Reading List iOS: Use external clock in ReadingListEntry.

ios/chrome/browser/reading_list/reading_list_download_service.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 "ios/chrome/browser/reading_list/reading_list_download_service.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file_enumerator.h"
@@ skipping 225 matching lines @@
     int64_t size,
     const std::string& title) {
   DCHECK(reading_list_model_->loaded());
   URLDownloader::SuccessState real_success_value = success;
   if (distilled_path.empty()) {
     real_success_value = URLDownloader::ERROR;
   }
   switch (real_success_value) {
     case URLDownloader::DOWNLOAD_SUCCESS:
     case URLDownloader::DOWNLOAD_EXISTS: {
-      int64_t now =
-          (base::Time::Now() - base::Time::UnixEpoch()).InMicroseconds();
-      reading_list_model_->SetEntryDistilledInfo(url, distilled_path,
-                                                 distilled_url, size, now);
+      reading_list_model_->SetEntryDistilledInfo(
+          url, distilled_path, distilled_url, size, base::Time::Now());
 
       std::string trimmed_title = base::CollapseWhitespaceASCII(title, false);
       if (!trimmed_title.empty())
         reading_list_model_->SetEntryTitle(url, trimmed_title);
 
       const ReadingListEntry* entry = reading_list_model_->GetEntryByURL(url);
       if (entry)
         UMA_HISTOGRAM_COUNTS_100("ReadingList.Download.Failures",
                                  entry->FailedDownloadCounter());
       UMA_HISTOGRAM_ENUMERATION("ReadingList.Download.Status", SUCCESS,
@@ skipping 37 matching lines @@
     for (auto& url : url_to_download_cellular_) {
       ScheduleDownloadEntry(url);
     }
   }
   if (type == net::NetworkChangeNotifier::CONNECTION_WIFI) {
     for (auto& url : url_to_download_wifi_) {
       ScheduleDownloadEntry(url);
     }
   }
 }