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

chrome/browser/history/history.h

Index: chrome/browser/history/history.h
diff --git a/chrome/browser/history/history.h b/chrome/browser/history/history.h
index fe835b1418e957e41b334937c38d3ea3b14b7ea6..be168ae67c4c9cd43df5dc1cdc559d071124bbaa 100644
--- a/chrome/browser/history/history.h
+++ b/chrome/browser/history/history.h
@@ -423,6 +423,13 @@ class HistoryService : public CancelableRequestProvider,
                         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