PrintPreview: Make ctrl-shift-p start the native print flow.

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 40 matching lines @@
   static void GetCurrentPrintPreviewStatus(const std::string& preview_ui_addr,
                                            int request_id,
                                            bool* cancel);
 
   // Returns a string to uniquely identify this PrintPreviewUI.
   std::string GetPrintPreviewUIAddress() const;
 
   // Notifies the Web UI of a print preview request with |request_id|.
   void OnPrintPreviewRequest(int request_id);
 
+  // Notifies the Web UI to show the system dialog.
+  void OnShowSystemDialog();
+
   // Notifies the Web UI about the page count of the request preview.
   void OnDidGetPreviewPageCount(
       const PrintHostMsg_DidGetPreviewPageCount_Params& params);
 
   // Notifies the Web UI of the default page layout according to the currently
   // selected printer and page size.
   void OnDidGetDefaultPageLayout(
       const printing::PageSizeMargins& page_layout);
 
   // Notifies the Web UI that the 0-based page |page_number| has been rendered.
@@ skipping 48 matching lines @@
   std::string initiator_url_;
 
   // Store the initiator tab title, used for populating the print preview tab
   // title.
   string16 initiator_tab_title_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_