Delete JumpListIconsOld and update revised links in every update

chrome/browser/win/jumplist_file_util.h

 // Copyright (c) 2017 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_WIN_JUMPLIST_FILE_UTIL_H_
 #define CHROME_BROWSER_WIN_JUMPLIST_FILE_UTIL_H_
 
-#include "base/files/file_path.h"
+#include "base/files/file_util.h"
 
 // Maximum number of icon files allowed to delete per jumplist update.
-const int kFileDeleteLimit = 100;
+const int kFileDeleteLimit = 60;

[grt (UTC plus 2), 2017/03/27 19:18:48]

why lower this? do metrics indicate that 100 is too much?

[chengx, 2017/03/27 20:26:08]

For users having no trouble in using Chrome, 60 and 100 make no difference. For
users who have already thousands of icons in the folder, the difference between
60 and 100 is that as of 60, it takes less time to delete icons per update, but
more times to delete them all. However, given that it is suspicious base::Delete
has no guarantee that the icons are gone even the function return value is
SUCCESS, reducing the limit from 100 to 60 may give users a litter better
experience. 

 
 // Folder delete status enumeration, used in Delete* methods below.
 // This is used for UMA. Do not delete entries, and keep in sync with
 // histograms.xml.
 enum FolderDeleteResult {
   SUCCEED = 0,
   // File name's length exceeds MAX_PATH. This shouldn't happen.
   FAIL_INVALID_FILE_PATH,
   // JumpListIcons{,Old} directories are read-only. This may heppen.
   FAIL_READ_ONLY_DIRECTORY,
   // Since JumpListIcons{,Old} are directories. This shouldn't happen.
   FAIL_DELETE_SINGLE_FILE,
   // JumpListIcons{,Old} should not have sub-directories, so this shouldn't
   // happen. If this happens, the root cause must be found.
   FAIL_SUBDIRECTORY_EXISTS,
   // Delete maximum files allowed succeeds. However, in the process of deleting
   // these files, it fails to delete some other files. This may happen.
   FAIL_DELETE_MAX_FILES_WITH_ERRORS,
   // Fail to delete maximum files allowed when the maximum attempt failures
   // are hit. This may heppen.
   FAIL_MAX_DELETE_FAILURES,
   // Fail to remove the raw empty directory. This may happen.
   FAIL_REMOVE_RAW_DIRECTORY,
   // Add new items before this one, always keep this one at the end.
   END
 };
 
-// An enumeration indicating if a directory is empty or not.
+// An enumeration indicating if a directory exists or if it is empty or not.
 // This is used for UMA. Do not delete entries, and keep in sync with
 // histograms.xml.
-enum DirectoryEmptyStatus {
+enum DirectoryStatus {
   EMPTY = 0,
   NON_EMPTY,
+  NON_EXIST,
   // Add new items before this one, always keep this one at the end.
-  EMPTY_STATUS_END
+  DIRECTORY_STATUS_END
 };
 
 // This method is similar to base::DeleteFileRecursive in
 // file_util_win.cc with the following differences.
 // 1) It has an input parameter |max_file_deleted| to specify the maximum files
 //    allowed to delete as well as the maximum attempt failures allowd per run.
 // 2) It deletes only the files in |path|. All subdirectories in |path| are
 //    untouched but are considered as attempt failures.
 // 3) Detailed delete status is returned.
 FolderDeleteResult DeleteFiles(const base::FilePath& path,
@@ skipping 14 matching lines @@
 // This method firstly calls DeleteDirectoryContent() to delete the contents in
 // |path|. If |path| is empty after the call, it is removed.
 FolderDeleteResult DeleteDirectory(const base::FilePath& path,
                                    int max_file_deleted);
 
 // Deletes the directory at |path| and records the result to UMA.
 void DeleteDirectoryAndLogResults(const base::FilePath& path,
                                   int max_file_deleted);
 
 #endif  // CHROME_BROWSER_WIN_JUMPLIST_FILE_UTIL_H_