Use previous target path when resuming a download after crash

content/public/browser/download_item.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.
 //
 // Each download is represented by a DownloadItem, and all DownloadItems
 // are owned by the DownloadManager which maintains a global list of all
 // downloads. DownloadItems are created when a user initiates a download,
 // and exist for the duration of the browser life time.
 //
 // Download observers:
@@ skipping 264 matching lines @@
   // Target path of an in-progress download. We may be downloading to a
   // temporary or intermediate file (specified by GetFullPath()); this is the
   // name we will use once the download completes.
   // May be empty if the target path hasn't yet been determined.
   virtual const base::FilePath& GetTargetFilePath() const = 0;
 
   // If the download forced a path rather than requesting name determination,
   // return the path requested.
   virtual const base::FilePath& GetForcedFilePath() const = 0;
 
+  // Get the target path that was used most recently. It could be either the
+  // forced file path, or the target file path, if any one of them is provided.
+  virtual base::FilePath GetLastUsedTargetPath() const {

[asanka, 2017/01/10 19:34:19]

= 0. But then again we shouldn't have this method at all.

[qinmin, 2017/01/10 22:06:29]

Done.

+    return base::FilePath();
+  }
+
   // Returns the file-name that should be reported to the user. If a display
   // name has been explicitly set using SetDisplayName(), this function returns
   // that display name. Otherwise returns the final target filename.
   virtual base::FilePath GetFileNameToReportUser() const = 0;
 
   // See TargetDisposition.
   virtual TargetDisposition GetTargetDisposition() const = 0;
 
   // Final hash of completely downloaded file, or partial hash of an interrupted
   // download; only valid if GetState() == COMPLETED or INTERRUPTED. If
@@ skipping 113 matching lines @@
   // return |name|. Has no effect on the final target filename.
   virtual void SetDisplayName(const base::FilePath& name) = 0;
 
   // Debug/testing -------------------------------------------------------------
   virtual std::string DebugString(bool verbose) const = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_ITEM_H_