Introducing SavePackageId and SaveItemId as distinct IdType<...>-based types.

content/browser/download/save_item.cc

 // Copyright (c) 2012 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/download/save_item.h"
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "content/browser/download/save_file.h"
 #include "content/browser/download/save_file_manager.h"
 #include "content/browser/download/save_package.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 namespace {
 
-int GetNextSaveItemId() {
-  static int g_next_save_item_id = 0;
+SaveItemId GetNextSaveItemId() {
+  static int g_next_save_item_id = 1;
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  return g_next_save_item_id++;
+  return SaveItemId::FromUnsafeValue(g_next_save_item_id++);
 }
 
 }  // namespace
 
 // Constructor for SaveItem when creating each saving job.
 SaveItem::SaveItem(const GURL& url,
                    const Referrer& referrer,
                    SavePackage* package,
                    SaveFileCreateInfo::SaveFileSource save_source)
     : save_item_id_(GetNextSaveItemId()),
@@ skipping 89 matching lines @@
   file_name_ = full_path_.BaseName();
   has_final_name_ = true;
 }
 
 void SaveItem::SetTotalBytes(int64_t total_bytes) {
   DCHECK_EQ(0, total_bytes_);
   total_bytes_ = total_bytes;
 }
 
 }  // namespace content