[NTP::SectionOrder] Add a flag to choose category ranker.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 492 matching lines @@
     {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, switches::kNtpSwitchToExistingTab,
      "disabled"},
     {IDS_FLAGS_NTP_SWITCH_TO_EXISTING_TAB_MATCH_URL,
      switches::kNtpSwitchToExistingTab, "url"},
     {IDS_FLAGS_NTP_SWITCH_TO_EXISTING_TAB_MATCH_HOST,
      switches::kNtpSwitchToExistingTab, "host"},
 };
 #endif  // OS_ANDROID
 
 #if defined(OS_ANDROID)
+const FeatureEntry::FeatureParam
+    kNTPSnippetsCategoryRankerFeatureVariationConstant[] = {
+        {"category_ranker", "constant"},
+};
+
+const FeatureEntry::FeatureParam
+    kNTPSnippetsCategoryRankerFeatureVariationClickBased[] = {
+        {"category_ranker", "click_based"},
+};
+
+const FeatureEntry::FeatureVariation
+    kNTPSnippetsCategoryRankerFeatureVariations[] = {
+        {"(constant)", kNTPSnippetsCategoryRankerFeatureVariationConstant,
+         arraysize(kNTPSnippetsCategoryRankerFeatureVariationConstant),
+         nullptr},
+        {"(click based)", kNTPSnippetsCategoryRankerFeatureVariationClickBased,
+         arraysize(kNTPSnippetsCategoryRankerFeatureVariationClickBased),
+         nullptr}};
+#endif  // OS_ANDROID
+
+#if defined(OS_ANDROID)
 const FeatureEntry::FeatureParam kNTPSnippetsFeatureVariationOnlyPersonal[] = {
     {"fetching_personalization", "personal"},
 };
 
 const FeatureEntry::FeatureParam kNTPSnippetsFeatureVariationServer[] = {
     {"content_suggestions_backend",
      ntp_snippets::kContentSuggestionsServer}};
 
 const FeatureEntry::FeatureParam
     kNTPSnippetsFeatureVariationServerNonPersonalized[] = {
@@ skipping 1309 matching lines @@
     {"disable-audio-support-for-desktop-share",
      IDS_FLAG_DISABLE_AUDIO_FOR_DESKTOP_SHARE,
      IDS_FLAG_DISABLE_AUDIO_FOR_DESKTOP_SHARE_DESCRIPTION, kOsAll,
      SINGLE_VALUE_TYPE(switches::kDisableAudioSupportForDesktopShare)},
 #if BUILDFLAG(ENABLE_EXTENSIONS)
     {"tab-for-desktop-share", IDS_FLAG_DISABLE_TAB_FOR_DESKTOP_SHARE,
      IDS_FLAG_DISABLE_TAB_FOR_DESKTOP_SHARE_DESCRIPTION, kOsAll,
      SINGLE_VALUE_TYPE(extensions::switches::kDisableTabForDesktopShare)},
 #endif  // ENABLE_EXTENSIONS
 #if defined(OS_ANDROID)
+    {"ntp-category-ranker", IDS_FLAGS_NTP_CATEGORY_RANKER_NAME,
+     IDS_FLAGS_NTP_CATEGORY_RANKER_DESCRIPTION, kOsAndroid,
+     FEATURE_WITH_VARIATIONS_VALUE_TYPE(
+         ntp_snippets::kCategoryRanker,
+         kNTPSnippetsCategoryRankerFeatureVariations,
+         ntp_snippets::kStudyName)},
     {"enable-ntp-snippets", IDS_FLAGS_ENABLE_NTP_SNIPPETS_NAME,
      IDS_FLAGS_ENABLE_NTP_SNIPPETS_DESCRIPTION, kOsAndroid,
      FEATURE_WITH_VARIATIONS_VALUE_TYPE(
          ntp_snippets::kContentSuggestionsFeature,
          kNTPSnippetsFeatureVariations,
          ntp_snippets::kStudyName)},
     {"enable-ntp-snippets-increased-visibility",
      IDS_FLAGS_ENABLE_NTP_SNIPPETS_VISIBILITY_NAME,
      IDS_FLAGS_ENABLE_NTP_SNIPPETS_VISIBILITY_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(ntp_snippets::kIncreasedVisibility)},
@@ skipping 489 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags