sql::MetaTable.next_download_id, DownloadManager::GetNextId()

chrome/browser/history/history.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_HISTORY_HISTORY_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_H_
 #pragma once
 
 #include <set>
 #include <vector>
@@ skipping 407 matching lines @@
       DownloadCreateCallback;
 
   // Begins a history request to create a new persistent entry for a download.
   // 'info' contains all the download's creation state, and 'callback' runs
   // when the history service request is complete.
   Handle CreateDownload(int32 id,
                         const DownloadHistoryInfo& info,
                         CancelableRequestConsumerBase* consumer,
                         DownloadCreateCallback* callback);
 
+  // Implemented by the caller of 'GetNextDownloadId' below.
+  typedef Callback1<int/*next_download_id*/>::Type DownloadNextIdCallback;
+
+  // Runs the callback with the next available download id.
+  Handle GetNextDownloadId(CancelableRequestConsumerBase* consumer,
+                           DownloadNextIdCallback* callback);
+
   // Implemented by the caller of 'QueryDownloads' below, and is called when the
   // history service has retrieved a list of all download state. The call
   typedef Callback1<std::vector<DownloadHistoryInfo>*>::Type
       DownloadQueryCallback;
 
   // Begins a history request to retrieve the state of all downloads in the
   // history db. 'callback' runs when the history service request is complete,
   // at which point 'info' contains an array of DownloadHistoryInfo, one per
   // download.
   Handle QueryDownloads(CancelableRequestConsumerBase* consumer,
@@ skipping 431 matching lines @@
   BookmarkService* bookmark_service_;
   bool no_db_;
 
   // True if needs top site migration.
   bool needs_top_sites_migration_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryService);
 };
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_H_