[fsp] Store observed entries in preferences.

chrome/browser/chromeos/file_system_provider/fake_provided_file_system.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_FAKE_PROVIDED_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FAKE_PROVIDED_FILE_SYSTEM_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 157 matching lines @@
   // called.
   void AbortMany(const std::vector<int>& task_ids,
                  const storage::AsyncFileUtil::StatusCallback& callback);
 
   ProvidedFileSystemInfo file_system_info_;
   Entries entries_;
   OpenedFilesMap opened_files_;
   int last_file_handle_;
   base::CancelableTaskTracker tracker_;
   ObserverList<ProvidedFileSystemObserver> observers_;
+  ObservedEntries observed_entries_;
 
   base::WeakPtrFactory<FakeProvidedFileSystem> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(FakeProvidedFileSystem);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FAKE_PROVIDED_FILE_SYSTEM_H_