Making offline previews freshness configurable

chrome/browser/android/offline_pages/offline_page_request_job.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/android/offline_pages/offline_page_request_job.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 294 matching lines @@
     return RequestResult::OFFLINE_PAGE_NOT_FOUND;
 
   // |web_contents_getter| is passed from IO thread. We need to check if
   // web contents is still valid.
   content::WebContents* web_contents = web_contents_getter.Run();
   if (!web_contents)
     return RequestResult::NO_WEB_CONTENTS;
 
   // If the page is being loaded on a slow network, only use the offline page
   // if it was created within the past day.
-  // TODO(romax): Make the constant be policy driven.
   if (network_state == NetworkState::PROHIBITIVELY_SLOW_NETWORK &&
       base::Time::Now() - offline_page->creation_time >
-          base::TimeDelta::FromDays(1)) {
+          previews::params::OfflinePreviewFreshnessDuration()) {
     return RequestResult::PAGE_NOT_FRESH;
   }
 
   // Since offline page will be loaded, it should be marked as accessed.
   OfflinePageModel* offline_page_model =
       OfflinePageModelFactory::GetForBrowserContext(
           web_contents->GetBrowserContext());
   // |offline_page_model| cannot be null because OfflinePageRequestInterceptor
   // will not be created under incognito mode.
   DCHECK(offline_page_model);
@@ skipping 359 matching lines @@
 
   URLRequestJob::NotifyHeadersComplete();
 }
 
 void OfflinePageRequestJob::SetDelegateForTesting(
     std::unique_ptr<Delegate> delegate) {
   delegate_ = std::move(delegate);
 }
 
 }  // namespace offline_pages