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 383 matching lines @@
   void ContinueIncognitoGetStorageCapacity(const QuotaSettings& settings);
   void DidGetStorageCapacity(
       const std::tuple<int64_t, int64_t>& total_and_available);
 
   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 std::tuple<int64_t, int64_t> CallGetVolumeInfo(
       GetVolumeInfoFn get_volume_info_fn,
       const base::FilePath& path);
   static std::tuple<int64_t, int64_t> GetVolumeInfo(const base::FilePath& path);
 
   const bool is_incognito_;
   const base::FilePath profile_path_;
 
   scoped_refptr<QuotaManagerProxy> proxy_;
@@ skipping 51 matching lines @@
 
 struct QuotaManagerDeleter {
   static void Destruct(const QuotaManager* manager) {
     manager->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_QUOTA_QUOTA_MANAGER_H_