Don't keep file system directories around if they contain unrelated files.

chrome/browser/browsing_data_remover.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_BROWSING_DATA_REMOVER_H_
 #define CHROME_BROWSER_BROWSING_DATA_REMOVER_H_
 #pragma once
 
 #include <set>
 
@@ skipping 235 matching lines @@
   // system: AppCache, Databases, FileSystems.
   void ClearQuotaManagedDataOnIOThread();
 
   // Callback to respond to QuotaManager::GetOriginsModifiedSince, which is the
   // core of 'ClearQuotaManagedDataOnIOThread'.
   void OnGotQuotaManagedOrigins(const std::set<GURL>& origins,
                                 quota::StorageType type);
 
   // Callback responding to deletion of a single quota managed origin's
   // persistent data
-  void OnQuotaManagedOriginDeletion(quota::QuotaStatusCode);
+  void OnQuotaManagedOriginDeletion(const GURL& origin,
+                                    quota::StorageType type,
+                                    quota::QuotaStatusCode);
 
   // Called to check whether all temporary and persistent origin data that
   // should be deleted has been deleted. If everything's good to go, invokes
   // OnQuotaManagedDataDeleted on the UI thread.
   void CheckQuotaManagedDataDeletionStatus();
 
   // Completion handler that runs on the UI thread once persistent data has been
   // deleted. Updates the waiting flag and invokes NotifyAndDeleteIfDone.
   void OnQuotaManagedDataDeleted();
 
@@ skipping 90 matching lines @@
 
   ObserverList<Observer> observer_list_;
 
   // Used if we need to clear history.
   CancelableRequestConsumer request_consumer_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataRemover);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_REMOVER_H_