[NTP::Downloads] Use last access time to filter old asset downloads.

chrome/browser/ntp_snippets/download_suggestions_provider.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 "chrome/browser/ntp_snippets/download_suggestions_provider.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 495 matching lines @@
   }
 
   std::vector<DownloadItem*> all_downloads;
   download_manager_->GetAllDownloads(&all_downloads);
   std::set<std::string> old_dismissed_ids = ReadAssetDismissedIDsFromPrefs();
   std::set<std::string> retained_dismissed_ids;
   cached_asset_downloads_.clear();
   for (DownloadItem* item : all_downloads) {
     std::string within_category_id =
         GetAssetDownloadPerCategoryID(item->GetId());
-    // TODO(vitaliii): Provide proper last access time here once it is collected
-    // for asset downloads.
     if (old_dismissed_ids.count(within_category_id)) {
       retained_dismissed_ids.insert(within_category_id);
     } else if (IsAssetDownloadCompleted(*item) &&
                !IsDownloadOutdated(GetAssetDownloadPublishedTime(*item),
-                                   base::Time())) {
+                                   item->GetLastAccessTime())) {
       cached_asset_downloads_.push_back(item);
       // We may already observe this item and, therefore, we remove the
       // observer first.
       item->RemoveObserver(this);
       item->AddObserver(this);
     }
   }
 
   if (old_dismissed_ids.size() != retained_dismissed_ids.size()) {
     StoreAssetDismissedIDsToPrefs(retained_dismissed_ids);
@@ skipping 318 matching lines @@
 void DownloadSuggestionsProvider::UnregisterDownloadItemObservers() {
   DCHECK_NE(download_manager_, nullptr);
 
   std::vector<DownloadItem*> all_downloads;
   download_manager_->GetAllDownloads(&all_downloads);
 
   for (DownloadItem* item : all_downloads) {
     item->RemoveObserver(this);
   }
 }