Update ReplaceIllegalCharactersInPath to handle quirks in HFS+ and VFS

content/browser/download/save_package.cc

 // 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.
 
 #include "content/browser/download/save_package.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 1224 matching lines @@
   }
 
   // Ask user for getting final saving name.
   name_with_proper_ext = EnsureMimeExtension(name_with_proper_ext,
                                              contents_mime_type);
   // Adjust extension for complete types.
   if (can_save_as_complete)
     name_with_proper_ext = EnsureHtmlExtension(name_with_proper_ext);
 
   base::FilePath::StringType file_name = name_with_proper_ext.value();
-  base::i18n::ReplaceIllegalCharactersInPath(&file_name, ' ');
+  base::i18n::ReplaceIllegalCharactersInPath(&file_name, '_');
   return base::FilePath(file_name);
 }
 
 base::FilePath SavePackage::EnsureHtmlExtension(const base::FilePath& name) {
   // If the file name doesn't have an extension suitable for HTML files,
   // append one.
   base::FilePath::StringType ext = name.Extension();
   if (!ext.empty())
     ext.erase(ext.begin());  // Erase preceding '.'.
   std::string mime_type;
@@ skipping 178 matching lines @@
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
   DCHECK(download_manager_);
 
   download_manager_->OnSavePackageSuccessfullyFinished(download_);
   StopObservation();
 }
 
 }  // namespace content