ServiceWorker: Introduce ServiceWorkerDiskCacheMigrator

content/browser/service_worker/service_worker_storage.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_storage.h"
 
 #include "base/bind_helpers.h"
 #include "base/files/file_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/sequenced_task_runner.h"
@@ skipping 1353 matching lines @@
       installing_registrations_.find(registration_id);
   if (found == installing_registrations_.end())
     return NULL;
   return found->second.get();
 }
 
 ServiceWorkerDiskCache* ServiceWorkerStorage::disk_cache() {
   if (disk_cache_)
     return disk_cache_.get();
 
-  disk_cache_.reset(new ServiceWorkerDiskCache);
+  disk_cache_ = ServiceWorkerDiskCache::CreateWithBlockFileBackend();
 
   base::FilePath path = GetDiskCachePath();
   if (path.empty()) {
     int rv = disk_cache_->InitWithMemBackend(kMaxMemDiskCacheSize,
                                              net::CompletionCallback());
     DCHECK_EQ(net::OK, rv);
     return disk_cache_.get();
   }
 
   int rv = disk_cache_->InitWithDiskBackend(
@@ skipping 426 matching lines @@
     callback.Run(SERVICE_WORKER_ERROR_FAILED);
     return;
   }
   DVLOG(1) << "Deleted ServiceWorkerDiskCache successfully.";
   ServiceWorkerMetrics::RecordDeleteAndStartOverResult(
       ServiceWorkerMetrics::DELETE_OK);
   callback.Run(SERVICE_WORKER_OK);
 }
 
 }  // namespace content