num suggestions - these affect how many suggestions are shown based on e.g.
 // focus, page context, provider, or URL v non-URL.
+// Note that all of these are overriden and default values used instead if
+// kNewSearchFeatures is disabled.
 extern const base::Feature kMaxZeroSuggestMatches;
-extern const base::Feature kOmniboxMaxURLMatches;
 extern const base::Feature kUIExperimentMaxAutocompleteMatches;
+// The default value is established here as a bool so it can be referred to in
+// OmniboxFieldTrial.
+extern const bool kOmniboxMaxURLMatchesEnabledByDefault;
+extern const base::Feature kOmniboxMaxURLMatches;
 
 // On-Focus Suggestions a.k.a. ZeroSuggest.
 extern const base::Feature kOnFocusSuggestions;