Split DownloadItem into an ABC, an Impl, and a Mock.

content/browser/download/download_manager.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.
 //
 // The DownloadManager object manages the process of downloading, including
 // updates to the history system and providing the information for displaying
 // the downloads view in the Destinations tab. There is one DownloadManager per
 // active browser context in Chrome.
 //
 // Download observers:
@@ skipping 36 matching lines @@
 #include "content/browser/download/download_id.h"
 #include "content/browser/download/download_item.h"
 #include "content/browser/download/download_status_updater_delegate.h"
 #include "content/browser/download/interrupt_reasons.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/net_errors.h"
 
 class DownloadFileManager;
 class DownloadIdFactory;
+class DownloadPersistentStoreInfo;
 class DownloadRequestHandle;
 class DownloadStatusUpdater;
 class GURL;
 class ResourceDispatcherHost;
 class TabContents;
 struct DownloadCreateInfo;
 struct DownloadSaveInfo;
 
 namespace content {
 class BrowserContext;
@@ skipping 350 matching lines @@
   DownloadIdFactory* id_factory_;
 
   // TODO(rdsmith): Remove when http://crbug.com/85408 is fixed.
   // For debugging only.
   int64 largest_db_handle_in_history_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadManager);
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_MANAGER_H_