Print Preview: Associating preview requests and responses using an identifier

chrome/browser/ui/webui/print_preview_ui.h

 // Copyright (c) 2011 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_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_
 #pragma once
 
 #include <string>
 
@@ skipping 28 matching lines @@
   void OnDidGetPreviewPageCount(int page_count);
 
   // Notify the Web UI that the 0-based page |page_number| has been rendered.
   void OnDidPreviewPage(int page_number);
 
   // Notify the Web UI renderer that preview data is available.
   // |expected_pages_count| specifies the total number of pages.
   // |job_title| is the title of the page being previewed.
   // |modifiable| indicates if the preview can be rerendered with different
   // print settings.
+  // |preview_request_id| indicates wich request resulted in this response.
   void OnPreviewDataIsAvailable(int expected_pages_count,
                                 const string16& job_title,
-                                bool modifiable);
+                                bool modifiable,
+                                int preview_request_id);
 
   // Notify the Web UI that a navigation has occurred in this tab. This is the
   // last chance to communicate with the source tab before the assocation is
   // erased.
   void OnNavigation();
 
   // Notify the Web UI that the print preview failed to render.
   void OnPrintPreviewFailed();
 
   // Notify the Web UI that the print preview request has been cancelled.
@@ skipping 25 matching lines @@
   // Weak pointer to the WebUI handler.
   PrintPreviewHandler* handler_;
 
   // The number of print preview requests in flight.
   uint32 request_count_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_