Add FilePath to base namespace.

chrome/browser/ui/user_data_dir_dialog.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_USER_DATA_DIR_DIALOG_H_
 #define CHROME_BROWSER_UI_USER_DATA_DIR_DIALOG_H_
 
+namespace base {
 class FilePath;
+}
 
 namespace chrome {
 
 // Shows a user data directory picker dialog. The method blocks while the dialog
 // is showing. If the user picks a directory, this method returns the chosen
 // directory. |user_data_dir| is the value of the directory we were not able to
 // use.
-FilePath ShowUserDataDirDialog(const FilePath& user_data_dir);
+base::FilePath ShowUserDataDirDialog(const base::FilePath& user_data_dir);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_USER_DATA_DIR_DIALOG_H_