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

content/browser/download/save_types.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DOWNLOAD_SAVE_TYPES_H_
 #define CONTENT_BROWSER_DOWNLOAD_SAVE_TYPES_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/files/file_path.h"
+#include "content/common/id_type.h"
 #include "url/gurl.h"
 
 namespace content {
 
+class SavePackage;
+using SavePackageId = IdType32<SavePackage>;
+
+class SaveItem;
+using SaveItemId = IdType32<SaveItem>;
+
 // Map from save_item_id into final file path.
-typedef std::map<int, base::FilePath> FinalNamesMap;
+using FinalNamesMap = std::map<SaveItemId, base::FilePath>;
 
 // This structure is used to handle and deliver some info
 // when processing each save item job.
 struct SaveFileCreateInfo {
   enum SaveFileSource {
     // This type indicates the source is not set.
     SAVE_FILE_FROM_UNKNOWN = -1,
     // This type indicates the save item needs to be retrieved from the network.
     SAVE_FILE_FROM_NET = 0,
     // This type indicates the save item needs to be retrieved from serializing
     // DOM.
     SAVE_FILE_FROM_DOM,
     // This type indicates the save item needs to be retrieved from local file
     // system.
     SAVE_FILE_FROM_FILE
   };
 
   // Constructor for SAVE_FILE_FROM_DOM and/or SAVE_FILE_FROM_FILE.
   SaveFileCreateInfo(const base::FilePath& path,
                      const GURL& url,
-                     int save_item_id,
-                     int save_package_id,
+                     SaveItemId save_item_id,
+                     SavePackageId save_package_id,
                      int render_process_id,
                      int render_frame_routing_id,
                      SaveFileSource save_source);
 
   // Constructor for SAVE_FILE_FROM_NET case.
   SaveFileCreateInfo(const GURL& url,
                      const GURL& final_url,
-                     int save_item_id,
-                     int save_package_id,
+                     SaveItemId save_item_id,
+                     SavePackageId save_package_id,
                      int render_process_id,
                      int render_frame_routing_id,
                      int request_id,
                      const std::string& content_disposition,
                      int64_t total_bytes);
 
   ~SaveFileCreateInfo();
 
   // SaveItem fields.
   // The local file path of saved file.
   base::FilePath path;
   // Original URL of the saved resource.
   GURL url;
   // Final URL of the saved resource since some URL might be redirected.
   GURL final_url;
   // The unique identifier of SaveItem object associated with this job.
-  int save_item_id;
+  SaveItemId save_item_id;
   // ID of SavePackage object.
-  int save_package_id;
+  SavePackageId save_package_id;
   // IDs for looking up the contents we are associated with.
   int render_process_id;
   int render_frame_routing_id;
   // Handle for informing the ResourceDispatcherHost of a UI based cancel.
   int request_id;
   // Disposition info from HTTP response.
   std::string content_disposition;
   // Total bytes of saved file.
   int64_t total_bytes;
   // Source type of saved file.
   SaveFileSource save_source;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_SAVE_TYPES_H_