Add base::FeatureParam<> struct

components/ntp_snippets/offline_pages/recent_tab_suggestions_provider.cc

 // Copyright 2016 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 "components/ntp_snippets/offline_pages/recent_tab_suggestions_provider.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 14 matching lines @@
 #include "ui/gfx/image/image.h"
 
 using offline_pages::ClientId;
 using offline_pages::DownloadUIAdapter;
 using offline_pages::DownloadUIItem;
 
 namespace ntp_snippets {
 
 namespace {
 
-const int kDefaultMaxSuggestionsCount = 5;
-
-const char* kMaxSuggestionsCountParamName = "recent_tabs_max_count";
-
-int GetMaxSuggestionsCount() {
-  return variations::GetVariationParamByFeatureAsInt(
-      kRecentOfflineTabSuggestionsFeature, kMaxSuggestionsCountParamName,
-      kDefaultMaxSuggestionsCount);
-}
+const base::FeatureParam<int> kMaxSuggestionsCountParam{
+    &kRecentOfflineTabSuggestionsFeature, "recent_tabs_max_count", 5};
 
 struct OrderUIItemsByMostRecentlyCreatedFirst {
   bool operator()(const DownloadUIItem* left,
                   const DownloadUIItem* right) const {
     return left->start_time > right->start_time;
   }
 };
 
 struct OrderUIItemsByUrlAndThenMostRecentlyCreatedFirst {
   bool operator()(const DownloadUIItem* left,
@@ skipping 218 matching lines @@
       std::unique(ui_items.begin(), ui_items.end(),
                   [](const DownloadUIItem* left, const DownloadUIItem* right) {
                     return left->url == right->url;
                   });
   ui_items.erase(new_end, ui_items.end());
   std::sort(ui_items.begin(), ui_items.end(),
             OrderUIItemsByMostRecentlyCreatedFirst());
   std::vector<ContentSuggestion> suggestions;
   for (const DownloadUIItem* ui_item : ui_items) {
     suggestions.push_back(ConvertUIItem(*ui_item));
-    if (static_cast<int>(suggestions.size()) == GetMaxSuggestionsCount()) {
+    if (static_cast<int>(suggestions.size()) ==
+        kMaxSuggestionsCountParam.Get()) {
       break;
     }
   }
   return suggestions;
 }
 
 void RecentTabSuggestionsProvider::InvalidateSuggestion(
     const std::string& ui_item_guid) {
   std::string offline_page_id = base::IntToString(
       recent_tabs_ui_adapter_->GetOfflineIdByGuid(ui_item_guid));
@@ skipping 15 matching lines @@
 }
 
 void RecentTabSuggestionsProvider::StoreDismissedIDsToPrefs(
     const std::set<std::string>& dismissed_ids) {
   prefs::StoreDismissedIDsToPrefs(pref_service_,
                                   prefs::kDismissedRecentOfflineTabSuggestions,
                                   dismissed_ids);
 }
 
 }  // namespace ntp_snippets