[fsp] Separate logic for saving/restoring state to a separate class.

chrome/browser/chromeos/file_system_provider/registry_interface.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 CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REGISTRY_INTERFACE_H_
+#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REGISTRY_INTERFACE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/chromeos/file_system_provider/observed_entry.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
+
+namespace chromeos {
+namespace file_system_provider {
+
+// Remembers and restores file systems in a persistent storage.
+class RegistryInterface {
+ public:
+  struct RestoredFileSystem;
+
+  // List of file systems together with their observed entries to be remounted.
+  typedef std::vector<RestoredFileSystem> RestoredFileSystems;
+
+  // Information about a file system to be restored.
+  struct RestoredFileSystem {
+    RestoredFileSystem();
+    ~RestoredFileSystem();
+
+    std::string extension_id;
+    MountOptions options;
+    ObservedEntries observed_entries;
+  };
+
+  virtual ~RegistryInterface();
+
+  // Remembers the file system in preferences, in order to remount after a
+  // reboot.
+  virtual void RememberFileSystem(
+      const ProvidedFileSystemInfo& file_system_info,
+      const ObservedEntries& observed_entries) = 0;
+
+  // Removes the file system from preferences, so it is not remounmted anymore
+  // after a reboot.
+  virtual void ForgetFileSystem(const std::string& extension_id,
+                                const std::string& file_system_id) = 0;
+
+  // Restores from preferences file systems mounted previously by the
+  // |extension_id| providing extension. The returned list should be used to
+  // remount them.
+  virtual scoped_ptr<RestoredFileSystems> RestoreFileSystems(
+      const std::string& extension_id) = 0;
+
+  // Updates a tag for the specified observed entry.
+  virtual void UpdateObservedEntryTag(
+      const ProvidedFileSystemInfo& file_system_info,
+      const ObservedEntry& observed_entry) = 0;
+};
+
+}  // namespace file_system_provider
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REGISTRY_INTERFACE_H_