[Offline Pages] Feature flag to allow concurrent background loading on svelte

components/offline_pages/offline_page_model_impl_unittest.cc

 // Copyright 2015 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/offline_pages/offline_page_model_impl.h"
 
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
@@ skipping 1233 matching lines @@
 
   // Check if feature is correctly enabled by command-line flag.
   scoped_feature_list.reset(new base::test::ScopedFeatureList);
   scoped_feature_list->InitFromCommandLine(
       std::string(kOfflineBookmarksFeature.name) + "," +
           kOfflinePagesSharingFeature.name,
       "");
   EXPECT_TRUE(offline_pages::IsOfflinePagesSharingEnabled());
 }
 
+TEST(CommandLineFlagsTest, OfflinePagesSvelteConcurrentLoading) {
+  // This feature is disabled by default.
+  EXPECT_FALSE(offline_pages::IsOfflinePagesSvelteConcurrentLoadingEnabled());
+
+  // Check if feature is correctly enabled by command-line flag.
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      kOfflinePagesSvelteConcurrentLoadingFeature);
+  EXPECT_TRUE(offline_pages::IsOfflinePagesSvelteConcurrentLoadingEnabled());
+}
+
 }  // namespace offline_pages