Fix crash when displaying system print dialog on Linux.

chrome/renderer/print_web_view_helper.cc

 // Copyright (c) 2012 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/renderer/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
@@ skipping 1521 matching lines @@
   return true;
 }
 
 bool PrintWebViewHelper::GetPrintSettingsFromUser(WebKit::WebFrame* frame,
                                                   const WebKit::WebNode& node,
                                                   int expected_pages_count,
                                                   bool use_browser_overlays) {
   PrintHostMsg_ScriptedPrint_Params params;
   PrintMsg_PrintPages_Params print_settings;
 
-  // host_window_ may be NULL at this point if the current window is a
-  // popup and the print() command has been issued from the parent. The
-  // receiver of this message has to deal with this.
-  params.host_window_id = render_view()->GetHostWindow();
   params.cookie = print_pages_params_->params.document_cookie;
   params.has_selection = frame->hasSelection();
   params.expected_pages_count = expected_pages_count;
   printing::MarginType margin_type = printing::DEFAULT_MARGINS;
   if (PrintingNodeOrPdfFrame(frame, node))
     margin_type = GetMarginsForPdf(frame, node);
   params.margin_type = margin_type;
 
   Send(new PrintHostMsg_DidShowPrintDialog(routing_id()));
 
@@ skipping 389 matching lines @@
   DCHECK(IsRendering());
   return prep_frame_view_->GetPrintCanvasSize();
 }
 
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
   pages_to_render_.clear();
   error_ = PREVIEW_ERROR_NONE;
 }