Print Preview: Fixing behavior of event listeners.

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 25 matching lines @@
   // Clear the existing print preview data.
   void ClearAllPreviewData();
 
   // Notify the Web UI that there is a print preview request.
   // There should be a matching call to OnPreviewDataIsAvailable() or
   // OnPrintPreviewFailed().
   void OnPrintPreviewRequest();
 
   // Notify the Web UI that the print preview will have |page_count| pages.
   // |is_modifiable| indicates if the preview can be rerendered with different
-  // print settings.
+  // print settings. |preview_request_id| indicates wich request resulted in
+  // this response.
   void OnDidGetPreviewPageCount(int document_cookie_,
                                 int page_count,
-                                bool is_modifiable);
+                                bool is_modifiable,
+                                int preview_request_id);
 
   // Notify the Web UI that the 0-based page |page_number| has been rendered.
-  void OnDidPreviewPage(int page_number);
+  // |preview_request_id| indicates wich request resulted in this response.
+  void OnDidPreviewPage(int page_number, int preview_request_id);
 
   // 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.
   // |preview_request_id| indicates wich request resulted in this response.
   void OnPreviewDataIsAvailable(int expected_pages_count,
                                 const string16& job_title,
                                 int preview_request_id);
 
   void OnReusePreviewData(int preview_request_id);
@@ skipping 40 matching lines @@
   // The number of print preview requests in flight.
   uint32 request_count_;
 
   // Document cookie from the initiator renderer.
   int document_cookie_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_