[Offline Pages] Make new archives have random file names.

components/offline_pages/core/offline_page_model_impl.cc

 // Copyright 2016 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 "components/offline_pages/core/offline_page_model_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 690 matching lines @@
     DeletePendingArchiver(archiver);
     return;
   }
   OfflinePageItem offline_page_item(url, offline_id, save_page_params.client_id,
                                     file_path, file_size, start_time);
   offline_page_item.title = title;
   offline_page_item.original_url = save_page_params.original_url;
   store_->AddOfflinePage(offline_page_item,
                          base::Bind(&OfflinePageModelImpl::OnAddOfflinePageDone,
                                     weak_ptr_factory_.GetWeakPtr(), archiver,
-                                    callback, offline_page_item));
+                                    file_path, callback, offline_page_item));
 }
 
 void OfflinePageModelImpl::OnAddOfflinePageDone(
     OfflinePageArchiver* archiver,
+    const base::FilePath& file_path,
     const SavePageCallback& callback,
     const OfflinePageItem& offline_page,
     ItemActionStatus status) {
   SavePageResult result;
 
   if (status == ItemActionStatus::SUCCESS) {
     offline_pages_[offline_page.offline_id] = offline_page;
     result = SavePageResult::SUCCESS;
     ReportPageHistogramAfterSave(policy_controller_.get(), offline_pages_,
                                  offline_page, GetCurrentTime());
     offline_event_logger_.RecordPageSaved(
         offline_page.client_id.name_space, offline_page.url.spec(),
         std::to_string(offline_page.offline_id));
   } else if (status == ItemActionStatus::ALREADY_EXISTS) {
+    // Remove the orphaned archive.  No callback necessary.
+    archive_manager_->DeleteArchive(file_path, base::Bind([](bool) {}));
     result = SavePageResult::ALREADY_EXISTS;
   } else {
     result = SavePageResult::STORE_FAILURE;
   }
   InformSavePageDone(callback, result, offline_page.client_id,
                      offline_page.offline_id);
   if (result == SavePageResult::SUCCESS) {
     DeleteExistingPagesWithSameURL(offline_page);
   } else {
     PostClearStorageIfNeededTask(false /* delayed */);
@@ skipping 345 matching lines @@
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, task);
 }
 
 base::Time OfflinePageModelImpl::GetCurrentTime() const {
   return testing_clock_ ? testing_clock_->Now() : base::Time::Now();
 }
 
 }  // namespace offline_pages