When the download folder does not exist, change the download folder to a user's "Downloads"

chrome/browser/download/save_package.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_DOWNLOAD_SAVE_PACKAGE_H_
 #define CHROME_BROWSER_DOWNLOAD_SAVE_PACKAGE_H_
 #pragma once
 
 #include <queue>
 #include <string>
@@ skipping 106 matching lines @@
 
   // Show or Open a saved page via the Windows shell.
   void ShowDownloadInShell();
 
   bool canceled() const { return user_canceled_ || disk_error_occurred_; }
   bool finished() const { return finished_; }
   SavePackageType save_type() const { return save_type_; }
   int tab_id() const { return tab_id_; }
   int id() const { return unique_id_; }
 
+  // Determines the saved file name based on the information of the
+  // current page, and then starts to download the page. This method
+  // runs in the background and may finish asynchronously after this
+  // method returns.
   void GetSaveInfo();
 
   // Statics -------------------------------------------------------------------
 
   // Used to disable prompting the user for a directory/filename of the saved
   // web page.  This is available for testing.
   static void SetShouldPromptUser(bool should_prompt);
 
   // Check whether we can do the saving page operation for the specified URL.
   static bool IsSavableURL(const GURL& url);
@@ skipping 52 matching lines @@
   void GetSerializedHtmlDataForCurrentPageWithLocalLinks();
 
   SaveItem* LookupItemInProcessBySaveId(int32 save_id);
   void PutInProgressItemToSavedMap(SaveItem* save_item);
 
   // Retrieves the URL to be saved from tab_contents_ variable.
   GURL GetUrlToBeSaved();
 
   void CreateDirectoryOnFileThread(const FilePath& website_save_dir,
                                    const FilePath& download_save_dir,
+                                   const FilePath& default_download_dir,
                                    const std::string& mime_type);
   void ContinueGetSaveInfo(const FilePath& suggested_path,
                            bool can_save_as_complete);
   void ContinueSave(const FilePath& final_name, int index);
 
   void OnReceivedSavableResourceLinksForCurrentPage(
       const std::vector<GURL>& resources_list,
       const std::vector<GURL>& referrers_list,
       const std::vector<GURL>& frames_list);
 
@@ skipping 109 matching lines @@
   friend class SavePackageTest;
   FRIEND_TEST_ALL_PREFIXES(SavePackageTest, TestSuggestedSaveNames);
   FRIEND_TEST_ALL_PREFIXES(SavePackageTest, TestLongSafePureFilename);
 
   ScopedRunnableMethodFactory<SavePackage> method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SavePackage);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_SAVE_PACKAGE_H_