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

chrome/browser/download/download_prefs.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 "chrome/browser/download/download_prefs.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
@@ skipping 43 matching lines @@
                             "",
                             PrefService::UNSYNCABLE_PREF);
   prefs->RegisterBooleanPref(prefs::kDownloadDirUpgraded,
                              false,
                              PrefService::UNSYNCABLE_PREF);
   prefs->RegisterIntegerPref(prefs::kSaveFileType,
                              SavePackage::SAVE_AS_COMPLETE_HTML,
                              PrefService::UNSYNCABLE_PREF);
 
   // The default download path is userprofile\download.
-  const FilePath& default_download_path =
-      download_util::GetDefaultDownloadDirectory();
+  FilePath default_download_path =
+      download_util::DefaultDownloadDirectory::Get();
   prefs->RegisterFilePathPref(prefs::kDownloadDefaultDirectory,
                               default_download_path,
                               PrefService::UNSYNCABLE_PREF);
 
 #if defined(OS_CHROMEOS)
   // Ensure that the download directory specified in the preferences exists.
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       NewRunnableFunction(&file_util::CreateDirectory, default_download_path));
 #endif  // defined(OS_CHROMEOS)
@@ skipping 75 matching lines @@
     extensions.erase(extensions.size() - 1);
 
   prefs_->SetString(prefs::kDownloadExtensionsToOpen, extensions);
 }
 
 bool DownloadPrefs::AutoOpenCompareFunctor::operator()(
     const FilePath::StringType& a,
     const FilePath::StringType& b) const {
   return FilePath::CompareLessIgnoreCase(a, b);
 }