Add base::FeatureParam<> struct

components/ntp_snippets/remote/json_request.cc

Index: components/ntp_snippets/remote/json_request.cc
diff --git a/components/ntp_snippets/remote/json_request.cc b/components/ntp_snippets/remote/json_request.cc
index 8627c49c57320983066e2e8a8a5064165790e00d..5ede74f917791f35ea8c032443e0196736e5f030 100644
--- a/components/ntp_snippets/remote/json_request.cc
+++ b/components/ntp_snippets/remote/json_request.cc
@@ -49,34 +49,23 @@ namespace internal {
 
 namespace {
 
-// Variation parameter for disabling the retry.
-const char kBackground5xxRetriesName[] = "background_5xx_retries_count";
+constexpr base::FeatureParam<int> kBackground5xxRetries{
+    &ntp_snippets::kArticleSuggestionsFeature, "background_5xx_retries_count",
+    0};
 
 // Variation parameter for sending UrlLanguageHistogram info to the server.
-const char kSendTopLanguagesName[] = "send_top_languages";
+constexpr base::FeatureParam<bool> kSendTopLanguages{
+    &ntp_snippets::kArticleSuggestionsFeature, "send_top_languages", false};
 
 // Variation parameter for sending UserClassifier info to the server.
-const char kSendUserClassName[] = "send_user_class";
+constexpr base::FeatureParam<bool> kSendUserClassNameParam{
+    &kArticleSuggestionsFeature, "send_user_class", false};
 
 int Get5xxRetryCount(bool interactive_request) {
   if (interactive_request) {
     return 2;
   }
-  return std::max(0, variations::GetVariationParamByFeatureAsInt(
-                         ntp_snippets::kArticleSuggestionsFeature,
-                         kBackground5xxRetriesName, 0));
-}
-
-bool IsSendingTopLanguagesEnabled() {
-  return variations::GetVariationParamByFeatureAsBool(
-      ntp_snippets::kArticleSuggestionsFeature, kSendTopLanguagesName,
-      /*default_value=*/true);
-}
-
-bool IsSendingUserClassEnabled() {
-  return variations::GetVariationParamByFeatureAsBool(
-      ntp_snippets::kArticleSuggestionsFeature, kSendUserClassName,
-      /*default_value=*/false);
+  return std::max(0, kBackground5xxRetries.Get());
 }
 
 // Translate the BCP 47 |language_code| into a posix locale string.
@@ -282,7 +271,7 @@ JsonRequest::Builder& JsonRequest::Builder::SetUrlRequestContextGetter(
 
 JsonRequest::Builder& JsonRequest::Builder::SetUserClassifier(
     const UserClassifier& user_classifier) {
-  if (IsSendingUserClassEnabled()) {
+  if (kSendUserClassNameParam.Get()) {
     user_class_ = GetUserClassString(user_classifier.GetUserClass());
   }
   return *this;
@@ -407,7 +396,7 @@ void JsonRequest::Builder::PrepareLanguages(
   // TODO(jkrcal): Add language model factory for iOS and add fakes to tests so
   // that |language_histogram| is never nullptr. Remove this check and add a
   // DCHECK into the constructor.
-  if (!language_histogram_ || !IsSendingTopLanguagesEnabled()) {
+  if (!language_histogram_ || !kSendTopLanguages.Get()) {
     return;
   }