Add base::FeatureParam<> struct

components/ntp_snippets/remote/remote_suggestions_fetcher.cc

Index: components/ntp_snippets/remote/remote_suggestions_fetcher.cc
diff --git a/components/ntp_snippets/remote/remote_suggestions_fetcher.cc b/components/ntp_snippets/remote/remote_suggestions_fetcher.cc
index 8bd852cedd2cc393fcb1e4dec8c531a5579151da..d20a1d14c3b881dcc719489621a1b7d3f71a8da9 100644
--- a/components/ntp_snippets/remote/remote_suggestions_fetcher.cc
+++ b/components/ntp_snippets/remote/remote_suggestions_fetcher.cc
@@ -50,8 +50,9 @@ const char kContentSuggestionsApiScope[] =
 const char kSnippetsServerNonAuthorizedFormat[] = "%s?key=%s";
 const char kAuthorizationRequestHeaderFormat[] = "Bearer %s";
 
-// Variation parameter for chrome-content-suggestions backend.
-const char kContentSuggestionsBackend[] = "content_suggestions_backend";
+constexpr base::FeatureParam<std::string> kContentSuggestionsBackend{
+    &kArticleSuggestionsFeature, "content_suggestions_backend",
+    kContentSuggestionsServer};
 
 const int kFetchTimeHistogramResolution = 5;
 
@@ -173,8 +174,7 @@ void FilterCategories(
 }  // namespace
 
 GURL GetFetchEndpoint(version_info::Channel channel) {
-  std::string endpoint = variations::GetVariationParamValueByFeature(
-      ntp_snippets::kArticleSuggestionsFeature, kContentSuggestionsBackend);
+  std::string endpoint = kContentSuggestionsBackend.Get();
   if (!endpoint.empty()) {
     return GURL{endpoint};
   }