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

chrome/browser/chromeos/file_system_provider/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/provided_file_system.h"
 
 #include <vector>
 
 #include "base/debug/trace_event.h"
 #include "base/files/file.h"
@@ skipping 458 matching lines @@
                                  weak_ptr_factory_.GetWeakPtr(),
                                  observed_path,
                                  change_type,
                                  base::Passed(&child_changes),
                                  it->second.last_tag,
                                  tag)));
 
   FOR_EACH_OBSERVER(ProvidedFileSystemObserver,
                     observers_,
                     OnObservedEntryChanged(file_system_info_,
-                                           observed_path,
+                                           it->second,
                                            change_type,
                                            child_changes_ref,
                                            auto_updater->CreateCallback()));
 
   return true;
 }
 
 base::WeakPtr<ProvidedFileSystemInterface> ProvidedFileSystem::GetWeakPtr() {
   return weak_ptr_factory_.GetWeakPtr();
 }
@@ skipping 52 matching lines @@
     return;
 
   // It's illegal to provide a tag which is not unique. As for now only an error
   // message is printed, but we may want to pass the error to the providing
   // extension. TODO(mtomasz): Consider it.
   if (!tag.empty() && tag == it->second.last_tag)
     LOG(ERROR) << "Tag specified, but same as the previous one.";
 
   it->second.last_tag = tag;
 
-  FOR_EACH_OBSERVER(
-      ProvidedFileSystemObserver,
-      observers_,
-      OnObservedEntryTagUpdated(file_system_info_, observed_path, tag));
+  FOR_EACH_OBSERVER(ProvidedFileSystemObserver,
+                    observers_,
+                    OnObservedEntryTagUpdated(file_system_info_, it->second));
 
   // If the observed entry is deleted, then unobserve it.
   if (change_type == ProvidedFileSystemObserver::DELETED)
     UnobserveEntry(observed_path, base::Bind(&EmptyStatusCallback));
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos