Make browsing_data component a layered component

chrome/browser/browsing_data/downloads_counter.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/browsing_data/downloads_counter.h"
 
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/profiles/profile.h"
-#include "components/browsing_data/pref_names.h"
+#include "components/browsing_data/core/pref_names.h"
 #include "content/public/browser/download_manager.h"
 
 DownloadsCounter::DownloadsCounter(Profile* profile)
     : BrowsingDataCounter(browsing_data::prefs::kDeleteDownloadHistory),
       profile_(profile) {}
 
 DownloadsCounter::~DownloadsCounter() {
 }
 
 void DownloadsCounter::Count() {
   content::DownloadManager* download_manager =
       content::BrowserContext::GetDownloadManager(profile_);
   std::vector<content::DownloadItem*> downloads;
   download_manager->GetAllDownloads(&downloads);
   base::Time begin_time = GetPeriodStart();
 
   ReportResult(std::count_if(
       downloads.begin(),
       downloads.end(),
       [begin_time](const content::DownloadItem* item) {
         return item->GetStartTime() >= begin_time &&
             DownloadHistory::IsPersisted(item);
       }));
 }