Get network resource usage from ChromeResourceDispatcherHostDelegate

chrome/browser/offline_pages/offliner_user_data.cc

 // Copyright 2017 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/offline_pages/offliner_user_data.h"
 
-class ResourceTrackerObserver;
-
 namespace offline_pages {
 
 void OfflinerUserData::AddToWebContents(content::WebContents* webcontents,
                                         BackgroundLoaderOffliner* offliner) {
   DCHECK(offliner);
   webcontents->SetUserData(UserDataKey(), std::unique_ptr<OfflinerUserData>(
                                               new OfflinerUserData(offliner)));
 }
 
 // static - gets the data pointer as a BackgroundLoaderOffliner
@@ skipping 13 matching lines @@
   OfflinerUserData* data = OfflinerUserData::FromWebContents(webcontents);
   if (data)
     return data->offliner();
 
   return nullptr;
 }
 
 }  // namespace offline_pages
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(offline_pages::OfflinerUserData);