[iOS] Add flag for local ZPS experiment

Bug: 1056781
Change-Id: Ie7c1421b4e6767d6f9714f75f2317555045ff951
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2581920
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Tomasz Wiszkowski <ender@google.com>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835828}

chrome/browser/flag-metadata.json

@@ -3623,6 +3623,11 @@
     "owners": [ "jdonnelly", "chrome-omnibox-team@google.com" ],
     "expiry_milestone": 89
   },
+  {
+    "name": "omnibox-local-history-zero-suggest",
+    "owners": ["rkgibson@google.com", "stkhapugin", "chrome-omnibox-team@google.com"],
+    "expiry_milestone": 92
+  },
   {
     "name": "omnibox-local-zero-suggest-frecency-ranking",
     "owners": [ "mahmadi", "chrome-omnibox-team@google.com" ],

components/omnibox/browser/local_history_zero_suggest_provider.cc

@@ -58,17 +58,22 @@ base::string16 GetSearchTermsFromURL(const GURL& url,
 // Whether zero suggest suggestions are allowed in the given context.
 // Invoked early, confirms all the conditions for zero suggestions are met.
 bool AllowLocalHistoryZeroSuggestSuggestions(const AutocompleteInput& input) {
+  // TODO: The default-enabling on Android predated the
+  // omnibox::kNewSearchFeatures flag, so Android is not gated by it. Because
+  // of that, the new kLocalHistoryZeroSuggest flag can't control Android
+  // behavior. Once the kNewSearchFeatures flag is removed,
+  // kLocalHistoryZeroSuggest can control the feature on all plattforms.
 #if defined(OS_ANDROID)  // Default-enabled on Android.
   return true;
 #else
   if (!base::FeatureList::IsEnabled(omnibox::kNewSearchFeatures))
     return false;
-#endif
 
-#if !defined(OS_IOS)  // Enabled by default on Desktop if not disabled by
-                      // kNewSearchFeatures.
-  return true;
-#else
+  // Flag is default-enabled on Android and Desktop.
+  if (base::FeatureList::IsEnabled(omnibox::kLocalHistoryZeroSuggest)) {
+    return true;
+  }
+
   const auto current_page_classification = input.current_page_classification();
   // Reactive Zero-Prefix Suggestions (rZPS) and basically all remote ZPS on the
   // NTP are expected to be displayed alongside local history zero-prefix
@@ -81,12 +86,6 @@ bool AllowLocalHistoryZeroSuggestSuggestions(const AutocompleteInput& input) {
           omnibox::kReactiveZeroSuggestionsOnNTPOmnibox)) {
     return true;
   }
-  // NTP Realbox.
-  if (current_page_classification == OmniboxEventProto::NTP_REALBOX &&
-      base::FeatureList::IsEnabled(
-          omnibox::kReactiveZeroSuggestionsOnNTPRealbox)) {
-    return true;
-  }
 
   return false;
 #endif

components/omnibox/browser/local_history_zero_suggest_provider_unittest.cc

@@ -80,7 +80,7 @@ class LocalHistoryZeroSuggestProviderTest
 #if defined(OS_IOS)  // Only needed for iOS.
     scoped_feature_list_ = std::make_unique<base::test::ScopedFeatureList>();
     scoped_feature_list_->InitAndEnableFeature(
-        omnibox::kReactiveZeroSuggestionsOnNTPRealbox);
+        omnibox::kLocalHistoryZeroSuggest);
 #endif
 
     // Add the fallback default search provider to the TemplateURLService so
@@ -452,7 +452,7 @@ TEST_F(LocalHistoryZeroSuggestProviderTest, Ranking) {
   // With frecency ranking disabled, more recent searches are ranked higher.
   scoped_feature_list_ = std::make_unique<base::test::ScopedFeatureList>();
   scoped_feature_list_->InitWithFeatures(
-      {omnibox::kReactiveZeroSuggestionsOnNTPRealbox},  // Enables the provider.
+      {omnibox::kLocalHistoryZeroSuggest},  // Enables the provider on iOS.
       {omnibox::kOmniboxLocalZeroSuggestFrecencyRanking});
 
   StartProviderAndWaitUntilDone();
@@ -462,7 +462,7 @@ TEST_F(LocalHistoryZeroSuggestProviderTest, Ranking) {
   // searches are just as frequent.
   scoped_feature_list_ = std::make_unique<base::test::ScopedFeatureList>();
   scoped_feature_list_->InitWithFeatures(
-      {omnibox::kReactiveZeroSuggestionsOnNTPRealbox,  // Enables the provider.
+      {omnibox::kLocalHistoryZeroSuggest,  // Enables the provider on iOS.
        omnibox::kOmniboxLocalZeroSuggestFrecencyRanking},
       {});
 
@@ -492,8 +492,8 @@ TEST_F(LocalHistoryZeroSuggestProviderTest, Freshness) {
   // Override the age threshold to 7 days.
   scoped_feature_list_ = std::make_unique<base::test::ScopedFeatureList>();
   scoped_feature_list_->InitWithFeaturesAndParameters(
-      {{omnibox::kReactiveZeroSuggestionsOnNTPRealbox,  // Enables the provider.
-        {}},
+
+      {{omnibox::kLocalHistoryZeroSuggest, {}},  // Enables the provider on iOS.
        {omnibox::kOmniboxLocalZeroSuggestAgeThreshold,
         {{OmniboxFieldTrial::kOmniboxLocalZeroSuggestAgeThresholdParam, "7"}}}},
       {});

components/omnibox/common/omnibox_features.cc

@@ -247,6 +247,10 @@ const base::Feature kReactiveZeroSuggestionsOnNTPRealbox{
     "OmniboxReactiveZeroSuggestionsOnNTPRealbox",
     base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Allows the LocalHistoryZeroSuggestProvider to use local search history.
+const base::Feature kLocalHistoryZeroSuggest{
+    "LocalHistoryZeroSuggest", enabled_by_default_desktop_android};
+
 // Features to provide non personalized head search suggestion from a compact
 // on device model. More specifically, feature name with suffix Incognito /
 // NonIncognito will only controls behaviors under incognito / non-incognito

components/omnibox/common/omnibox_features.h

@@ -66,6 +66,7 @@ extern const base::Feature kOnFocusSuggestionsContextualWeb;
 extern const base::Feature kOnFocusSuggestionsContextualWebOnContent;
 extern const base::Feature kReactiveZeroSuggestionsOnNTPOmnibox;
 extern const base::Feature kReactiveZeroSuggestionsOnNTPRealbox;
+extern const base::Feature kLocalHistoryZeroSuggest;
 // Related, kMaxZeroSuggestMatches.
 
 // On Device Head Suggest.

ios/chrome/browser/flags/about_flags.mm

@@ -338,6 +338,10 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
          omnibox::kUIExperimentMaxAutocompleteMatches,
          kOmniboxUIMaxAutocompleteMatchesVariations,
          "OmniboxUIMaxAutocompleteVariations")},
+    {"omnibox-local-history-zero-suggest",
+     flag_descriptions::kOmniboxLocalHistoryZeroSuggestName,
+     flag_descriptions::kOmniboxLocalHistoryZeroSuggestDescription,
+     flags_ui::kOsIos, FEATURE_VALUE_TYPE(omnibox::kLocalHistoryZeroSuggest)},
     {"infobar-ui-reboot", flag_descriptions::kInfobarUIRebootName,
      flag_descriptions::kInfobarUIRebootDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(kIOSInfobarUIReboot)},

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -334,6 +334,12 @@ const char kOmniboxOnFocusSuggestionsDescription[] =
     "before the user has typed any input. This provides overrides for the "
     "default suggestion locations.";
 
+const char kOmniboxLocalHistoryZeroSuggestName[] =
+    "Omnibox local zero-prefix suggestions";
+const char kOmniboxLocalHistoryZeroSuggestDescription[] =
+    "Configures the omnibox zero-prefix suggestion to use local search "
+    "history.";
+
 const char kRefactoredNTPName[] = "Enables refactored new tab page";
 const char kRefactoredNTPDescription[] =
     "When enabled, the new tab page is replaced with the refactored version, "

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -291,6 +291,17 @@ extern const char kOmniboxOnDeviceHeadSuggestionsNonIncognitoDescription[];
 extern const char kOmniboxOnFocusSuggestionsName[];
 extern const char kOmniboxOnFocusSuggestionsDescription[];
 
+// Title and description for the flag to control Omnibox Local zero-prefix
+// suggestions.
+extern const char kOmniboxLocalHistoryZeroSuggestName[];
+extern const char kOmniboxLocalHistoryZeroSuggestDescription[];
+
+#if defined(__IPHONE_13_4)
+// Title and description for the flag to enable pointer support on tablets.
+extern const char kPointerSupportName[];
+extern const char kPointerSupportDescription[];
+#endif  // defined(__IPHONE_13_4)
+
 // Title and description for the flag that enables the refactored new tab page.
 extern const char kRefactoredNTPName[];
 extern const char kRefactoredNTPDescription[];