Add new feature flag to enable background loader for downloads

components/offline_pages/offline_page_feature.cc

Index: components/offline_pages/offline_page_feature.cc
diff --git a/components/offline_pages/offline_page_feature.cc b/components/offline_pages/offline_page_feature.cc
index 0d161d6158e216aa6f9108e573864e0f30f77dac..1b560a0123c3155e7e46b7d20705baeceda94319 100644
--- a/components/offline_pages/offline_page_feature.cc
+++ b/components/offline_pages/offline_page_feature.cc
@@ -29,10 +29,14 @@ const base::Feature kOfflinePagesCTFeature {
 const base::Feature kOfflinePagesSharingFeature{
     "OfflinePagesSharing", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kBackgroundLoaderForDownloadsFeature{
+    "BackgroundLoadingForDownloads", base::FEATURE_ENABLED_BY_DEFAULT};
+
 bool IsOfflinePagesEnabled() {
   return IsOfflineBookmarksEnabled() || IsOffliningRecentPagesEnabled() ||
          IsOfflinePagesBackgroundLoadingEnabled() ||
-         IsOfflinePagesCTEnabled() || IsOfflinePagesSharingEnabled();
+         IsOfflinePagesCTEnabled() || IsOfflinePagesSharingEnabled() ||
+         IsBackgroundLoaderForDownloadsEnabled();
 }
 
 bool IsOfflineBookmarksEnabled() {
@@ -55,4 +59,8 @@ bool IsOfflinePagesSharingEnabled() {
   return base::FeatureList::IsEnabled(kOfflinePagesSharingFeature);
 }
 
+bool IsBackgroundLoaderForDownloadsEnabled() {
+  return base::FeatureList::IsEnabled(kBackgroundLoaderForDownloadsFeature);
+}
+
 }  // namespace offline_pages