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

base/path_service.cc

 // 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.
 
 #include "base/path_service.h"
 
 #ifdef OS_WIN
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
@@ skipping 187 matching lines @@
 
   if (path.empty())
     return false;
 
   AddToCache(key, path);
 
   *result = path;
   return true;
 }
 
+void PathService::Set(int key, const FilePath& path) {
+  AddToCache(key, path);
+}
+
 bool PathService::Override(int key, const FilePath& path) {
   PathData* path_data = GetPathData();
   DCHECK(path_data);
   DCHECK_GT(key, base::DIR_CURRENT) << "invalid path key";
 
   FilePath file_path = path;
 
   // Make sure the directory exists. We need to do this before we translate
   // this to the absolute path because on POSIX, AbsolutePath fails if called
   // on a non-existant path.
@@ skipping 41 matching lines @@
   p = new Provider;
   p->is_static = false;
   p->func = func;
   p->next = path_data->providers;
 #ifndef NDEBUG
   p->key_start = key_start;
   p->key_end = key_end;
 #endif
   path_data->providers = p;
 }