Ntp: use AMP urls for content suggestions when available.

components/ntp_snippets/features.cc

Index: components/ntp_snippets/features.cc
diff --git a/components/ntp_snippets/features.cc b/components/ntp_snippets/features.cc
index 085257bc24d4cb05859a7827ee3313290e0dbfc7..03cfbc3bf45f0831f3d6c9836aa39d7f2e8254df 100644
--- a/components/ntp_snippets/features.cc
+++ b/components/ntp_snippets/features.cc
@@ -41,4 +41,7 @@ const base::Feature kForeignSessionsSuggestionsFeature{
 const base::Feature kFetchMoreFeature{"NTPSuggestionsFetchMore",
                                       base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kPreferAmpUrlsFeature{"NTPPreferAmpUrls",
+                                          base::FEATURE_ENABLED_BY_DEFAULT};
+
 }  // namespace ntp_snippets