Downloads: Added transient flag to download item and download database

components/history/core/browser/download_database.h

 // Copyright (c) 2012 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 COMPONENTS_HISTORY_CORE_BROWSER_DOWNLOAD_DATABASE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_DOWNLOAD_DATABASE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 78 matching lines @@
   // download table.
   bool MigrateDownloadTabUrl();
 
   // Returns true if able to add the site_url column to the download
   // table.
   bool MigrateDownloadSiteInstanceUrl();
 
   // Returns true if able to add last_access_time column to the download table.
   bool MigrateDownloadLastAccessTime();
 
+  // Returns true if able to add transient column to the download table.
+  bool MigrateDownloadTransient();
+
   // Creates the downloads table if needed.
   bool InitDownloadTable();
 
   // Used to quickly clear the downloads. First you would drop it, then you
   // would re-initialize it.
   bool DropDownloadTable();
 
  private:
   FRIEND_TEST_ALL_PREFIXES(HistoryBackendDBTest,
                            ConfirmDownloadInProgressCleanup);
@@ skipping 36 matching lines @@
   // to use for respectively an undefined value and in case of a crash.
   DownloadInterruptReason download_interrupt_reason_none_;
   DownloadInterruptReason download_interrupt_reason_crash_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadDatabase);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_DOWNLOAD_DATABASE_H_