[NTP Snippets] Move kOfflinePageSuggestionsFeature into the component

components/ntp_snippets/features.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/features.h"
 
 namespace ntp_snippets {
 
 const base::Feature kArticleSuggestionsFeature{
     "NTPArticleSuggestions", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kBookmarkSuggestionsFeature{
     "NTPBookmarkSuggestions", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kOfflinePageSuggestionsFeature{
+    "NTPOfflinePageSuggestions", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kContentSuggestionsFeature{
     "NTPSnippets", base::FEATURE_DISABLED_BY_DEFAULT};
 
 }  // namespace ntp_snippets