Cancel the pending print preview request when the user request to show the system dialog.

chrome/browser/ui/webui/print_preview_ui.cc

 // 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.
 
 #include "chrome/browser/ui/webui/print_preview_ui.h"
 
 #include <map>
 
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
@@ skipping 201 matching lines @@
 }
 
 void PrintPreviewUI::OnTabDestroyed() {
   handler_->OnTabDestroyed();
 }
 
 void PrintPreviewUI::OnFileSelectionCancelled() {
   CallJavascriptFunction("fileSelectionCancelled");
 }
 
+void PrintPreviewUI::OnCancelPendingPreviewRequest() {
+  g_print_preview_request_id_map.Get().Set(preview_ui_addr_str_, -1);
+}
+
 void PrintPreviewUI::OnPrintPreviewFailed() {
   CallJavascriptFunction("printPreviewFailed");
 }
 
 PrintPreviewDataService* PrintPreviewUI::print_preview_data_service() {
   return PrintPreviewDataService::GetInstance();
 }