Adds the ability for save dialogs to take a default extension....

chrome/browser/download/download_manager.cc

 // Copyright (c) 2006-2008 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 <time.h>
 
 #include "chrome/browser/download/download_manager.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 590 matching lines @@
     // We must ask the user for the place to put the download.
     if (!select_file_dialog_.get())
       select_file_dialog_ = SelectFileDialog::Create(this);
 
     TabContents* contents = tab_util::GetTabContentsByID(
         info->render_process_id, info->render_view_id);
     HWND owning_hwnd =
         contents ? GetAncestor(contents->GetContainerHWND(), GA_ROOT) : NULL;
     select_file_dialog_->SelectFile(SelectFileDialog::SELECT_SAVEAS_FILE,
                                     std::wstring(), info->suggested_path,
+                                    std::wstring(), std::wstring(),
                                     owning_hwnd, info);
   } else {
     // No prompting for download, just continue with the suggested name.
     ContinueStartDownload(info, info->suggested_path);
   }
 }
 
 void DownloadManager::ContinueStartDownload(DownloadCreateInfo* info,
                                             const std::wstring& target_path) {
   scoped_ptr<DownloadCreateInfo> infop(info);
@@ skipping 705 matching lines @@
   std::vector<DownloadItem*> searched_downloads;
   for (std::vector<int64>::iterator it = results->begin();
        it != results->end(); ++it) {
     DownloadMap::iterator dit = downloads_.find(*it);
     if (dit != downloads_.end())
       searched_downloads.push_back(dit->second);
   }
 
   requestor->SetDownloads(searched_downloads);
 }