Offline Page Cache uses user interaction triggers for saving pages.

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"
 
 namespace offline_pages {
 
 extern const base::Feature kOfflineBookmarksFeature;
 extern const base::Feature kOffliningRecentPagesFeature;
+extern const base::Feature kOffliningUsesNavigationTriggersFeature;
 extern const base::Feature kOfflinePagesSvelteConcurrentLoadingFeature;
 extern const base::Feature kOfflinePagesCTFeature;
 extern const base::Feature kOfflinePagesSharingFeature;
 extern const base::Feature kBackgroundLoaderForDownloadsFeature;
 extern const base::Feature kOfflinePagesAsyncDownloadFeature;
 extern const base::Feature kNewBackgroundLoaderFeature;
 
 // Returns true if saving bookmarked pages for offline viewing is enabled.
 bool IsOfflineBookmarksEnabled();
 
 // Returns true if offlining of recent pages (aka 'Last N pages') is enabled.
 bool IsOffliningRecentPagesEnabled();
 
+// Returns true only if both offlining of recent pages is enabled and navigation
+// events should be used to create snapshots of recent pages.
+bool IsOffliningRecentPagesUsingNavigationTriggers();
+
+// Returns true only if both offlining of recent pages is enabled and user
+// interaction events should be used to create snapshots of recent pages.
+bool IsOffliningRecentPagesUsingInteractionTriggers();
+
 // Returns true if offline CT features are enabled.  See crbug.com/620421.
 bool IsOfflinePagesCTEnabled();
 
 // Returns true if offline page sharing is enabled.
 bool IsOfflinePagesSharingEnabled();
 
 // Returns true if saving a foreground tab that is taking too long using the
 // background scheduler is enabled.
 bool IsBackgroundLoaderForDownloadsEnabled();
 
 // 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();
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_FEATURE_H_