Add systeminfo.storage API implementation skeleton

chrome/browser/extensions/api/systeminfo_storage/storage_info_provider.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_STORAGE_INFO_PROVIDER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_SYSTEMINFO_STORAGE_STORAGE_INFO_PROVIDER_H_
+
+#include "chrome/common/extensions/api/experimental_systeminfo_storage.h"
+
+namespace extensions {
+namespace systeminfo {
+// Unknown storage type.
+extern const char kStorageTypeUnknown[];
+// Hard disk.
+extern const char kStorageTypeHardDisk[];
+// Removable storage, e.g. USB device, flash card reader.
+extern const char kStorageTypeRemovable[];
+}  // namespace systeminfo
+
+// An interface for retrieving storage information on different platforms.
+class StorageInfoProvider {
+ public:
+   // Return a StorageInfoProvider instance. The caller is responsible for
+   // destroying it.
+   static StorageInfoProvider* Create();
+
+   virtual ~StorageInfoProvider() {}
+
+   // Return true if succeed to get storage information, other return fasle.
+   // Should be implemented on different platforms.
+   virtual bool GetStorageInfo(
+       api::experimental_systeminfo_storage::StorageInfo* info) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_SYSTEMINFO_STORAGE_STORAGE_INFO_PROVIDER_H_