[fsp] Add throttling for number of opened files.

chrome/browser/chromeos/file_system_provider/abort_callback.h

+// Copyright 2015 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_CHROMEOS_FILE_SYSTEM_PROVIDER_ABORT_CALLBACK_H_
+#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_ABORT_CALLBACK_H_
+
+#include "base/callback.h"
+#include "storage/browser/fileapi/async_file_util.h"
+
+namespace chromeos {
+namespace file_system_provider {
+
+typedef base::Callback<void(
+    const storage::AsyncFileUtil::StatusCallback& callback)> AbortCallback;
+
+}  // namespace file_system_provider
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_ABORT_CALLBACK_H_