Add a parameter to enable native UI

Bug: crbug.com/1144732
Change-Id: I02b0f55361cb4211b8862a62be4d841c15e2ad68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2536054
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Auto-Submit: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827145}

ios/chrome/browser/flags/about_flags.mm

@@ -239,6 +239,12 @@ const FeatureEntry::FeatureVariation
         {"(show one)", kAutofillUseMobileLabelDisambiguationShowOne,
          base::size(kAutofillUseMobileLabelDisambiguationShowOne), nullptr}};
 
+const FeatureEntry::FeatureParam kDiscoverFeedInNtpEnableNativeUI[] = {
+    {kDiscoverFeedIsNativeUIEnabled, "true"}};
+const FeatureEntry::FeatureVariation kDiscoverFeedInNtpVariations[] = {
+    {"Native UI", kDiscoverFeedInNtpEnableNativeUI,
+     base::size(kDiscoverFeedInNtpEnableNativeUI), nullptr}};
+
 // To add a new entry, add to the end of kFeatureEntries. There are four
 // distinct types of entries:
 // . ENABLE_DISABLE_VALUE: entry is either enabled, disabled, or uses the
@@ -519,7 +525,9 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(kSafetyCheckIOS)},
     {"new-content-suggestions-feed", flag_descriptions::kDiscoverFeedInNtpName,
      flag_descriptions::kDiscoverFeedInNtpDescription, flags_ui::kOsIos,
-     FEATURE_VALUE_TYPE(kDiscoverFeedInNtp)},
+     FEATURE_WITH_PARAMS_VALUE_TYPE(kDiscoverFeedInNtp,
+                                    kDiscoverFeedInNtpVariations,
+                                    "IOSDiscoverFeed")},
     {"autofill-enable-card-nickname-upstream",
      flag_descriptions::kAutofillEnableCardNicknameUpstreamName,
      flag_descriptions::kAutofillEnableCardNicknameUpstreamDescription,

ios/chrome/browser/ui/content_suggestions/content_suggestions_feature.h

@@ -12,6 +12,10 @@
 // Use IsDiscoverFeedEnabled() instead of this constant directly.
 extern const base::Feature kDiscoverFeedInNtp;
 
+// A parameter to indicate whether the native UI is enabled for the discover
+// feed.
+extern const char kDiscoverFeedIsNativeUIEnabled[];
+
 // Whether the Discover feed is enabled instead of the Zine feed.
 bool IsDiscoverFeedEnabled();
 

ios/chrome/browser/ui/content_suggestions/content_suggestions_feature.mm

@@ -12,6 +12,10 @@
 const base::Feature kDiscoverFeedInNtp{"DiscoverFeedInNtp",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
+// A parameter to indicate whether the native UI is enabled for the discover
+// feed.
+const char kDiscoverFeedIsNativeUIEnabled[] = "DiscoverFeedIsNativeUIEnabled";
+
 bool IsDiscoverFeedEnabled() {
   return base::FeatureList::IsEnabled(kDiscoverFeedInNtp);
 }