Pass Callback by value on PostTaskAndReply family

storage/browser/quota/quota_manager.h

 // Copyright 2013 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 STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_
 #define STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_
 
 #include <stdint.h>
 
 #include <deque>
@@ skipping 431 matching lines @@
                                          QuotaStatusCode status,
                                          int64_t quota_unused);
   void DidInitializeTemporaryOriginsInfo(bool success);
   void DidGetAvailableSpace(int64_t space);
   void DidDatabaseWork(bool success);
 
   void DeleteOnCorrectThread() const;
 
   void PostTaskAndReplyWithResultForDBThread(
       const tracked_objects::Location& from_here,
-      const base::Callback<bool(QuotaDatabase*)>& task,
-      const base::Callback<void(bool)>& reply);
+      base::Callback<bool(QuotaDatabase*)> task,
+      base::Callback<void(bool)> reply);
 
   static int64_t CallGetAmountOfFreeDiskSpace(
       GetVolumeInfoFn get_vol_info_fn,
       const base::FilePath& profile_path);
   static bool GetVolumeInfo(const base::FilePath& path,
                             uint64_t* available_space,
                             uint64_t* total_size);
 
   const bool is_incognito_;
   const base::FilePath profile_path_;
@@ skipping 52 matching lines @@
 
 struct QuotaManagerDeleter {
   static void Destruct(const QuotaManager* manager) {
     manager->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_