4 files changed, 21 insertions, 1 deletions
diff --git a/printing/print_job_constants.cc b/printing/print_job_constants.cc
index 5442690..31075f6 100644
--- a/printing/print_job_constants.cc
+++ b/printing/print_job_constants.cc
@@ -24,4 +24,7 @@ const char kSettingPrintToPDF[] = "printToPDF";
 // Printer name.
 const char kSettingPrinterName[] = "printerName";
 
+// Print job duplex setting.
+const char kSettingTwoSided[] = "twoSided";
+
 }  // namespace printing
diff --git a/printing/print_job_constants.h b/printing/print_job_constants.h
index b34915c..42c6f69 100644
--- a/printing/print_job_constants.h
+++ b/printing/print_job_constants.h
@@ -13,6 +13,7 @@ extern const char kSettingCopies[];
 extern const char kSettingLandscape[];
 extern const char kSettingPrintToPDF[];
 extern const char kSettingPrinterName[];
+extern const char kSettingTwoSided[];
 
 }  // namespace printing
 
diff --git a/printing/printing_context_mac.h b/printing/printing_context_mac.h
index e19ceba..0979b18 100644
--- a/printing/printing_context_mac.h
+++ b/printing/printing_context_mac.h
@@ -63,6 +63,10 @@ class PrintingContextMac : public PrintingContext {
   // Returns true if the orientation was set.
   bool SetOrientationIsLandscape(bool landscape);
 
+  // Sets duplex mode in PMPrintSettings.
+  // Returns true if duplex mode is set.
+  bool SetDuplexModeIsTwoSided(bool two_sided);
+
   // The native print info object.
   scoped_nsobject<NSPrintInfo> print_info_;
 
diff --git a/printing/printing_context_mac.mm b/printing/printing_context_mac.mm
index 25f0ef6..063197e 100644
--- a/printing/printing_context_mac.mm
+++ b/printing/printing_context_mac.mm
@@ -93,10 +93,12 @@ PrintingContext::Result PrintingContextMac::UpdatePrintSettings(
   std::string printer_name;
   int copies;
   bool collate;
+  bool two_sided;
   if (!job_settings.GetBoolean(kSettingLandscape, &landscape) ||
       !job_settings.GetString(kSettingPrinterName, &printer_name) ||
       !job_settings.GetInteger(kSettingCopies, &copies) ||
-      !job_settings.GetBoolean(kSettingCollate, &collate)) {
+      !job_settings.GetBoolean(kSettingCollate, &collate) ||
+      !job_settings.GetBoolean(kSettingTwoSided, &two_sided)) {
     return OnError();
   }
 
@@ -112,6 +114,9 @@ PrintingContext::Result PrintingContextMac::UpdatePrintSettings(
   if (!SetOrientationIsLandscape(landscape))
     return OnError();
 
+  if (!SetDuplexModeIsTwoSided(two_sided))
+    return OnError();
+
   [print_info_.get() updateFromPMPrintSettings];
 
   InitPrintSettingsFromPrintInfo(ranges);
@@ -173,6 +178,13 @@ bool PrintingContextMac::SetOrientationIsLandscape(bool landscape) {
   return true;
 }
 
+bool PrintingContextMac::SetDuplexModeIsTwoSided(bool two_sided) {
+  PMDuplexMode duplexSetting = two_sided ? kPMDuplexNoTumble : kPMDuplexNone;
+  PMPrintSettings pmPrintSettings =
+      static_cast<PMPrintSettings>([print_info_.get() PMPrintSettings]);
+  return PMSetDuplex(pmPrintSettings, duplexSetting) == noErr;
+}
+
 void PrintingContextMac::ParsePrintInfo(NSPrintInfo* print_info) {
   ResetSettings();
   print_info_.reset([print_info retain]);