Add an identity (id) to system drag & drop.

chrome/common/render_messages.h

 // Copyright (c) 2006-2008 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 CHROME_COMMON_RENDER_MESSAGES_H_
 #define CHROME_COMMON_RENDER_MESSAGES_H_
 
 #include <string>
 #include <vector>
 #include <map>
@@ skipping 1521 matching lines @@
   static void Log(const param_type& p, std::wstring* l) {
     l->append(L"<WebPreferences>");
   }
 };
 
 // Traits for WebDropData
 template <>
 struct ParamTraits<WebDropData> {
   typedef WebDropData param_type;
   static void Write(Message* m, const param_type& p) {
+    WriteParam(m, p.identity);
     WriteParam(m, p.url);
     WriteParam(m, p.url_title);
     WriteParam(m, p.file_extension);
     WriteParam(m, p.filenames);
     WriteParam(m, p.plain_text);
     WriteParam(m, p.text_html);
     WriteParam(m, p.html_base_url);
     WriteParam(m, p.file_description_filename);
     WriteParam(m, p.file_contents);
   }
   static bool Read(const Message* m, void** iter, param_type* p) {
     return
+      ReadParam(m, iter, &p->identity) &&
       ReadParam(m, iter, &p->url) &&
       ReadParam(m, iter, &p->url_title) &&
       ReadParam(m, iter, &p->file_extension) &&
       ReadParam(m, iter, &p->filenames) &&
       ReadParam(m, iter, &p->plain_text) &&
       ReadParam(m, iter, &p->text_html) &&
       ReadParam(m, iter, &p->html_base_url) &&
       ReadParam(m, iter, &p->file_description_filename) &&
       ReadParam(m, iter, &p->file_contents);
   }
@@ skipping 178 matching lines @@
 };
 
 
 }  // namespace IPC
 
 
 #define MESSAGES_INTERNAL_FILE "chrome/common/render_messages_internal.h"
 #include "chrome/common/ipc_message_macros.h"
 
 #endif  // CHROME_COMMON_RENDER_MESSAGES_H_