[fsp] Pass proper data to Notify().

chrome/browser/chromeos/file_system_provider/provided_file_system_observer.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_PROVIDED_FILE_SYSTEM_OBSERVER_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_OBSERVER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 33 matching lines @@
     ChildChange();
     ~ChildChange();
 
     base::FilePath entry_path;
     ChangeType change_type;
   };
 
   // Called when an observed entry is changed, including removals. |callback|
   // *must* be called after the entry change is handled. Once all observers
   // call the callback, the tag will be updated and OnObservedEntryTagUpdated
-  // called.
+  // called. The reference to |child_changes| is valid at least as long as
+  // |callback|.
   virtual void OnObservedEntryChanged(
       const ProvidedFileSystemInfo& file_system_info,
       const base::FilePath& observed_path,
       ChangeType change_type,
       const ChildChanges& child_changes,
       const base::Closure& callback) = 0;
 
   // Called when tag value is updated for the observed entry.
   virtual void OnObservedEntryTagUpdated(
       const ProvidedFileSystemInfo& file_system_info,
       const base::FilePath& observed_path) = 0;
 
   // Called when list of observed entries is changed.
   virtual void OnObservedEntryListChanged(
       const ProvidedFileSystemInfo& file_system_info) = 0;
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_PROVIDED_FILE_SYSTEM_OBSERVER_H_