Files.app: Provide detailed change information on onDirectoryChanged event

chrome/browser/chromeos/drive/change_list_loader_observer.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_CHROMEOS_DRIVE_CHANGE_LIST_LOADER_OBSERVER_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_CHANGE_LIST_LOADER_OBSERVER_H_
 
 namespace base {
 class FilePath;
 }  // namespace base
 
 namespace drive {
+class FileChange;
 namespace internal {
 
 // Interface for classes that need to observe events from ChangeListLoader.
 // All events are notified on UI thread.
 class ChangeListLoaderObserver {
  public:
-  // Triggered when a content of a directory has been changed.
-  // |directory_path| is a virtual directory path representing the
-  // changed directory.
-  virtual void OnDirectoryChanged(const base::FilePath& directory_path) {}
+  // Triggered when the content of a directory is reloaded. The content may
+  // changed.  |directory_path| is a virtual directory path representing the
+  // reloaded directory.
+  virtual void OnDirectoryReloaded(const base::FilePath& directory_path) {}
+
+  // Triggered when content(s) in drive has been changed.
+  virtual void OnFileChanged(const FileChange& changed_files) {}
 
   // Triggered when loading from the server is complete.
   virtual void OnLoadFromServerComplete() {}
 
   // Triggered when loading is complete for the first time, either from the
   // the server or the cache. To be precise, for the latter case, we do not
   // load anything from the cache. We just check that the resource metadata
   // is stored locally thus can be used.
   virtual void OnInitialLoadComplete() {}
 
  protected:
   virtual ~ChangeListLoaderObserver() {}
 };
 
 }  // namespace internal
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_CHANGE_LIST_LOADER_OBSERVER_H_