Don't prematurely delete script resources when registration is deleted

content/browser/service_worker/service_worker_database.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_database.h"
 
 #include <string>
 
 #include "base/file_util.h"
 #include "base/location.h"
@@ skipping 580 matching lines @@
   registration.last_update_check = time;
 
   leveldb::WriteBatch batch;
   PutRegistrationDataToBatch(registration, &batch);
   return WriteBatch(&batch);
 }
 
 ServiceWorkerDatabase::Status ServiceWorkerDatabase::DeleteRegistration(
     int64 registration_id,
     const GURL& origin,
+    int64* version_id,
     std::vector<int64>* newly_purgeable_resources) {
   DCHECK(sequence_checker_.CalledOnValidSequencedThread());
   Status status = LazyOpen(false);
   if (IsNewOrNonexistentDatabase(status))
     return STATUS_OK;
   if (status != STATUS_OK)
     return status;
   if (!origin.is_valid())
     return STATUS_ERROR_FAILED;
 
@@ skipping 12 matching lines @@
     batch.Delete(CreateUniqueOriginKey(origin));
   }
 
   // Delete a registration specified by |registration_id|.
   batch.Delete(CreateRegistrationKey(registration_id, origin));
 
   // Delete resource records associated with the registration.
   for (std::vector<RegistrationData>::const_iterator itr =
            registrations.begin(); itr != registrations.end(); ++itr) {
     if (itr->registration_id == registration_id) {
+      *version_id = itr->version_id;
       status = DeleteResourceRecords(
           itr->version_id, newly_purgeable_resources, &batch);
       if (status != STATUS_OK)
         return status;
       break;
     }
   }
 
   return WriteBatch(&batch);
 }
@@ skipping 461 matching lines @@
     const tracked_objects::Location& from_here,
     Status status) {
   if (status != ServiceWorkerDatabase::STATUS_OK)
     Disable(from_here, status);
   UMA_HISTOGRAM_ENUMERATION(kWriteResultHistogramLabel,
                             status,
                             ServiceWorkerDatabase::STATUS_ERROR_MAX);
 }
 
 }  // namespace content