Delay DownloadManager creation by adding a callback queue to DownloadService

chrome/browser/download/download_extension_api.h

 // Copyright (c) 2011 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 CHROME_BROWSER_DOWNLOAD_DOWNLOAD_EXTENSION_API_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_EXTENSION_API_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 244 matching lines @@
 
 class ExtensionDownloadsEventRouter : public DownloadManager::Observer {
  public:
   explicit ExtensionDownloadsEventRouter(Profile* profile);
   virtual ~ExtensionDownloadsEventRouter();
 
   virtual void ModelChanged() OVERRIDE;
   virtual void ManagerGoingDown() OVERRIDE;
 
  private:
+  void Init(DownloadManager* manager);
   void DispatchEvent(const char* event_name, base::Value* json_arg);
   typedef base::hash_map<int, DownloadItem*> ItemMap;
   typedef std::set<int> DownloadIdSet;
 
   Profile* profile_;
   DownloadManager* manager_;
   DownloadIdSet downloads_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionDownloadsEventRouter);
 };
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_EXTENSION_API_H_