[fsp] Store observed entries in preferences.

chrome/browser/chromeos/file_system_provider/fake_provided_file_system.cc

 // 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.
 
 #include "chrome/browser/chromeos/file_system_provider/fake_provided_file_system.h"
 
 #include "base/files/file.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "net/base/io_buffer.h"
 
@@ skipping 330 matching lines @@
     const {
   return file_system_info_;
 }
 
 RequestManager* FakeProvidedFileSystem::GetRequestManager() {
   NOTREACHED();
   return NULL;
 }
 
 ObservedEntries* FakeProvidedFileSystem::GetObservedEntries() {
-  NOTREACHED();
-  return NULL;
+  return &observed_entries_;
 }
 
 void FakeProvidedFileSystem::AddObserver(ProvidedFileSystemObserver* observer) {
   DCHECK(observer);
   observers_.AddObserver(observer);
 }
 
 void FakeProvidedFileSystem::RemoveObserver(
     ProvidedFileSystemObserver* observer) {
   DCHECK(observer);
@@ skipping 39 matching lines @@
     const std::vector<int>& task_ids,
     const storage::AsyncFileUtil::StatusCallback& callback) {
   for (size_t i = 0; i < task_ids.size(); ++i) {
     tracker_.TryCancel(task_ids[i]);
   }
   callback.Run(base::File::FILE_OK);
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos