Implement ClearHistory for all ntp_snippets providers

components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h

Index: components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h
diff --git a/components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h b/components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h
index 4666acda1f6eb900f11c086b19b17131d8bf7194..b056deaeb309cdcc4b882347ee6019479e73f4cc 100644
--- a/components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h
+++ b/components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h
@@ -66,6 +66,9 @@ std::vector<const bookmarks::BookmarkNode*> GetRecentlyVisitedBookmarks(
 std::vector<const bookmarks::BookmarkNode*> GetDismissedBookmarksForDebugging(
     bookmarks::BookmarkModel* bookmark_model);
 
+// Removes last visited date metadata for all bookmarks.
+void RemoveAllLastVisitDates(bookmarks::BookmarkModel* bookmark_model);
+
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_BOOKMARKS_BOOKMARK_LAST_VISIT_UTILS_H_