Move two browser-side File API unittests next to the files they cover.

content/browser/fileapi/sandbox_database_test_helper.h

-// Copyright 2014 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 CONTENT_BROWSER_FILEAPI_SANDBOX_DATABASE_TEST_HELPER_H_
-#define CONTENT_BROWSER_FILEAPI_SANDBOX_DATABASE_TEST_HELPER_H_
-
-#include <stddef.h>
-
-#include "third_party/leveldatabase/src/db/filename.h"
-
-namespace base {
-class FilePath;
-}
-
-namespace content {
-
-void CorruptDatabase(const base::FilePath& db_path,
-                     leveldb::FileType type,
-                     ptrdiff_t offset,
-                     size_t size);
-
-void DeleteDatabaseFile(const base::FilePath& db_path,
-                        leveldb::FileType type);
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_FILEAPI_SANDBOX_DATABASE_TEST_HELPER_H_