Add systeminfo.storage API implementation skeleton

chrome/browser/extensions/api/systeminfo_storage/systeminfo_storage_api.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_EXTENSIONS_API_SYSTEMINFO_STORAGE_SYSTEMINFO_STORAGE_API_H_
+#define CHROME_BROWSER_EXTENSIONS_API_SYSTEMINFO_STORAGE_SYSTEMINFO_STORAGE_API_H_
+
+#include "chrome/browser/extensions/extension_function.h"
+
+namespace extensions {
+
+// Implement systeminfo.storage.get API. It is an asynchronous call relative to
+// browser UI thread.
+class SysteminfoStorageGetFunction : public AsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.systeminfo.storage.get");
+
+  SysteminfoStorageGetFunction();
+
+  virtual ~SysteminfoStorageGetFunction();
+
+ private:
+  virtual bool RunImpl() OVERRIDE;
+
+  // Called on FILE thread to get storage information
+  void WorkOnFileThread();
+
+  // Respond the result back to UI thread
+  void RespondOnUIThread(bool success);
+};  // SysteminfoStorageGetFunction
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_SYSTEMINFO_STORAGE_SYSTEMINFO_STORAGE_API_H_