Add FilePath to base namespace.

webkit/fileapi/file_system_database_test_helper.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 WEBKIT_FILEAPI_FILE_SYSTEM_DATABASE_TEST_HELPER_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_DATABASE_TEST_HELPER_H_
 
 #include <cstddef>
 
 #include "third_party/leveldatabase/src/db/filename.h"
 
+namespace base {
 class FilePath;
+}
 
 namespace fileapi {
 
-void CorruptDatabase(const FilePath& db_path,
+void CorruptDatabase(const base::FilePath& db_path,
                      leveldb::FileType type,
                      ptrdiff_t offset,
                      size_t size);
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_DATABASE_TEST_HELPER_H_