Implement ClearHistory for all ntp_snippets providers

components/ntp_snippets/bookmarks/bookmark_last_visit_utils.cc

 // Copyright 2016 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/ntp_snippets/bookmarks/bookmark_last_visit_utils.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 214 matching lines @@
 
   // Insert into |result|.
   std::vector<const BookmarkNode*> result;
   for (const BookmarkModel::URLAndTitle& bookmark : bookmarks) {
     result.push_back(
         bookmark_model->GetMostRecentlyAddedUserNodeForURL(bookmark.url));
   }
   return result;
 }
 
+void RemoveAllLastVisitDates(bookmarks::BookmarkModel* bookmark_model) {
+  // Get all the bookmark URLs.
+  std::vector<BookmarkModel::URLAndTitle> bookmark_urls;
+  bookmark_model->GetBookmarks(&bookmark_urls);
+
+  for (const BookmarkModel::URLAndTitle& url_and_title : bookmark_urls) {
+    // Get all bookmarks for the given URL.
+    std::vector<const BookmarkNode*> bookmarks_for_url;
+    bookmark_model->GetNodesByURL(url_and_title.url, &bookmarks_for_url);
+
+    for (const BookmarkNode* bookmark : bookmarks_for_url) {
+      bookmark_model->DeleteNodeMetaInfo(bookmark, kBookmarkLastVisitDateKey);
+    }
+  }
+}
+
 }  // namespace ntp_snippets