Added DownloadItem::Observer to JobController.

content/browser/background_fetch/background_fetch_context.h

 // 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.
 
 #ifndef CONTENT_BROWSER_BACKGROUND_FETCH_BACKGROUND_FETCH_CONTEXT_H_
 #define CONTENT_BROWSER_BACKGROUND_FETCH_BACKGROUND_FETCH_CONTEXT_H_
 
 #include <unordered_map>
 
 #include "base/macros.h"
@@ skipping 35 matching lines @@
   BackgroundFetchDataManager* GetDataManagerForTesting() {
     return &background_fetch_data_manager_;
   }
 
  private:
   friend class base::DeleteHelper<BackgroundFetchContext>;
   friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
   friend class base::RefCountedThreadSafe<BackgroundFetchContext,
                                           BrowserThread::DeleteOnUIThread>;
 
-  virtual ~BackgroundFetchContext();
+  ~BackgroundFetchContext();
 
   void CreateRequest(const BackgroundFetchJobInfo& job_info,
                      std::vector<BackgroundFetchRequestInfo>& request_infos);
 
   void ShutdownOnIO();
 
   // |this| is owned by the BrowserContext via the StoragePartition.
   BrowserContext* browser_context_;
   StoragePartition* storage_partition_;
 
   scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
   BackgroundFetchDataManager background_fetch_data_manager_;
 
   std::unordered_map<std::string, std::unique_ptr<BackgroundFetchJobController>>
       job_map_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundFetchContext);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BACKGROUND_FETCH_BACKGROUND_FETCH_CONTEXT_H_