[Resumption 9/11] Handle filename determination for resumed downloads.

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 137 matching lines @@
 
   // Show the download via the OS shell.
   virtual void ShowDownloadInShell() = 0;
 
   // State accessors -----------------------------------------------------------
 
   virtual int32 GetId() const = 0;
   virtual DownloadId GetGlobalId() const = 0;
   virtual DownloadState GetState() const = 0;
 
-  // Only valid if |GetState() == DownloadItem::INTERRUPTED|.
+  // Returns the most recent interrupt reason for this download. Returns
+  // DOWNLOAD_INTERRUPT_REASON_NONE if there is no previous interrupt reason.
+  // Cancelled downloads return DOWNLOAD_INTERRUPT_REASON_USER_CANCELLED. If
+  // the download was resumed, then the return value is the interrupt reason
+  // prior to resumption.
   virtual DownloadInterruptReason GetLastReason() const = 0;
 
   virtual bool IsPaused() const = 0;
   virtual bool IsTemporary() const = 0;
 
   // Returns true if the download can be resumed. A download can be resumed if
   // an in-progress download was paused or if an interrupted download requires
   // user-interaction to resume.
   virtual bool CanResume() const = 0;
 
@@ skipping 154 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_