Fix a typo in CUPS duplex printer detection code.

chrome/browser/printing/print_system_task_proxy.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/printing/print_system_task_proxy.h"
 
 #include <ctype.h>
 
 #include <string>
 #include <vector>
@@ skipping 405 matching lines @@
     file_util::Delete(ppd_file_path, false);
     return;
   }
 
   ppd_file_t* ppd = ppdOpenFile(ppd_file_path.value().c_str());
   if (ppd) {
 #if !defined(OS_MACOSX)
     printing_internal::mark_lpoptions(printer_name, &ppd);
 #endif
     ppd_choice_t* duplex_choice = ppdFindMarkedChoice(ppd, kDuplex);
-    if (duplex_choice) {
+    if (!duplex_choice) {
       ppd_option_t* option = ppdFindOption(ppd, kDuplex);
       if (option)
         duplex_choice = ppdFindChoice(option, option->defchoice);
     }
 
     if (duplex_choice) {
       if (base::strcasecmp(duplex_choice->choice, kDuplexNone) != 0) {
         set_duplex_as_default = true;
         default_duplex_setting_value = printing::LONG_EDGE;
       } else {
@@ skipping 98 matching lines @@
       base::Bind(&PrintSystemTaskProxy::SendPrinterCapabilities, this,
                  settings_info.DeepCopy()));
 }
 
 void PrintSystemTaskProxy::SendPrinterCapabilities(
     DictionaryValue* settings_info) {
   if (handler_)
     handler_->SendPrinterCapabilities(*settings_info);
   delete settings_info;
 }