Adds a first integration test for the Recent Tabs feature.

components/offline_pages/core/offline_page_feature.h

 // 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.
 
 #ifndef COMPONENTS_OFFLINE_PAGES_CORE_OFFLINE_PAGE_FEATURE_H_
 #define COMPONENTS_OFFLINE_PAGES_CORE_OFFLINE_PAGE_FEATURE_H_
 
 #include "base/feature_list.h"
 #include "build/build_config.h"
 
@@ skipping 27 matching lines @@
 // Returns true if concurrent background loading is enabled for svelte.
 bool IsOfflinePagesSvelteConcurrentLoadingEnabled();
 
 // Returns true if downloading a page asynchonously is enabled.
 bool IsOfflinePagesAsyncDownloadEnabled();
 
 // Returns true if we should use background loader rather than prerenderer
 // to offline pages.
 bool ShouldUseNewBackgroundLoader();
 
+// Returns true if a command line for test has been set that shortens the
+// snapshot delay.
+bool ShouldUseTestingSnapshotDelay();
+
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_FEATURE_H_