Make FileManagerDialog::SelectFileImpl() properly accept simple filenames as default path.

chrome/browser/ui/views/file_manager_dialog.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/ui/views/file_manager_dialog.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/extensions/extension_file_browser_private_api.h"
@@ skipping 181 matching lines @@
       BrowserList::FindBrowserWithWindow(owner_window) :
       BrowserList::GetLastActive());
   if (!owner_browser) {
     NOTREACHED() << "Can't find owning browser";
     return;
   }
 
   FilePath virtual_path;
   if (!FileManagerUtil::ConvertFileToRelativeFileSystemPath(
           owner_browser->profile(), default_path, &virtual_path)) {
-    virtual_path = FilePath();
+    virtual_path = default_path.BaseName();
   }
 
   hasMultipleFileTypeChoices_ =
       file_types ? file_types->extensions.size() > 1 : true;
 
   GURL file_browser_url = FileManagerUtil::GetFileBrowserUrlWithParams(
       type, title, virtual_path, file_types, file_type_index,
       default_extension);
   TabContentsWrapper* tab = owner_browser->GetSelectedTabContentsWrapper();
   ExtensionDialog* dialog = ExtensionDialog::Show(file_browser_url,
       owner_browser, tab->tab_contents(),
       kFileManagerWidth, kFileManagerHeight,
       this /* ExtensionDialog::Observer */);
   if (!dialog) {
     LOG(ERROR) << "Unable to create extension dialog";
     return;
   }
 
   // Connect our listener to FileDialogFunction's per-tab callbacks.
   int32 tab_id = (tab ? tab->restore_tab_helper()->session_id().id() : 0);
   AddPending(tab_id);
 
   extension_dialog_ = dialog;
   params_ = params;
   tab_id_ = tab_id;
   owner_window_ = owner_window;
 }